Sample records for early big bang

  1. An embedding for the big bang

    NASA Technical Reports Server (NTRS)

    Wesson, Paul S.

    1994-01-01

    A cosmological model is given that has good physical properties for the early and late universe but is a hypersurface in a flat five-dimensional manifold. The big bang can therefore be regarded as an effect of a choice of coordinates in a truncated higher-dimensional geometry. Thus the big bang is in some sense a geometrical illusion.

  2. Frontiers of Big Bang cosmology and primordial nucleosynthesis

    NASA Astrophysics Data System (ADS)

    Mathews, Grant J.; Cheoun, Myung-Ki; Kajino, Toshitaka; Kusakabe, Motohiko; Yamazaki, Dai G.

    2012-11-01

    We summarize some current research on the formation and evolution of the universe and overview some of the key questions surrounding the the big bang. There are really only two observational cosmological probes of the physics of the early universe. Of those two, the only probe during the relevant radiation dominated epoch is the yield of light elements during the epoch of big bang nucleosynthesis. The synthesis of light elements occurs in the temperature regime from 108 to 1010 K and times of about 1 to 104 sec into the big bang. The other probe is the spectrum of temperature fluctuations in the CMB which (among other things) contains information of the first quantum fluctuations in the universe, along with details of the distribution and evolution of dark matter, baryonic matter and photons up to the surface of photon last scattering. Here, we emphasize the role of these probes in answering some key questions of the big bang and early universe cosmology.

  3. The Big Bang Theory

    ScienceCinema

    Lincoln, Don

    2018-01-16

    The Big Bang is the name of the most respected theory of the creation of the universe. Basically, the theory says that the universe was once smaller and denser and has been expending for eons. One common misconception is that the Big Bang theory says something about the instant that set the expansion into motion, however this isn’t true. In this video, Fermilab’s Dr. Don Lincoln tells about the Big Bang theory and sketches some speculative ideas about what caused the universe to come into existence.

  4. The Big Bang Theory

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lincoln, Don

    The Big Bang is the name of the most respected theory of the creation of the universe. Basically, the theory says that the universe was once smaller and denser and has been expending for eons. One common misconception is that the Big Bang theory says something about the instant that set the expansion into motion, however this isn’t true. In this video, Fermilab’s Dr. Don Lincoln tells about the Big Bang theory and sketches some speculative ideas about what caused the universe to come into existence.

  5. The Big Bang Singularity

    NASA Astrophysics Data System (ADS)

    Ling, Eric

    The big bang theory is a model of the universe which makes the striking prediction that the universe began a finite amount of time in the past at the so called "Big Bang singularity." We explore the physical and mathematical justification of this surprising result. After laying down the framework of the universe as a spacetime manifold, we combine physical observations with global symmetrical assumptions to deduce the FRW cosmological models which predict a big bang singularity. Next we prove a couple theorems due to Stephen Hawking which show that the big bang singularity exists even if one removes the global symmetrical assumptions. Lastly, we investigate the conditions one needs to impose on a spacetime if one wishes to avoid a singularity. The ideas and concepts used here to study spacetimes are similar to those used to study Riemannian manifolds, therefore we compare and contrast the two geometries throughout.

  6. The big bang

    NASA Astrophysics Data System (ADS)

    Silk, Joseph

    Our universe was born billions of years ago in a hot, violent explosion of elementary particles and radiation - the big bang. What do we know about this ultimate moment of creation, and how do we know it? Drawing upon the latest theories and technology, this new edition of The big bang, is a sweeping, lucid account of the event that set the universe in motion. Joseph Silk begins his story with the first microseconds of the big bang, on through the evolution of stars, galaxies, clusters of galaxies, quasars, and into the distant future of our universe. He also explores the fascinating evidence for the big bang model and recounts the history of cosmological speculation. Revised and updated, this new edition features all the most recent astronomical advances, including: Photos and measurements from the Hubble Space Telescope, Cosmic Background Explorer Satellite (COBE), and Infrared Space Observatory; the latest estimates of the age of the universe; new ideas in string and superstring theory; recent experiments on neutrino detection; new theories about the presence of dark matter in galaxies; new developments in the theory of the formation and evolution of galaxies; the latest ideas about black holes, worm holes, quantum foam, and multiple universes.

  7. The Whole Shebang: How Science Produced the Big Bang Model.

    ERIC Educational Resources Information Center

    Ferris, Timothy

    2002-01-01

    Offers an account of the accumulation of evidence that has led scientists to have confidence in the big bang theory of the creation of the universe. Discusses the early work of Ptolemy, Copernicus, Kepler, Galileo, and Newton, noting the rise of astrophysics, and highlighting the birth of the big bang model (the cosmic microwave background theory…

  8. Big Bang Circus

    NASA Astrophysics Data System (ADS)

    Ambrosini, C.

    2011-06-01

    Big Bang Circus is an opera I composed in 2001 and which was premiered at the Venice Biennale Contemporary Music Festival in 2002. A chamber group, four singers and a ringmaster stage the story of the Universe confronting and interweaving two threads: how early man imagined it and how scientists described it. Surprisingly enough fancy, myths and scientific explanations often end up using the same images, metaphors and sometimes even words: a strong tension, a drumskin starting to vibrate, a shout…

  9. Big Bang Titanic: New Dark Energy (Vacuum Gravity) Cosmic Model Emerges Upon Falsification of The Big Bang By Disproof of Its Central Assumptions

    NASA Astrophysics Data System (ADS)

    Gentry, Robert

    2011-04-01

    Physicists who identify the big bang with the early universe should have first noted from Hawking's A Brief History of Time, p. 42, that he ties Hubble's law to Doppler shifts from galaxy recession from a nearby center, not to bb's unvalidated and thus problematical expansion redshifts. Our PRL submission LJ12135 describes such a model, but in it Hubble's law is due to Doppler and vacuum gravity effects, the 2.73K CBR is vacuum gravity shifted blackbody cavity radiation from an outer galactic shell, and its (1 + z)-1 dilation and (M,z) relations closely fit high-z SNe Ia data; all this strongly implies our model's vacuum energy is the elusive dark energy. We also find GPS operation's GR effects falsify big bang's in-flight expansion redshift paradigm, and hence the big bang, by showing λ changes occur only at emission. Surprisingly we also discover big bang's CBR prediction is T < 2x10-8 K, not the observed 2.73K. So instead of the 2.73K affirming the big bang as cosmologists claim, it actually disproves it, to which the DAE's response is most enigmatic -- namely, CBR photons expand dλ/dt > 0, while galactic photons shrink dλ/dt < 0. Contrary to a PRL editor's claim, the above results show LJ12135 fits PRL guidelines for papers that replace established theories. For details see alphacosmos.net.

  10. Constraining antimatter domains in the early universe with big bang nucleosynthesis.

    PubMed

    Kurki-Suonio, H; Sihvola, E

    2000-04-24

    We consider the effect of a small-scale matter-antimatter domain structure on big bang nucleosynthesis and place upper limits on the amount of antimatter in the early universe. For small domains, which annihilate before nucleosynthesis, this limit comes from underproduction of 4He. For larger domains, the limit comes from 3He overproduction. Since most of the 3He from &pmacr; 4He annihilation are themselves annihilated, the main source of primordial 3He is the photodisintegration of 4He by the electromagnetic cascades initiated by the annihilation.

  11. Quantum nature of the big bang.

    PubMed

    Ashtekar, Abhay; Pawlowski, Tomasz; Singh, Parampreet

    2006-04-14

    Some long-standing issues concerning the quantum nature of the big bang are resolved in the context of homogeneous isotropic models with a scalar field. Specifically, the known results on the resolution of the big-bang singularity in loop quantum cosmology are significantly extended as follows: (i) the scalar field is shown to serve as an internal clock, thereby providing a detailed realization of the "emergent time" idea; (ii) the physical Hilbert space, Dirac observables, and semiclassical states are constructed rigorously; (iii) the Hamiltonian constraint is solved numerically to show that the big bang is replaced by a big bounce. Thanks to the nonperturbative, background independent methods, unlike in other approaches the quantum evolution is deterministic across the deep Planck regime.

  12. Big Bang Day : The Great Big Particle Adventure - 3. Origins

    ScienceCinema

    None

    2017-12-09

    In this series, comedian and physicist Ben Miller asks the CERN scientists what they hope to find. If the LHC is successful, it will explain the nature of the Universe around us in terms of a few simple ingredients and a few simple rules. But the Universe now was forged in a Big Bang where conditions were very different, and the rules were very different, and those early moments were crucial to determining how things turned out later. At the LHC they can recreate conditions as they were billionths of a second after the Big Bang, before atoms and nuclei existed. They can find out why matter and antimatter didn't mutually annihilate each other to leave behind a Universe of pure, brilliant light. And they can look into the very structure of space and time - the fabric of the Universe

  13. Baryon symmetric big bang cosmology

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.

    1978-01-01

    Both the quantum theory and Einsteins theory of special relativity lead to the supposition that matter and antimatter were produced in equal quantities during the big bang. It is noted that local matter/antimatter asymmetries may be reconciled with universal symmetry by assuming (1) a slight imbalance of matter over antimatter in the early universe, annihilation, and a subsequent remainder of matter; (2) localized regions of excess for one or the other type of matter as an initial condition; and (3) an extremely dense, high temperature state with zero net baryon number; i.e., matter/antimatter symmetry. Attention is given to the third assumption, which is the simplest and the most in keeping with current knowledge of the cosmos, especially as pertains the universality of 3 K background radiation. Mechanisms of galaxy formation are discussed, whereby matter and antimatter might have collided and annihilated each other, or have coexisted (and continue to coexist) at vast distances. It is pointed out that baryon symmetric big bang cosmology could probably be proved if an antinucleus could be detected in cosmic radiation.

  14. Big Bang Day : The Great Big Particle Adventure - 3. Origins

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    None

    In this series, comedian and physicist Ben Miller asks the CERN scientists what they hope to find. If the LHC is successful, it will explain the nature of the Universe around us in terms of a few simple ingredients and a few simple rules. But the Universe now was forged in a Big Bang where conditions were very different, and the rules were very different, and those early moments were crucial to determining how things turned out later. At the LHC they can recreate conditions as they were billionths of a second after the Big Bang, before atoms and nucleimore » existed. They can find out why matter and antimatter didn't mutually annihilate each other to leave behind a Universe of pure, brilliant light. And they can look into the very structure of space and time - the fabric of the Universe« less

  15. A Quantum Universe Before the Big Bang(s)?

    NASA Astrophysics Data System (ADS)

    Veneziano, Gabriele

    2017-08-01

    The predictions of general relativity have been verified by now in a variety of different situations, setting strong constraints on any alternative theory of gravity. Nonetheless, there are strong indications that general relativity has to be regarded as an approximation of a more complete theory. Indeed theorists have long been looking for ways to connect general relativity, which describes the cosmos and the infinitely large, to quantum physics, which has been remarkably successful in explaining the infinitely small world of elementary particles. These two worlds, however, come closer and closer to each other as we go back in time all the way up to the big bang. Actually, modern cosmology has changed completely the old big bang paradigm: we now have to talk about (at least) two (big?) bangs. If we know quite something about the one closer to us, at the end of inflation, we are much more ignorant about the one that may have preceded inflation and possibly marked the beginning of time. No one doubts that quantum mechanics plays an essential role in answering these questions: unfortunately a unified theory of gravity and quantum mechanics is still under construction. Finding such a synthesis and confirming it experimentally will no doubt be one of the biggest challenges of this century’s physics.

  16. Neutrino mixing and big bang nucleosynthesis

    NASA Astrophysics Data System (ADS)

    Bell, Nicole

    2003-04-01

    We analyse active-active neutrino mixing in the early universe and show that transformation of neutrino-antineutrino asymmetries between flavours is unavoidable when neutrino mixing angles are large. This process is a standard Mikheyev-Smirnov-Wolfenstein flavour transformation, modified by the synchronisation of momentum states which results from neutrino-neutrino forward scattering. The new constraints placed on neutrino asymmetries eliminate the possibility of degenerate big bang nucleosynthesis.Implications of active-sterile neutrino mixing will also be reviewed.

  17. Fixing the Big Bang Theory's Lithium Problem

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2017-02-01

    How did our universe come into being? The Big Bang theory is a widely accepted and highly successful cosmological model of the universe, but it does introduce one puzzle: the cosmological lithium problem. Have scientists now found a solution?Too Much LithiumIn the Big Bang theory, the universe expanded rapidly from a very high-density and high-temperature state dominated by radiation. This theory has been validated again and again: the discovery of the cosmic microwave background radiation and observations of the large-scale structure of the universe both beautifully support the Big Bang theory, for instance. But one pesky trouble-spot remains: the abundance of lithium.The arrows show the primary reactions involved in Big Bang nucleosynthesis, and their flux ratios, as predicted by the authors model, are given on the right. Synthesizing primordial elements is complicated! [Hou et al. 2017]According to Big Bang nucleosynthesis theory, primordial nucleosynthesis ran wild during the first half hour of the universes existence. This produced most of the universes helium and small amounts of other light nuclides, including deuterium and lithium.But while predictions match the observed primordial deuterium and helium abundances, Big Bang nucleosynthesis theory overpredicts the abundance of primordial lithium by about a factor of three. This inconsistency is known as the cosmological lithium problem and attempts to resolve it using conventional astrophysics and nuclear physics over the past few decades have not been successful.In a recent publicationled by Suqing Hou (Institute of Modern Physics, Chinese Academy of Sciences) and advisorJianjun He (Institute of Modern Physics National Astronomical Observatories, Chinese Academy of Sciences), however, a team of scientists has proposed an elegant solution to this problem.Time and temperature evolution of the abundances of primordial light elements during the beginning of the universe. The authors model (dotted lines

  18. How quantum is the big bang?

    PubMed

    Bojowald, Martin

    2008-06-06

    When quantum gravity is used to discuss the big bang singularity, the most important, though rarely addressed, question is what role genuine quantum degrees of freedom play. Here, complete effective equations are derived for isotropic models with an interacting scalar to all orders in the expansions involved. The resulting coupling terms show that quantum fluctuations do not affect the bounce much. Quantum correlations, however, do have an important role and could even eliminate the bounce. How quantum gravity regularizes the big bang depends crucially on properties of the quantum state.

  19. COBE looks back to the Big Bang

    NASA Technical Reports Server (NTRS)

    Mather, John C.

    1993-01-01

    An overview is presented of NASA-Goddard's Cosmic Background Explorer (COBE), the first NASA satellite designed to observe the primeval explosion of the universe. The spacecraft carries three extremely sensitive IR and microwave instruments designed to measure the faint residual radiation from the Big Bang and to search for the formation of the first galaxies. COBE's far IR absolute spectrophotometer has shown that the Big Bang radiation has a blackbody spectrum, proving that there was no large energy release after the explosion.

  20. Big bang photosynthesis and pregalactic nucleosynthesis of light elements

    NASA Technical Reports Server (NTRS)

    Audouze, J.; Lindley, D.; Silk, J.

    1985-01-01

    Two nonstandard scenarios for pregalactic synthesis of the light elements (H-2, He-3, He-4, and Li-7) are developed. Big bang photosynthesis occurs if energetic photons, produced by the decay of massive neutrinos or gravitinos, partially photodisintegrate He-4 (formed in the standard hot big bang) to produce H-2 and He-3. In this case, primordial nucleosynthesis no longer constrains the baryon density of the universe, or the number of neutrino species. Alternatively, one may dispense partially or completely with the hot big bang and produce the light elements by bombardment of primordial gas, provided that He-4 is synthesized by a later generation of massive stars.

  1. A Big Bang versus a Small Bang Approach: A Case Study of the Expeditionary Combat Support System (ECSS) and the Maintenance, Repair, and Overhaul Initiative (MROi)

    DTIC Science & Technology

    resource planning (ERP) solution called the Expeditionary Combat Support System (ECSS), a big - bang approach. In early 2012, the ECSS program was cancelled...Repair, and Overhaul initiative (MROi), a small- bang approach, to increase enterprise visibility and efficiency across all three Air Logistics

  2. Introduction to big bang nucleosynthesis and modern cosmology

    NASA Astrophysics Data System (ADS)

    Mathews, Grant J.; Kusakabe, Motohiko; Kajino, Toshitaka

    Primordial nucleosynthesis remains as one of the pillars of modern cosmology. It is the testing ground upon which many cosmological models must ultimately rest. It is our only probe of the universe during the important radiation-dominated epoch in the first few minutes of cosmic expansion. This paper reviews the basic equations of space-time, cosmology, and big bang nucleosynthesis. We also summarize the current state of observational constraints on primordial abundances along with the key nuclear reactions and their uncertainties. We summarize which nuclear measurements are most crucial during the big bang. We also review various cosmological models and their constraints. In particular, we analyze the constraints that big bang nucleosynthesis places upon the possible time variation of fundamental constants, along with constraints on the nature and origin of dark matter and dark energy, long-lived supersymmetric particles, gravity waves, and the primordial magnetic field.

  3. Introduction to Big Bang nucleosynthesis - Open and closed models, anisotropies

    NASA Astrophysics Data System (ADS)

    Tayler, R. J.

    1982-10-01

    A variety of observations suggest that the universe had a hot dense origin and that the pregalactic composition of the universe was determined by nuclear reactions that occurred in the first few minutes. There is no unique hot Big Bang theory, but the simplest version produces a primeval chemical composition that is in good qualitative agreement with the abundances deduced from observation. Whether or not any Big Bang theory will provide quantitative agreement with observations depends on a variety of factors in elementary particle physics (number and masses of stable or long-lived particles, half-life of neutron, structure of grand unified theories) and from observational astronomy (present mean baryon density of the universe, the Hubble constant and deceleration parameter). The influence of these factors on the abundances is discussed, as is the effect of departures from homogeneity and isotropy in the early universe.

  4. Re-evaluation of the immunological Big Bang.

    PubMed

    Flajnik, Martin F

    2014-11-03

    Classically the immunological 'Big Bang' of adaptive immunity was believed to have resulted from the insertion of a transposon into an immunoglobulin superfamily gene member, initiating antigen receptor gene rearrangement via the RAG recombinase in an ancestor of jawed vertebrates. However, the discovery of a second, convergent adaptive immune system in jawless fish, focused on the so-called variable lymphocyte receptors (VLRs), was arguably the most exciting finding of the past decade in immunology and has drastically changed the view of immune origins. The recent report of a new lymphocyte lineage in lampreys, defined by the antigen receptor VLRC, suggests that there were three lymphocyte lineages in the common ancestor of jawless and jawed vertebrates that co-opted different antigen receptor supertypes. The transcriptional control of these lineages during development is predicted to be remarkably similar in both the jawless (agnathan) and jawed (gnathostome) vertebrates, suggesting that an early 'division of labor' among lymphocytes was a driving force in the emergence of adaptive immunity. The recent cartilaginous fish genome project suggests that most effector cytokines and chemokines were also present in these fish, and further studies of the lamprey and hagfish genomes will determine just how explosive the Big Bang actually was. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Baryon symmetric big-bang cosmology. [matter-antimatter symmetry

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.

    1978-01-01

    The framework of baryon-symmetric big-bang cosmology offers the greatest potential for deducing the evolution of the universe as a consequence of physical laws and processes with the minimum number of arbitrary assumptions as to initial conditions in the big-bang. In addition, it offers the possibility of explaining the photon-baryon ratio in the universe and how galaxies and galaxy clusters are formed, and also provides the only acceptable explanation at present for the origin of the cosmic gamma ray background radiation.

  6. Elementary Cosmology: From Aristotle's Universe to the Big Bang and Beyond

    NASA Astrophysics Data System (ADS)

    Kolata, James J.

    2015-11-01

    Cosmology is the study of the origin, size, and evolution of the entire universe. Every culture has developed a cosmology, whether it be based on religious, philosophical, or scientific principles. In this book, the evolution of the scientific understanding of the Universe in Western tradition is traced from the early Greek philosophers to the most modern 21st century view. After a brief introduction to the concept of the scientific method, the first part of the book describes the way in which detailed observations of the Universe, first with the naked eye and later with increasingly complex modern instruments, ultimately led to the development of the ``Big Bang'' theory. The second part of the book traces the evolution of the Big Bang including the very recent observation that the expansion of the Universe is itself accelerating with time.

  7. Regularization of the big bang singularity with random perturbations

    NASA Astrophysics Data System (ADS)

    Belbruno, Edward; Xue, BingKan

    2018-03-01

    We show how to regularize the big bang singularity in the presence of random perturbations modeled by Brownian motion using stochastic methods. We prove that the physical variables in a contracting universe dominated by a scalar field can be continuously and uniquely extended through the big bang as a function of time to an expanding universe only for a discrete set of values of the equation of state satisfying special co-prime number conditions. This result significantly generalizes a previous result (Xue and Belbruno 2014 Class. Quantum Grav. 31 165002) that did not model random perturbations. This result implies that the extension from a contracting to an expanding universe for the discrete set of co-prime equation of state is robust, which is a surprising result. Implications for a purely expanding universe are discussed, such as a non-smooth, randomly varying scale factor near the big bang.

  8. Constraining axion dark matter with Big Bang Nucleosynthesis

    DOE PAGES

    Blum, Kfir; D'Agnolo, Raffaele Tito; Lisanti, Mariangela; ...

    2014-08-04

    We show that Big Bang Nucleosynthesis (BBN) significantly constrains axion-like dark matter. The axion acts like an oscillating QCD θ angle that redshifts in the early Universe, increasing the neutron–proton mass difference at neutron freeze-out. An axion-like particle that couples too strongly to QCD results in the underproduction of during BBN and is thus excluded. The BBN bound overlaps with much of the parameter space that would be covered by proposed searches for a time-varying neutron EDM. The QCD axion does not couple strongly enough to affect BBN

  9. Constraining axion dark matter with Big Bang Nucleosynthesis

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Blum, Kfir; D'Agnolo, Raffaele Tito; Lisanti, Mariangela

    We show that Big Bang Nucleosynthesis (BBN) significantly constrains axion-like dark matter. The axion acts like an oscillating QCD θ angle that redshifts in the early Universe, increasing the neutron–proton mass difference at neutron freeze-out. An axion-like particle that couples too strongly to QCD results in the underproduction of during BBN and is thus excluded. The BBN bound overlaps with much of the parameter space that would be covered by proposed searches for a time-varying neutron EDM. The QCD axion does not couple strongly enough to affect BBN

  10. Drosophila Big bang regulates the apical cytocortex and wing growth through junctional tension.

    PubMed

    Tsoumpekos, Giorgos; Nemetschke, Linda; Knust, Elisabeth

    2018-03-05

    Growth of epithelial tissues is regulated by a plethora of components, including signaling and scaffolding proteins, but also by junctional tension, mediated by the actomyosin cytoskeleton. However, how these players are spatially organized and functionally coordinated is not well understood. Here, we identify the Drosophila melanogaster scaffolding protein Big bang as a novel regulator of growth in epithelial cells of the wing disc by ensuring proper junctional tension. Loss of big bang results in the reduction of the regulatory light chain of nonmuscle myosin, Spaghetti squash. This is associated with an increased apical cell surface, decreased junctional tension, and smaller wings. Strikingly, these phenotypic traits of big bang mutant discs can be rescued by expressing constitutively active Spaghetti squash. Big bang colocalizes with Spaghetti squash in the apical cytocortex and is found in the same protein complex. These results suggest that in epithelial cells of developing wings, the scaffolding protein Big bang controls apical cytocortex organization, which is important for regulating cell shape and tissue growth. © 2018 Tsoumpekos et al.

  11. Hubble Spies Big Bang Frontiers

    NASA Image and Video Library

    2017-12-08

    Observations by the NASA/ESA Hubble Space Telescope have taken advantage of gravitational lensing to reveal the largest sample of the faintest and earliest known galaxies in the universe. Some of these galaxies formed just 600 million years after the big bang and are fainter than any other galaxy yet uncovered by Hubble. The team has determined for the first time with some confidence that these small galaxies were vital to creating the universe that we see today. An international team of astronomers, led by Hakim Atek of the Ecole Polytechnique Fédérale de Lausanne, Switzerland, has discovered over 250 tiny galaxies that existed only 600-900 million years after the big bang— one of the largest samples of dwarf galaxies yet to be discovered at these epochs. The light from these galaxies took over 12 billion years to reach the telescope, allowing the astronomers to look back in time when the universe was still very young. Read more: www.nasa.gov/feature/goddard/hubble-spies-big-bang-frontiers Credit: NASA/ESA NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

  12. State of the Universe. If Not with a Big Bang, Then What?

    ERIC Educational Resources Information Center

    Peterson, Ivars

    1991-01-01

    The Big Bang Theory and alternatives to the Big Bang Theory as an explanation for the origin of the universe are discussed. The importance of the discovery of redshift, the percentage of hydrogen found in old stars, and the existence of a uniform sea of radiation are explained. (KR)

  13. Calixarenes and cations: a time-lapse photography of the big-bang.

    PubMed

    Casnati, Alessandro

    2013-08-07

    The outstanding cation complexation properties emerging from the pioneering studies on calixarene ligands during a five-year period in the early 1980s triggered a big-bang burst of publications on such macrocycles that is still lasting at a distance of more than 30 years. A time-lapse photography of this timeframe is proposed which allows the readers to pinpoint the contributions of the different research groups.

  14. BIG BANG NUCLEOSYNTHESIS WITH A NON-MAXWELLIAN DISTRIBUTION

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bertulani, C. A.; Fuqua, J.; Hussein, M. S.

    The abundances of light elements based on the big bang nucleosynthesis model are calculated using the Tsallis non-extensive statistics. The impact of the variation of the non-extensive parameter q from the unity value is compared to observations and to the abundance yields from the standard big bang model. We find large differences between the reaction rates and the abundance of light elements calculated with the extensive and the non-extensive statistics. We found that the observations are consistent with a non-extensive parameter q = 1{sub -} {sub 0.12}{sup +0.05}, indicating that a large deviation from the Boltzmann-Gibbs statistics (q = 1)more » is highly unlikely.« less

  15. Cosmological BCS mechanism and the big bang singularity

    NASA Astrophysics Data System (ADS)

    Alexander, Stephon; Biswas, Tirthabir

    2009-07-01

    We provide a novel mechanism that resolves the big bang singularity present in Friedman-Lemaitre-Robertson-Walker space-times without the need for ghost fields. Building on the fact that a four-fermion interaction arises in general relativity when fermions are covariantly coupled, we show that at early times the decrease in scale factor enhances the correlation between pairs of fermions. This enhancement leads to a BCS-like condensation of the fermions and opens a gap dynamically driving the Hubble parameter H to zero and results in a nonsingular bounce, at least in some special cases.

  16. Limits to the primordial helium abundance in the baryon-inhomogeneous big bang

    NASA Technical Reports Server (NTRS)

    Mathews, G. J.; Schramm, D. N.; Meyer, B. S.

    1993-01-01

    The parameter space for baryon inhomogeneous big bang models is explored with the goal of determining the minimum helium abundance obtainable in such models while still satisfying the other light-element constraints. We find that the constraint of (D + He-3)/H less than 10 exp -4 restricts the primordial helium mass fraction from baryon-inhomogeneous big bang models to be greater than 0.231 even for a scenario which optimizes the effects of the inhomogeneities and destroys the excess lithium production. Thus, this modification to the standard big bang as well as the standard homogeneous big bang model itself would be falsifiable by observation if the primordial He-4 abundance were observed to be less than 0.231. Furthermore, a present upper limit to the observed helium mass fraction of Y(obs)(p) less than 0.24 implies that the maximum baryon-to-photon ratio allowable in the inhomogeneous models corresponds to eta less than 2.3 x 10 exp -9 (omega(b) h-squared less than 0.088) even if all conditions are optimized.

  17. Out of the white hole: a holographic origin for the Big Bang

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Pourhasan, Razieh; Afshordi, Niayesh; Mann, Robert B., E-mail: rpourhasan@perimeterinstitute.ca, E-mail: nafshordi@pitp.ca, E-mail: rbmann@uwaterloo.ca

    While most of the singularities of General Relativity are expected to be safely hidden behind event horizons by the cosmic censorship conjecture, we happen to live in the causal future of the classical Big Bang singularity, whose resolution constitutes the active field of early universe cosmology. Could the Big Bang be also hidden behind a causal horizon, making us immune to the decadent impacts of a naked singularity? We describe a braneworld description of cosmology with both 4d induced and 5D bulk gravity (otherwise known as Dvali-Gabadadze-Porati, or DGP model), which exhibits this feature: the universe emerges as a sphericalmore » 3-brane out of the formation of a 5D Schwarzschild black hole. In particular, we show that a pressure singularity of the holographic fluid, discovered earlier, happens inside the white hole horizon, and thus need not be real or imply any pathology. Furthermore, we outline a novel mechanism through which any thermal atmosphere for the brane, with comoving temperature of ∼20% of the 5D Planck mass can induce scale-invariant primordial curvature perturbations on the brane, circumventing the need for a separate process (such as cosmic inflation) to explain current cosmological observations. Finally, we note that 5D space-time is asymptotically flat, and thus potentially allows an S-matrix or (after minor modifications) an AdS/CFT description of the cosmological Big Bang.« less

  18. Antigravity and the big crunch/big bang transition

    NASA Astrophysics Data System (ADS)

    Bars, Itzhak; Chen, Shih-Hung; Steinhardt, Paul J.; Turok, Neil

    2012-08-01

    We point out a new phenomenon which seems to be generic in 4d effective theories of scalar fields coupled to Einstein gravity, when applied to cosmology. A lift of such theories to a Weyl-invariant extension allows one to define classical evolution through cosmological singularities unambiguously, and hence construct geodesically complete background spacetimes. An attractor mechanism ensures that, at the level of the effective theory, generic solutions undergo a big crunch/big bang transition by contracting to zero size, passing through a brief antigravity phase, shrinking to zero size again, and re-emerging into an expanding normal gravity phase. The result may be useful for the construction of complete bouncing cosmologies like the cyclic model.

  19. Pre-Big Bang Bubbles from the Gravitational Instability of Generic String Vacua

    NASA Astrophysics Data System (ADS)

    Buonanno, A.; Damour, T.; Veneziano, G.

    1998-06-01

    We formulate the basic postulate of pre-big bang cosmology as one of 'asymptotic past triviality', by which we mean that the initial state is a generic perturbative solution of the tree-level low-energy effective action. Each such singular space-like hypersurface of gravitational collapse becomes, in the string-frame metric, the usual big-bang t = 0 hypersurface, i.e. the place of birth of a baby Friedmann universe after a period of dilaton-driven inflation. Specializing to the spherically-symmetric case, we review and reinterpret previous work on the subject, and propose a simple, scale-invariant criterion for collapse/inflation in terms of asymptotic data at past null infinity. Those data should determine whether, when, and where collapse/inflation occurs, and, when it does, fix its characteristics, including anisotropies on the big bang hypersurface whose imprint could have survived till now. Using Bayesian probability concepts, we finally attempt to answer some fine-tuning objections recently moved to the pre-gib bang scenario.

  20. Heavy element production in inhomogeneous big bang nucleosynthesis

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Matsuura, Shunji; Fujimoto, Shin-ichirou; Nishimura, Sunao

    2005-12-15

    We present a new astrophysical site of the big bang nucleosynthesis (BBN) that are very peculiar compared with the standard BBN. Some models of the baryogenesis suggest that very high baryon density regions were formed in the early universe. On the other hand, recent observations suggest that heavy elements already exist in high red-shifts and the origin of these elements become a big puzzle. Motivated by these, we investigate BBN in very high baryon density regions. BBN proceeds in proton-rich environment, which is known to be like the p-process. However, by taking very heavy nuclei into account, we find thatmore » BBN proceeds through both the p-process and the r-process simultaneously. P-nuclei such as {sup 92}Mo, {sup 94}Mo, {sup 96}Ru, {sup 98}Ru whose origin is not well known are also synthesized.« less

  1. Big Bang 6Li nucleosynthesis studied deep underground (LUNA collaboration)

    NASA Astrophysics Data System (ADS)

    Trezzi, D.; Anders, M.; Aliotta, M.; Bellini, A.; Bemmerer, D.; Boeltzig, A.; Broggini, C.; Bruno, C. G.; Caciolli, A.; Cavanna, F.; Corvisiero, P.; Costantini, H.; Davinson, T.; Depalo, R.; Elekes, Z.; Erhard, M.; Ferraro, F.; Formicola, A.; Fülop, Zs.; Gervino, G.; Guglielmetti, A.; Gustavino, C.; Gyürky, Gy.; Junker, M.; Lemut, A.; Marta, M.; Mazzocchi, C.; Menegazzo, R.; Mossa, V.; Pantaleo, F.; Prati, P.; Rossi Alvarez, C.; Scott, D. A.; Somorjai, E.; Straniero, O.; Szücs, T.; Takacs, M.

    2017-03-01

    The correct prediction of the abundances of the light nuclides produced during the epoch of Big Bang Nucleosynthesis (BBN) is one of the main topics of modern cosmology. For many of the nuclear reactions that are relevant for this epoch, direct experimental cross section data are available, ushering the so-called "age of precision". The present work addresses an exception to this current status: the 2H(α,γ)6Li reaction that controls 6Li production in the Big Bang. Recent controversial observations of 6Li in metal-poor stars have heightened the interest in understanding primordial 6Li production. If confirmed, these observations would lead to a second cosmological lithium problem, in addition to the well-known 7Li problem. In the present work, the direct experimental cross section data on 2H(α,γ)6Li in the BBN energy range are reported. The measurement has been performed deep underground at the LUNA (Laboratory for Underground Nuclear Astrophysics) 400 kV accelerator in the Laboratori Nazionali del Gran Sasso, Italy. The cross section has been directly measured at the energies of interest for Big Bang Nucleosynthesis for the first time, at Ecm = 80, 93, 120, and 133 keV. Based on the new data, the 2H(α,γ)6Li thermonuclear reaction rate has been derived. Our rate is even lower than previously reported, thus increasing the discrepancy between predicted Big Bang 6Li abundance and the amount of primordial 6Li inferred from observations.

  2. Supernova bangs as a tool to study big bang

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Blinnikov, S. I., E-mail: Sergei.Blinnikov@itep.ru

    Supernovae and gamma-ray bursts are the most powerful explosions in observed Universe. This educational review tells about supernovae and their applications in cosmology. It is explained how to understand the production of light in the most luminous events with minimum required energy of explosion. These most luminous phenomena can serve as primary cosmological distance indicators. Comparing the observed distance dependence on red shift with theoretical models one can extract information on evolution of the Universe from Big Bang until our epoch.

  3. Electron screening and its effects on big-bang nucleosynthesis

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wang Biao; Bertulani, C. A.; Balantekin, A. B.

    We study the effects of electron screening on nuclear reaction rates occurring during the big-bang nucleosynthesis epoch. The sensitivity of the predicted elemental abundances on electron screening is studied in detail. It is shown that electron screening does not produce noticeable results in the abundances unless the traditional Debye-Hueckel model for the treatment of electron screening in stellar environments is enhanced by several orders of magnitude. This work rules out electron screening as a relevant ingredient to big-bang nucleosynthesis, confirming a previous study [see Itoh et al., Astrophys. J. 488, 507 (1997)] and ruling out exotic possibilities for the treatmentmore » of screening beyond the mean-field theoretical approach.« less

  4. Capture reactions on C-14 in nonstandard big bang nucleosynthesis

    NASA Technical Reports Server (NTRS)

    Wiescher, Michael; Gorres, Joachim; Thielemann, Friedrich-Karl

    1990-01-01

    Nonstandard big bang nucleosynthesis leads to the production of C-14. The further reaction path depends on the depletion of C-14 by either photon, alpha, or neutron capture reactions. The nucleus C-14 is of particular importance in these scenarios because it forms a bottleneck for the production of heavier nuclei A greater than 14. The reaction rates of all three capture reactions at big bang conditions are discussed, and it is shown that the resulting reaction path, leading to the production of heavier elements, is dominated by the (p, gamma) and (n, gamma) rates, contrary to earlier suggestions.

  5. Pre-Big-Bang bubbles from the gravitational instability of generic string vacua

    NASA Astrophysics Data System (ADS)

    Buonanno, A.; Damour, T.; Veneziano, G.

    1999-03-01

    We formulate the basic postulate of pre-Big-Bang cosmology as one of ``asymptotic past triviality", by which we mean that the initial state is a generic perturbative solution of the tree-level low-energy effective action. Such a past-trivial ``string vacuum'' is made of an arbitrary ensemble of incoming gravitational and dilatonic waves, and is generically prone to gravitational instability, leading to the possible formation of many black holes hiding singular space-like hypersurfaces. Each such singular space-like hypersurface of gravitational collapse becomes, in the string-frame metric, the usual Big-Bang t=0 hypersurface, i.e. the place of birth of a baby Friedmann universe after a period of dilaton-driven inflation. Specializing to the spherically symmetric case, we review and reinterpret previous work on the subject, and propose a simple, scale-invariant criterion for collapse/inflation in terms of asymptotic data at past null infinity. Those data should determine whether, when, and where collapse/inflation occurs, and, when it does, fix its characteristics, including anisotropies on the Big-Bang hypersurface whose imprint could have survived till now. Using Bayesian probability concepts, we finally attempt to answer some fine-tuning objections recently moved to the pre-Big-Bang scenario.

  6. Big bang nucleosynthesis: The strong nuclear force meets the weak anthropic principle

    NASA Astrophysics Data System (ADS)

    MacDonald, J.; Mullan, D. J.

    2009-08-01

    Contrary to a common argument that a small increase in the strength of the strong force would lead to destruction of all hydrogen in the big bang due to binding of the diproton and the dineutron with a catastrophic impact on life as we know it, we show that provided the increase in strong force coupling constant is less than about 50% substantial amounts of hydrogen remain. The reason is that an increase in strong force strength leads to tighter binding of the deuteron, permitting nucleosynthesis to occur earlier in the big bang at higher temperature than in the standard big bang. Photodestruction of the less tightly bound diproton and dineutron delays their production to after the bulk of nucleosynthesis is complete. The decay of the diproton can, however, lead to relatively large abundances of deuterium.

  7. Primordial alchemy: from the Big Bang to the present universe

    NASA Astrophysics Data System (ADS)

    Steigman, Gary

    Of the light nuclides observed in the universe today, D, 3He, 4He, and 7Li are relics from its early evolution. The primordial abundances of these relics, produced via Big Bang Nucleosynthesis (BBN) during the first half hour of the evolution of the universe provide a unique window on Physics and Cosmology at redshifts ~1010. Comparing the BBN-predicted abundances with those inferred from observational data tests the consistency of the standard cosmological model over ten orders of magnitude in redshift, constrains the baryon and other particle content of the universe, and probes both Physics and Cosmology beyond the current standard models. These lectures are intended to introduce students, both of theory and observation, to those aspects of the evolution of the universe relevant to the production and evolution of the light nuclides from the Big Bang to the present. The current observational data is reviewed and compared with the BBN predictions and the implications for cosmology (e.g., universal baryon density) and particle physics (e.g., relativistic energy density) are discussed. While this comparison reveals the stunning success of the standard model(s), there are currently some challenge which leave open the door for more theoretical and observational work with potential implications for astronomy, cosmology, and particle physics.

  8. Big-bang nucleosynthesis and the baryon density of the universe.

    PubMed

    Copi, C J; Schramm, D N; Turner, M S

    1995-01-13

    For almost 30 years, the predictions of big-bang nucleosynthesis have been used to test the big-bang model to within a fraction of a second of the bang. The agreement between the predicted and observed abundances of deuterium, helium-3, helium-4, and lithium-7 confirms the standard cosmology model and allows accurate determination of the baryon density, between 1.7 x 10(-31) and 4.1 x 10(-31) grams per cubic centimeter (corresponding to about 1 to 15 percent of the critical density). This measurement of the density of ordinary matter is pivotal to the establishment of two dark-matter problems: (i) most of the baryons are dark, and (ii) if the total mass density is greater than about 15 percent of the critical density, as many determinations indicate, the bulk of the dark matter must be "non-baryonic," composed of elementary particles left from the earliest moments.

  9. The Big Bang, Genesis, and Knocking on Heaven's Door

    NASA Astrophysics Data System (ADS)

    Gentry, Robert

    2012-03-01

    Michael Shermer recently upped the ante in the big bang-Genesis controversy by citing Lisa Randall's provocative claim (Science 334, 762 (2011)) that ``it is inconceivable that God could continue to intervene without introducing a material trace of his actions.'' So does Randall's and Shermer's agreement that no such evidence exists disprove God's existence? Not in my view because my 1970s Science, Nature and ARNS publications, and my article in the 1982 AAAS Western Division's Symposium Proceedings, Evolution Confronts Creation, all contain validation of God's existence via discovery of His Fingerprints of Creation and falsification of the big bang and geological evolution. These results came to wide public/scientific attention in my testimony at the 1981 Arkansas creation/evolution trial. There ACLU witness G Brent Dalrymple from the USGS -- and 2005 Medal of Science recipient from President Bush -- admitted I had discovered a tiny mystery (primordial polonium radiohalos) in granite rocks that indicated their almost instant creation. As a follow-up in 1992 and 1995 he sent out SOS letters to the entire AGU membership that the polonium halo evidence for fiat creation still existed and that someone needed to urgently find a naturalistic explanation for them. Is the physics community guilty of a Watergate-type cover-up of this discovery of God's existence and falsification of the big bang? For the answer see www.halos.tv.

  10. Big Bang Bifurcation Analysis and Allee Effect in Generic Growth Functions

    NASA Astrophysics Data System (ADS)

    Leonel Rocha, J.; Taha, Abdel-Kaddous; Fournier-Prunaret, D.

    2016-06-01

    The main purpose of this work is to study the dynamics and bifurcation properties of generic growth functions, which are defined by the population size functions of the generic growth equation. This family of unimodal maps naturally incorporates a principal focus of ecological and biological research: the Allee effect. The analysis of this kind of extinction phenomenon allows to identify a class of Allee’s functions and characterize the corresponding Allee’s effect region and Allee’s bifurcation curve. The bifurcation analysis is founded on the performance of fold and flip bifurcations. The dynamical behavior is rich with abundant complex bifurcation structures, the big bang bifurcations of the so-called “box-within-a-box” fractal type being the most outstanding. Moreover, these bifurcation cascades converge to different big bang bifurcation curves with distinct kinds of boxes, where for the corresponding parameter values several attractors are associated. To the best of our knowledge, these results represent an original contribution to clarify the big bang bifurcation analysis of continuous 1D maps.

  11. Disproof of Big Bang's Foundational Expansion Redshift Assumption Overthrows the Big Bang and Its No-Center Universe and Is Replaced by a Spherically Symmetric Model with Nearby Center with the 2.73 K CMR Explained by Vacuum Gravity and Doppler Effects

    NASA Astrophysics Data System (ADS)

    Gentry, Robert

    2015-04-01

    Big bang theory holds its central expansion redshift assumption quickly reduced the theorized radiation flash to ~ 1010 K, and then over 13.8 billion years reduced it further to the present 2.73 K CMR. Weinberg claims this 2.73 K value agrees with big bang theory so well that ``...we can be sure that this radiation was indeed left over from a time about a million years after the `big bang.' '' (TF3M, p180, 1993 ed.) Actually his conclusion is all based on big bang's in-flight wavelength expansion being a valid physical process. In fact all his surmising is nothing but science fiction because our disproof of GR-induced in-flight wavelength expansion [1] definitely proves the 2.73 K CMR could never have been the wavelength-expanded relic of any radiation, much less the presumed big bang's. This disproof of big bang's premier prediction is a death blow to the big bang as it is also to the idea that the redshifts in Hubble's redshift relation are expansion shifts; this negates Friedmann's everywhere-the-same, no-center universe concept and proves it does have a nearby Center, a place which can be identified in Psalm 103:19 and in Revelation 20:11 as the location of God's eternal throne. Widely published (Science, Nature, ARNS) evidence of Earth's fiat creation will also be presented. The research is supported by the God of Creation. This paper [1] is in for publication.

  12. The ripples of "The Big (agricultural) Bang": the spread of early wheat cultivation.

    PubMed

    Abbo, Shahal; Gopher, Avi; Peleg, Zvi; Saranga, Yehoshua; Fahima, Tzion; Salamini, Francesco; Lev-Yadun, Simcha

    2006-08-01

    Demographic expansion and (or) migrations leave their mark in the pattern of DNA polymorphisms of the respective populations. Likewise, the spread of cultural phenomena can be traced by dating archaeological finds and reconstructing their direction and pace. A similar course of events is likely to have taken place following the "Big Bang" of the agricultural spread in the Neolithic Near East from its core area in southeastern Turkey. Thus far, no attempts have been made to track the movement of the founder genetic stocks of the first crop plants from their core area based on the genetic structure of living plants. In this minireview, we re-interpret recent wheat DNA polymorphism data to detect the genetic ripples left by the early wave of advance of Neolithic wheat farming from its core area. This methodology may help to suggest a model charting the spread of the first farming phase prior to the emergence of truly domesticated wheat types (and other such crops), thereby increasing our resolution power in studying this revolutionary period of human cultural, demographic, and social evolution.

  13. A Big Bang model of human colorectal tumor growth.

    PubMed

    Sottoriva, Andrea; Kang, Haeyoun; Ma, Zhicheng; Graham, Trevor A; Salomon, Matthew P; Zhao, Junsong; Marjoram, Paul; Siegmund, Kimberly; Press, Michael F; Shibata, Darryl; Curtis, Christina

    2015-03-01

    What happens in early, still undetectable human malignancies is unknown because direct observations are impractical. Here we present and validate a 'Big Bang' model, whereby tumors grow predominantly as a single expansion producing numerous intermixed subclones that are not subject to stringent selection and where both public (clonal) and most detectable private (subclonal) alterations arise early during growth. Genomic profiling of 349 individual glands from 15 colorectal tumors showed an absence of selective sweeps, uniformly high intratumoral heterogeneity (ITH) and subclone mixing in distant regions, as postulated by our model. We also verified the prediction that most detectable ITH originates from early private alterations and not from later clonal expansions, thus exposing the profile of the primordial tumor. Moreover, some tumors appear 'born to be bad', with subclone mixing indicative of early malignant potential. This new model provides a quantitative framework to interpret tumor growth dynamics and the origins of ITH, with important clinical implications.

  14. The Big Bang and the Search for a Theory of Everything

    NASA Technical Reports Server (NTRS)

    Kogut, Alan

    2010-01-01

    How did the universe begin? Is the gravitational physics that governs the shape and evolution of the cosmos connected in a fundamental way to the sub-atomic physics of particle colliders? Light from the Big Bang still permeates the universe and carries within it faint clues to the physics at the start of space and time. I will describe how current and planned measurements of the cosmic microwave background will observe the Big Bang to provide new insight into a "Theory of Everything" uniting the physics of the very large with the physics of the very small.

  15. Particle physics catalysis of thermal big bang nucleosynthesis.

    PubMed

    Pospelov, Maxim

    2007-06-08

    We point out that the existence of metastable, tau>10(3) s, negatively charged electroweak-scale particles (X-) alters the predictions for lithium and other primordial elemental abundances for A>4 via the formation of bound states with nuclei during big bang nucleosynthesis. In particular, we show that the bound states of X- with helium, formed at temperatures of about T=10(8) K, lead to the catalytic enhancement of 6Li production, which is 8 orders of magnitude more efficient than the standard channel. In particle physics models where subsequent decay of X- does not lead to large nonthermal big bang nucleosynthesis effects, this directly translates to the level of sensitivity to the number density of long-lived X- particles (tau>10(5) s) relative to entropy of nX-/s less, approximately <3x10(-17), which is one of the most stringent probes of electroweak scale remnants known to date.

  16. Kasner solutions, climbing scalars and big-bang singularity

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Condeescu, Cezar; Dudas, Emilian, E-mail: cezar.condeescu@roma2.infn.it, E-mail: emilian.dudas@cpht.polytechnique.fr

    We elaborate on a recently discovered phenomenon where a scalar field close to big-bang is forced to climb a steep potential by its dynamics. We analyze the phenomenon in more general terms by writing the leading order equations of motion near the singularity. We formulate the conditions for climbing to exist in the case of several scalars and after inclusion of higher-derivative corrections and we apply our results to some models of moduli stabilization. We analyze an example with steep stabilizing potential and notice again a related critical behavior: for a potential steepness above a critical value, going backwards towardsmore » big-bang, the scalar undergoes wilder oscillations, with the steep potential pushing it back at every passage and not allowing the scalar to escape to infinity. Whereas it was pointed out earlier that there are possible implications of the climbing phase to CMB, we point out here another potential application, to the issue of initial conditions in inflation.« less

  17. Big bang nucleosynthesis: An update

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Olive, Keith A.

    An update on the standard model of big bang nucleosynthesis (BBN) is presented. With the value of the baryon-tophoton ratio determined to high precision by WMAP, standard BBN is a parameter-free theory. In this context, the theoretical prediction for the abundances of D, {sup 4}He, and {sup 7}Li is discussed and compared to their observational determination. While concordance for D and {sup 4}He is satisfactory, the prediction for {sup 7}Li exceeds the observational determination by a factor of about four. Possible solutions to this problem are discussed.

  18. Constructing "Nerdiness": Characterisation in "The Big Bang Theory"

    ERIC Educational Resources Information Center

    Bednarek, Monika

    2012-01-01

    This paper analyses the linguistic construction of the televisual character Sheldon--the "main nerd" in the sitcom "The Big Bang Theory" (CBS, 2007-), approaching this construction of character through both computerised and "manual" linguistic analysis. More specifically, a computer analysis of dialogue (using concordances and keyword analysis) in…

  19. The onset of star formation 250 million years after the Big Bang

    NASA Astrophysics Data System (ADS)

    Hashimoto, Takuya; Laporte, Nicolas; Mawatari, Ken; Ellis, Richard S.; Inoue, Akio K.; Zackrisson, Erik; Roberts-Borsani, Guido; Zheng, Wei; Tamura, Yoichi; Bauer, Franz E.; Fletcher, Thomas; Harikane, Yuichi; Hatsukade, Bunyo; Hayatsu, Natsuki H.; Matsuda, Yuichi; Matsuo, Hiroshi; Okamoto, Takashi; Ouchi, Masami; Pelló, Roser; Rydberg, Claes-Erik; Shimizu, Ikkoh; Taniguchi, Yoshiaki; Umehata, Hideki; Yoshida, Naoki

    2018-05-01

    A fundamental quest of modern astronomy is to locate the earliest galaxies and study how they influenced the intergalactic medium a few hundred million years after the Big Bang1-3. The abundance of star-forming galaxies is known to decline4,5 from redshifts of about 6 to 10, but a key question is the extent of star formation at even earlier times, corresponding to the period when the first galaxies might have emerged. Here we report spectroscopic observations of MACS1149-JD16, a gravitationally lensed galaxy observed when the Universe was less than four per cent of its present age. We detect an emission line of doubly ionized oxygen at a redshift of 9.1096 ± 0.0006, with an uncertainty of one standard deviation. This precisely determined redshift indicates that the red rest-frame optical colour arises from a dominant stellar component that formed about 250 million years after the Big Bang, corresponding to a redshift of about 15. Our results indicate that it may be possible to detect such early episodes of star formation in similar galaxies with future telescopes.

  20. The onset of star formation 250 million years after the Big Bang.

    PubMed

    Hashimoto, Takuya; Laporte, Nicolas; Mawatari, Ken; Ellis, Richard S; Inoue, Akio K; Zackrisson, Erik; Roberts-Borsani, Guido; Zheng, Wei; Tamura, Yoichi; Bauer, Franz E; Fletcher, Thomas; Harikane, Yuichi; Hatsukade, Bunyo; Hayatsu, Natsuki H; Matsuda, Yuichi; Matsuo, Hiroshi; Okamoto, Takashi; Ouchi, Masami; Pelló, Roser; Rydberg, Claes-Erik; Shimizu, Ikkoh; Taniguchi, Yoshiaki; Umehata, Hideki; Yoshida, Naoki

    2018-05-01

    A fundamental quest of modern astronomy is to locate the earliest galaxies and study how they influenced the intergalactic medium a few hundred million years after the Big Bang 1-3 . The abundance of star-forming galaxies is known to decline 4,5 from redshifts of about 6 to 10, but a key question is the extent of star formation at even earlier times, corresponding to the period when the first galaxies might have emerged. Here we report spectroscopic observations of MACS1149-JD1 6 , a gravitationally lensed galaxy observed when the Universe was less than four per cent of its present age. We detect an emission line of doubly ionized oxygen at a redshift of 9.1096 ± 0.0006, with an uncertainty of one standard deviation. This precisely determined redshift indicates that the red rest-frame optical colour arises from a dominant stellar component that formed about 250 million years after the Big Bang, corresponding to a redshift of about 15. Our results indicate that it may be possible to detect such early episodes of star formation in similar galaxies with future telescopes.

  1. Quantization of Big Bang in Crypto-Hermitian Heisenberg Picture

    NASA Astrophysics Data System (ADS)

    Znojil, Miloslav

    A background-independent quantization of the Universe near its Big Bang singularity is considered using a drastically simplified toy model. Several conceptual issues are addressed. (1) The observable spatial-geometry characteristics of our empty-space expanding Universe is sampled by the time-dependent operator $Q=Q(t)$ of the distance between two space-attached observers (``Alice and Bob''). (2) For any pre-selected guess of the simple, non-covariant time-dependent observable $Q(t)$ one of the Kato's exceptional points (viz., $t=\\tau_{(EP)}$) is postulated {\\em real-valued}. This enables us to treat it as the time of Big Bang. (3) During our ``Eon'' (i.e., at all $t>\\tau_{(EP)}$) the observability status of operator $Q(t)$ is mathematically guaranteed by its self-adjoint nature with respect to an {\\em ad hoc} Hilbert-space metric $\\Theta(t) \

  2. The Big Bang Theory and the Nature of Science

    NASA Astrophysics Data System (ADS)

    Arthury, Luiz Henrique Martins; Peduzzi, Luiz O. Q.

    2015-12-01

    Modern cosmology was constituted, throughout the twentieth century to the present days, as a very productive field of research, resulting in major discoveries that attest to its explanatory power. The Big Bang Theory, the generic and popular name of the standard model of cosmology, is probably the most daring research program of physics and astronomy, trying to recreate the evolution of our observable universe. But contrary to what you might think, its conjectures are of a degree of refinement and corroborative evidence that make it our best explanation for the history of our cosmos. The Big Bang Theory is also an excellent field to discuss issues regarding the scientific activity itself. In this paper we discuss the main elements of this theory with an epistemological look, resulting in a text quite useful to work on educational activities with related goals.

  3. The Friedmann-Lemaître-Robertson-Walker Big Bang Singularities are Well Behaved

    NASA Astrophysics Data System (ADS)

    Stoica, Ovidiu Cristinel

    2016-01-01

    We show that the Big Bang singularity of the Friedmann-Lemaître-Robertson-Walker model does not raise major problems to General Relativity. We prove a theorem showing that the Einstein equation can be written in a non-singular form, which allows the extension of the spacetime before the Big Bang. The physical interpretation of the fields used is discussed. These results follow from our research on singular semi-Riemannian geometry and singular General Relativity.

  4. Big Bang Day: 5 Particles - 3. The Anti-particle

    ScienceCinema

    None

    2017-12-09

    Simon Singh looks at the stories behind the discovery of 5 of the universe's most significant subatomic particles: the Electron, the Quark, the Anti-particle, the Neutrino and the "next particle". 3. The Anti-particle. It appears to be the stuff of science fiction. Associated with every elementary particle is an antiparticle which has the same mass and opposite charge. Should the two meet and combine, the result is annihilation - and a flash of light. Thanks to mysterious processes that occurred after the Big Bang there are a vastly greater number of particles than anti-particles. So how could their elusive existence be proved? At CERN particle physicists are crashing together subatomic particles at incredibly high speeds to create antimatter, which they hope will finally reveal what happened at the precise moment of the Big Bang to create the repertoire of elementary particles and antiparticles in existence today.

  5. Entropy Growth in the Early Universe and Confirmation of Initial Big Bang Conditions

    NASA Astrophysics Data System (ADS)

    Beckwith, Andrew

    2009-09-01

    This paper shows how increased entropy values from an initially low big bang level can be measured experimentally by counting relic gravitons. Furthermore the physical mechanism of this entropy increase is explained via analogies with early-universe phase transitions. The role of Jack Ng's (2007, 2008a, 2008b) revised infinite quantum statistics in the physics of gravitational wave detection is acknowledged. Ng's infinite quantum statistics can be used to show that ΔS~ΔNgravitons is a startmg point to the increasing net universe cosmological entropy. Finally, in a nod to similarities AS ZPE analysis, it is important to note that the resulting ΔS~ΔNgravitons ≠ 1088, that in fact it is much lower, allowing for evaluating initial graviton production as an emergent field phenomena, which may be similar to how ZPE states can be used to extract energy from a vacuum if entropy is not maximized. The rapid increase in entropy so alluded to without near sudden increases to 1088 may be enough to allow successful modeling of relic graviton production for entropy in a manner similar to ZPE energy extraction from a vacuum state.

  6. Evidence for Evolution as Support for Big Bang

    NASA Astrophysics Data System (ADS)

    Gopal-Krishna

    1997-12-01

    With the exception of ZERO, the concept of BIG BANG is by far the most bizarre creation of the human mind. Three classical pillars of the Big Bang model of the origin of the universe are generally thought to be: (i) The abundances of the light elements; (ii) the microwave back-ground radiation; and (iii) the change with cosmic epoch in the average properties of galaxies (both active and non-active types). Evidence is also mounting for redshift dependence of the intergalactic medium, as discussed elsewhere in this volume in detail. In this contribution, I endeavour to highlight a selection of recent advances pertaining to the third category. The widely different levels of confidence in the claimed observational constraints in the field of cosmology can be guaged from the following excerpts from two leading astrophysicists: "I would bet odds of 10 to 1 on the validity of the general 'hot Big Bang' concept as a description of how our universe has evolved since it was around 1 sec. old" -M. Rees (1995), in 'Perspectives in Astrophysical Cosmology' CUP. "With the much more sensitive observations available today, no astrophysical property shows evidence of evolution, such as was claimed in the 1950s to disprove the Steady State theory" -F. Hoyle (1987), in 'Fifty years in cosmology', B. M. Birla Memorial Lecture, Hyderabad, India. The burgeoning multi-wavelength culture in astronomy has provided a tremendous boost to observational cosmology in recent years. We now proceed to illustrate this with a sequence of examples which reinforce the picture of an evolving universe. Also provided are some relevant details of the data used in these studies so that their scope can be independently judged by the readers.

  7. Beyond Einstein: From the Big Bang to Black Holes

    NASA Astrophysics Data System (ADS)

    White, N.

    Beyond Einstein is a science-driven program of missions, education and outreach, and technology, to address three questions: What powered the Big Bang? What happens to space, time, and matter at the edge of a Black Hole? What is the mysterious Dark Energy pulling the universe apart? To address the science objectives, Beyond Einstein contains several interlinked elements. The strategic missions Constellation-X and LISA primarily investigate the nature of black holes. Constellation-X is a spectroscopic observatory that uses X-ray emitting atoms as clocks to follow the fate of matter falling into black holes. LISA will be the first space-based gravitational wave observatory uses gravitational waves to measure the dynamic structure of space and time around black holes. Moderate sized probes that are fully competed, peer-reviewed missions (300M-450M) launched every 3-5 years to address the focussed science goals: 1) Determine the nature of the Dark Energy that dominates the universe, 2) Search for the signature of the beginning of the Big Bang in the microwave background and 3) Take a census of Black Holes of all sizes and ages in the universe. The final element is a Technology Program to enable ultimate Vision Missions (after 2015) to directly detect gravitational waves echoing from the beginning of the Big Bang, and to directly image matter near the event horizon of a Black Hole. An associated Education and Public Outreach Program will inspire the next generation of scientists, and support national science standards and benchmarks.

  8. EMR implementation: big bang or a phased approach?

    PubMed

    Owens, Kathleen

    2008-01-01

    There are two major strategies to implementing an EMR: the big-bang approach and the phased, or incremental, approach. Each strategy has pros and cons that must be considered. This article discusses these approaches and the risks and benefits of each as well as some training strategies that can be used with either approach.

  9. From the Big Bang to the Nobel Prize and on to James Webb Space Telescope

    NASA Technical Reports Server (NTRS)

    Mather, John C.

    2008-01-01

    The history of the universe in a nutshell, from the Big Bang to now, and on to the future - John Mather will tell the story of how we got here, how the Universe began with a Big Bang, how it could have produced an Earth where sentient beings can live, and how those beings are discovering their history. Mather was Project Scientist for NASA's Cosmic Background Explorer (COBE) satellite, which measured the spectrum (the color) of the heat radiation from the Big Bang, discovered hot and cold spots in that radiation, and hunted for the first objects that formed after the great explosion. He will explain Einstein's biggest mistake, show how Edwin Hubble discovered the expansion of the universe, how the COBE mission was built, and how the COBE data support the Big Bang theory. He will also show NASA's plans for the next great telescope in space, the James Webb Space Telescope. It will look even farther back in time than the Hubble Space Telescope, and will look inside the dusty cocoons where stars and planets are being born today. Planned for launch in 2013, it may lead to another Nobel Prize for some lucky observer.

  10. From the Big Bang to the Nobel Prize and on to James Webb Space Telescope

    NASA Technical Reports Server (NTRS)

    Mather, John C.

    2008-01-01

    The history of the universe in a nutshell, from the Big Bang to now. and on to the future - John Mather will tell the story of how we got here, how the Universe began with a Big Bang, how it could have produced an Earth where sentient beings can live, and how those beings are discovering their history. Mather was Project Scientist for NASA's Cosmic Background Explorer (COBE) satellite, which measured the spectrum (the color) of the heat radiation from the Big Bang, discovered hot and cold spots in that radiation, and hunted for the first objects that formed after the great explosion. He will explain Einstein's biggest mistake, show how Edwin Hubble discovered the expansion of the universe, how the COBE mission was built, and how the COBE data support the Big Bang theory. He will also show NASA's plans for the next great telescope in space, the James Webb Space Telescope. It will look even farther back in time than the Hubble Space Telescope, and will look inside the dusty cocoons where stars and planets are being born today. Planned for launch in 2013, it may lead to another Nobel Prize for some lucky observer.

  11. A large neutral fraction of cosmic hydrogen a billion years after the Big Bang.

    PubMed

    Wyithe, J Stuart B; Loeb, Abraham

    2004-02-26

    The fraction of ionized hydrogen left over from the Big Bang provides evidence for the time of formation of the first stars and quasar black holes in the early Universe; such objects provide the high-energy photons necessary to ionize hydrogen. Spectra of the two most distant known quasars show nearly complete absorption of photons with wavelengths shorter than the Lyman alpha transition of neutral hydrogen, indicating that hydrogen in the intergalactic medium (IGM) had not been completely ionized at a redshift of z approximately 6.3, about one billion years after the Big Bang. Here we show that the IGM surrounding these quasars had a neutral hydrogen fraction of tens of per cent before the quasar activity started, much higher than the previous lower limits of approximately 0.1 per cent. Our results, when combined with the recent inference of a large cumulative optical depth to electron scattering after cosmological recombination therefore suggest the presence of a second peak in the mean ionization history of the Universe.

  12. Big Bang Day: 5 Particles - 3. The Anti-particle

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    None

    2009-10-07

    Simon Singh looks at the stories behind the discovery of 5 of the universe's most significant subatomic particles: the Electron, the Quark, the Anti-particle, the Neutrino and the "next particle". 3. The Anti-particle. It appears to be the stuff of science fiction. Associated with every elementary particle is an antiparticle which has the same mass and opposite charge. Should the two meet and combine, the result is annihilation - and a flash of light. Thanks to mysterious processes that occurred after the Big Bang there are a vastly greater number of particles than anti-particles. So how could their elusive existencemore » be proved? At CERN particle physicists are crashing together subatomic particles at incredibly high speeds to create antimatter, which they hope will finally reveal what happened at the precise moment of the Big Bang to create the repertoire of elementary particles and antiparticles in existence today.« less

  13. Big Bang Cosmic Titanic: Cause for Concern?

    NASA Astrophysics Data System (ADS)

    Gentry, Robert

    2013-04-01

    This abstract alerts physicists to a situation that, unless soon addressed, may yet affect PRL integrity. I refer to Stanley Brown's and DAE Robert Caldwell's rejection of PRL submission LJ12135, A Cosmic Titanic: Big Bang Cosmology Unravels Upon Discovery of Serious Flaws in Its Foundational Expansion Redshift Assumption, by their claim that BB is an established theory while ignoring our paper's Titanic, namely, that BB's foundational spacetime expansion redshifts assumption has now been proven to be irrefutably false because it is contradicted by our seminal discovery that GPS operation unequivocally proves that GR effects do not produce in-flight photon wavelength changes demanded by this central assumption. This discovery causes the big bang to collapse as quickly as did Ptolemaic cosmology when Copernicus discovered its foundational assumption was heliocentric, not geocentric. Additional evidence that something is amiss in PRL's treatment of LJ12135 comes from both Brown and EiC Gene Spouse agreeing to meet at my exhibit during last year's Atlanta APS to discuss this cover-up issue. Sprouse kept his commitment; Brown didn't. Question: If Brown could have refuted my claim of a cover-up, why didn't he come to present it before Gene Sprouse? I am appealing LJ12135's rejection.

  14. Probing the Big Bang with LEP

    NASA Technical Reports Server (NTRS)

    Schramm, David N.

    1990-01-01

    It is shown that LEP probes the Big Bang in two significant ways: (1) nucleosynthesis, and (2) dark matter constraints. In the first case, LEP verifies the cosmological standard model prediction on the number of neutrino types, thus strengthening the conclusion that the cosmological baryon density is approximately 6 percent of the critical value. In the second case, LEP shows that the remaining non-baryonic cosmological matter must be somewhat more massive and/or more weakly interacting than the favorite non-baryonic dark matter candidates of a few years ago.

  15. The Big Bang and Cosmic Inflation

    NASA Astrophysics Data System (ADS)

    Guth, Alan H.

    2014-03-01

    A summary is given of the key developments of cosmology in the 20th century, from the work of Albert Einstein to the emergence of the generally accepted hot big bang model. The successes of this model are reviewed, but emphasis is placed on the questions that the model leaves unanswered. The remainder of the paper describes the inflationary universe model, which provides plausible answers to a number of these questions. It also offers a possible explanation for the origin of essentially all the matter and energy in the observed universe.

  16. "Big Bang" as a result result of the curvature-driven first-order phase transition in the early cold Universe

    NASA Astrophysics Data System (ADS)

    Pashitskii, E. A.; Pentegov, V. I.

    We suggest that the "Big Bang" may be a result of the first-order phase transition driven by changing scalar curvature of the 4D space-time in the expanding cold Universe, filled with nonlinear scalar field φ and neutral matter with equation of state p = vɛ (where p and ɛ are pressure and energy density of matter). We consider a Lagrangian for scalar field in curved space-time with nonlinearity φ, which along with the quadratic term -ΣR|φ|2 (where Σ is interaction constant and R is scalar curvature) contains a term ΣR(φ +φ+) linear in φ. Due to this term the condition for the extrema of the potential energy of the scalar field is given by a cubic equation. Provided v > 1/3 the scalar curvature R = [κ(3v-1)ɛ - 4Γ (where κ and Γ are Einstein's gravitational and cosmological constants) decreases along with decreasing " in the process of the Universe's expansion, and at some critical value Rc < 0 a first-order phase transition occurs, driven by an "external field" parameter proportional to R. Given certain conditions the critical radius of the early Universe at the point of the first-order phase transition may reach arbitrary large values, so this scenario of unrestricted "inflation" of the Universe may be called "hyperinflation". Beyond the point of phase transition the system is rolling down into the potential minimum releasing the potential energy of scalar field with subsequent powerful heating of the Universe playing the role of "Big Bang".

  17. Von Bertalanffy's dynamics under a polynomial correction: Allee effect and big bang bifurcation

    NASA Astrophysics Data System (ADS)

    Leonel Rocha, J.; Taha, A. K.; Fournier-Prunaret, D.

    2016-02-01

    In this work we consider new one-dimensional populational discrete dynamical systems in which the growth of the population is described by a family of von Bertalanffy's functions, as a dynamical approach to von Bertalanffy's growth equation. The purpose of introducing Allee effect in those models is satisfied under a correction factor of polynomial type. We study classes of von Bertalanffy's functions with different types of Allee effect: strong and weak Allee's functions. Dependent on the variation of four parameters, von Bertalanffy's functions also includes another class of important functions: functions with no Allee effect. The complex bifurcation structures of these von Bertalanffy's functions is investigated in detail. We verified that this family of functions has particular bifurcation structures: the big bang bifurcation of the so-called “box-within-a-box” type. The big bang bifurcation is associated to the asymptotic weight or carrying capacity. This work is a contribution to the study of the big bang bifurcation analysis for continuous maps and their relationship with explosion birth and extinction phenomena.

  18. From the Big Bang to the Nobel Prize and on to James Webb Space Telescope

    NASA Technical Reports Server (NTRS)

    Mather, John C.

    2009-01-01

    The history of the universe in a nutshell, from the Big Bang to now, and on to the future - John Mather will tell the story of how we got here, how the Universe began with a Big Bang, how it could have produced an Earth where sentient beings can live, and how those beings are discovering their history. Mather was Project Scientist for NASA s Cosmic Background Explorer (COBE) satellite, which measured the spectrum (the color) of the heat radiation from the Big Bang, discovered hot and cold spots in that radiation, and hunted for the first objects that formed after the great explosion. He will explain Einstein s biggest mistake, show how Edwin Hubble discovered the expansion of the universe, how the COBE mission was built, and how the COBE data support the Big Bang theory. He will also show NASA s plans for the next great telescope in space, the James Webb Space Telescope. It will look even farther back in time than the Hubble Space Telescope, and will look inside the dusty cocoons where stars and planets are being born today. Planned for launch in 2013, it may lead to another Nobel Prize for some lucky observer.

  19. From the Big Bang to the Nobel Prize and on to the James Webb Space Telescope

    NASA Technical Reports Server (NTRS)

    Mather, John C.

    2008-01-01

    The history of the universe in a nutshell, from the Big Bang to now. and on to the future - John Mather will tell the story of how we got here, how the Universe began with a Big Bang, how it could have produced an Earth where sentient beings can live, and how those beings are discovering their history. Mather was Project Scientist for NASA's Cosmic Background Explorer (COBE) satellite, which measured the spectrum (the color) of the heat radiation from the Big Bang, discovered hot and cold spots in that radiation, and hunted for the first objects that formed after the great explosion. He will explain Einstein's biggest mistake, show how Edwin Hubble discovered the expansion of the univerre, how the COBE mission was built, and how the COBE data support the Big Bang theory. He will also show NASA's plans for the next great telescope in space, the Jarnes Webb Space Telescope. It will look even farther back in time than the Hubble Space Telescope, and will look inside the dusty cocoons where rtars and planets are being born today. Planned for launch in 2013, it may lead to another Nobel Prize for some lucky observer.

  20. Big Bang Day : Afternoon Play - Torchwood: Lost Souls

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    None

    2009-10-13

    Martha Jones, ex-time traveller and now working as a doctor for a UN task force, has been called to CERN where they're about to activate the Large Hadron Collider. Once activated, the Collider will fire beams of protons together recreating conditions a billionth of a second after the Big Bang - and potentially allowing the human race a greater insight into what the Universe is made of. But so much could go wrong - it could open a gateway to a parallel dimension, or create a black hole - and now voices from the past are calling out to peoplemore » and scientists have started to disappear... Where have the missing scientists gone? What is the secret of the glowing man? What is lurking in the underground tunnel? And do the dead ever really stay dead? Lost Souls is a spin-off from the award-winning BBC Wales TV production Torchwood. It stars John Barrowman, Freema Agyeman, Eve Myles, Gareth David-Lloyd, Lucy Montgomery (of Titty Bang Bang) and Stephen Critchlow.« less

  1. Big Bang Day : Afternoon Play - Torchwood: Lost Souls

    ScienceCinema

    None

    2017-12-09

    Martha Jones, ex-time traveller and now working as a doctor for a UN task force, has been called to CERN where they're about to activate the Large Hadron Collider. Once activated, the Collider will fire beams of protons together recreating conditions a billionth of a second after the Big Bang - and potentially allowing the human race a greater insight into what the Universe is made of. But so much could go wrong - it could open a gateway to a parallel dimension, or create a black hole - and now voices from the past are calling out to people and scientists have started to disappear... Where have the missing scientists gone? What is the secret of the glowing man? What is lurking in the underground tunnel? And do the dead ever really stay dead? Lost Souls is a spin-off from the award-winning BBC Wales TV production Torchwood. It stars John Barrowman, Freema Agyeman, Eve Myles, Gareth David-Lloyd, Lucy Montgomery (of Titty Bang Bang) and Stephen Critchlow.

  2. The big bang as a higher-dimensional shock wave

    NASA Astrophysics Data System (ADS)

    Wesson, P. S.; Liu, H.; Seahra, S. S.

    2000-06-01

    We give an exact solution of the five-dimensional field equations which describes a shock wave moving in time and the extra (Kaluza-Klein) coordinate. The matter in four-dimensional spacetime is a cosmology with good physical properties. The solution suggests to us that the 4D big bang was a 5D shock wave.

  3. A simple all-time model for the birth, big bang, and death of the universe

    NASA Astrophysics Data System (ADS)

    Fischer, Arthur E.

    We model the standard ΛCDM model of the universe by the spatially flat FLRW line element dsΛCDM2 = -c2dt2 + 8πGρm,0 Λc22/3 sinh 1 23Λct4/3dσ Euclid2 which we extend for all time t ∈ (-∞,∞). Although there is a cosmological singularity at the big bang t = 0, since the spatial part of the metric collapses to zero, nevertheless, this line element is defined for all time t ∈ (-∞,∞), is C∞ for all t≠0, is C1 differentiable at t = 0, and is non-degenerate and solves Friedmann’s equation for all t≠0. Thus, we can use this extended line element to model the universe from its past-asymptotic initial state dS4- at t = -∞, through the big bang at t = 0, and onward to its future-asymptotic final state dS4+ at t = ∞. Since in this model the universe existed before the big bang, we conclude that (1) the universe was not created de novo at the big bang and (2) cosmological singularities such as black holes or the big bang itself need not be an end to spacetime. Our model shows that the universe was asymptotically created de novo out of nothing at t = -∞ from an unstable vacuum negative half de Sitter dsdS4-2 initial state and then dies asymptotically at t = ∞ as the stable positive half de Sitter dsdS4+2 final state. Since the de Sitter states are vacuum matter states, our model shows that the universe was created from nothing at t = -∞ and dies at t = ∞ to nothing.

  4. Beyond Einstein: from the Big Bang to black holes

    NASA Astrophysics Data System (ADS)

    White, Nicholas E.; Diaz, Alphonso V.

    2004-01-01

    How did the Universe begin? Does time have a beginning and an end? Does space have edges? Einstein's theory of relativity replied to these ancient questions with three startling predictions: that the Universe is expanding from a Big Bang; that black holes so distort space and time that time stops at their edges; and that a dark energy could be pulling space apart, sending galaxies forever beyond the edge of the visible Universe. Observations confirm these remarkable predictions, the last finding only four years ago. Yet Einstein's legacy is incomplete. His theory raises - but cannot answer - three profound questions: What powered the Big Bang? What happens to space, time and matter at the edge of a black hole? and, What is the mysterious dark energy pulling the Universe apart? The Beyond Einstein program within NASA's office of space science aims to answer these questions, employing a series of missions linked by powerful new technologies and complementary approaches to shared science goals. The program also serves as a potent force with which to enhance science education and science literacy.

  5. Astrophysical S-factor for destructive reactions of lithium-7 in big bang nucleosynthesis

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Komatsubara, Tetsuro; Kwon, YoungKwan; Moon, JunYoung

    One of the most prominent success with the Big Bang models is the precise reproduction of mass abundance ratio for {sup 4}He. In spite of the success, abundances of lithium isotopes are still inconsistent between observations and their calculated results, which is known as lithium abundance problem. Since the calculations were based on the experimental reaction data together with theoretical estimations, more precise experimental measurements may improve the knowledge of the Big Bang nucleosynthesis. As one of the destruction process of lithium-7, we have performed measurements for the reaction cross sections of the {sup 7}L({sup 3}He,p){sup 9}Be reaction.

  6. Observable gravitational waves in pre-big bang cosmology: an update

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gasperini, M., E-mail: gasperini@ba.infn.it

    In the light of the recent results concerning CMB observations and GW detection we address the question of whether it is possible, in a self-consistent inflationary framework, to simultaneously generate a spectrum of scalar metric perturbations in agreement with Planck data and a stochastic background of primordial gravitational radiation compatible with the design sensitivity of aLIGO/Virgo and/or eLISA. We suggest that this is possible in a string cosmology context, for a wide region of the parameter space of the so-called pre-big bang models. We also discuss the associated values of the tensor-to-scalar ratio relevant to the CMB polarization experiments. Wemore » conclude that future, cross-correlated results from CMB observations and GW detectors will be able to confirm or disprove pre-big bang models and—in any case—will impose new significant constraints on the basic string theory/cosmology parameters.« less

  7. Astrophysical Li-7 as a product of big bang nucleosynthesis and galactic cosmic-ray spallation

    NASA Technical Reports Server (NTRS)

    Olive, Keith A.; Schramm, David N.

    1992-01-01

    The astrophysical Li-7 abundance is considered to be largely primordial, while the Be and B abundances are thought to be due to galactic cosmic ray (GCR) spallation reactions on top of a much smaller big bang component. But GCR spallation should also produce Li-7. As a consistency check on the combination of big bang nucleosynthesis and GCR spallation, the Be and B data from a sample of hot population II stars is used to subtract from the measured Li-7 abundance an estimate of the amount generated by GCR spallation for each star in the sample, and then to add to this baseline an estimate of the metallicity-dependent augmentation of Li-7 due to spallation. The singly reduced primordial Li-7 abundance is still consistent with big bang nucleosynthesis, and a single GCR spallation model can fit the Be, B, and corrected Li-7 abundances for all the stars in the sample.

  8. Lepton asymmetry, neutrino spectral distortions, and big bang nucleosynthesis

    NASA Astrophysics Data System (ADS)

    Grohs, E.; Fuller, George M.; Kishimoto, C. T.; Paris, Mark W.

    2017-03-01

    We calculate Boltzmann neutrino energy transport with self-consistently coupled nuclear reactions through the weak-decoupling-nucleosynthesis epoch in an early universe with significant lepton numbers. We find that the presence of lepton asymmetry enhances processes which give rise to nonthermal neutrino spectral distortions. Our results reveal how asymmetries in energy and entropy density uniquely evolve for different transport processes and neutrino flavors. The enhanced distortions in the neutrino spectra alter the expected big bang nucleosynthesis light element abundance yields relative to those in the standard Fermi-Dirac neutrino distribution cases. These yields, sensitive to the shapes of the neutrino energy spectra, are also sensitive to the phasing of the growth of distortions and entropy flow with time/scale factor. We analyze these issues and speculate on new sensitivity limits of deuterium and helium to lepton number.

  9. Was the Big Bang hot?

    NASA Technical Reports Server (NTRS)

    Wright, E. L.

    1983-01-01

    Techniques for verifying the spectrum defined by Woody and Richards (WR, 1981), which serves as a base for dust-distorted models of the 3 K background, are discussed. WR detected a sharp deviation from the Planck curve in the 3 K background. The absolute intensity of the background may be determined by the frequency dependence of the dipole anisotropy of the background or the frequency dependence effect in galactic clusters. Both methods involve the Doppler shift; analytical formulae are defined for characterization of the dipole anisotropy. The measurement of the 30-300 GHz spectra of cold galactic dust may reveal the presence of significant amounts of needle-shaped grains, which would in turn support a theory of a cold Big Bang.

  10. Big bang and the policy prescription: health care meets the market in New Zealand.

    PubMed

    Gauld, R D

    2000-10-01

    This article discusses events that led up to and the aftermath of New Zealand's radical health sector restructuring of 1993. It suggests that "big bang" policy change facilitated the introduction of a set of market-oriented ideas describable as a policy prescription. In general, the new system performed poorly, in keeping with problems of market failure endemic in health care. The system was subsequently restructured, and elements of the 1993 structures were repackaged through a series of incremental changes. Based on the New Zealand experience, big bang produces change but not necessarily a predictive model, and the policy prescription has been oversold.

  11. Effects of anisotropy and spatial curvature on the pre-big-bang scenario

    NASA Astrophysics Data System (ADS)

    Clancy, Dominic; Lidsey, James E.; Tavakol, Reza

    1998-08-01

    A class of exact, anisotropic cosmological solutions to the vacuum Brans-Dicke theory of gravity is considered within the context of the pre-big-bang scenario. Included in this class are the Bianchi type III, V and VIh models and the spatially isotropic, negatively curved Friedmann-Robertson-Walker universe. The effects of large anisotropy and spatial curvature are determined. In contrast with a negatively curved Friedmann-Robertson-Walker model, there exist regions of the parameter space in which the combined effects of curvature and anisotropy prevent the occurrence of inflation. When inflation is possible, the necessary and sufficient conditions for successful pre-big-bang inflation are more stringent than in the isotropic models. The initial state for these models is established and corresponds in general to a gravitational plane wave.

  12. The Big Bang: UK Young Scientists' and Engineers' Fair 2010

    ERIC Educational Resources Information Center

    Allison, Simon

    2010-01-01

    The Big Bang: UK Young Scientists' and Engineers' Fair is an annual three-day event designed to promote science, technology, engineering and maths (STEM) careers to young people aged 7-19 through experiential learning. It is supported by stakeholders from business and industry, government and the community, and brings together people from various…

  13. A Guided Inquiry on Hubble Plots and the Big Bang

    ERIC Educational Resources Information Center

    Forringer, Ted

    2014-01-01

    In our science for non-science majors course "21st Century Physics," we investigate modern "Hubble plots" (plots of velocity versus distance for deep space objects) in order to discuss the Big Bang, dark matter, and dark energy. There are two potential challenges that our students face when encountering these topics for the…

  14. The role of antimatter in big-bang cosmology

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.

    1973-01-01

    Big bang cosmology is discussed with reference to both its strong points and gaps. Characteristics of a spectral component of red shifted gamma-radiation from cosmological matter-antimatter annihilation show a flattening of the gamma-ray spectrum in the vicinity of 1 MeV, an increased gamma-ray flux between 1 and 100 MeV, and a very steep spectrum between 50 and 135 MeV. This data fits well with the theoretical predictions in energy and intensity.

  15. The Last Big Bang

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    McGuire, Austin D.; Meade, Roger Allen

    As one of the very few people in the world to give the “go/no go” decision to detonate a nuclear device, Austin “Mac” McGuire holds a very special place in the history of both the Los Alamos National Laboratory and the world. As Commander of Joint Task Force Unit 8.1.1, on Christmas Island in the spring and summer of 1962, Mac directed the Los Alamos data collection efforts for twelve of the last atmospheric nuclear detonations conducted by the United States. Since data collection was at the heart of nuclear weapon testing, it fell to Mac to make the ultimatemore » decision to detonate each test device. He calls his experience THE LAST BIG BANG, since these tests, part of Operation Dominic, were characterized by the dramatic displays of the heat, light, and sounds unique to atmospheric nuclear detonations – never, perhaps, to be witnessed again.« less

  16. Lepton asymmetry, neutrino spectral distortions, and big bang nucleosynthesis

    DOE PAGES

    Grohs, E.; Fuller, George M.; Kishimoto, C. T.; ...

    2017-03-03

    In this paper, we calculate Boltzmann neutrino energy transport with self-consistently coupled nuclear reactions through the weak-decoupling-nucleosynthesis epoch in an early universe with significant lepton numbers. We find that the presence of lepton asymmetry enhances processes which give rise to nonthermal neutrino spectral distortions. Our results reveal how asymmetries in energy and entropy density uniquely evolve for different transport processes and neutrino flavors. The enhanced distortions in the neutrino spectra alter the expected big bang nucleosynthesis light element abundance yields relative to those in the standard Fermi-Dirac neutrino distribution cases. These yields, sensitive to the shapes of the neutrino energymore » spectra, are also sensitive to the phasing of the growth of distortions and entropy flow with time/scale factor. Finally, we analyze these issues and speculate on new sensitivity limits of deuterium and helium to lepton number.« less

  17. Lepton asymmetry, neutrino spectral distortions, and big bang nucleosynthesis

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Grohs, E.; Fuller, George M.; Kishimoto, C. T.

    In this paper, we calculate Boltzmann neutrino energy transport with self-consistently coupled nuclear reactions through the weak-decoupling-nucleosynthesis epoch in an early universe with significant lepton numbers. We find that the presence of lepton asymmetry enhances processes which give rise to nonthermal neutrino spectral distortions. Our results reveal how asymmetries in energy and entropy density uniquely evolve for different transport processes and neutrino flavors. The enhanced distortions in the neutrino spectra alter the expected big bang nucleosynthesis light element abundance yields relative to those in the standard Fermi-Dirac neutrino distribution cases. These yields, sensitive to the shapes of the neutrino energymore » spectra, are also sensitive to the phasing of the growth of distortions and entropy flow with time/scale factor. Finally, we analyze these issues and speculate on new sensitivity limits of deuterium and helium to lepton number.« less

  18. Big bang nucleosynthesis revisited via Trojan Horse method measurements

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Pizzone, R. G.; Spartá, R.; Spitaleri, C.

    Nuclear reaction rates are among the most important input for understanding primordial nucleosynthesis and, therefore, for a quantitative description of the early universe. An up-to-date compilation of direct cross-sections of {sup 2}H(d, p){sup 3}H, {sup 2}H(d, n){sup 3}He, {sup 7}Li(p, α){sup 4}He, and {sup 3}He(d, p){sup 4}He reactions is given. These are among the most uncertain cross-sections used and input for big bang nucleosynthesis calculations. Their measurements through the Trojan Horse method are also reviewed and compared with direct data. The reaction rates and the corresponding recommended errors in this work were used as input for primordial nucleosynthesis calculations tomore » evaluate their impact on the {sup 2}H, {sup 3,4}He, and {sup 7}Li primordial abundances, which are then compared with observations.« less

  19. From the Big Bang to the Nobel Prize and on to James Webb Space Telescope

    NASA Technical Reports Server (NTRS)

    Mather, John C.

    2008-01-01

    The Big Bang 13.7 billion years ago started the expansion of our piece of the universe, and portions of it stopped expanding and made stars, galaxies, planets, and people. I summarize the history of the universe, and explain how humans have learned about its size, its expansion, and its constituents. The COBE (Cosmic Background Explorer) mission measured the remnant heat radiation from the Big Bang, showed that its color (spectrum) matches the predictions perfectly, and discovered hot and cold spots in the radiation that reveal the primordial density variations that enabled us to exist. My current project, the James Webb Space Telescope (JWST), is the planned successor to the Hubble Space Telescope, and will extend its scientific discoveries to ever greater distances and ever closer to the Big Bang itself. Its infrared capabilities enable it to see inside dust clouds to study the formation of stars and planets, and it may reveal the atmospheric properties of planets around other stars. Planned for launch in 2013, it is an international project led by NASA along with the European and Canadian Space Agencies.

  20. Detection of pristine gas two billion years after the Big Bang.

    PubMed

    Fumagalli, Michele; O'Meara, John M; Prochaska, J Xavier

    2011-12-02

    In the current cosmological model, only the three lightest elements were created in the first few minutes after the Big Bang; all other elements were produced later in stars. To date, however, heavy elements have been observed in all astrophysical environments. We report the detection of two gas clouds with no discernible elements heavier than hydrogen. These systems exhibit the lowest heavy-element abundance in the early universe, and thus are potential fuel for the most metal-poor halo stars. The detection of deuterium in one system at the level predicted by primordial nucleosynthesis provides a direct confirmation of the standard cosmological model. The composition of these clouds further implies that the transport of heavy elements from galaxies to their surroundings is highly inhomogeneous.

  1. Big bang nucleosynthesis: The standard model and alternatives

    NASA Technical Reports Server (NTRS)

    Schramm, David N.

    1991-01-01

    Big bang nucleosynthesis provides (with the microwave background radiation) one of the two quantitative experimental tests of the big bang cosmological model. This paper reviews the standard homogeneous-isotropic calculation and shows how it fits the light element abundances ranging from He-4 at 24% by mass through H-2 and He-3 at parts in 10(exp 5) down to Li-7 at parts in 10(exp 10). Furthermore, the recent large electron positron (LEP) (and the stanford linear collider (SLC)) results on the number of neutrinos are discussed as a positive laboratory test of the standard scenario. Discussion is presented on the improved observational data as well as the improved neutron lifetime data. Alternate scenarios of decaying matter or of quark-hadron induced inhomogeneities are discussed. It is shown that when these scenarios are made to fit the observed abundances accurately, the resulting conlusions on the baryonic density relative to the critical density, omega(sub b) remain approximately the same as in the standard homogeneous case, thus, adding to the robustness of the conclusion that omega(sub b) approximately equals 0.06. This latter point is the driving force behind the need for non-baryonic dark matter (assuming omega(sub total) = 1) and the need for dark baryonic matter, since omega(sub visible) is less than omega(sub b).

  2. Deep mixing of 3He: reconciling Big Bang and stellar nucleosynthesis.

    PubMed

    Eggleton, Peter P; Dearborn, David S P; Lattanzio, John C

    2006-12-08

    Low-mass stars, approximately 1 to 2 solar masses, near the Main Sequence are efficient at producing the helium isotope 3He, which they mix into the convective envelope on the giant branch and should distribute into the Galaxy by way of envelope loss. This process is so efficient that it is difficult to reconcile the low observed cosmic abundance of 3He with the predictions of both stellar and Big Bang nucleosynthesis. Here we find, by modeling a red giant with a fully three-dimensional hydrodynamic code and a full nucleosynthetic network, that mixing arises in the supposedly stable and radiative zone between the hydrogen-burning shell and the base of the convective envelope. This mixing is due to Rayleigh-Taylor instability within a zone just above the hydrogen-burning shell, where a nuclear reaction lowers the mean molecular weight slightly. Thus, we are able to remove the threat that 3He production in low-mass stars poses to the Big Bang nucleosynthesis of 3He.

  3. Constraints on massive gravity theory from big bang nucleosynthesis

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lambiase, G., E-mail: lambiase@sa.infn.it

    The massive gravity cosmology is studied in the scenario of big bang nucleosynthesis. By making use of current bounds on the deviation from the fractional mass, we derive the constraints on the free parameters of the theory. The cosmological consequences of the model are also analyzed in the framework of the PAMELA experiment, i.e. an excess of positron events, that the conventional cosmology and particle physics cannot explain.

  4. Where Are the Logical Errors in the Theory of Big Bang?

    NASA Astrophysics Data System (ADS)

    Kalanov, Temur Z.

    2015-04-01

    The critical analysis of the foundations of the theory of Big Bang is proposed. The unity of formal logic and of rational dialectics is methodological basis of the analysis. It is argued that the starting point of the theory of Big Bang contains three fundamental logical errors. The first error is the assumption that a macroscopic object (having qualitative determinacy) can have an arbitrarily small size and can be in the singular state (i.e., in the state that has no qualitative determinacy). This assumption implies that the transition, (macroscopic object having the qualitative determinacy) --> (singular state of matter that has no qualitative determinacy), leads to loss of information contained in the macroscopic object. The second error is the assumption that there are the void and the boundary between matter and void. But if such boundary existed, then it would mean that the void has dimensions and can be measured. The third error is the assumption that the singular state of matter can make a transition into the normal state without the existence of the program of qualitative and quantitative development of the matter, without controlling influence of other (independent) object. However, these assumptions conflict with the practice and, consequently, formal logic, rational dialectics, and cybernetics. Indeed, from the point of view of cybernetics, the transition, (singular state of the Universe) -->(normal state of the Universe),would be possible only in the case if there was the Managed Object that is outside the Universe and have full, complete, and detailed information about the Universe. Thus, the theory of Big Bang is a scientific fiction.

  5. A Guided Inquiry on Hubble Plots and the Big Bang

    NASA Astrophysics Data System (ADS)

    Forringer, Ted

    2014-04-01

    In our science for non-science majors course "21st Century Physics," we investigate modern "Hubble plots" (plots of velocity versus distance for deep space objects) in order to discuss the Big Bang, dark matter, and dark energy. There are two potential challenges that our students face when encountering these topics for the first time. The first challenge is in understanding and interpreting Hubble plots. The second is that some of our students have religious or cultural objections to the concept of a "Big Bang" or a universe that is billions of years old. This paper presents a guided inquiry exercise that was created with the goal of introducing students to Hubble plots and giving them the opportunity to discover for themselves why we believe our universe started with an explosion billions of years ago. The exercise is designed to be completed before the topics are discussed in the classroom. We did the exercise during a one hour and 45 minute "lab" time and it was done in groups of three or four students, but it would also work as an individual take-home assignment.

  6. Making a Big Bang on the small screen

    NASA Astrophysics Data System (ADS)

    Thomas, Nick

    2010-01-01

    While the quality of some TV sitcoms can leave viewers feeling cheated out of 30 minutes of their lives, audiences and critics are raving about the science-themed US comedy The Big Bang Theory. First shown on the CBS network in 2007, the series focuses on two brilliant postdoc physicists, Leonard and Sheldon, who are totally absorbed by science. Adhering to the stereotype, they also share a fanatical interest in science fiction, video-gaming and comic books, but unfortunately lack the social skills required to connect with their 20-something nonacademic contemporaries.

  7. Nuclear Receptors, RXR, and the Big Bang.

    PubMed

    Evans, Ronald M; Mangelsdorf, David J

    2014-03-27

    Isolation of genes encoding the receptors for steroids, retinoids, vitamin D, and thyroid hormone and their structural and functional analysis revealed an evolutionarily conserved template for nuclear hormone receptors. This discovery sparked identification of numerous genes encoding related proteins, termed orphan receptors. Characterization of these orphan receptors and, in particular, of the retinoid X receptor (RXR) positioned nuclear receptors at the epicenter of the "Big Bang" of molecular endocrinology. This Review provides a personal perspective on nuclear receptors and explores their integrated and coordinated signaling networks that are essential for multicellular life, highlighting the RXR heterodimer and its associated ligands and transcriptional mechanism. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Deep Mixing of 3He: Reconciling Big Bang and Stellar Nucleosynthesis

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Eggleton, P P; Dearborn, D P; Lattanzio, J

    2006-07-26

    Low-mass stars, {approx} 1-2 solar masses, near the Main Sequence are efficient at producing {sup 3}He, which they mix into the convective envelope on the giant branch and should distribute into the Galaxy by way of envelope loss. This process is so efficient that it is difficult to reconcile the low observed cosmic abundance of {sup 3}He with the predictions of both stellar and Big Bang nucleosynthesis. In this paper we find, by modeling a red giant with a fully three-dimensional hydrodynamic code and a full nucleosynthetic network, that mixing arises in the supposedly stable and radiative zone between themore » hydrogen-burning shell and the base of the convective envelope. This mixing is due to Rayleigh-Taylor instability within a zone just above the hydrogen-burning shell, where a nuclear reaction lowers the mean molecular weight slightly. Thus we are able to remove the threat that {sup 3}He production in low-mass stars poses to the Big Bang nucleosynthesis of {sup 3}He.« less

  9. After the Big Bang: What's Next in Design Education? Time to Relax?

    ERIC Educational Resources Information Center

    Fleischmann, Katja

    2015-01-01

    The article "Big Bang technology: What's next in design education, radical innovation or incremental change?" (Fleischmann, 2013) appeared in the "Journal of Learning Design" Volume 6, Issue 3 in 2013. Two years on, Associate Professor Fleischmann reflects upon her original article within this article. Although it has only been…

  10. Discrete size optimization of steel trusses using a refined big bang-big crunch algorithm

    NASA Astrophysics Data System (ADS)

    Hasançebi, O.; Kazemzadeh Azad, S.

    2014-01-01

    This article presents a methodology that provides a method for design optimization of steel truss structures based on a refined big bang-big crunch (BB-BC) algorithm. It is shown that a standard formulation of the BB-BC algorithm occasionally falls short of producing acceptable solutions to problems from discrete size optimum design of steel trusses. A reformulation of the algorithm is proposed and implemented for design optimization of various discrete truss structures according to American Institute of Steel Construction Allowable Stress Design (AISC-ASD) specifications. Furthermore, the performance of the proposed BB-BC algorithm is compared to its standard version as well as other well-known metaheuristic techniques. The numerical results confirm the efficiency of the proposed algorithm in practical design optimization of truss structures.

  11. Gamma-rays and the case for baryon symmetric big-bang cosmology

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.

    1977-01-01

    The baryon symmetric big-bang cosmologies offer an explanation of the present photon-baryon ratio in the universe, the best present explanation of the diffuse gamma-ray background spectrum in the 1-200 MeV range, and a mechanism for galaxy formation. In regard to He production, evidence is discussed that nucleosynthesis of He may have taken place after the galaxies were formed.

  12. ``All that Matter ... in One Big Bang ...'', &Other Cosmological Singularities

    NASA Astrophysics Data System (ADS)

    Elizalde, Emilio

    2018-02-01

    The first part of this paper contains a brief description of the beginnings of modern cosmology, which, the author will argue, was most likely born in the Year 1912. Some of the pieces of evidence presented here have emerged from recent research in the history of science, and are not usually shared with the general audiences in popular science books. In special, the issue of the correct formulation of the original Big Bang concept, according to the precise words of Fred Hoyle, is discussed. Too often, this point is very deficiently explained (when not just misleadingly) in most of the available generalist literature. Other frequent uses of the same words, Big Bang, as to name the initial singularity of the cosmos, and also whole cosmological models, are then addressed, as evolutions of its original meaning. Quantum and inflationary additions to the celebrated singularity theorems by Penrose, Geroch, Hawking and others led to subsequent results by Borde, Guth and Vilenkin. And corresponding corrections to the Einstein field equations have originated, in particular, $R^2$, $f(R)$, and scalar-tensor gravities, giving rise to a plethora of new singularities. For completeness, an updated table with a classification of the same is given.

  13. Reply to 'Comment on 'Heavy element production in inhomogeneous big bang nucleosynthesis''

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Matsuura, Shunji; Fujimoto, Shin-ichirou; Hashimoto, Masa-aki

    2007-03-15

    This is a reply to Rauscher [Phys. Rev. D 75, 068301 (2007)]. We studied heavy element production in the high baryon density region in the early universe [Phys. Rev. D 72, 123505 (2005)]. However, it is claimed by Rauscher [Phys. Rev. D 75, 068301 (2007)] that a small scale but high baryon density region contradicts observations for the light element abundance or, in order not to contradict the observations, the high density region must be so small that it cannot affect the present heavy element abundance. In this paper, we study big bang nucleosynthesis in the high baryon density regionmore » and show that in certain parameter spaces it is possible to produce enough of the heavy element without contradiction to cosmic microwave background and light element observations.« less

  14. The case for the relativistic hot big bang cosmology

    NASA Technical Reports Server (NTRS)

    Peebles, P. J. E.; Schramm, D. N.; Kron, R. G.; Turner, E. L.

    1991-01-01

    What has become the standard model in cosmology is described, and some highlights are presented of the now substantial range of evidence that most cosmologists believe convincingly establishes this model, the relativistic hot big bang cosmology. It is shown that this model has yielded a set of interpretations and successful predictions that substantially outnumber the elements used in devising the theory, with no well-established empirical contradictions. Brief speculations are made on how the open puzzles and work in progress might affect future developments in this field.

  15. Molecular evolution of colorectal cancer: from multistep carcinogenesis to the big bang.

    PubMed

    Amaro, Adriana; Chiara, Silvana; Pfeffer, Ulrich

    2016-03-01

    Colorectal cancer is characterized by exquisite genomic instability either in the form of microsatellite instability or chromosomal instability. Microsatellite instability is the result of mutation of mismatch repair genes or their silencing through promoter methylation as a consequence of the CpG island methylator phenotype. The molecular causes of chromosomal instability are less well characterized. Genomic instability and field cancerization lead to a high degree of intratumoral heterogeneity and determine the formation of cancer stem cells and epithelial-mesenchymal transition mediated by the TGF-β and APC pathways. Recent analyses using integrated genomics reveal different phases of colorectal cancer evolution. An initial phase of genomic instability that yields many clones with different mutations (big bang) is followed by an important, previously not detected phase of cancer evolution that consists in the stabilization of several clones and a relatively flat outgrowth. The big bang model can best explain the coexistence of several stable clones and is compatible with the fact that the analysis of the bulk of the primary tumor yields prognostic information.

  16. Towards Limits on Neutrino Mixing Parameters from Nucleosynthesis in the Big Bang and Supernovae

    NASA Astrophysics Data System (ADS)

    Cardall, Christian Young

    1997-11-01

    Astrophysical environments can often provide stricter limits on neutrino mass and mixing parameters than terrestrial experiments. However, before firm limits can be found, there must be confidence in the understanding of the astrophysical environment being used to make these limits. In this dissertation, progress towards limits on neutrino mixing parameters from big bang nucleosynthesis and supernova r-process nucleosynthesis is sought. By way of assessment of current knowledge of neutrino oscillation parameters, we examine the potential for a 'natural' three-neutrino mixing scheme (one without sterile neutrinos) to satisfy available data and astrophysical arguments. A small parameter space currently exists for a natural three-neutrino oscillation solution meeting known constraints. If such a solution is ruled out, and current hints about neutrino oscillations are confirmed, mixing between active and sterile neutrinos will probably be required. Because mixing between active and sterile neutrinos with parameters appropriate for the atmospheric or solar neutrino problems increases the primordial 4He abundance, big bang nucleosynthesis considerations can place limits on such mixing. In the present work the overall consistency of standard big bang nucleosynthesis is discussed in light of recent discordant determinations of the primordial deuterium abundance. Cosmological considerations favor a larger baryon density, which supports the lower reported value of D/H. Studies of limits on active-sterile neutrino mixing derived from big bang nucleosynthesis considerations are here extended to consider the dependance of these constraints on the primordial deuterium abundance. If the neutrino-heated ejecta in the post-core-bounce supernova environment is the site of r-process nucleosynthesis, limits can be placed on mixing between νe, and νsbμ, or νsbτ. Refined limits will require a better understanding of this r-process environment, since current supernova models do not

  17. The Big Bang as scientific fact.

    PubMed

    Faber, S M

    2001-12-01

    In the year 1900, humanity had barely a notion of our place on the cosmic stage, and no inkling at all of how we got here. The one hundred short years of the twentieth century sufficed to unravel 14 billion years of cosmic history and how those grand events, after 9 billions of years or so, set the stage for the birth of our own home, the Solar System. The key events in this history are not hard to comprehend; they can be sketched in a few brief pages. This precious knowledge is part of our shared heritage as human beings and is fundamental to the future prospects of our species. Without it, we are ignorant of the powerful forces that have shaped our past and that will shape our destiny in the future. Read here the cosmic history of humanity, beginning with the Big Bang.

  18. Constraining nuclear data via cosmological observations: Neutrino energy transport and big bang nucleosynthesis

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Paris, Mark W.; Fuller, George M.; Grohs, Evan Bradley

    Here, we introduce a new computational capability that moves toward a self-consistent calculation of neutrino transport and nuclear reactions for big bang nucleosynthesis (BBN). Such a self-consistent approach is needed to be able to extract detailed information about nuclear reactions and physics beyond the standard model from precision cosmological observations of primordial nuclides and the cosmic microwave background radiation. We also calculate the evolution of the early universe through the epochs of weak decoupling, weak freeze-out and big bang nucleosynthesis (BBN) by simultaneously coupling a full strong, electromagnetic, and weak nuclear reaction network with a multi-energy group Boltzmann neutrino energymore » transport scheme. The modular structure of our approach allows the dissection of the relative contributions of each process responsible for evolving the dynamics of the early universe. Such an approach allows a detailed account of the evolution of the active neutrino energy distribution functions alongside and self-consistently with the nuclear reactions and entropy/heat generation and flow between the neutrino and photon/electron/positron/baryon plasma components. Our calculations reveal nonlinear feedback in the time evolution of neutrino distribution functions and plasma thermodynamic conditions. We discuss the time development of neutrino spectral distortions and concomitant entropy production and extraction from the plasma. These effects result in changes in the computed values of the BBN deuterium and helium-4 yields that are on the order of a half-percent relative to a baseline standard BBN calculation with no neutrino transport. This is an order of magnitude larger effect than in previous estimates. For particular implementations of quantum corrections in plasma thermodynamics, our calculations show a 0.4% increase in deuterium and a 0.6% decrease in 4He over our baseline. The magnitude of these changes are on the order of uncertainties

  19. Constraining nuclear data via cosmological observations: Neutrino energy transport and big bang nucleosynthesis

    NASA Astrophysics Data System (ADS)

    Paris, Mark; Fuller, George; Grohs, Evan; Kishimoto, Chad; Vlasenko, Alexey

    2017-09-01

    We introduce a new computational capability that moves toward a self-consistent calculation of neutrino transport and nuclear reactions for big bang nucleosynthesis (BBN). Such a self-consistent approach is needed to be able to extract detailed information about nuclear reactions and physics beyond the standard model from precision cosmological observations of primordial nuclides and the cosmic microwave background radiation. We calculate the evolution of the early universe through the epochs of weak decoupling, weak freeze-out and big bang nucleosynthesis (BBN) by simultaneously coupling a full strong, electromagnetic, and weak nuclear reaction network with a multi-energy group Boltzmann neutrino energy transport scheme. The modular structure of our approach allows the dissection of the relative contributions of each process responsible for evolving the dynamics of the early universe. Such an approach allows a detailed account of the evolution of the active neutrino energy distribution functions alongside and self-consistently with the nuclear reactions and entropy/heat generation and 'ow between the neutrino and photon/electron/positron/baryon plasma components. Our calculations reveal nonlinear feedback in the time evolution of neutrino distribution functions and plasma thermodynamic conditions. We discuss the time development of neutrino spectral distortions and concomitant entropy production and extraction from the plasma. These e↑ects result in changes in the computed values of the BBN deuterium and helium-4 yields that are on the order of a half-percent relative to a baseline standard BBN calculation with no neutrino transport. This is an order of magnitude larger e↑ect than in previous estimates. For particular implementations of quantum corrections in plasma thermodynamics, our calculations show a 0.4% increase in deuterium and a 0.6% decrease in 4He over our baseline. The magnitude of these changes are on the order of uncertainties in the nuclear

  20. Constraining nuclear data via cosmological observations: Neutrino energy transport and big bang nucleosynthesis

    DOE PAGES

    Paris, Mark W.; Fuller, George M.; Grohs, Evan Bradley; ...

    2017-09-13

    Here, we introduce a new computational capability that moves toward a self-consistent calculation of neutrino transport and nuclear reactions for big bang nucleosynthesis (BBN). Such a self-consistent approach is needed to be able to extract detailed information about nuclear reactions and physics beyond the standard model from precision cosmological observations of primordial nuclides and the cosmic microwave background radiation. We also calculate the evolution of the early universe through the epochs of weak decoupling, weak freeze-out and big bang nucleosynthesis (BBN) by simultaneously coupling a full strong, electromagnetic, and weak nuclear reaction network with a multi-energy group Boltzmann neutrino energymore » transport scheme. The modular structure of our approach allows the dissection of the relative contributions of each process responsible for evolving the dynamics of the early universe. Such an approach allows a detailed account of the evolution of the active neutrino energy distribution functions alongside and self-consistently with the nuclear reactions and entropy/heat generation and flow between the neutrino and photon/electron/positron/baryon plasma components. Our calculations reveal nonlinear feedback in the time evolution of neutrino distribution functions and plasma thermodynamic conditions. We discuss the time development of neutrino spectral distortions and concomitant entropy production and extraction from the plasma. These effects result in changes in the computed values of the BBN deuterium and helium-4 yields that are on the order of a half-percent relative to a baseline standard BBN calculation with no neutrino transport. This is an order of magnitude larger effect than in previous estimates. For particular implementations of quantum corrections in plasma thermodynamics, our calculations show a 0.4% increase in deuterium and a 0.6% decrease in 4He over our baseline. The magnitude of these changes are on the order of uncertainties

  1. Cool Cosmology: ``WHISPER" better than ``BANG"

    NASA Astrophysics Data System (ADS)

    Carr, Paul

    2007-10-01

    Cosmologist Fred Hoyle coined ``big bang'' as a term of derision for Belgian priest George Lemaitre's prediction that the universe had originated from the expansion of a ``primeval atom'' in space-time. Hoyle referred to Lamaitre's hypothesis sarcastically as ``this big bang idea'' during a program broadcast on March 28, 1949 on the BBC. Hoyle's continuous creation or steady state theory can not explain the microwave background radiation or cosmic whisper discovered by Penzias and Wilson in 1964. The expansion and subsequent cooling of Lemaitre's hot ``primeval atom'' explains the whisper. ``Big bang'' makes no physical sense, as there was no matter (or space) to carry the sound that Hoyle's term implies. The ``big bang'' is a conjecture. New discoveries may be able to predict the observed ``whispering cosmos'' as well as dark matter and the nature of dark energy. The ``whispering universe'' is cooler cosmology than the big bang. Reference: Carr, Paul H. 2006. ``From the 'Music of the Spheres' to the 'Whispering Cosmos.' '' Chapter 3 of Beauty in Science and Spirit. Beech River Books. Center Ossipee, NH, http://www.MirrorOfNature.org.

  2. Before the Big Bang? A Novel Resolution of a Profound Cosmological Puzzle

    ScienceCinema

    Penrose, Roger

    2018-01-24

    The second law of thermodynamics says, in effect, that things get more random as time progresses. Thus, we can deduce that the beginning of the universe - the Big Bang - must have been an extraordinarily precisely organized state. What was the nature of this state? How can such a special state have come about? In Penrose's talk, a novel explanation is suggested.

  3. Through the big bang: Continuing Einstein's equations beyond a cosmological singularity

    NASA Astrophysics Data System (ADS)

    Koslowski, Tim A.; Mercati, Flavio; Sloan, David

    2018-03-01

    All measurements are comparisons. The only physically accessible degrees of freedom (DOFs) are dimensionless ratios. The objective description of the universe as a whole thus predicts only how these ratios change collectively as one of them is changed. Here we develop a description for classical Bianchi IX cosmology implementing these relational principles. The objective evolution decouples from the volume and its expansion degree of freedom. We use the relational description to investigate both vacuum dominated and quiescent Bianchi IX cosmologies. In the vacuum dominated case the relational dynamical system predicts an infinite amount of change of the relational DOFs, in accordance with the well known chaotic behaviour of Bianchi IX. In the quiescent case the relational dynamical system evolves uniquely though the point where the decoupled scale DOFs predict the big bang/crunch. This is a non-trivial prediction of the relational description; the big bang/crunch is not the end of physics - it is instead a regular point of the relational evolution. Describing our solutions as spacetimes that satisfy Einstein's equations, we find that the relational dynamical system predicts two singular solutions of GR that are connected at the hypersurface of the singularity such that relational DOFs are continuous and the orientation of the spatial frame is inverted.

  4. Big Bang Tumor Growth and Clonal Evolution.

    PubMed

    Sun, Ruping; Hu, Zheng; Curtis, Christina

    2018-05-01

    The advent and application of next-generation sequencing (NGS) technologies to tumor genomes has reinvigorated efforts to understand clonal evolution. Although tumor progression has traditionally been viewed as a gradual stepwise process, recent studies suggest that evolutionary rates in tumors can be variable with periods of punctuated mutational bursts and relative stasis. For example, Big Bang dynamics have been reported, wherein after transformation, growth occurs in the absence of stringent selection, consistent with effectively neutral evolution. Although first noted in colorectal tumors, effective neutrality may be relatively common. Additionally, punctuated evolution resulting from mutational bursts and cataclysmic genomic alterations have been described. In this review, we contrast these findings with the conventional gradualist view of clonal evolution and describe potential clinical and therapeutic implications of different evolutionary modes and tempos. Copyright © 2018 Cold Spring Harbor Laboratory Press; all rights reserved.

  5. Big-bang nucleosynthesis revisited

    NASA Technical Reports Server (NTRS)

    Olive, Keith A.; Schramm, David N.; Steigman, Gary; Walker, Terry P.

    1989-01-01

    The homogeneous big-bang nucleosynthesis yields of D, He-3, He-4, and Li-7 are computed taking into account recent measurements of the neutron mean-life as well as updates of several nuclear reaction rates which primarily affect the production of Li-7. The extraction of primordial abundances from observation and the likelihood that the primordial mass fraction of He-4, Y(sub p) is less than or equal to 0.24 are discussed. Using the primordial abundances of D + He-3 and Li-7 we limit the baryon-to-photon ratio (eta in units of 10 exp -10) 2.6 less than or equal to eta(sub 10) less than or equal to 4.3; which we use to argue that baryons contribute between 0.02 and 0.11 to the critical energy density of the universe. An upper limit to Y(sub p) of 0.24 constrains the number of light neutrinos to N(sub nu) less than or equal to 3.4, in excellent agreement with the LEP and SLC collider results. We turn this argument around to show that the collider limit of 3 neutrino species can be used to bound the primordial abundance of He-4: 0.235 less than or equal to Y(sub p) less than or equal to 0.245.

  6. Big bang nucleosynthesis and the quark-hadron transition

    NASA Technical Reports Server (NTRS)

    Kurki-Suonio, Hannu; Matzner, Richard A.; Olive, Keith A.; Schramm, David N.

    1990-01-01

    An examination and brief review is made of the effects of quark-hadron transition induced fluctuations on Big Bang nucleosynthesis. It is shown that cosmologically critical densities in baryons are difficult to reconcile with observation, but the traditional baryon density constraints from homogeneous calculations might be loosened by as much as 50 percent, to 0.3 of critical density, and the limit on the number of neutrino flavors remains about N(sub nu) is less than or approximately 4. To achieve baryon densities of greater than or approximately 0.3 of critical density would require initial density contrasts R is much greater the 10(exp e), whereas the simplest models for the transition seem to restrict R to less than of approximately 10(exp 2).

  7. Big Bang nucleosynthesis and the Quark-Hadron transition

    NASA Technical Reports Server (NTRS)

    Kurki-Suonio, Hannu; Matzner, Richard A.; Olive, Keith A.; Schramm, David N.

    1989-01-01

    An examination and brief review is made of the effects of quark-hadron transistion induced fluctuations on Big Bang nucleosynthesis. It is shown that cosmologically critical densities in baryons are difficult to reconcile with observation, but the traditional baryon density constraints from homogeneous calculations might be loosened by as much as 50 percent, to 0.3 of critical density, and the limit on the number of neutrino flavors remains about N(sub nu) is less than or approximately 4. To achieve baryon densities of greater than or approximately 0.3 of critical density would require initial density contrasts R is much greater the 10(exp 3), whereas the simplest models for the transition seem to restrict R to less than of approximately 10(exp 2).

  8. Lorentz invariance violation in the neutrino sector: a joint analysis from big bang nucleosynthesis and the cosmic microwave background

    NASA Astrophysics Data System (ADS)

    Dai, Wei-Ming; Guo, Zong-Kuan; Cai, Rong-Gen; Zhang, Yuan-Zhong

    2017-06-01

    We investigate constraints on Lorentz invariance violation in the neutrino sector from a joint analysis of big bang nucleosynthesis and the cosmic microwave background. The effect of Lorentz invariance violation during the epoch of big bang nucleosynthesis changes the predicted helium-4 abundance, which influences the power spectrum of the cosmic microwave background at the recombination epoch. In combination with the latest measurement of the primordial helium-4 abundance, the Planck 2015 data of the cosmic microwave background anisotropies give a strong constraint on the deformation parameter since adding the primordial helium measurement breaks the degeneracy between the deformation parameter and the physical dark matter density.

  9. Standard big bang nucleosynthesis and primordial CNO abundances after Planck

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Coc, Alain; Uzan, Jean-Philippe; Vangioni, Elisabeth, E-mail: coc@csnsm.in2p3.fr, E-mail: uzan@iap.fr, E-mail: vangioni@iap.fr

    Primordial or big bang nucleosynthesis (BBN) is one of the three historical strong evidences for the big bang model. The recent results by the Planck satellite mission have slightly changed the estimate of the baryonic density compared to the previous WMAP analysis. This article updates the BBN predictions for the light elements using the cosmological parameters determined by Planck, as well as an improvement of the nuclear network and new spectroscopic observations. There is a slight lowering of the primordial Li/H abundance, however, this lithium value still remains typically 3 times larger than its observed spectroscopic abundance in halo starsmore » of the Galaxy. According to the importance of this ''lithium problem{sup ,} we trace the small changes in its BBN calculated abundance following updates of the baryonic density, neutron lifetime and networks. In addition, for the first time, we provide confidence limits for the production of {sup 6}Li, {sup 9}Be, {sup 11}B and CNO, resulting from our extensive Monte Carlo calculation with our extended network. A specific focus is cast on CNO primordial production. Considering uncertainties on the nuclear rates around the CNO formation, we obtain CNO/H ≈ (5-30)×10{sup -15}. We further improve this estimate by analyzing correlations between yields and reaction rates and identified new influential reaction rates. These uncertain rates, if simultaneously varied could lead to a significant increase of CNO production: CNO/H∼10{sup -13}. This result is important for the study of population III star formation during the dark ages.« less

  10. The Big Bang of tissue growth: Apical cell constriction turns into tissue expansion.

    PubMed

    Janody, Florence

    2018-03-05

    How tissue growth is regulated during development and cancer is a fundamental question in biology. In this issue, Tsoumpekos et al. (2018. J. Cell Biol. https://doi.org/10.1083/jcb.201705104) and Forest et al. (2018. J. Cell Biol. https://doi.org/10.1083/jcb.201705107) identify Big bang (Bbg) as an important growth regulator of the Drosophila melanogaster wing imaginal disc. © 2018 Janody.

  11. On the initial regime of pre-big bang cosmology

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gasperini, M., E-mail: gasperini@ba.infn.it

    The production of a background of super-horizon curvature perturbations with the appropriate (red) spectrum needed to trigger the cosmic anisotropies observed on large scales is associated, in the context of pre-big bang inflation, with a phase of growing string coupling. The extension towards the past of such a phase is not limited in time by the dynamical backreaction of the quantum perturbations of the cosmological geometry and of its sources. A viable, slightly red spectrum of scalar perturbations can thus be the output of an asymptotic, perturbative regime which is well compatible with an initial string-vacuum state satisfying the postulatemore » of 'Asymptotic Past Triviality'.« less

  12. The Biological Big Bang model for the major transitions in evolution.

    PubMed

    Koonin, Eugene V

    2007-08-20

    concepts of the emergence of protein folds by recombination of small structural units and origin of viruses and cells from a pre-cellular compartmentalized pool of recombining genetic elements. The model is extended to encompass other major transitions. It is proposed that bacterial and archaeal phyla emerged independently from two distinct populations of primordial cells that, originally, possessed leaky membranes, which made the cells prone to rampant gene exchange; and that the eukaryotic supergroups emerged through distinct, secondary endosymbiotic events (as opposed to the primary, mitochondrial endosymbiosis). This biphasic model of evolution is substantially analogous to the scenario of the origin of universes in the eternal inflation version of modern cosmology. Under this model, universes like ours emerge in the infinite multiverse when the eternal process of exponential expansion, known as inflation, ceases in a particular region as a result of false vacuum decay, a first order phase transition process. The result is the nucleation of a new universe, which is traditionally denoted Big Bang, although this scenario is radically different from the Big Bang of the traditional model of an expanding universe. Hence I denote the phase transitions at the end of each inflationary epoch in the history of life Biological Big Bangs (BBB). A Biological Big Bang (BBB) model is proposed for the major transitions in life's evolution. According to this model, each transition is a BBB such that new classes of biological entities emerge at the end of a rapid phase of evolution (inflation) that is characterized by extensive exchange of genetic information which takes distinct forms for different BBBs. The major types of new forms emerge independently, via a sampling process, from the pool of recombining entities of the preceding generation. This process is envisaged as being qualitatively different from tree-pattern cladogenesis.

  13. Measurements of Radiative Capture Cross Sections at Big Bang Energies

    NASA Astrophysics Data System (ADS)

    Tanaka, Masaomi; Fukuda, Mitsunori; Tanaka, Yutaro; Du, Hang; Ohnishi, Kousuke; Yagi, Shoichi; Sugihara, Takanobu; Hori, Taichi; Nakamura, Shoken; Yanagihara, Rikuto; Matsuta, Kensaku; Mihara, Mototsugu; Nishimura, Daiki; Iwakiri, Shuichi; Kambayashi, Shohei; Kunimatsu, Shota; Sakakibara, Hikaru; Yamaoka, Shintaro

    We measured d(p, γ )3He cross sections at ECM = 0.12, 0.19, 0.44, and 0.57 MeV. In this energy region, available experimental values are systematically smaller than the recent calculation, so that additional experiments are desired for understanding the Big Bang Nucleosynthesis. The experiment was performed by bombarding proton beams to the D2 gas target with the 5 MV Van de Graaff accelerator at Osaka University. The experimental d(p, γ )3He cross sections of the present study are systematically larger than previous data. On the other hand, recent theoretical results by Marcucci et al. are in good agreement with present experimental results.

  14. The "big bang" implementation: not for the faint of heart.

    PubMed

    Anderson, Linda K; Stafford, Cynthia J

    2002-01-01

    Replacing a hospital's obsolete mainframe computer system with a modern integrated clinical and administrative information system presents multiple challenges. When the new system is activated in one weekend, in "big bang" fashion, the challenges are magnified. Careful planning is essential to ensure that all hospital staff are fully prepared for this transition, knowing this conversion will involve system downtime, procedural changes, and the resulting stress that naturally accompanies change. Implementation concerns include staff preparation and training, process changes, continuity of patient care, and technical and administrative support. This article outlines how the University of Missouri Health Care addressed these operational concerns during this dramatic information system conversion.

  15. Quantum Oscillations Can Prevent the Big Bang Singularity in an Einstein-Dirac Cosmology

    NASA Astrophysics Data System (ADS)

    Finster, Felix; Hainzl, Christian

    2010-01-01

    We consider a spatially homogeneous and isotropic system of Dirac particles coupled to classical gravity. The dust and radiation dominated closed Friedmann-Robertson-Walker space-times are recovered as limiting cases. We find a mechanism where quantum oscillations of the Dirac wave functions can prevent the formation of the big bang or big crunch singularity. Thus before the big crunch, the collapse of the universe is stopped by quantum effects and reversed to an expansion, so that the universe opens up entering a new era of classical behavior. Numerical examples of such space-times are given, and the dependence on various parameters is discussed. Generically, one has a collapse after a finite number of cycles. By fine-tuning the parameters we construct an example of a space-time which satisfies the dominant energy condition and is time-periodic, thus running through an infinite number of contraction and expansion cycles.

  16. Change of government: one more big bang health care reform in England's National Health Service.

    PubMed

    Hunter, David J

    2011-01-01

    Once again the National Health Service (NHS) in England is undergoing major reform, following the election of a new coalition government keen to reduce the role of the state and cut back on big government. The NHS has been undergoing continuous reform since the 1980s. Yet, despite the significant transaction costs incurred, there is no evidence that the claimed benefits have been achieved. Many of the same problems endure. The reforms follow the direction of change laid down by the last Conservative government in the early 1990s, which the recent Labour government did not overturn despite a commitment to do so. Indeed, under Labour, the NHS was subjected to further market-style changes that have paved the way for the latest round of reform. The article considers the appeal of big bang reform, questions its purpose and value, and critically appraises the nature and extent of the proposed changes in this latest round of reform. It warns that the NHS in its current form may not survive the changes, as they open the way to privatization and a weakening of its public service ethos.

  17. Communicating the Nature of Science through "The Big Bang Theory": Evidence from a Focus Group Study

    ERIC Educational Resources Information Center

    Li, Rashel; Orthia, Lindy A.

    2016-01-01

    In this paper, we discuss a little-studied means of communicating about or teaching the nature of science (NOS)--through fiction television. We report some results of focus group research which suggest that the American sitcom "The Big Bang Theory" (2007-present), whose main characters are mostly working scientists, has influenced…

  18. Underground Study of Big Bang Nucleosynthesis in the Precision Era of Cosmology

    NASA Astrophysics Data System (ADS)

    Gustavino, Carlo

    2017-03-01

    Big Bang Nucleosinthesis (BBN) theory provides definite predictions for the abundance of light elements produced in the early universe, as far as the knowledge of the relevant nuclear processes of the BBN chain is accurate. At BBN energies (30 ≲ Ecm ≲ 300 MeV) the cross section of many BBN processes is very low because of the Coulomb repulsion between the interacting nuclei. For this reason it is convenient to perform the measurements deep underground. Presently the world's only facility operating underground is LUNA (Laboratory for Undergound Nuclear astrophysics) at LNGS ("Laboratorio Nazionale del Gran Sasso", Italy). In this presentation the BBN measurements of LUNA are briefly reviewed and discussed. It will be shown that the ongoing study of the D(p, γ)3He reaction is of primary importance to derive the baryon density of universe Ωb with high accuracy. Moreover, this study allows to constrain the existence of the so called "dark radiation", composed by undiscovered relativistic species permeating the universe, such as sterile neutrinos.

  19. Observational constraints on secret neutrino interactions from big bang nucleosynthesis

    NASA Astrophysics Data System (ADS)

    Huang, Guo-yuan; Ohlsson, Tommy; Zhou, Shun

    2018-04-01

    We investigate possible interactions between neutrinos and massive scalar bosons via gϕν ¯ν ϕ (or massive vector bosons via gVν ¯γμν Vμ) and explore the allowed parameter space of the coupling constant gϕ (or gV) and the scalar (or vector) boson mass mϕ (or mV) by requiring that these secret neutrino interactions (SNIs) should not spoil the success of big bang nucleosynthesis (BBN). Incorporating the SNIs into the evolution of the early Universe in the BBN era, we numerically solve the Boltzmann equations and compare the predictions for the abundances of light elements with observations. It turns out that the constraint on gϕ and mϕ in the scalar-boson case is rather weak, due to a small number of degrees of freedom (d.o.f.). However, in the vector-boson case, the most stringent bound on the coupling gV≲6 ×10-10 at 95% confidence level is obtained for mV≃1 MeV , while the bound becomes much weaker gV≲8 ×10-6 for smaller masses mV≲10-4 MeV . Moreover, we discuss in some detail how the SNIs affect the cosmological evolution and the abundances of the lightest elements.

  20. Big bang nucleosynthesis - The standard model and alternatives

    NASA Technical Reports Server (NTRS)

    Schramm, David N.

    1991-01-01

    The standard homogeneous-isotropic calculation of the big bang cosmological model is reviewed, and alternate models are discussed. The standard model is shown to agree with the light element abundances for He-4, H-2, He-3, and Li-7 that are available. Improved observational data from recent LEP collider and SLC results are discussed. The data agree with the standard model in terms of the number of neutrinos, and provide improved information regarding neutron lifetimes. Alternate models are reviewed which describe different scenarios for decaying matter or quark-hadron induced inhomogeneities. The baryonic density relative to the critical density in the alternate models is similar to that of the standard model when they are made to fit the abundances. This reinforces the conclusion that the baryonic density relative to critical density is about 0.06, and also reinforces the need for both nonbaryonic dark matter and dark baryonic matter.

  1. No ``explosion'' in Big Bang cosmology: teaching kids the truth of what cosmologists really know

    NASA Astrophysics Data System (ADS)

    Gangui, Alejandro

    2011-06-01

    Common wisdom says that cosmologists are smart: they have developed a theory that can explain the ``origin of the universe''. Every time an astro-related, heavily funded ``big-science'' project comes to the media, naturally the question arises: will science -through this or that experiment- explain the origin of the cosmos? Can this be done with the LHC, for example? Will this dream machine create other universes? Of course, the very words we employ in cosmology reinforce this misconception: so Big Bang must be associated with an ``explosion'', even if a ``peculiar'' one, as it took place nowhere (there was presumably no space before the beginning) and happened virtually in no time (supposedly, space-time was created on this peculiar -singular- event). Right, the issue sounds confusing. Let us imagine what kids may get out of all this. We have recently presented a series of brief astronomy and cosmology books aimed at helping both kids and their teachers in these and other arcane subjects, all introduced with carefully chosen words and images that young children can understand. In particular, Volume Four deals with the Big Bang and emphasizes the notion of ``evolution'' as opposed to the -wrong- notion of ``origin'' behind the scientific model. We then explain some of the pillars of Big Bang cosmology: the expansion of space that drags away distant galaxies, as seen in the redshift of their emitted light; the build-up of light elements in a cooling bath of radiation, as explained by primordial nucleosynthesis; and the existence and main features of the ubiquitous cosmic microwave background radiation, where theory and observations agree to a highly satisfactory degree. Of course, one cannot attempt to answer the ``origins'' question when it is well known that all theories so far break down close to this origin (if there was actually an origin). It is through observations, analyses, lively discussions and recognition of the basic limitations of current theories and

  2. Galaxies 800 million years after the Big Bang seen with the Atacama Large Millimetre Array

    NASA Astrophysics Data System (ADS)

    Smit, Renske

    2018-01-01

    The identification of galaxies in the first billion years after the Big Bang presents a challenge for even the largest optical telescopes. When the Atacama Large Millimetre Array (ALMA) started science operations in 2011 it presented a tantalising opportunity to identify and characterise these first sources of light in a new window of the electromagnetic spectrum. I will present new sources successfully identified at z=6.8 using ALMA; the first spectroscopic confirmations of typical star-forming galaxies during the Epoch or Reionization using a sub-millimetre telescope. Moreover, these observations reveal the gas kinematics of such distant sources for the first time. The velocity gradient in these galaxies indicate that these galaxies likely have similar dynamical properties as the turbulent, yet rotation-dominated disks that have been observed for Hα emitting galaxies 2 billion years later at cosmic noon. This novel approach for confirming galaxies during Reionization paves the way for larger studies of distant galaxies with spectroscopic redshifts. Particularly important, this opens up opportunities for the measurement of high angular-resolution dynamics in galaxies less than one billion years after the Big Bang.

  3. Neutrino energy transport in weak decoupling and big bang nucleosynthesis

    DOE PAGES

    Grohs, Evan Bradley; Paris, Mark W.; Kishimoto, Chad T.; ...

    2016-04-21

    In this study, we calculate the evolution of the early universe through the epochs of weak decoupling, weak freeze-out and big bang nucleosynthesis (BBN) by simultaneously coupling a full strong, electromagnetic, and weak nuclear reaction network with a multienergy group Boltzmann neutrino energy transport scheme. The modular structure of our code provides the ability to dissect the relative contributions of each process responsible for evolving the dynamics of the early universe in the absence of neutrino flavor oscillations. Such an approach allows a detailed accounting of the evolution of the νe, ν¯e, νμ, ν¯μ, ντ, ν¯τ energy distribution functions alongsidemore » and self-consistently with the nuclear reactions and entropy/heat generation and flow between the neutrino and photon/electron/positron/baryon plasma components. This calculation reveals nonlinear feedback in the time evolution of neutrino distribution functions and plasma thermodynamic conditions (e.g., electron-positron pair densities), with implications for the phasing between scale factor and plasma temperature; the neutron-to-proton ratio; light-element abundance histories; and the cosmological parameter N eff. We find that our approach of following the time development of neutrino spectral distortions and concomitant entropy production and extraction from the plasma results in changes in the computed value of the BBN deuterium yield. For example, for particular implementations of quantum corrections in plasma thermodynamics, our calculations show a 0.4% increase in deuterium. These changes are potentially significant in the context of anticipated improvements in observational and nuclear physics uncertainties.« less

  4. Neutrino energy transport in weak decoupling and big bang nucleosynthesis

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Grohs, Evan Bradley; Paris, Mark W.; Kishimoto, Chad T.

    In this study, we calculate the evolution of the early universe through the epochs of weak decoupling, weak freeze-out and big bang nucleosynthesis (BBN) by simultaneously coupling a full strong, electromagnetic, and weak nuclear reaction network with a multienergy group Boltzmann neutrino energy transport scheme. The modular structure of our code provides the ability to dissect the relative contributions of each process responsible for evolving the dynamics of the early universe in the absence of neutrino flavor oscillations. Such an approach allows a detailed accounting of the evolution of the νe, ν¯e, νμ, ν¯μ, ντ, ν¯τ energy distribution functions alongsidemore » and self-consistently with the nuclear reactions and entropy/heat generation and flow between the neutrino and photon/electron/positron/baryon plasma components. This calculation reveals nonlinear feedback in the time evolution of neutrino distribution functions and plasma thermodynamic conditions (e.g., electron-positron pair densities), with implications for the phasing between scale factor and plasma temperature; the neutron-to-proton ratio; light-element abundance histories; and the cosmological parameter N eff. We find that our approach of following the time development of neutrino spectral distortions and concomitant entropy production and extraction from the plasma results in changes in the computed value of the BBN deuterium yield. For example, for particular implementations of quantum corrections in plasma thermodynamics, our calculations show a 0.4% increase in deuterium. These changes are potentially significant in the context of anticipated improvements in observational and nuclear physics uncertainties.« less

  5. Gamma rays and the case for baryon symmetric big-bang cosmology

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.

    1977-01-01

    The baryon symmetric big-bang cosmologies offer an explanation of the present photon-baryon ratio in the universe, the best present explanation of the diffuse gamma-ray background spectrum in the 1 to 200 MeV range, and a mechanism for galaxy formation. In the context of an open universe model, the value of omega which best fits the present gamma-ray data is omega equals approx. 0.1 which does not conflict with upper limits on Comptonization distortion of the 3K background radiation. In regard to He production, evidence is discussed that nucleosynthesis of He may have taken place after the galaxies were formed.

  6. COBE's search for structure in the Big Bang

    NASA Technical Reports Server (NTRS)

    Soffen, Gerald (Editor); Guerny, Gene (Editor); Keating, Thomas (Editor); Moe, Karen (Editor); Sullivan, Walter (Editor); Truszkowski, Walt (Editor)

    1989-01-01

    The launch of Cosmic Background Explorer (COBE) and the definition of Earth Observing System (EOS) are two of the major events at NASA-Goddard. The three experiments contained in COBE (Differential Microwave Radiometer (DMR), Far Infrared Absolute Spectrophotometer (FIRAS), and Diffuse Infrared Background Experiment (DIRBE)) are very important in measuring the big bang. DMR measures the isotropy of the cosmic background (direction of the radiation). FIRAS looks at the spectrum over the whole sky, searching for deviations, and DIRBE operates in the infrared part of the spectrum gathering evidence of the earliest galaxy formation. By special techniques, the radiation coming from the solar system will be distinguished from that of extragalactic origin. Unique graphics will be used to represent the temperature of the emitting material. A cosmic event will be modeled of such importance that it will affect cosmological theory for generations to come. EOS will monitor changes in the Earth's geophysics during a whole solar color cycle.

  7. Dark/visible parallel universes and Big Bang nucleosynthesis

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bertulani, C. A.; Frederico, T.; Fuqua, J.

    We develop a model for visible matter-dark matter interaction based on the exchange of a massive gray boson called herein the Mulato. Our model hinges on the assumption that all known particles in the visible matter have their counterparts in the dark matter. We postulate six families of particles five of which are dark. This leads to the unavoidable postulation of six parallel worlds, the visible one and five invisible worlds. A close study of big bang nucleosynthesis (BBN), baryon asymmetries, cosmic microwave background (CMB) bounds, galaxy dynamics, together with the Standard Model assumptions, help us to set a limitmore » on the mass and width of the new gauge boson. Modification of the statistics underlying the kinetic energy distribution of particles during the BBN is also discussed. The changes in reaction rates during the BBN due to a departure from the Debye-Hueckel electron screening model is also investigated.« less

  8. The Big Bang, COBE, and the Relic Radiation of Creation (LBNL Science at the Theater)

    ScienceCinema

    Smoot, George [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2018-05-23

    Berkeley Lab's George Smoot won the 2006 Physics Nobel Prize, together with John Mather of NASA Goddard Space Flight Center, for "the discovery of the blackbody form and anisotropy of the cosmic microwave background radiation." The anisotropy showed as small variations in the map of the early universe. This research looks back into the infant universe and provides a better understanding of the origin of galaxies and stars. The cosmic background radiation is a tool to understand the structure and history of the universe and the structure of space-time. These observations have provided increased support for the big bang theory of the universe's origin. The Cosmic Background Explorer (COBE) NASA satellite, launched in 1989, carries instruments that measured various aspects of cosmic microwave background radiation, and produced the data for these compelling scientific results, which opened up a field that continues very actively today.

  9. The Big Bang, COBE, and the Relic Radiation of Creation (LBNL Science at the Theater)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Smoot, George

    Berkeley Lab's George Smoot won the 2006 Physics Nobel Prize, together with John Mather of NASA Goddard Space Flight Center, for "the discovery of the blackbody form and anisotropy of the cosmic microwave background radiation." The anisotropy showed as small variations in the map of the early universe. This research looks back into the infant universe and provides a better understanding of the origin of galaxies and stars. The cosmic background radiation is a tool to understand the structure and history of the universe and the structure of space-time. These observations have provided increased support for the big bang theorymore » of the universe's origin. The Cosmic Background Explorer (COBE) NASA satellite, launched in 1989, carries instruments that measured various aspects of cosmic microwave background radiation, and produced the data for these compelling scientific results, which opened up a field that continues very actively today.« less

  10. The Biological Big Bang model for the major transitions in evolution

    PubMed Central

    Koonin, Eugene V

    2007-01-01

    previously developed concepts of the emergence of protein folds by recombination of small structural units and origin of viruses and cells from a pre-cellular compartmentalized pool of recombining genetic elements. The model is extended to encompass other major transitions. It is proposed that bacterial and archaeal phyla emerged independently from two distinct populations of primordial cells that, originally, possessed leaky membranes, which made the cells prone to rampant gene exchange; and that the eukaryotic supergroups emerged through distinct, secondary endosymbiotic events (as opposed to the primary, mitochondrial endosymbiosis). This biphasic model of evolution is substantially analogous to the scenario of the origin of universes in the eternal inflation version of modern cosmology. Under this model, universes like ours emerge in the infinite multiverse when the eternal process of exponential expansion, known as inflation, ceases in a particular region as a result of false vacuum decay, a first order phase transition process. The result is the nucleation of a new universe, which is traditionally denoted Big Bang, although this scenario is radically different from the Big Bang of the traditional model of an expanding universe. Hence I denote the phase transitions at the end of each inflationary epoch in the history of life Biological Big Bangs (BBB). Conclusion A Biological Big Bang (BBB) model is proposed for the major transitions in life's evolution. According to this model, each transition is a BBB such that new classes of biological entities emerge at the end of a rapid phase of evolution (inflation) that is characterized by extensive exchange of genetic information which takes distinct forms for different BBBs. The major types of new forms emerge independently, via a sampling process, from the pool of recombining entities of the preceding generation. This process is envisaged as being qualitatively different from tree-pattern cladogenesis. Reviewers This article

  11. Beyond Einstein: From the Big Bang to Black Holes

    NASA Technical Reports Server (NTRS)

    2005-01-01

    How did the Universe begin? Does time have a beginning and an end? Does space have edges? The questions are clear and simple. They are as old as human curiosity. But the answers have always seemed beyond the reach of science. Until now. In their attempts to understand how space, time, and matter are connected, Einstein and his successors made three predictions. First, space is expanding from a Big Bang; second, space and time can tie themselves into contorted knots called black holes where time actually comes to a halt; third, space itself contains some kind of energy that is pull- ing the Universe apart. Each of these three predictions seemed so fantastic when it was made that everyone, including Einstein himself, regarded them as unlikely. Incredibly, all three have turned out to be true. Yet Einstein's legacy is one of deep mystery, because his theories are silent on three questions raised by his fantastic predictions: (1) What powered the Big Bang? (2) What happens to space, time, and matter at the edge of a black hole? (3) What is the mysterious dark energy pulling the Universe apart? The answers to these questions-which lie at the crux of where our current theories fail us-will lead to a profound, new understanding of the nature of time and space. To find answers, however, we must venture beyond Einstein. The answers require new theories, such as the inflationary Universe and new insights in high-energy particle theory. Like Einstein s theories, these make fantastic predictions that seem hard to believe: unseen dimensions and entire universes beyond our own. We must find facts to confront and guide these new theories. Powerful new technologies now make this possible. And NASA and its partners are developing an armada of space-based observatories to chart the path to discovery. Here is where the Beyond Einstein story begins. By exploring the three questions that are Einstein s legacy, we begin the next revolution in understanding our Universe. We plot our way

  12. Measurement of the photodissociation of the deuteron at energies relevant to Big Bang nucleosynthesis

    NASA Astrophysics Data System (ADS)

    Hannaske, R.; Bemmerer, D.; Beyer, R.; Birgersson, E.; Ferrari, A.; Grosse, E.; Junghans, A. R.; Kempe, M.; Kögler, T.; Kosev, K.; Marta, M.; Massarczyk, R.; Matic, A.; Schilling, K. D.; Schramm, G.; Schwengner, R.; Wagner, A.; Yakorev, D.

    2016-01-01

    The photodissociation of the deuteron is a key reaction in Big Bang nucleosynthesis, but is only sparsely measured in the relevant energy range. To determine the cross section of the d(γ,n)p reaction we used pulsed bremsstrahlung and measured the time-of-flight of the neutrons. In this article, we describe how the efficiency of the neutron detectors was experimentally determined and how the modification of the neutron spectrum by parts of the experimental setup was simulated and corrected.

  13. A magnified young galaxy from about 500 million years after the Big Bang.

    PubMed

    Zheng, Wei; Postman, Marc; Zitrin, Adi; Moustakas, John; Shu, Xinwen; Jouvel, Stephanie; Høst, Ole; Molino, Alberto; Bradley, Larry; Coe, Dan; Moustakas, Leonidas A; Carrasco, Mauricio; Ford, Holland; Benítez, Narciso; Lauer, Tod R; Seitz, Stella; Bouwens, Rychard; Koekemoer, Anton; Medezinski, Elinor; Bartelmann, Matthias; Broadhurst, Tom; Donahue, Megan; Grillo, Claudio; Infante, Leopoldo; Jha, Saurabh W; Kelson, Daniel D; Lahav, Ofer; Lemze, Doron; Melchior, Peter; Meneghetti, Massimo; Merten, Julian; Nonino, Mario; Ogaz, Sara; Rosati, Piero; Umetsu, Keiichi; van der Wel, Arjen

    2012-09-20

    Re-ionization of the intergalactic medium occurred in the early Universe at redshift z ≈ 6-11, following the formation of the first generation of stars. Those young galaxies (where the bulk of stars formed) at a cosmic age of less than about 500 million years (z ≲ 10) remain largely unexplored because they are at or beyond the sensitivity limits of existing large telescopes. Understanding the properties of these galaxies is critical to identifying the source of the radiation that re-ionized the intergalactic medium. Gravitational lensing by galaxy clusters allows the detection of high-redshift galaxies fainter than what otherwise could be found in the deepest images of the sky. Here we report multiband observations of the cluster MACS J1149+2223 that have revealed (with high probability) a gravitationally magnified galaxy from the early Universe, at a redshift of z = 9.6 ± 0.2 (that is, a cosmic age of 490 ± 15 million years, or 3.6 per cent of the age of the Universe). We estimate that it formed less than 200 million years after the Big Bang (at the 95 per cent confidence level), implying a formation redshift of ≲14. Given the small sky area that our observations cover, faint galaxies seem to be abundant at such a young cosmic age, suggesting that they may be the dominant source for the early re-ionization of the intergalactic medium.

  14. Cosmological space-times with resolved Big Bang in Yang-Mills matrix models

    NASA Astrophysics Data System (ADS)

    Steinacker, Harold C.

    2018-02-01

    We present simple solutions of IKKT-type matrix models that can be viewed as quantized homogeneous and isotropic cosmological space-times, with finite density of microstates and a regular Big Bang (BB). The BB arises from a signature change of the effective metric on a fuzzy brane embedded in Lorentzian target space, in the presence of a quantized 4-volume form. The Hubble parameter is singular at the BB, and becomes small at late times. There is no singularity from the target space point of view, and the brane is Euclidean "before" the BB. Both recollapsing and expanding universe solutions are obtained, depending on the mass parameters.

  15. The big bang as a result of the first-order phase transition driven by a change of the scalar curvature in an expanding early Universe: The “hyperinflation” scenario

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Pashitskii, E. A., E-mail: pashitsk@iop.kiev.ua; Pentegov, V. I.

    We suggest that the Big Bang could be a result of the first-order phase transition driven by a change in the scalar curvature of the 4D spacetime in an expanding cold Universe filled with a nonlinear scalar field φ and neutral matter with an equation of state p = νε (where p and ε are the pressure and energy density of the matter, respectively). We consider the Lagrangian of a scalar field with nonlinearity φ{sup 4} in a curved spacetime that, along with the term–ξR|φ|{sup 2} quadratic in φ (where ξ is the interaction constant between the scalar and gravitationalmore » fields and R is the scalar curvature), contains the term ξRφ{sub 0}(φ + φ{sup +}) linear in φ, where φ{sub 0} is the vacuum mean of the scalar field amplitude. As a consequence, the condition for the existence of extrema of the scalar-field potential energy is reduced to an equation cubic in φ. Provided that ν > 1/3, the scalar curvature R = [κ(3ν–1)ε–4Λ] (where κ and Λ are Einstein’s gravitational and cosmological constants, respectively) decreases with decreasing ε as the Universe expands, and a first-order phase transition in variable “external field” parameter proportional to R occurs at some critical value R{sub c} < 0. Under certain conditions, the critical radius of the early Universe at the point of the first-order phase transition can reach an arbitrary large value, so that this scenario of unrestricted “inflation” of the Universe may be called “hyperinflation.” After the passage through the phase-transition point, the scalar-field potential energy should be rapidly released, which must lead to strong heating of the Universe, playing the role of the Big Bang.« less

  16. A high abundance of massive galaxies 3-6 billion years after the Big Bang.

    PubMed

    Glazebrook, Karl; Abraham, Roberto G; McCarthy, Patrick J; Savaglio, Sandra; Chen, Hsiao-Wen; Crampton, David; Murowinski, Rick; Jørgensen, Inger; Roth, Kathy; Hook, Isobel; Marzke, Ronald O; Carlberg, R G

    2004-07-08

    Hierarchical galaxy formation is the model whereby massive galaxies form from an assembly of smaller units. The most massive objects therefore form last. The model succeeds in describing the clustering of galaxies, but the evolutionary history of massive galaxies, as revealed by their visible stars and gas, is not accurately predicted. Near-infrared observations (which allow us to measure the stellar masses of high-redshift galaxies) and deep multi-colour images indicate that a large fraction of the stars in massive galaxies form in the first 5 Gyr (refs 4-7), but uncertainties remain owing to the lack of spectra to confirm the redshifts (which are estimated from the colours) and the role of obscuration by dust. Here we report the results of a spectroscopic redshift survey that probes the most massive and quiescent galaxies back to an era only 3 Gyr after the Big Bang. We find that at least two-thirds of massive galaxies have appeared since this era, but also that a significant fraction of them are already in place in the early Universe.

  17. STANDARD BIG BANG NUCLEOSYNTHESIS UP TO CNO WITH AN IMPROVED EXTENDED NUCLEAR NETWORK

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Coc, Alain; Goriely, Stephane; Xu, Yi

    Primordial or big bang nucleosynthesis (BBN) is one of the three strong pieces of evidence for the big bang model together with the expansion of the universe and cosmic microwave background radiation. In this study, we improve the standard BBN calculations taking into account new nuclear physics analyses and enlarge the nuclear network up to sodium. This is, in particular, important to evaluate the primitive value of CNO mass fraction that could affect Population III stellar evolution. For the first time we list the complete network of more than 400 reactions with references to the origin of the rates, includingmore » Almost-Equal-To 270 reaction rates calculated using the TALYS code. Together with the cosmological light elements, we calculate the primordial beryllium, boron, carbon, nitrogen, and oxygen nuclei. We performed a sensitivity study to identify the important reactions for CNO, {sup 9}Be, and boron nucleosynthesis. We re-evaluated those important reaction rates using experimental data and/or theoretical evaluations. The results are compared with precedent calculations: a primordial beryllium abundance increase by a factor of four compared to its previous evaluation, but we note a stability for B/H and for the CNO/H abundance ratio that remains close to its previous value of 0.7 Multiplication-Sign 10{sup -15}. On the other hand, the extension of the nuclear network has not changed the {sup 7}Li value, so its abundance is still 3-4 times greater than its observed spectroscopic value.« less

  18. From the Big Bang to the Nobel Prize and the JWST

    NASA Technical Reports Server (NTRS)

    Mather, John C.

    2007-01-01

    I will describe the history of the universe, from the Big Bang to 2013, when the JWST is to be launched to look back towards our beginnings. I will discuss how the COBE results led to the Nobel Prize, how the COBE results have been confirmed and extended, and their implications for future observations. The James Webb Space Telescope will be used to examine every part of our history from the first stars and galaxies to the formation of individual stars and planets and the delivery of life-supporting materials to the Earth. I will describe the plans for the JWST and how observers may use it. With luck, the JWST may produce a Nobel Prize for some discovery we can only guess today.

  19. Constraint on slepton intergenerational mixing from big-bang nucleosynthesis

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kohri, Kazunori; Ohta, Shingo; Sato, Joe

    We find constraint on intergenerational mixing of slepton from big-bang nucleosynthesis (BBN). Today, we know that there exist lepton flavor violation (LFV) from the observation of neutrino oscillation, though there do not exist LFV in the standard model of particle physics (SM). LFV in charged lepton sector (cLFV) have also been expected to exist. From theoretical point of view, the effects of long-lived stau on BBN have been investigated and it is known that the stau can solve the cosmological 7Li problem. However, in the study so far, tau flavor is exactly conserved and it contradict with the existence ofmore » cLFV. In this study, we generalize the flavor to be violated and call the stau as slepton. Even if the violation is tiny, it drastically changes the lifetime and the evolution of relic density of the slepton. Thus we analyze the effects of the long-lived slepton on BBN, and constrain the magnitude of the cLFV.« less

  20. On the use of big-bang method to generate low-energy structures of atomic clusters modeled with pair potentials of different ranges.

    PubMed

    Marques, J M C; Pais, A A C C; Abreu, P E

    2012-02-05

    The efficiency of the so-called big-bang method for the optimization of atomic clusters is analysed in detail for Morse pair potentials with different ranges; here, we have used Morse potentials with four different ranges, from long- ρ = 3) to short-ranged ρ = 14) interactions. Specifically, we study the efficacy of the method in discovering low-energy structures, including the putative global minimum, as a function of the potential range and the cluster size. A new global minimum structure for long-ranged ρ = 3) Morse potential at the cluster size of n= 240 is reported. The present results are useful to assess the maximum cluster size for each type of interaction where the global minimum can be discovered with a limited number of big-bang trials. Copyright © 2011 Wiley Periodicals, Inc.

  1. Nuclear polarization effects in big bang nucleosynthesis

    NASA Astrophysics Data System (ADS)

    Voronchev, Victor T.; Nakao, Yasuyuki

    2015-10-01

    A standard nuclear reaction network for big bang nucleosynthesis (BBN) simulations operates with spin-averaged nuclear inputs—unpolarized reaction cross sections. At the same time, the major part of reactions controlling the abundances of light elements is spin dependent, i.e., their cross sections depend on the mutual orientation of reacting particle spins. Primordial magnetic fields in the BBN epoch may to a certain degree polarize particles and thereby affect some reactions between them, introducing uncertainties in standard BBN predictions. To clarify the points, we have examined the effects of induced polarization on key BBN reactions—p (n ,γ )d , d (d ,p )t , d (d ,n )He 3 , t (d ,n )α , He 3 (n ,p )t , He 3 (d ,p )α , Li 7 (p ,α )α , Be 7 (n ,p )Li 7 —and the abundances of elements with A ≤7 . It has been obtained that the magnetic field with the strength B0≤1012 G (at the temperature of 109 K ) has almost no effect on the reaction cross sections, and the spin polarization mechanism plays a minor role in the element production, changing the abundances at most by 0.01%. However, if the magnetic field B0 reaches 1015 G its effect on the key reactions appears and becomes appreciable at B0≳1016 G . In particular, it has been found that such a field can increase the p (n ,γ )d cross section (relevant to the starting point of BBN) by a factor of 2 and at the same time almost block the He 3 (n ,p )t reaction responsible for the interconversion of A =3 nuclei in the early Universe. This suggests that the spin polarization effects may become important in nonstandard scenarios of BBN considering the existence of local magnetic bubbles inside which the field can reach ˜1015 G .

  2. The big bang of hemofiltration: the beginning of a new era in the third millennium for extra-corporeal blood purification!

    PubMed

    Honore', P M; Joannes-Boyau, O; Merson, L; Boer, W; Piette, V; Galloy, A-C; Janvier, G

    2006-07-01

    Since the last decade, hemofiltration and especially high volume hemofiltration has rapidly evolved from a somewhat experimental treatment towards a potentially effective 'adjunctive' therapy in severe septic shock and especially refractory or catecholamine resistant hypodynamic septic shock. Nevertheless, this approach lacks prospective randomized studies (PRT'S) evaluating the critical role of early hemofiltration in sepsis. An important step forward which could be called the 'big bang' in term of hemofiltration was the publication of a PRT in patients with acute renal failure (ARF) (1). Before this study (2), nobody believed that hemofiltration could change the survival rate in intensive care. Since that big bang, many physicians consider that hemofiltration at a certain dose can change the survival rate in intensive care. So the world of hemofiltration in ICU is not a definitive world, it is still in expansion. Indeed, we now have to try to define what will be the exact dose we need in septic acute renal failure. This dose might well be 'higher' than 35 ml/kg/hour in the septic acute renal failure 'group' as suggested by many studies (2-5). At present, it is the issue of continuous dose of high volume hemofiltration that has to be tested in future randomized studies. Since the Vicenza study (2) has shown that 35 ml/kg/h is the best dose in terms of survival, dealing with non septic acute renal failure in ICU, several studies from different groups have shown that, in septic acute renal failure, a higher dose might correlate with better survival. This has also been shown in some way by the study of the 'Vicenza group' but not with a statistically significant value (2). New PRT'S have just started in Europe like the IVOIRE study (hIgh VOlume in Intensive caRE) (6) and the RENAL study. Another large study is looking more basically at dose in non septic acute renal failure in Australasia and is led by the group of Rinaldo Bellomo in Melbourne (7) as well as the ATN

  3. Can history improve big bang health reform? Commentary.

    PubMed

    Marchildon, Gregory P

    2018-07-01

    At present, the professional skills of the historian are rarely relied upon when health policies are being formulated. There are numerous reasons for this, one of which is the natural desire of decision-makers to break with the past when enacting big bang policy change. This article identifies the strengths professional historians bring to bear on policy development using the establishment and subsequent reform of universal health coverage as an example. Historians provide pertinent and historically informed context; isolate the forces that have historically allowed for major reform; and separate the truly novel reforms from those attempted or implemented in the past. In addition, the historian's use of primary sources allows potentially new and highly salient facts to guide the framing of the policy problem and its solution. This paper argues that historians are critical for constructing a viable narrative of the establishment and evolution of universal health coverage policies. The lack of this narrative makes it difficult to achieve an accurate assessment of systemic gaps in coverage and access, and the design or redesign of universal health coverage that can successfully close these gaps.

  4. The big bang? An eventful year in workers' compensation.

    PubMed

    Guidotti, Tee L

    2006-01-01

    Workers' compensation in the past two years has been dominated by events in California, which have been so fundamental as to merit the term big bang. Passage of Senate Bill 899 has led to a comprehensive program of reform in access to medical care, access to rehabilitation services, temporary and permanent disability, evidence-based management, dispute resolution, and system innovation. Two noteworthy developments thus arose: a new requirement for apportionment by cause in causation analysis, and the adoption of evidence-based criteria for impairment assessment, treatment guidelines, and, soon, utilization review. Elsewhere in the United States, changes were modest, but extensive legislative activity in Texas suggests that Texas will be next to make major changes. In Canada, the Workers' Compensation Board of British Columbia has adopted an ambitious strategic initiative, and there is a Canadawide movement to establish presumption for certain diseases in firefighters. Suggestions for future directions include an increased emphasis on prevention, integration of programs, worker participation, enhancing the expertise of health care professionals, evidence-based management, process evaluation, and opportunities for innovation.

  5. Did God create our universe? Theological reflections on the Big Bang, inflation, and quantum cosmologies.

    PubMed

    Russell, R J

    2001-12-01

    The sciences and the humanities, including theology, form an epistemic hierarchy that ensures both constraint and irreducibility. At the same time, theological methodology is analogous to scientific methodology, though with several important differences. This model of interaction between science and theology can be seen illustrated in a consideration of the relation between contemporary cosmology (Big Bang cosmology, cosmic inflation, and quantum cosmology) and Christian systematic and natural theology. In light of developments in cosmology, the question of origins has become theologically less interesting than that of the cosmic evolution of a contingent universe.

  6. Advanced Modeling in Excel: from Water Jets to Big Bang

    NASA Astrophysics Data System (ADS)

    Ignatova, Olga; Chyzhyk, D.; Willis, C.; Kazachkov, A.

    2006-12-01

    An international students’ project is presented focused on application of Open Office and Excel spreadsheets for modeling of projectile-motion type dynamical systems. Variation of the parameters of plotted and animated families of jets flowing at different angles out of the holes in the wall of water-filled reservoir [1,2] revealed unexpected peculiarities of the envelopes, vertices, intersections and landing points of virtual trajectories. Comparison with real-life systems and rigorous calculations were performed to prove predictions of computer experiments. By same technique, the kinematics of fireworks was analyzed. On this basis two-dimensional ‘firework’ computer model of Big Bang was designed and studied, its relevance and limitations checked. 1.R.Ehrlich, Turning the World Inside Out, (Princeton University Press, Princeton, NJ, 1990), pp. 98-100. 2.A.Kazachkov, Yu.Bogdan, N.Makarovsky, N.Nedbailo. A Bucketful of Physics, in R.Pinto, S.Surinach (eds), International Conference Physics Teacher Education Beyond 2000. Selected Contributions (Elsevier Editions, Paris, 2001), pp.563-564. Sponsored by Courtney Willis.

  7. Revisiting big-bang nucleosynthesis constraints on long-lived decaying particles

    NASA Astrophysics Data System (ADS)

    Kawasaki, Masahiro; Kohri, Kazunori; Moroi, Takeo; Takaesu, Yoshitaro

    2018-01-01

    We study the effects of long-lived massive particles, which decayed during the big-bang nucleosynthesis (BBN) epoch, on the primordial abundance of light elements. Compared to previous studies, (i) the reaction rates of standard BBN reactions are updated, (ii) the most recent observational data on the light element abundance and cosmological parameters are used, (iii) the effects of the interconversion of energetic nucleons at the time of inelastic scattering with background nuclei are considered, and (iv) the effects of the hadronic shower induced by energetic high-energy antinucleons are included. We compare the theoretical predictions on the primordial abundance of light elements with the latest observational constraints, and we derive upper bounds on the relic abundance of the decaying particle as a function of its lifetime. We also apply our analysis to an unstable gravitino, the superpartner of a graviton in supersymmetric theories, and obtain constraints on the reheating temperature after inflation.

  8. Influence of Parallel Dark Matter Sectors on Big Bang Nucleosynthesis

    NASA Astrophysics Data System (ADS)

    Challa, Venkata Sai Sreeharsha

    Big Bang Nucleosynthesis (BBN) is a phenomenological theory that describes the synthesis of light nuclei after a few seconds of the cosmic time in the primordial universe. The twelve nuclear reactions in the first few seconds of the cosmic history are constrained by factors such as baryon to photon ratio, number of neutrino families, and present day element abundances. The belief that the expansion of the universe must be slowed down by gravity, was defeated by the recent observation of an accelerated expansion of the universe. Friedmann equations, which describe the cosmic dynamics, need to be revised considering also the existence of dark matter, another recent astronomical observation. The effects of multiple parallel universes of dark matter (dark sectors) on the accelerated expansion of the universe are studied. Collectively, these additional effects will lead to a new cosmological model. We had developed a numerical code on BBN to address the effects of such dark sectors on the abundances of all the light elements. We have studied the effect of degrees of freedom of dark-matter in the early universe on primordial abundances of light elements. The predicted abundances of light elements are compared with observed constraints to obtain bounds on the number of dark sectors, NDM. Comparison of the obtained results with the observations during the BBN epoch shows that the number of dark matter sectors are only loosely constrained, and the dark matter sectors are colder than the ordinary matter sectors. Also, we verified that the existence of parallel dark matter sectors with colder temperatures does not affect the constraints set by observations on the number of neutrino families, Nnu .

  9. Refined scenario of standard Big Bang nucleosynthesis allowing for nonthermal nuclear reactions in the primordial plasma

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Voronchev, Victor T.; Nakao, Yasuyuki; Nakamura, Makoto

    The standard scenario of big bang nucleosynthesis (BBN) is generalized to take into account nonthermal nuclear reactions in the primordial plasma. These reactions are naturally triggered in the BBN epoch by fast particles generated in various exoergic processes. It is found that, although such particles can appreciably enhance the rates of some individual reactions, their influence on the whole process of element production is not significant. The nonthermal corrections to element abundances are obtained to be 0.1% ({sup 3}H), -0.03% ({sup 7}Li), and 0.34 %-0.63% (CNO group).

  10. Big History or the 13800 million years from the Big Bang to the Human Brain

    NASA Astrophysics Data System (ADS)

    Gústafsson, Ludvik E.

    2017-04-01

    Big History is the integrated history of the Cosmos, Earth, Life, and Humanity. It is an attempt to understand our existence as a continuous unfolding of processes leading to ever more complex structures. Three major steps in the development of the Universe can be distinguished, the first being the creation of matter/energy and forces in the context of an expanding universe, while the second and third steps were reached when completely new qualities of matter came into existence. 1. Matter comes out of nothing Quantum fluctuations and the inflation event are thought to be responsible for the creation of stable matter particles in what is called the Big Bang. Along with simple particles the universe is formed. Later larger particles like atoms and the most simple chemical elements hydrogen and helium evolved. Gravitational contraction of hydrogen and helium formed the first stars und later on the first galaxies. Massive stars ended their lives in violent explosions releasing heavier elements like carbon, oxygen, nitrogen, sulfur and iron into the universe. Subsequent star formation led to star systems with bodies containing these heavier elements. 2. Matter starts to live About 9200 million years after the Big Bang a rather inconspicous star of middle size formed in one of a billion galaxies. The leftovers of the star formation clumped into bodies rotating around the central star. In some of them elements like silicon, oxygen, iron and many other became the dominant matter. On the third of these bodies from the central star much of the surface was covered with an already very common chemical compound in the universe, water. Fluid water and plenty of various elements, especially carbon, were the ingredients of very complex chemical compounds that made up even more complex structures. These were able to replicate themselves. Life had appeared, the only occasion that we human beings know of. Life evolved subsequently leading eventually to the formation of multicellular

  11. Renaming the Big Bang: A Case Study of Popular Ideas on Cosmology

    NASA Astrophysics Data System (ADS)

    Fienberg, R. T.; Beatty, J. K.; Dinsmoor, D. T.; Ferris, T.; Downs, H.; Sagan, C.

    1993-12-01

    In the August 1993 Sky & Telescope one of us (T. F.) argued that the term "Big Bang" is misleading, trivializing, and inappropriately bellicose to describe the event that gave rise to the physical universe as depicted by the standard cosmological model. We issued a challenge to all interested persons to try to come up with a better name. Although we offered no prize, the challenge aroused widespread interest: over a period of three months some 13,000 entries were submitted from 41 countries. Some came from professional astronomers, but most came from nonscientists -- from kindergartners and octogenarians, prison inmates and physicians, and many others. This outpouring of creative, pedestrian, religious, ingenious, confused, profound, and insightful suggestions offers an unprecedented look at laypeoples' thinking about the origin of the universe. Some of the suggested new names for the theory are highly original and appropriate.

  12. Effects of sterile neutrino and extra-dimension on big bang nucleosynthesis

    NASA Astrophysics Data System (ADS)

    Jang, Dukjae; Kusakabe, Motohiko; Cheoun, Myung-Ki

    2018-04-01

    We study effects of the sterile neutrino in the five-dimensional universe on the big bang nucleosynthesis (BBN). Since the five-dimensional universe model leads to an additional term in the Friedmann equation and the energy density of the sterile neutrino increases the total energy density, this model can affect the primordial abundance via changing the cosmic expansion rate. The energy density of the sterile neutrino can be determined by a rate equation for production of the sterile neutrino. We show that not only the mixing angle and the mass of the sterile neutrino, but also a resonant effect in the oscillation between sterile and active neutrinos is important to determine a relic abundance of the sterile neutrino. In this study, we also investigate how the sterile neutrino in extra-dimensional model can affect the BBN, and constrain the parameters related to the above properties of the sterile neutrino by using the observational primordial abundances of light elements.

  13. The Big Bang of picorna-like virus evolution antedates the radiation of eukaryotic supergroups.

    PubMed

    Koonin, Eugene V; Wolf, Yuri I; Nagasaki, Keizo; Dolja, Valerian V

    2008-12-01

    The recent discovery of RNA viruses in diverse unicellular eukaryotes and developments in evolutionary genomics have provided the means for addressing the origin of eukaryotic RNA viruses. The phylogenetic analyses of RNA polymerases and helicases presented in this Analysis article reveal close evolutionary relationships between RNA viruses infecting hosts from the Chromalveolate and Excavate supergroups and distinct families of picorna-like viruses of plants and animals. Thus, diversification of picorna-like viruses probably occurred in a 'Big Bang' concomitant with key events of eukaryogenesis. The origins of the conserved genes of picorna-like viruses are traced to likely ancestors including bacterial group II retroelements, the family of HtrA proteases and DNA bacteriophages.

  14. Constraining f(T) teleparallel gravity by big bang nucleosynthesis: f(T) cosmology and BBN.

    PubMed

    Capozziello, S; Lambiase, G; Saridakis, E N

    2017-01-01

    We use Big Bang Nucleosynthesis (BBN) observational data on the primordial abundance of light elements to constrain f ( T ) gravity. The three most studied viable f ( T ) models, namely the power law, the exponential and the square-root exponential are considered, and the BBN bounds are adopted in order to extract constraints on their free parameters. For the power-law model, we find that the constraints are in agreement with those obtained using late-time cosmological data. For the exponential and the square-root exponential models, we show that for reliable regions of parameters space they always satisfy the BBN bounds. We conclude that viable f ( T ) models can successfully satisfy the BBN constraints.

  15. Astrophysical S-factor of the 32He(α,γ) 733 7Be reaction in the Big-Bang nucleosynthesis

    NASA Astrophysics Data System (ADS)

    Ghamary, Motahareh; Sadeghi, Hossein; Mohammadi, Saeed

    2018-05-01

    In the present work, we have studied the properties of the 23He(α , γ) 47Be reaction. The direct radiative capture nuclear reactions in the Big-Bang nucleosynthesis mainly, are done in the external areas of inter-nuclear interaction range and play an essential role in nuclear astrophysics. Among of these reactions, the 23He(α , γ) 47Be reaction with Q = 1.586 MeV is the main part of the Big-Bang nucleosynthesis chain reactions. This reaction can be used to understand the physical and chemical properties of the sun as well as can be justified the lake of the observed solar neutrino in the detector of the Earth. Since product neutrino fluxes are predicated in the center of the sun by the decay of 7Be and 8B, and almost are proportional to the astrophysical S-factor for the 23He(α , γ) 47Be reaction, S34. The 23He(α , γ) 47Be reaction is considered the key to solve the solar neutrino puzzle. Finally, we have astrophysical S-factor obtained for the ground S1,3/2-, first excited S1,1/2-and total S34 states by modern nucleon-nucleon two-body local potential models. We have also compared the obtained S-factor with experimental data and other theoretical works.

  16. Origins of Genes: "Big Bang" or Continuous Creation?

    NASA Astrophysics Data System (ADS)

    Kesse, Paul K.; Gibbs, Adrian

    1992-10-01

    Many protein families are common to all cellular organisms, indicating that many genes have ancient origins. Genetic variation is mostly attributed to processes such as mutation, duplication, and rearrangement of ancient modules. Thus it is widely assumed that much of present-day genetic diversity can be traced by common ancestry to a molecular "big bang." A rarely considered alternative is that proteins may arise continuously de novo. One mechanism of generating different coding sequences is by "overprinting," in which an existing nucleotide sequence is translated de novo in a different reading frame or from noncoding open reading frames. The clearest evidence for overprinting is provided when the original gene function is retained, as in overlapping genes. Analysis of their phylogenies indicates which are the original genes and which are their informationally novel partners. We report here the phylogenetic relationships of overlapping coding sequences from steroid-related receptor genes and from tymovirus, luteovirus, and lentivirus genomes. For each pair of overlapping coding sequences, one is confined to a single lineage, whereas the other is more widespread. This suggests that the phylogenetically restricted coding sequence arose only in the progenitor of that lineage by translating an out-of-frame sequence to yield the new polypeptide. The production of novel exons by alternative splicing in thyroid receptor and lentivirus genes suggests that introns can be a valuable evolutionary source for overprinting. New genes and their products may drive major evolutionary changes.

  17. Origins of genes: "big bang" or continuous creation?

    PubMed Central

    Keese, P K; Gibbs, A

    1992-01-01

    Many protein families are common to all cellular organisms, indicating that many genes have ancient origins. Genetic variation is mostly attributed to processes such as mutation, duplication, and rearrangement of ancient modules. Thus it is widely assumed that much of present-day genetic diversity can be traced by common ancestry to a molecular "big bang." A rarely considered alternative is that proteins may arise continuously de novo. One mechanism of generating different coding sequences is by "overprinting," in which an existing nucleotide sequence is translated de novo in a different reading frame or from noncoding open reading frames. The clearest evidence for overprinting is provided when the original gene function is retained, as in overlapping genes. Analysis of their phylogenies indicates which are the original genes and which are their informationally novel partners. We report here the phylogenetic relationships of overlapping coding sequences from steroid-related receptor genes and from tymovirus, luteovirus, and lentivirus genomes. For each pair of overlapping coding sequences, one is confined to a single lineage, whereas the other is more widespread. This suggests that the phylogenetically restricted coding sequence arose only in the progenitor of that lineage by translating an out-of-frame sequence to yield the new polypeptide. The production of novel exons by alternative splicing in thyroid receptor and lentivirus genes suggests that introns can be a valuable evolutionary source for overprinting. New genes and their products may drive major evolutionary changes. PMID:1329098

  18. Big-Bang-Gate Cosmic Titanic: Why Aren't Physics Journal's Editors Bringing It To The Center of Scientific Attention

    NASA Astrophysics Data System (ADS)

    Gentry, Robert

    2010-02-01

    Until now science's greatest debacle occurred when Copernicus exposed Ptolemaic cosmologists' 1300 hundred year-long fraud that it must be true because observations fit theory so well, while they ignored the untested state of its central assumption of Earth centered planetary motion. With much hubris modern physicists are confident this could never happen again, that the integrity of physics journals editors suffices to guarantee that a challenge to the reigning cosmological theory -- big bang cosmology -- would immediately be brought to the center of scientific attention for analysis and discussion. In fact a decade ago it was reported [MPLA 2619 (1997); arXiv:gr-gc/9806061] that, like Ptolemaic cosmology before it, big bang's central assumption that GR expansion effects cause in-flight expansion had never been tested and, further, that experimental testing of it using GR operation of the GPS showed it to be false. This result proves it is impossible for the 2.73 K CBR to be fireball relic radiation. These results were expanded in CERN reports EXT-2003-021;022, but have been uniformly rejected by physics journals, one of which accepted a paper similar to CERN EXT-2003-022, only to reject it a few days later with the admission not to publish it because of fearing reaction of the worldwide physics community. For update on my PRL submission see http://www.alphacosmos.net. )

  19. First direct measurement of the 2H(α,γ)6Li cross section at big bang energies and the primordial lithium problem.

    PubMed

    Anders, M; Trezzi, D; Menegazzo, R; Aliotta, M; Bellini, A; Bemmerer, D; Broggini, C; Caciolli, A; Corvisiero, P; Costantini, H; Davinson, T; Elekes, Z; Erhard, M; Formicola, A; Fülöp, Zs; Gervino, G; Guglielmetti, A; Gustavino, C; Gyürky, Gy; Junker, M; Lemut, A; Marta, M; Mazzocchi, C; Prati, P; Rossi Alvarez, C; Scott, D A; Somorjai, E; Straniero, O; Szücs, T

    2014-07-25

    Recent observations of (6)Li in metal poor stars suggest a large production of this isotope during big bang nucleosynthesis (BBN). In standard BBN calculations, the (2)H(α,γ)(6)Li reaction dominates (6)Li production. This reaction has never been measured inside the BBN energy region because its cross section drops exponentially at low energy and because the electric dipole transition is strongly suppressed for the isoscalar particles (2)H and α at energies below the Coulomb barrier. Indirect measurements using the Coulomb dissociation of (6)Li only give upper limits owing to the dominance of nuclear breakup processes. Here, we report on the results of the first measurement of the (2)H(α,γ)(6)Li cross section at big bang energies. The experiment was performed deep underground at the LUNA 400 kV accelerator in Gran Sasso, Italy. The primordial (6)Li/(7)Li isotopic abundance ratio has been determined to be (1.5 ± 0.3) × 10(-5), from our experimental data and standard BBN theory. The much higher (6)Li/(7)Li values reported for halo stars will likely require a nonstandard physics explanation, as discussed in the literature.

  20. big bang gene modulates gut immune tolerance in Drosophila.

    PubMed

    Bonnay, François; Cohen-Berros, Eva; Hoffmann, Martine; Kim, Sabrina Y; Boulianne, Gabrielle L; Hoffmann, Jules A; Matt, Nicolas; Reichhart, Jean-Marc

    2013-02-19

    Chronic inflammation of the intestine is detrimental to mammals. Similarly, constant activation of the immune response in the gut by the endogenous flora is suspected to be harmful to Drosophila. Therefore, the innate immune response in the gut of Drosophila melanogaster is tightly balanced to simultaneously prevent infections by pathogenic microorganisms and tolerate the endogenous flora. Here we describe the role of the big bang (bbg) gene, encoding multiple membrane-associated PDZ (PSD-95, Discs-large, ZO-1) domain-containing protein isoforms, in the modulation of the gut immune response. We show that in the adult Drosophila midgut, BBG is present at the level of the septate junctions, on the apical side of the enterocytes. In the absence of BBG, these junctions become loose, enabling the intestinal flora to trigger a constitutive activation of the anterior midgut immune response. This chronic epithelial inflammation leads to a reduced lifespan of bbg mutant flies. Clearing the commensal flora by antibiotics prevents the abnormal activation of the gut immune response and restores a normal lifespan. We now provide genetic evidence that Drosophila septate junctions are part of the gut immune barrier, a function that is evolutionarily conserved in mammals. Collectively, our data suggest that septate junctions are required to maintain the subtle balance between immune tolerance and immune response in the Drosophila gut, which represents a powerful model to study inflammatory bowel diseases.

  1. Hepatic encephalopathy: Ever closer to its big bang

    PubMed Central

    Souto, Pablo A; Marcotegui, Ariel R; Orbea, Lisandro; Skerl, Juan; Perazzo, Juan Carlos

    2016-01-01

    Hepatic encephalopathy (HE) is a neuropsychiatric disorder that commonly complicates the course of patients with liver disease. Despite the fact that the syndrome was probably first recognized hundreds of years ago, the exact pathogenesis still remains unclear. Minimal hepatic encephalopathy (MHE) is the earliest form of HE and is estimated to affect more that 75% of patients with liver cirrhosis. It is characterized by cognitive impairment predominantly attention, reactiveness and integrative function with very subtle clinical manifestations. The development of MHE is associated with worsen in driving skills, daily activities and the increase of overall mortality. Skeletal muscle has the ability to shift from ammonia producer to ammonia detoxifying organ. Due to its large size, becomes the main ammonia detoxifying organ in case of chronic liver failure and muscular glutamine-synthase becomes important due to the failing liver and brain metabolic activity. Gut is the major glutamine consumer and ammonia producer organ in the body. Hepatocellular dysfunction due to liver disease, results in an impaired clearance of ammonium and in its inter-organ trafficking. Intestinal bacteria, can also represent an extra source of ammonia production and in cirrhosis, small intestinal bacterial overgrowth and symbiosis can be observed. In the study of HE, to get close to MHE is to get closer to its big bang; and from here, to travel less transited roads such as skeletal muscle and intestine, is to go even closer. The aim of this editorial is to expose this road for further and deeper work. PMID:27895414

  2. Hepatic encephalopathy: Ever closer to its big bang.

    PubMed

    Souto, Pablo A; Marcotegui, Ariel R; Orbea, Lisandro; Skerl, Juan; Perazzo, Juan Carlos

    2016-11-14

    Hepatic encephalopathy (HE) is a neuropsychiatric disorder that commonly complicates the course of patients with liver disease. Despite the fact that the syndrome was probably first recognized hundreds of years ago, the exact pathogenesis still remains unclear. Minimal hepatic encephalopathy (MHE) is the earliest form of HE and is estimated to affect more that 75% of patients with liver cirrhosis. It is characterized by cognitive impairment predominantly attention, reactiveness and integrative function with very subtle clinical manifestations. The development of MHE is associated with worsen in driving skills, daily activities and the increase of overall mortality. Skeletal muscle has the ability to shift from ammonia producer to ammonia detoxifying organ. Due to its large size, becomes the main ammonia detoxifying organ in case of chronic liver failure and muscular glutamine-synthase becomes important due to the failing liver and brain metabolic activity. Gut is the major glutamine consumer and ammonia producer organ in the body. Hepatocellular dysfunction due to liver disease, results in an impaired clearance of ammonium and in its inter-organ trafficking. Intestinal bacteria, can also represent an extra source of ammonia production and in cirrhosis, small intestinal bacterial overgrowth and symbiosis can be observed. In the study of HE, to get close to MHE is to get closer to its big bang; and from here, to travel less transited roads such as skeletal muscle and intestine, is to go even closer. The aim of this editorial is to expose this road for further and deeper work.

  3. Implementing Big History.

    ERIC Educational Resources Information Center

    Welter, Mark

    2000-01-01

    Contends that world history should be taught as "Big History," a view that includes all space and time beginning with the Big Bang. Discusses five "Cardinal Questions" that serve as a course structure and address the following concepts: perspectives, diversity, change and continuity, interdependence, and causes. (CMK)

  4. Bugs and the big bang.

    PubMed

    Parsons, Jenni

    2008-10-01

    Now that's a cheery thought! Somewhere more than 100 km below the Geneva countryside two parallel beams of subatomic particles are whizzing around a 27 km circuit in opposite directions at about 99% of the speed of light, doing over 11 000 laps per second. Physicists hope to create a 'bang' that won't end the world, but will unlock some of its mysteries. I confess I have never thought of physicists as poets, but they certainly come up with some evocative models to explain the unknown such as 'dark matter', the invisible skeleton stretching through space; or 'dark energy', which drives the expansion of the universe; or the grandiose 'God's particle' (officially named 'Higgs boson') postulated to endow other particles with mass. These are concepts both too large and too small to grasp.

  5. Nobel laureates in fiction: From La fin du monde to The Big Bang Theory.

    PubMed

    Brodesco, Alberto

    2018-05-01

    The history of the Nobel Prize, since its establishment, interlaces with the history of the public image of science. The aim of this article is to illustrate cinematic scientists, portrayed precisely in their moment of maximum glory. The films and television shows upon which the study is based compose a corpus of 189 media texts. The article identifies three main areas that concern the relation between the Nobel Prize and its audiovisual representations: biopics of real Nobel laureates, the presence of real or fictional Nobel laureates in the film or the show plot, and films and TV series that depict the Nobel ceremony. The article then focuses on four texts that deserve a detailed examination: La fin du monde, The Prize, The Simpsons and The Big Bang Theory. The conclusion compares the representation of the Nobel scientist with general changes in the image of the scientist conveyed by cinema and television.

  6. Big Bangs in Galaxy Clusters: Using X-ray Temperature Maps to Trace Merger Histories in Clusters with Radio Halos/Relics

    NASA Astrophysics Data System (ADS)

    Burns, Jack O.; Datta, Abhirup; Hallman, Eric J.

    2016-06-01

    Galaxy clusters are assembled through large and small mergers which are the most energetic events ("bangs") since the Big Bang. Cluster mergers "stir" the intracluster medium (ICM) creating shocks and turbulence which are illuminated by ~Mpc-sized radio features called relics and halos. These shocks heat the ICM and are detected in x-rays via thermal emission. Disturbed morphologies in x-ray surface brightness and temperatures are direct evidence for cluster mergers. In the radio, relics (in the outskirts of the clusters) and halos (located near the cluster core) are also clear signposts of recent mergers. Our recent ENZO cosmological simulations suggest that around a merger event, radio emission peaks very sharply (and briefly) while the x-ray emission rises and decays slowly. Hence, a sample of galaxy clusters that shows both luminous x-ray emission and radio relics/halos are good candidates for very recent mergers. We are in the early stages of analyzing a unique sample of 48 galaxy clusters with (i) known radio relics and/or halos and (ii) significant archival x-ray observations (>50 ksec) from Chandra and/or XMM. We have developed a new x-ray data analysis pipeline, implemented on parallel processor supercomputers, to create x-ray surface brightness, high fidelity temperature, and pressure maps of these clusters in order to study merging activity. The temperature maps are made using three different map-making techniques: Weighted Voronoi Tessellation, Adaptive Circular Binning, and Contour Binning. In this talk, we will show preliminary results for several clusters, including Abell 2744 and the Bullet cluster. This work is supported by NASA ADAP grant NNX15AE17G.

  7. A Big Bang model of human colorectal tumor growth

    PubMed Central

    Sottoriva, Andrea; Kang, Haeyoun; Ma, Zhicheng; Graham, Trevor A.; Salomon, Matthew P.; Zhao, Junsong; Marjoram, Paul; Siegmund, Kimberly; Press, Michael F.; Shibata, Darryl; Curtis, Christina

    2015-01-01

    What happens in the early, still undetectable human malignancy is unknown because direct observations are impractical. Here we present and validate a “Big Bang” model, whereby tumors grow predominantly as a single expansion producing numerous intermixed sub-clones that are not subject to stringent selection, and where both public (clonal) and most detectable private (subclonal) alterations arise early during growth. Genomic profiling of 349 individual glands from 15 colorectal tumors revealed the absence of selective sweeps, uniformly high intra-tumor heterogeneity (ITH), and sub-clone mixing in distant regions, as postulated by our model. We also verified the prediction that most detectable ITH originates from early private alterations, and not from later clonal expansions, thus exposing the profile of the primordial tumor. Moreover, some tumors appear born-to-be-bad, with sub-clone mixing indicative of early malignant potential. This new model provides a quantitative framework to interpret tumor growth dynamics and the origins of ITH with significant clinical implications. PMID:25665006

  8. A Big Bang Lab

    ERIC Educational Resources Information Center

    Scheider, Walter

    2005-01-01

    The February 2005 issue of The Science Teacher (TST) reminded everyone that by learning how scientists study stars, students gain an understanding of how science measures things that can not be set up in lab, either because they are too big, too far away, or happened in a very distant past. The authors of "How Far are the Stars?" show how the…

  9. Galaxy formation from annihilation-generated supersonic turbulence in the baryon-symmetric big-bang cosmology and the gamma ray background spectrum

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.; Puget, J. L.

    1972-01-01

    Following the big-bang baryon symmetric cosmology of Omnes, the redshift was calculated to be on the order of 500-600. It is show that, at these redshifts, annihilation pressure at the boundaries between regions of matter and antimatter drives large scale supersonic turbulence which can trigger galaxy formation. This picture is consistent with the gamma-ray background observations discussed previously. Gravitational binding of galaxies then occurs at a redshift of about 70, at which time vortical turbulent velocities of about 3 x 10 to the 7th power cm/s lead to angular momenta for galaxies comparable with measured values.

  10. The 'big bang' theory of the origin of psychosis and the faculty of language.

    PubMed

    Crow, Timothy J

    2008-07-01

    language and modern Homo sapiens (the 'big bang'). The expression of genes within the homologous region is influenced by the extent to which the X and Y chromosomes pair in male meiosis (referred to as MSUC "meiotic suppression of unpaired chromosomes"). This mechanism generates epigenetic diversity relating to the species capacity for language; it is proposed as the basis of the genetic predisposition to psychosis. Language and psychosis have a common origin in the genetic event (the 'big bang') that defined the species.

  11. Big bang nucleosynthesis, the CMB, and the origin of matter and space-time

    NASA Astrophysics Data System (ADS)

    Mathews, Grant J.; Gangopadhyay, Mayukh; Sasankan, Nishanth; Ichiki, Kiyotomo; Kajino, Toshitaka

    2018-04-01

    We summarize some applications of big bang nucleosythesis (BBN) and the cosmic microwave background (CMB) to constrain the first moments of the creation of matter in the universe. We review the basic elements of BBN and how it constraints physics of the radiation-dominated epoch. In particular, how the existence of higher dimensions impacts the cosmic expansion through the projection of curvature from the higher dimension in the "dark radiation" term. We summarize current constraints from BBN and the CMB on this brane-world dark radiation term. At the same time, the existence of extra dimensions during the earlier inflation impacts the tensor to scalar ratio and the running spectral index as measured in the CMB. We summarize how the constraints on inflation shift when embedded in higher dimensions. Finally, one expects that the universe was born out of a complicated multiverse landscape near the Planck time. In these moments the energy scale of superstrings was obtainable during the early moments of chaotic inflation. We summarize the quest for cosmological evidence of the birth of space-time out of the string theory landscape. We will explore the possibility that a superstring excitations may have made itself known via a coupling to the field of inflation. This may have left an imprint of "dips" in the power spectrum of temperature fluctuations in the cosmic microwave background. The identification of this particle as a superstring is possible because there may be evidence for different oscillator states of the same superstring that appear on different scales on the sky. It will be shown that from this imprint one can deduce the mass, number of oscillations, and coupling constant for the superstring. Although the evidence is marginal, this may constitute the first observation of a superstring in Nature.

  12. Most Distant X-Ray Jet Yet Discovered Provides Clues To Big Bang

    NASA Astrophysics Data System (ADS)

    2003-11-01

    The most distant jet ever observed was discovered in an image of a quasar made by NASA's Chandra X-ray Observatory. Extending more than 100,000 light years from the supermassive black hole powering the quasar, the jet of high-energy particles provides astronomers with information about the intensity of the cosmic microwave background radiation 12 billion years ago. The discovery of this jet was a surprise to the astronomers, according to team members. Astronomers had previously known the distant quasar GB1508+5714 to be a powerful X-ray source, but there had been no indication of any complex structure or a jet. "This jet is especially significant because it allows us to probe the cosmic background radiation 1.4 billion years after the Big Bang," said Aneta Siemiginowska of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., lead author of a report on this research in the November 20th Astrophysical Journal Letters. Prior to this discovery, the most distant confirmed X-ray jet corresponded to a time about 3 billion years after the Big Bang. Quasars are thought to be galaxies that harbor an active central supermassive black hole fueled by infalling gas and stars. This accretion process is often observed to be accompanied by the generation of powerful high-energy jets. Radio image of GB1508 Radio Image of GB1508 As the electrons in the jet fly away from the quasar at near the speed of light, they move through the sea of cosmic background radiation left over from the hot early phase of the universe. When a fast-moving electron collides with one of these background photons, it can boost the photon's energy up into the X-ray band. The X-ray brightness of the jet depends on the power in the electron beam and the intensity of the background radiation. "Everyone assumes that the background radiation will change in a predictable way with time, but it is important to have this check on the predictions," said Siemiginowska. "This jet is hopefully just the

  13. A galaxy rapidly forming stars 700 million years after the Big Bang at redshift 7.51.

    PubMed

    Finkelstein, S L; Papovich, C; Dickinson, M; Song, M; Tilvi, V; Koekemoer, A M; Finkelstein, K D; Mobasher, B; Ferguson, H C; Giavalisco, M; Reddy, N; Ashby, M L N; Dekel, A; Fazio, G G; Fontana, A; Grogin, N A; Huang, J-S; Kocevski, D; Rafelski, M; Weiner, B J; Willner, S P

    2013-10-24

    Of several dozen galaxies observed spectroscopically that are candidates for having a redshift (z) in excess of seven, only five have had their redshifts confirmed via Lyman α emission, at z = 7.008, 7.045, 7.109, 7.213 and 7.215 (refs 1-4). The small fraction of confirmed galaxies may indicate that the neutral fraction in the intergalactic medium rises quickly at z > 6.5, given that Lyman α is resonantly scattered by neutral gas. The small samples and limited depth of previous observations, however, makes these conclusions tentative. Here we report a deep near-infrared spectroscopic survey of 43 photometrically-selected galaxies with z > 6.5. We detect a near-infrared emission line from only a single galaxy, confirming that some process is making Lyman α difficult to detect. The detected emission line at a wavelength of 1.0343 micrometres is likely to be Lyman α emission, placing this galaxy at a redshift z = 7.51, an epoch 700 million years after the Big Bang. This galaxy's colours are consistent with significant metal content, implying that galaxies become enriched rapidly. We calculate a surprisingly high star-formation rate of about 330 solar masses per year, which is more than a factor of 100 greater than that seen in the Milky Way. Such a galaxy is unexpected in a survey of our size, suggesting that the early Universe may harbour a larger number of intense sites of star formation than expected.

  14. The Early Universe: Searching for Evidence of Cosmic Inflation

    NASA Technical Reports Server (NTRS)

    Chuss, David T.

    2012-01-01

    In the past two decades, our understanding of the evolution and fate of the universe has increased dramatically. This "Age of Precision Cosmology" has been ushered in by measurements that have both elucidated the details of the Big Bang cosmology and set the direction for future lines of inquiry. Our universe appears to consist of 5% baryonic matter; 23% of the universe's energy content is dark matter which is responsible for the observed structure in the universe; and 72% of the energy density is so-called "dark energy" that is currently accelerating the expansion of the universe. In addition, our universe has been measured to be geometrically flat to 1 %. These observations and related details of the Big Bang paradigm have hinted that the universe underwent an epoch of accelerated expansion known as "inflation" early in its history. In this talk, I will review the highlights of modern cosmology, focusing on the contributions made by measurements of the cosmic microwave background, the faint afterglow of the Big Bang. I will also describe new instruments designed to measure the polarization of the cosmic microwave background in order to search for evidence of cosmic inflation.

  15. Study of the 2H(p,γ)3He reaction in the Big Bang Nucleosynthesis energy range at LUNA

    NASA Astrophysics Data System (ADS)

    Mossa, Viviana

    2018-01-01

    Deuterium is the first nucleus produced in the Universe, whose accumulation marks the beginning of the so called Big Bang Nucleosynthesis (BBN). Its primordial abundance is very sensitive to some cosmological parameters like the baryon density and the number of the neutrino families. Presently the main obstacle to an accurate theoretical deuterium abundance evaluation is due to the poor knowledge of the 2H(p,γ)3He cross section at BBN energies. The aim of the present work is to describe the experimental approach proposed by the LUNA collaboration, whose goal is to measure, with unprecedented precision, the total and the differential cross section of the reaction in the 30 < Ec.m. [keV] < 300 energy range.

  16. High Energy Density Plasmas (HEDP) for studies of basic nuclear science relevant to Stellar and Big Bang Nucleosynthesis

    NASA Astrophysics Data System (ADS)

    Frenje, Johan

    2014-06-01

    Thermonuclear reaction rates and nuclear processes have been explored traditionally by means of conventional accelerator experiments, which are difficult to execute at conditions relevant to stellar nucleosynthesis. Thus, nuclear reactions at stellar energies are often studied through extrapolations from higher-energy data or in low-background underground experiments. Even when measurements are possible using accelerators at relevant energies, thermonuclear reaction rates in stars are inherently different from those in accelerator experiments. The fusing nuclei are surrounded by bound electrons in accelerator experiments, whereas electrons occupy mainly continuum states in a stellar environment. Nuclear astrophysics research will therefore benefit from an enlarged toolkit for studies of nuclear reactions. In this presentation, we report on the first use of High Energy Density Plasmas for studies of nuclear reactions relevant to basic nuclear science, stellar and Big Bang nucleosynthesis. These experiments were carried out at the OMEGA laser facility at University of Rochester and the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory, in which spherical capsules were irradiated with powerful lasers to compress and heat the fuel to high enough temperatures and densities for nuclear reactions to occur. Four experiments will be highlighted in this presentation. In the first experiment, the differential cross section for the elastic neutron-triton (n-T) scattering at 14.1 MeV was measured with significantly higher accuracy than achieved in accelerator experiments. In the second experiment, the T(t,2n)4He reaction, a mirror reaction to the 3He(3He,2p)4He reaction that plays an important role in the proton-proton chain that transforms hydrogen into ordinary 4He in stars like our Sun, was studied at energies in the range 15-40 keV. In the third experiment, the 3He+3He solar fusion reaction was studied directly, and in the fourth experiment, we

  17. In 'big bang' major incidents do triage tools accurately predict clinical priority?: a systematic review of the literature.

    PubMed

    Kilner, T M; Brace, S J; Cooke, M W; Stallard, N; Bleetman, A; Perkins, G D

    2011-05-01

    The term "big bang" major incidents is used to describe sudden, usually traumatic,catastrophic events, involving relatively large numbers of injured individuals, where demands on clinical services rapidly outstrip the available resources. Triage tools support the pre-hospital provider to prioritise which patients to treat and/or transport first based upon clinical need. The aim of this review is to identify existing triage tools and to determine the extent to which their reliability and validity have been assessed. A systematic review of the literature was conducted to identify and evaluate published data validating the efficacy of the triage tools. Studies using data from trauma patients that report on the derivation, validation and/or reliability of the specific pre-hospital triage tools were eligible for inclusion.Purely descriptive studies, reviews, exercises or reports (without supporting data) were excluded. The search yielded 1982 papers. After initial scrutiny of title and abstract, 181 papers were deemed potentially applicable and from these 11 were identified as relevant to this review (in first figure). There were two level of evidence one studies, three level of evidence two studies and six level of evidence three studies. The two level of evidence one studies were prospective validations of Clinical Decision Rules (CDR's) in children in South Africa, all the other studies were retrospective CDR derivation, validation or cohort studies. The quality of the papers was rated as good (n=3), fair (n=7), poor (n=1). There is limited evidence for the validity of existing triage tools in big bang major incidents.Where evidence does exist it focuses on sensitivity and specificity in relation to prediction of trauma death or severity of injury based on data from single or small number patient incidents. The Sacco system is unique in combining survivability modelling with the degree by which the system is overwhelmed in the triage decision system. The

  18. Georges Lemaître: The Priest Who Invented the Big Bang

    NASA Astrophysics Data System (ADS)

    Lambert, Dominique

    This contribution gives a concise survey of Georges Lemaître works and life, shedding some light on less-known aspects. Lemaître is a Belgian catholic priest who gave for the first time in 1927 the explanation of the Hubble law and who proposed in 1931 the "Primeval Atom Hypothesis", considered as the first step towards the Big Bang cosmology. But the scientific work of Lemaître goes far beyond Physical Cosmology. Indeed, he contributed also to the theory of Cosmis Rays, to the Spinor theory, to Analytical mechanics (regularization of 3- Bodies problem), to Numerical Analysis (Fast Fourier Transform), to Computer Science (he introduced and programmed the first computer of Louvain),… Lemaître took part to the "Science and Faith" debate. He defended a position that has some analogy with the NOMA principle, making a sharp distinction between what he called the "two paths to Truth" (a scientific one and a theological one). In particular, he never made a confusion between the theological concept of "creation" and the scientific notion of "natural beginning" (initial singularity). Lemaître was deeply rooted in his faith and sacerdotal vocation. Remaining a secular priest, he belonged to a community of priests called "The Friends of Jesus", characterized by a deep spirituality and special vows (for example the vow of poverty). He had also an apostolic activity amongst Chinese students.

  19. REVIEWS OF TOPICAL PROBLEMS: The neutrino mass in elementary-particle physics and in big bang cosmology

    NASA Astrophysics Data System (ADS)

    Zel'dovich, Ya B.; Khlopov, M. Yu

    1981-09-01

    Some theoretical aspects of a nonzero value for the neutrino rest mass and its possible implications for physics are discussed. The nature of the neutrino mass is analyzed, as well as the physical consequences that may derive from the existence of new helicity states for the neutrino or from lepton charge nonconservation if the mass is of Dirac or Majorana character, respectively. Massive neutrinos are examined in the context of grand unified theories combining the weak, strong, and electromagnetic interactions. Searches for neutrino-mass effects in β decay and for neutrino oscillations are reviewed. Several astrophysical effects of the neutrino mass are described: solar-neutrino oscillations, the decay of primordial neutrinos, the feasibility of detecting massive primordial neutrinos experimentally. The predictions of big bang theory regarding the neutrino number density in the universe are analyzed, and a discussion is given of the influence neutrino oscillations might have on the neutrino density and on cosmological nucleosynthesis.

  20. The Early Universe and High-Energy Physics.

    ERIC Educational Resources Information Center

    Schramm, David N.

    1983-01-01

    Many properties of new particle field theories can only be tested by comparing their predictions about the physical conditions immediately after the big bang with what can be reconstructed about this event from astronomical data. Facts/questions about big bang, unified field theories, and universe epochs/mass are among the topics discussed. (JN)

  1. The new model of the Big Bang and the Universe expansion. A comparison with modern observational data and cosmological theories

    NASA Astrophysics Data System (ADS)

    Kraiko, A. N.; Valiyev, Kh. F.

    2016-10-01

    The new model of the Big Bang and the Universe expansion is constructed. It is based on solutions in classical and in relativistic statements of problem on the dispersion into the void of the gas compressed into a point or in a finite, but for further negligible, volume. If to restrict in relativistic statement gas speed value v by the speed of light (υ =| v |

  2. The apical scaffold big bang binds to spectrins and regulates the growth of Drosophila melanogaster wing discs.

    PubMed

    Forest, Elodie; Logeay, Rémi; Géminard, Charles; Kantar, Diala; Frayssinoux, Florence; Heron-Milhavet, Lisa; Djiane, Alexandre

    2018-03-05

    During development, cell numbers are tightly regulated, ensuring that tissues and organs reach their correct size and shape. Recent evidence has highlighted the intricate connections between the cytoskeleton and the regulation of the key growth control Hippo pathway. Looking for apical scaffolds regulating tissue growth, we describe that Drosophila melanogaster big bang (Bbg), a poorly characterized multi-PDZ scaffold, controls epithelial tissue growth without affecting epithelial polarity and architecture. bbg -mutant tissues are smaller, with fewer cells that are less apically constricted than normal. We show that Bbg binds to and colocalizes tightly with the β-heavy-Spectrin/Kst subunit at the apical cortex and promotes Yki activity, F-actin enrichment, and the phosphorylation of the myosin II regulatory light chain Spaghetti squash. We propose a model in which the spectrin cytoskeleton recruits Bbg to the cortex, where Bbg promotes actomyosin contractility to regulate epithelial tissue growth. © 2018 Forest et al.

  3. Effects of sterile neutrinos and an extra dimension on big bang nucleosynthesis

    NASA Astrophysics Data System (ADS)

    Jang, Dukjae; Kusakabe, Motohiko; Cheoun, Myung-Ki

    2018-02-01

    By assuming the existence of extra-dimensional sterile neutrinos in the big bang nucleosynthesis (BBN) epoch, we investigate the sterile neutrino (νs) effects on the BBN and constrain some parameters associated with the νs properties. First, for the cosmic expansion rate, we take into account effects of a five-dimensional bulk and intrinsic tension of the brane embedded in the bulk and constrain a key parameter of the extra dimension by using the observational element abundances. Second, effects of the νs traveling on or off the brane are considered. In this model, the effective mixing angle between a νs and an active neutrino depends on energy, which may give rise to a resonance effect on the mixing angle. Consequently, the reaction rate of the νs can be drastically changed during the cosmic evolution. We estimated abundances and temperature of the νs by solving the rate equation as a function of temperature until the sterile neutrino decoupling. We then find that the relic abundance of the νs is drastically enhanced by the extra dimension and maximized for a characteristic resonance energy Eres≳0.01 GeV . Finally, some constraints related to the νs, i.e., mixing angle and mass difference, are discussed in detail with the comparison of our BBN calculations corrected by the extra-dimensional νs to observational data on light element abundances.

  4. THE ANATOMY OF AN EXTREME STARBURST WITHIN 1.3 Gyr OF THE BIG BANG REVEALED BY ALMA

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Carilli, C. L.; Riechers, D.; Walter, F.

    We present further analysis of the [C II] 158 {mu}m fine structure line and thermal dust continuum emission from the archetype extreme starburst/active galactic nucleus (AGN) group of galaxies in the early universe, BRI 1202-0725 at z = 4.7, using the Atacama Large Millimeter Array. The group has long been noted for having a closely separated (26 kpc in projection) FIR-hyperluminous quasar host galaxy and an optically obscured submillimeter galaxy (SMG). A short ALMA test observation reveals a rich laboratory for the study of the myriad processes involved in clustered massive galaxy formation in the early universe. Strong [C II]more » emission from the SMG and the quasar have been reported earlier by Wagg et al. based on these observations. In this paper, we examine in more detail the imaging results from the ALMA observations, including velocity channel images, position-velocity plots, and line moment images. We present detections of [C II] emission from two Ly{alpha}-selected galaxies in the group, demonstrating the relative ease with which ALMA can detect the [C II] emission from lower star formation rate galaxies at high redshift. Imaging of the [C II] emission shows a clear velocity gradient across the SMG, possibly indicating rotation or a more complex dynamical system on a scale {approx}10 kpc. There is evidence in the quasar spectrum and images for a possible outflow toward the southwest, as well as more extended emission (a {sup b}ridge{sup )}, between the quasar and the SMG, although the latter could simply be emission from Ly{alpha}-1 blending with that of the quasar at the limited spatial resolution of the current observations. These results provide an unprecedented view of a major merger of gas-rich galaxies driving extreme starbursts and AGN accretion during the formation of massive galaxies and supermassive black holes within 1.3 Gyr of the big bang.« less

  5. Engine of life and big bang of evolution: a personal perspective.

    PubMed

    Barber, James

    2004-01-01

    Photosystem II (PS II) is the engine for essentially all life on our planet and its beginning 2.5 billion years ago was the 'big bang of evolution.' It produces reducing equivalents for making organic compounds on an enormous scale and at the same time provides us with an oxygenic atmosphere and protection against UV radiation (in the form of the ozone layer). In 1967, when I began my career in photosynthesis research, little was known about PS II. The Z-scheme had been formulated [Hill and Bendall (1960) Nature 186: 136-137] and Boardman and Anderson [(1964) Nature 203: 166-167] had isolated PS II as a discrete biochemical entity. PS II was known not only to be the source of oxygen but of variable chlorophyll fluorescence [Duysens and Sweers (1963) In: Studies on Microalgae and Photosynthetic Bacteria, pp. 353-372. University of Tokyo Press, Tokyo] and delayed chlorophyll fluorescence [Arnold and Davidson (1954) J Gen Physiol 37: 677-684]. P680 had just been discovered [Döring et al. (1967) Z Naturforsch 22b: 639-644]. No wonder the 'black box of PS II' was described at that time by Bessel Kok and George Cheniae [Current Topics in Bioenergetics 1: 1-47 (1966)] as the 'inner sanctum of photosynthesis.' What a change in our level of understanding of PS II since then! The contributions of many talented scientists have unraveled the mechanisms and structural basis of PS II function and we are now very close to revealing the molecular details of the remarkable and thermodynamically demanding reaction which it catalyzes, namely the splitting of water into its elemental constituents. It has been a privilege to be involved in this journey.

  6. Implication of the Proton-Deuteron Radiative Capture for Big Bang Nucleosynthesis.

    PubMed

    Marcucci, L E; Mangano, G; Kievsky, A; Viviani, M

    2016-03-11

    The astrophysical S factor for the radiative capture d(p,γ)^{3}He in the energy range of interest for big bang nucleosynthesis (BBN) is calculated using an ab initio approach. The nuclear Hamiltonian retains both two- and three-nucleon interactions-the Argonne v_{18} and the Urbana IX, respectively. Both one- and many-body contributions to the nuclear current operator are included. The former retain for the first time, besides the 1/m leading order contribution (m is the nucleon mass), also the next-to-leading order term, proportional to 1/m^{3}. The many-body currents are constructed in order to satisfy the current conservation relation with the adopted Hamiltonian model. The hyperspherical harmonics technique is applied to solve the A=3 bound and scattering states. Particular attention is paid in this second case in order to obtain, in the energy range of BBN, an uncertainty on the astrophysical S factor of the order or below ∼1%. Then, in this energy range, the S factor is found to be ∼10% larger than the currently adopted values. Part of this increase (1%-3%) is due to the 1/m^{3} one-body operator, while the remaining is due to the new more accurate scattering wave functions. We have studied the implication of this new determination for the d(p,γ)^{3}He S factor on the deuterium primordial abundance. We find that the predicted theoretical value for ^{2}H/H is in excellent agreement with its experimental determination, using the most recent determination of the baryon density of the Planck experiment, and with a standard number of relativistic degrees of freedom N_{eff}=3.046 during primordial nucleosynthesis. This calls for a more accurate measurement of the astrophysical S factor in order to confirm the present predictions.

  7. QCD development in the early universe

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gromov, N. A., E-mail: gromov@dm.komisc.ru

    The high-energy limit of Quantum Chromodynamics is generated by the contraction of its gauge groups. Contraction parameters are taken identical with those of the Electroweak Model and tend to zero when energy increases. At the infinite energy limit all quarks lose masses and have only one color degree of freedom. The limit model represents the development of Quantum Chromodynamics in the early Universe from the Big Bang up to the end of several milliseconds.

  8. Origin of matter and space-time in the big bang

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mathews, G. J.; Kajino, T.; Yamazaki, D.

    We review the case for and against a bulk cosmic motion resulting from the quantum entanglement of our universe with the multiverse beyond our horizon. Within the current theory for the selection of the initial state of the universe from the landscape multiverse there is a generic prediction that pre-inflation quantum entanglement with other universes should give rise to a cosmic bulk flow with a correlation length of order horizon size and a velocity field relative to the expansion frame of the universe. Indeed, the parameters of this motion are are tightly constrained. A robust prediction can be deduced indicatingmore » that there should be an overall motion of of about 800 km/s relative to the background space time as defined by the cosmic microwave background (CMB). This talk will summarize the underlying theoretical motivation for this hypothesis. Of course our motion relative to the background space time (CMB dipole) has been known for decades and is generally attributed to the gravitational pull of the local super cluster. However, this cosmic peculiar velocity field has been recently deduced out to very large distances well beyond that of the local super cluster by using X-ray galaxy clusters as tracers of matter motion. This is achieved via the kinematic component of the Sunyaev-Zeldovich (KSZ) effect produced by Compton scattering of cosmic microwave background photons from the local hot intracluster gas. As such, this method measures peculiar velocity directly in the frame of the cluster. Similar attempts by our group and others have attempted to independently assess this bulk flow via Type la supernova redshifts. In this talk we will review the observation case for and against the existence of this bulk flow based upon the observations and predictions of the theory. If this interpretation is correct it has profound implications in that we may be observing for the first time both the physics that occurred before the big bang and the existence of the

  9. Big Bang, inflation, standard Physics… and the potentialities of new Physics and alternative cosmologies. Present statuts of observational and experimental Cosmology. Open questions and potentialities of alternative cosmologies

    NASA Astrophysics Data System (ADS)

    Gonzalez-Mestres, Luis

    2016-11-01

    A year ago, we wrote [1] that the field of Cosmology was undergoing a positive and constructive crisis. The possible development of more direct links between the Mathematical Physics aspects of cosmological patterns and the interpretation of experimental and observational results was particularly emphasized. Controversies on inflation are not really new, but in any case inflation is not required in pre-Big Bang models and the validity of the standard Big Bang + inflation + ΛCDM pattern has not by now been demonstrated by data. Planck has even explicitly reported the existence of "anomalies". Remembering the far-reaching work of Yoichiro Nambu published in 1959-61, it seems legitimate to underline the need for a cross-disciplinary approach in the presence of deep, unsolved theoretical problems concerning new domains of matter properties and of the physical world. The physics of a possible preonic vacuum and the associated cosmology constitute one of these domains. If the vacuum is made of superluminal preons (superbradyons), and if standard particles are vacuum excitations, how to build a suitable theory to describe the internal structure of such a vacuum at both local and cosmic level? Experimental programs (South Pole, Atacama, AUGER, Telescope Array…) and observational ones (Planck, JEM-EUSO…) devoted to the study of cosmic microwave background radiation (CMB) and of ultra-high energy cosmic rays (UHECR) are crucial to elucidate such theoretical interrogations and guide new phenomenological developments. Together with a brief review of the observational and experimental situation, we also examine the main present theoretical and phenomenological problems and point out the role new physics and alternative cosmologies can potentially play. The need for data analyses less focused a priori on the standard models of Particle Physics and Cosmology is emphasized in this discussion. An example of a new approach to both fields is provided by the pre-Big Bang pattern

  10. Big bounce, slow-roll inflation, and dark energy from conformal gravity

    NASA Astrophysics Data System (ADS)

    Gegenberg, Jack; Rahmati, Shohreh; Seahra, Sanjeev S.

    2017-02-01

    We examine the cosmological sector of a gauge theory of gravity based on the SO(4,2) conformal group of Minkowski space. We allow for conventional matter coupled to the spacetime metric as well as matter coupled to the field that gauges special conformal transformations. An effective vacuum energy appears as an integration constant, and this allows us to recover the late time acceleration of the Universe. Furthermore, gravitational fields sourced by ordinary cosmological matter (i.e. dust and radiation) are significantly weakened in the very early Universe, which has the effect of replacing the big bang with a big bounce. Finally, we find that this bounce is followed by a period of nearly exponential slow roll inflation that can last long enough to explain the large scale homogeneity of the cosmic microwave background.

  11. Nuclear and particle physics in the early universe

    NASA Technical Reports Server (NTRS)

    Schramm, D. N.

    1981-01-01

    Basic principles and implications of Big Bang cosmology are reviewed, noting the physical evidence of a previous universe temperature of 10,000 K and theoretical arguments such as grand unification decoupling indicating a primal temperature of 10 to the 15th eV. The Planck time of 10 to the -43rd sec after the Big Bang is set as the limit before which gravity was quantized and nothing is known. Gauge theories of elementary particle physics are reviewed for successful predictions of similarity in weak and electromagnetic interactions and quantum chromodynamic predictions for strong interactions. The large number of photons in the universe relative to the baryons is considered and the grand unified theories are cited as showing the existence of baryon nonconservation as an explanation. Further attention is given to quark-hadron phase transition, the decoupling for the weak interaction and relic neutrinos, and Big Bang nucleosynthesis.

  12. WMAP - A Glimpse of the Early Universe

    NASA Technical Reports Server (NTRS)

    Wollack, Edward

    2009-01-01

    The early Universe was incredibly hot, dense, and homogeneous. A powerful probe of this time is provided by the relic radiation which we refer to today as the Cosmic Microwave Background (CMB). Images produced from this light contain the earliest glimpse of the Universe after the "Big Bang" and the signature of the evolution of its contents. By exploiting these clues, precise constraints on the age, mass density, and geometry of the early Universe can be derived. The history of this intriguing cosmological detective story will be reviewed. Recent results from NASA's Wilkinson Microwave Anisotropy Probe (WMAP) will be presented.

  13. Big Questions: Missing Antimatter

    ScienceCinema

    Lincoln, Don

    2018-06-08

    Einstein's equation E = mc2 is often said to mean that energy can be converted into matter. More accurately, energy can be converted to matter and antimatter. During the first moments of the Big Bang, the universe was smaller, hotter and energy was everywhere. As the universe expanded and cooled, the energy converted into matter and antimatter. According to our best understanding, these two substances should have been created in equal quantities. However when we look out into the cosmos we see only matter and no antimatter. The absence of antimatter is one of the Big Mysteries of modern physics. In this video, Fermilab's Dr. Don Lincoln explains the problem, although doesn't answer it. The answer, as in all Big Mysteries, is still unknown and one of the leading research topics of contemporary science.

  14. Supersonic gas streams enhance the formation of massive black holes in the early universe

    NASA Astrophysics Data System (ADS)

    Hirano, Shingo; Hosokawa, Takashi; Yoshida, Naoki; Kuiper, Rolf

    2017-09-01

    Supermassive black holes existed less than a billion years after the Big Bang. Because black holes can grow at a maximum rate that depends on their current mass, it has been difficult to understand how such massive black holes could have formed so quickly. Hirano et al. developed simulations to show that streaming motions—velocity offsets between the gas and dark matter components—could have produced black holes with tens of thousands of solar masses in the early universe. That's big enough to grow into the supermassive black holes that we observe today.

  15. Steering Quantum Dynamics of a Two-Qubit System via Optimal Bang-Bang Control

    NASA Astrophysics Data System (ADS)

    Hu, Juju; Ke, Qiang; Ji, Yinghua

    2018-02-01

    The optimization of control time for quantum systems has been an important field of control science attracting decades of focus, which is beneficial for efficiency improvement and decoherence suppression caused by the environment. Based on analyzing the advantages and disadvantages of the existing Lyapunov control, using a bang-bang optimal control technique, we investigate the fast state control in a closed two-qubit quantum system, and give three optimized control field design methods. Numerical simulation experiments indicate the effectiveness of the methods. Compared to the standard Lyapunov control or standard bang-bang control method, the optimized control field design methods effectively shorten the state control time and avoid high-frequency oscillation that occurs in bang-bang control.

  16. Consensus on items and quantities of clinical equipment required to deal with a mass casualties big bang incident: a national Delphi study.

    PubMed

    Duncan, Edward A S; Colver, Keith; Dougall, Nadine; Swingler, Kevin; Stephenson, John; Abhyankar, Purva

    2014-02-22

    Major short-notice or sudden impact incidents, which result in a large number of casualties, are rare events. However health services must be prepared to respond to such events appropriately. In the United Kingdom (UK), a mass casualties incident is when the normal response of several National Health Service organizations to a major incident, has to be supported with extraordinary measures. Having the right type and quantity of clinical equipment is essential, but planning for such emergencies is challenging. To date, the equipment stored for such events has been selected on the basis of local clinical judgment and has evolved without an explicit evidence-base. This has resulted in considerable variations in the types and quantities of clinical equipment being stored in different locations. This study aimed to develop an expert consensus opinion of the essential items and minimum quantities of clinical equipment that is required to treat 100 people at the scene of a big bang mass casualties event. A three round modified Delphi study was conducted with 32 experts using a specifically developed web-based platform. Individuals were invited to participate if they had personal clinical experience of providing a pre-hospital emergency medical response to a mass casualties incident, or had responsibility in health emergency planning for mass casualties incidents and were in a position of authority within the sphere of emergency health planning. Each item's importance was measured on a 5-point Likert scale. The quantity of items required was measured numerically. Data were analyzed using nonparametric statistics. Experts achieved consensus on a total of 134 items (54%) on completion of the study. Experts did not reach consensus on 114 (46%) items. Median quantities and interquartile ranges of the items, and their recommended quantities were identified and are presented. This study is the first to produce an expert consensus on the items and quantities of clinical equipment

  17. Big Questions: Missing Antimatter

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lincoln, Don

    2013-08-27

    Einstein's equation E = mc2 is often said to mean that energy can be converted into matter. More accurately, energy can be converted to matter and antimatter. During the first moments of the Big Bang, the universe was smaller, hotter and energy was everywhere. As the universe expanded and cooled, the energy converted into matter and antimatter. According to our best understanding, these two substances should have been created in equal quantities. However when we look out into the cosmos we see only matter and no antimatter. The absence of antimatter is one of the Big Mysteries of modern physics.more » In this video, Fermilab's Dr. Don Lincoln explains the problem, although doesn't answer it. The answer, as in all Big Mysteries, is still unknown and one of the leading research topics of contemporary science.« less

  18. HD 140283: A STAR IN THE SOLAR NEIGHBORHOOD THAT FORMED SHORTLY AFTER THE BIG BANG

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bond, Howard E.; Nelan, Edmund P.; VandenBerg, Don A.

    HD 140283 is an extremely metal-deficient and high-velocity subgiant in the solar neighborhood, having a location in the Hertzsprung-Russell diagram where absolute magnitude is most sensitive to stellar age. Because it is bright, nearby, unreddened, and has a well-determined chemical composition, this star avoids most of the issues involved in age determinations for globular clusters. Using the Fine Guidance Sensors on the Hubble Space Telescope, we have measured a trigonometric parallax of 17.15 {+-} 0.14 mas for HD 140283, with an error one-fifth of that determined by the Hipparcos mission. Employing modern theoretical isochrones, which include effects of helium diffusion,more » revised nuclear reaction rates, and enhanced oxygen abundance, we use the precise distance to infer an age of 14.46 {+-} 0.31 Gyr. The quoted error includes only the uncertainty in the parallax, and is for adopted surface oxygen and iron abundances of [O/H] = -1.67 and [Fe/H] = -2.40. Uncertainties in the stellar parameters and chemical composition, especially the oxygen content, now contribute more to the error budget for the age of HD 140283 than does its distance, increasing the total uncertainty to about {+-}0.8 Gyr. Within the errors, the age of HD 140283 does not conflict with the age of the Universe, 13.77 {+-} 0.06 Gyr, based on the microwave background and Hubble constant, but it must have formed soon after the big bang.« less

  19. Hydro-gravitational-dynamics cosmology is crucial to astrobiology and the biological big bang at two million years

    NASA Astrophysics Data System (ADS)

    Gibson, Carl H.

    2015-09-01

    Hydro-Gravitational-Dynamics (HGD) cosmology predicts that the 1012 s (30 Kyr) H-He4 plasma protogalaxies become, by viscous fragmentation, proto-globular-star-cluster PGC clumps of a trillion small planets, at the 1013 s transition to gas. Larger planets and stars result from mergers of these hot 3000 K hydrogen planets in the PGCs. Stardust oxides of life chemicals C, N, O, Fe, Si seed the planets when the stars explode as supernovae. Hydrogen reduces the metal oxides and silicates to metal and rocky planet cores with massive hot water oceans at critical water temperature 647 K in which organic chemistry and life can develop. Because information is continually exchanged between the merging planets, they form a cosmic soup. The biological big bang occurs between 2 Myr when liquid water rains hot deep oceans in the cooling cosmos, and 8 Myr when the oceans freeze6. Thus, HGD cosmology explains the Hoyle/Wickramasinghe concept of cometary panspermia by giving a vast, hot, nourishing, cosmological primordial soup for abiogenesis, and the means for transmitting the resulting life forms and their evolving RNA/DNA mechanisms widely throughout the universe. A primordial astrophysical basis is provided for astrobiology by HGD cosmology. Concordance ΛCDMHC cosmology is rendered obsolete by the observation of complex life on Earth.

  20. Classical and quantum Big Brake cosmology for scalar field and tachyonic models

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kamenshchik, A. Yu.; Manti, S.

    We study a relation between the cosmological singularities in classical and quantum theory, comparing the classical and quantum dynamics in some models possessing the Big Brake singularity - the model based on a scalar field and two models based on a tachyon-pseudo-tachyon field . It is shown that the effect of quantum avoidance is absent for the soft singularities of the Big Brake type while it is present for the Big Bang and Big Crunch singularities. Thus, there is some kind of a classical - quantum correspondence, because soft singularities are traversable in classical cosmology, while the strong Big Bangmore » and Big Crunch singularities are not traversable.« less

  1. Unsolved Mysteries of Science: A Mind-Expanding Journey through a Universe of Big Bangs, Particle Waves, and Other Perplexing Concepts

    NASA Astrophysics Data System (ADS)

    Malone, John

    2001-08-01

    A LIVELY EXPLORATION OF THE BIGGEST QUESTIONS IN SCIENCE How Did the Universe Begin? The Big Bang has been the accepted theory for decades, but does it explain everything? How Did Life on Earth Get Started? What triggered the cell division that started the evolutionary chain? Did life come from outer space, buried in a chunk of rock? What is Gravity? Newton's apple just got the arguments started, Einstein made things more complicated. Just how does gravity fit in with quantum theory? What Is the Inside of the Earth Like? What exactly is happening beneath our feet, and can we learn enough to help predict earthquakes and volcanic eruptions? How Do We Learn Language? Is language acquisition an inborn biological ability, or does every child have to start from scratch? Is There a Missing Link? The story of human evolution is not complete. In addition to hoaxes such as "Piltdown Man" and extraordinary finds such as "Lucy," many puzzles remain. What, in the end, do we mean by a "missing link"?

  2. Solving fuel-optimal low-thrust orbital transfers with bang-bang control using a novel continuation technique

    NASA Astrophysics Data System (ADS)

    Zhu, Zhengfan; Gan, Qingbo; Yang, Xin; Gao, Yang

    2017-08-01

    We have developed a novel continuation technique to solve optimal bang-bang control for low-thrust orbital transfers considering the first-order necessary optimality conditions derived from Lawden's primer vector theory. Continuation on the thrust amplitude is mainly described in this paper. Firstly, a finite-thrust transfer with an ;On-Off-On; thrusting sequence is modeled using a two-impulse transfer as initial solution, and then the thrust amplitude is decreased gradually to find an optimal solution with minimum thrust. Secondly, the thrust amplitude is continued from its minimum value to positive infinity to find the optimal bang-bang control, and a thrust switching principle is employed to determine the control structure by monitoring the variation of the switching function. In the continuation process, a bifurcation of bang-bang control is revealed and the concept of critical thrust is proposed to illustrate this phenomenon. The same thrust switching principle is also applicable to the continuation on other parameters, such as transfer time, orbital phase angle, etc. By this continuation technique, fuel-optimal orbital transfers with variable mission parameters can be found via an automated algorithm, and there is no need to provide an initial guess for the costate variables. Moreover, continuation is implemented in the solution space of bang-bang control that is either optimal or non-optimal, which shows that a desired solution of bang-bang control is obtained via continuation on a single parameter starting from an existing solution of bang-bang control. Finally, numerical examples are presented to demonstrate the effectiveness of the proposed continuation technique. Specifically, this continuation technique provides an approach to find multiple solutions satisfying the first-order necessary optimality conditions to the same orbital transfer problem, and a continuation strategy is presented as a preliminary approach for solving the bang-bang control of many

  3. 'Big Bang' tomography as a new route to atomic-resolution electron tomography.

    PubMed

    Van Dyck, Dirk; Jinschek, Joerg R; Chen, Fu-Rong

    2012-06-13

    Until now it has not been possible to image at atomic resolution using classical electron tomographic methods, except when the target is a perfectly crystalline nano-object imaged along a few zone axes. The main reasons are that mechanical tilting in an electron microscope with sub-ångström precision over a very large angular range is difficult, that many real-life objects such as dielectric layers in microelectronic devices impose geometrical constraints and that many radiation-sensitive objects such as proteins limit the total electron dose. Hence, there is a need for a new tomographic scheme that is able to deduce three-dimensional information from only one or a few projections. Here we present an electron tomographic method that can be used to determine, from only one viewing direction and with sub-ångström precision, both the position of individual atoms in the plane of observation and their vertical position. The concept is based on the fact that an experimentally reconstructed exit wave consists of the superposition of the spherical waves that have been scattered by the individual atoms of the object. Furthermore, the phase of a Fourier component of a spherical wave increases with the distance of propagation at a known 'phase speed'. If we assume that an atom is a point-like object, the relationship between the phase and the phase speed of each Fourier component is linear, and the distance between the atom and the plane of observation can therefore be determined by linear fitting. This picture has similarities with Big Bang cosmology, in which the Universe expands from a point-like origin such that the distance of any galaxy from the origin is linearly proportional to the speed at which it moves away from the origin (Hubble expansion). The proof of concept of the method has been demonstrated experimentally for graphene with a two-layer structure and it will work optimally for similar layered materials, such as boron nitride and molybdenum disulphide.

  4. Bang-bang Model for Regulation of Local Blood Flow

    PubMed Central

    Golub, Aleksander S.; Pittman, Roland N.

    2013-01-01

    The classical model of metabolic regulation of blood flow in muscle tissue implies the maintenance of basal tone in arterioles of resting muscle and their dilation in response to exercise and/or tissue hypoxia via the evoked production of vasodilator metabolites by myocytes. A century-long effort to identify specific metabolites responsible for explaining active and reactive hyperemia has not been successful. Furthermore, the metabolic theory is not compatible with new knowledge on the role of physiological radicals (e.g., nitric oxide, NO, and superoxide anion, O2−) in the regulation of microvascular tone. We propose a model of regulation in which muscle contraction and active hyperemia are considered the physiologically normal state. We employ the “bang-bang” or “on/off” regulatory model which makes use of a threshold and hysteresis; a float valve to control the water level in a tank is a common example of this type of regulation. Active bang-bang regulation comes into effect when the supply of oxygen and glucose exceeds the demand, leading to activation of membrane NADPH oxidase, release of O2− into the interstitial space and subsequent neutralization of the interstitial NO. Switching arterioles on/off when local blood flow crosses the threshold is realized by a local cell circuit with the properties of a bang-bang controller, determined by its threshold, hysteresis and dead-band. This model provides a clear and unambiguous interpretation of the mechanism to balance tissue demand with a sufficient supply of nutrients and oxygen. PMID:23441827

  5. COBE - New sky maps of the early universe

    NASA Technical Reports Server (NTRS)

    Smoot, G. F.

    1991-01-01

    This paper presents early results obtained from the first six months of measurements of the cosmic microwave background (CMB) by instruments aboard NASA's Cosmic Background Explorer (COBE) satellite and discusses the implications for cosmology. The three instruments: FIRAS, DMR, and DIRBE have operated well and produced significant new results. The FIRAS measurement of the CMB spectrum supports the standard big bang nucleosynthesis model. The maps made from the DMR instrument measurements show a surprisingly smooth early universe. The measurements are sufficiently precise that we must pay careful attention to potential systematic errors. The maps of galactic and local emission produced by the DIRBE instrument will be needed to identify foregrounds from extragalactic emission and thus to interpret the terms of events in the early universe.

  6. New effects of a long-lived negatively charged massive particle on big bang nucleosynthesis

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kusakabe, Motohiko; Kim, K. S.; Cheoun, Myung-Ki

    Primordial {sup 7}Li abundance inferred from observations of metal-poor stars is a factor of about 3 lower than the theoretical value of standard big bang nucleosynthesis (BBN) model. One of the solutions to the Li problem is {sup 7}Be destruction during the BBN epoch caused by a long-lived negatively charged massive particle, X{sup −}. The particle can bind to nuclei, and X-bound nuclei (X-nuclei) can experience new reactions. The radiative X{sup −} capture by {sup 7}Be nuclei followed by proton capture of the bound state of {sup 7}Be and X{sup −} ({sup 7}Be{sub x}) is a possible {sup 7}Be destructionmore » reaction. Since the primordial abundance of {sup 7}Li originates mainly from {sup 7}Li produced via the electron capture of {sup 7}Be after BBN, the {sup 7}Be destruction provides a solution to the {sup 7}Li problem. We suggest a new route of {sup 7}Be{sub x} formation, that is the {sup 7}Be charge exchange at the reaction of {sup 7}Be{sup 3+} ion and X{sup −}. The formation rate depends on the ionization fraction of {sup 7}Be{sup 3+} ion, the charge exchange cross section of {sup 7}Be{sup 3+}, and the probability that excited states {sup 7}Be{sub x}* produced at the charge exchange are converted to the ground state. We find that this reaction can be equally important as or more important than ordinary radiative recombination of {sup 7}Be and X{sup −}. The effect of this new route is shown in a nuclear reaction network calculation.« less

  7. Construction of nonsingular pre-big-bang and ekpyrotic cosmologies and the resulting density perturbations

    NASA Astrophysics Data System (ADS)

    Tsujikawa, Shinji; Brandenberger, Robert; Finelli, Fabio

    2002-10-01

    We consider the construction of nonsingular pre-big-bang and ekpyrotic type cosmological models realized by the addition to the action of specific higher-order terms stemming from quantum corrections. We study models involving general relativity coupled to a single scalar field with a potential motivated by the ekpyrotic scenario. We find that the inclusion of the string loop and quantum correction terms in the string frame makes it possible to obtain solutions of the variational equations which are nonsingular and bouncing in the Einstein frame, even when a negative exponential potential is present, as is the case in the ekpyrotic scenario. This allows us to discuss the evolution of cosmological perturbations without the need to invoke matching conditions between two Einstein universes, one representing the contracting branch, the second the expanding branch. We analyze the spectra of perturbations produced during the bouncing phase and find that the spectrum of curvature fluctuations in the model proposed originally to implement the ekpyrotic scenario has a large blue tilt (nR=3). Except for instabilities introduced on small scales, the result agrees with what is obtained by imposing continuity of the induced metric and of the extrinsic curvature across a constant scalar field (up to k2 corrections equal to the constant energy density) matching surface between the contracting and the expanding Einstein universes. We also discuss nonsingular cosmological solutions obtained when a Gauss-Bonnet term with a coefficient suitably dependent on the scalar matter field is added to the action in the Einstein frame with a potential for the scalar field present. In this scenario, nonsingular solutions are found which start in an asymptotically flat state, undergo a period of superexponential inflation, and end with a graceful exit. The spectrum of fluctuations is also calculated in this case.

  8. The Big 5: Teacher Knowledge and Skill Acquisition in Early Literacy

    ERIC Educational Resources Information Center

    Vesay, Joanne P.; Gischlar, Karen L.

    2013-01-01

    In this study, the investigators surveyed 215 early childhood educators throughout New Jersey and eastern Pennsylvania to determine teacher knowledge and training in early literacy instruction, with a focus on The 5 Big Ideas in Reading as identified by the National Reading Panel: phonological awareness, accuracy and fluency, alphabetic principle,…

  9. WMAP - A Portrait of the Early Universe

    NASA Technical Reports Server (NTRS)

    Wollack, Edward J.

    2008-01-01

    A host of astrophysical observations suggest that early Universe was incredibly hot, dense, and homogeneous. A powerful probe of this time is provided by the relic radiation which we refer to today as the Cosmic Microwave Background (CMB). Images produced from this light contain the earliest glimpse of the Universe after the 'Big Bang' and the signature of the evolution of its contents. By exploiting these clues, constraints on the age, mass density, and geometry of the early Universe can be derived. A brief history of the evolution of the microwave radiometer systems and map making approaches used in advancing these aspects our understanding of cosmological will be reviewed. In addition, an overview of the results from NASA's Wilkinson Microwave Anisotropy (WMAP) will be presented.

  10. Little Kids, Big Worries: Stress-Busting Tips for Early Childhood Classrooms

    ERIC Educational Resources Information Center

    Honig, Alice Sterling

    2010-01-01

    Research shows that stress in the crucial early years of a child's life can pose dramatic, lasting challenges to development, learning, and behavior. This is the practical book early childhood professionals need to recognize stress in young children--and intervene with proven relief strategies before pressures turn into big problems. Developed by…

  11. [Fatal alveolar haemorrhage following a "bang" of cannabis].

    PubMed

    Grassin, F; André, M; Rallec, B; Combes, E; Vinsonneau, U; Paleiron, N

    2011-09-01

    The new methods of cannabis consumption (home made water pipe or "bang") may be responsible for fatal respiratory complications. We present a case, with fatal outcome, of a man of 19 years with no previous history other than an addiction to cannabis using "bang". He was admitted to intensive care with acute dyspnoea. A CT scan showed bilateral, diffuse alveolar shadowing. He was anaemic with an Hb of 9.3g/l. Bronchoalveolar lavage revealed massive alveolar haemorrhage. Investigations for infection and immunological disorder were negative and toxicology was negative except for cannabis. Antibiotic treatment was given and favourable progress allowed early discharge. Death occurred 15 days later due to alveolar haemorrhage following a further "bang" of cannabis. Autopsy showed toxic alveolar haemorrhage. The probable mechanism is pulmonary damage due to acid anhydrides released by the incomplete combustion of cannabis in contact with plastic. These acids have a double effect on the lungs: a direct toxicity with severe inflammation of the mucosa leading to alveolar haemorrhage and subsequently the acid anhydrides may lead to the syndrome of intra-alveolar haemorrhage and anaemia described in occupational lung diseases by Herbert in Oxford in 1979. It manifests itself by haemoptysis and intravascular haemolysis. We draw attention to the extremely serious potential consequences of new methods of using cannabis, particularly the use of "bang" in homemade plastic materials. Copyright © 2011 SPLF. Published by Elsevier Masson SAS. All rights reserved.

  12. HD 140283: A Star in the Solar Neighborhood that Formed Shortly after the Big Bang

    NASA Astrophysics Data System (ADS)

    Bond, Howard E.; Nelan, Edmund P.; VandenBerg, Don A.; Schaefer, Gail H.; Harmer, Dianne

    2013-03-01

    HD 140283 is an extremely metal-deficient and high-velocity subgiant in the solar neighborhood, having a location in the Hertzsprung-Russell diagram where absolute magnitude is most sensitive to stellar age. Because it is bright, nearby, unreddened, and has a well-determined chemical composition, this star avoids most of the issues involved in age determinations for globular clusters. Using the Fine Guidance Sensors on the Hubble Space Telescope, we have measured a trigonometric parallax of 17.15 ± 0.14 mas for HD 140283, with an error one-fifth of that determined by the Hipparcos mission. Employing modern theoretical isochrones, which include effects of helium diffusion, revised nuclear reaction rates, and enhanced oxygen abundance, we use the precise distance to infer an age of 14.46 ± 0.31 Gyr. The quoted error includes only the uncertainty in the parallax, and is for adopted surface oxygen and iron abundances of [O/H] = -1.67 and [Fe/H] = -2.40. Uncertainties in the stellar parameters and chemical composition, especially the oxygen content, now contribute more to the error budget for the age of HD 140283 than does its distance, increasing the total uncertainty to about ±0.8 Gyr. Within the errors, the age of HD 140283 does not conflict with the age of the Universe, 13.77 ± 0.06 Gyr, based on the microwave background and Hubble constant, but it must have formed soon after the big bang. Based in part on observations made with the NASA/ESA Hubble Space Telescope, obtained by the Space Telescope Science Institute. STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

  13. Anisotropic, nonsingular early universe model leading to a realistic cosmology

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dechant, Pierre-Philippe; Lasenby, Anthony N.; Hobson, Michael P.

    2009-02-15

    We present a novel cosmological model in which scalar field matter in a biaxial Bianchi IX geometry leads to a nonsingular 'pancaking' solution: the hypersurface volume goes to zero instantaneously at the 'big bang', but all physical quantities, such as curvature invariants and the matter energy density remain finite, and continue smoothly through the big bang. We demonstrate that there exist geodesics extending through the big bang, but that there are also incomplete geodesics that spiral infinitely around a topologically closed spatial dimension at the big bang, rendering it, at worst, a quasiregular singularity. The model is thus reminiscent ofmore » the Taub-NUT vacuum solution in that it has biaxial Bianchi IX geometry and its evolution exhibits a dimensionality reduction at a quasiregular singularity; the two models are, however, rather different, as we will show in a future work. Here we concentrate on the cosmological implications of our model and show how the scalar field drives both isotropization and inflation, thus raising the question of whether structure on the largest scales was laid down at a time when the universe was still oblate (as also suggested by [T. S. Pereira, C. Pitrou, and J.-P. Uzan, J. Cosmol. Astropart. Phys. 9 (2007) 6.][C. Pitrou, T. S. Pereira, and J.-P. Uzan, J. Cosmol. Astropart. Phys. 4 (2008) 4.][A. Guemruekcueoglu, C. Contaldi, and M. Peloso, J. Cosmol. Astropart. Phys. 11 (2007) 005.]). We also discuss the stability of our model to small perturbations around biaxiality and draw an analogy with cosmological perturbations. We conclude by presenting a separate, bouncing solution, which generalizes the known bouncing solution in closed FRW universes.« less

  14. SETI as a part of Big History

    NASA Astrophysics Data System (ADS)

    Maccone, Claudio

    2014-08-01

    Big History is an emerging academic discipline which examines history scientifically from the Big Bang to the present. It uses a multidisciplinary approach based on combining numerous disciplines from science and the humanities, and explores human existence in the context of this bigger picture. It is taught at some universities. In a series of recent papers ([11] through [15] and [17] through [18]) and in a book [16], we developed a new mathematical model embracing Darwinian Evolution (RNA to Humans, see, in particular, [17] and Human History (Aztecs to USA, see [16]) and then we extrapolated even that into the future up to ten million years (see 18), the minimum time requested for a civilization to expand to the whole Milky Way (Fermi paradox). In this paper, we further extend that model in the past so as to let it start at the Big Bang (13.8 billion years ago) thus merging Big History, Evolution on Earth and SETI (the modern Search for ExtraTerrestrial Intelligence) into a single body of knowledge of a statistical type. Our idea is that the Geometric Brownian Motion (GBM), so far used as the key stochastic process of financial mathematics (Black-Sholes models and related 1997 Nobel Prize in Economics!) may be successfully applied to the whole of Big History. In particular, in this paper we derive Big History Theory based on GBMs: just as the GBM is the “movie” unfolding in time, so the Statistical Drake Equation is its “still picture”, static in time, and the GBM is the time-extension of the Drake Equation. Darwinian Evolution on Earth may be easily described as an increasing GBM in the number of living species on Earth over the last 3.5 billion years. The first of them was RNA 3.5 billion years ago, and now 50

  15. Resonant Production of Sterile Neutrinos in the Early Universe

    NASA Astrophysics Data System (ADS)

    Gilbert, Lauren; Grohs, Evan; Fuller, George M.

    2016-06-01

    This study examines the cosmological impacts of a light resonantly produced sterile neutrino in the early universe. Such a neutrino could be produced through lepton number-driven Mikheyev-Smirnov-Wolfenstein (MSW) conversion of active neutrinos around big bang nucleosynthesis (BBN), resulting in a non-thermal spectrum of both sterile and electron neutrinos. During BBN, the neutron-proton ratio depends sensitively on the electron neutrino flux. If electron neutrinos are being converted to sterile neutrinos, this makes the n/p ratio a probe of possible new physics. We use observations of primordial Yp and D/H to place limits on this process.

  16. Experimental challenge to the big-bang nucleosynthesis - Cosmological 7Li problem in BBN

    NASA Astrophysics Data System (ADS)

    Kubono, S.; Kawabata, T.; Hou, S. Q.; He, J. J.

    2018-04-01

    The primordial nucleosynthesis(BBN) right after the big bang (BB) is one of the key elements that basically support the BB model. The BBN is well known that it produced primarily light elements, and explains reasonably most of the elemental abundances. However, there remains an interesting and serious question. That is so called the cosmological 7Li problem in BBN. The BBN simulations using nuclear data together with the recent detailed micro-wave background measurements explain most of the light elements including D, 4He, etc, but the 7Li abundance is over predicted roughly by a factor of three. Although this problem should be investigated in all the fields relevant including physics and astronomical observations, I will concentrate my discussion on the nuclear physics side, especially the recent progress for studying the last possible major destruction process of 7Be, the 7Be(n,α)4He reaction, which would reduce the overproduction if the cross section is large. There are several efforts recently made for the 7Be(n,α)4He reaction in the world. A new theoretical estimate was made compiling all available data of the mirror reaction 7Li(p,α)4He, suggesting about one order smaller reaction rate than the ones currently being used (Wagoner rate). The n-TOF group measured some part of the s-wave components of the reaction, suggesting that the s-wave contributions are much smaller than the Wagoner rate. The p-wave component was measured clearly at RCNP, Osaka using the time-reverse reaction 4He(α,n)7Be, indicating that the p-wave contribution dominates at the effective temperature region for the BBN. However, the sum of the s-wave and p-wave contributions is about one order of magnitude smaller than the Wagoner rate. It should be of great interest to confirm by the indirect method, Trojan-Horse method to deduce cross sections at the effective temperature region, and also see the cross sections for a wider energy range systematically, which is under way by the BELICOS

  17. Big Science for Growing Minds: Constructivist Classrooms for Young Thinkers. Early Childhood Education Series

    ERIC Educational Resources Information Center

    Brooks, Jacqueline Grennon

    2011-01-01

    Strong evidence from recent brain research shows that the intentional teaching of science is crucial in early childhood. "Big Science for Growing Minds" describes a groundbreaking curriculum that invites readers to rethink science education through a set of unifying concepts or "big ideas." Using an integrated learning approach, the author shows…

  18. Using Supercomputers to Probe the Early Universe

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Giorgi, Elena Edi

    For decades physicists have been trying to decipher the first moments after the Big Bang. Using very large telescopes, for example, scientists scan the skies and look at how fast galaxies move. Satellites study the relic radiation left from the Big Bang, called the cosmic microwave background radiation. And finally, particle colliders, like the Large Hadron Collider at CERN, allow researchers to smash protons together and analyze the debris left behind by such collisions. Physicists at Los Alamos National Laboratory, however, are taking a different approach: they are using computers. In collaboration with colleagues at University of California San Diego,more » the Los Alamos researchers developed a computer code, called BURST, that can simulate conditions during the first few minutes of cosmological evolution.« less

  19. The Biggest Bangs Since the Big Bang: Unveiling Mergers of Galaxy Clusters with Radio Halos/Relics Using X-ray Temperature Maps

    NASA Astrophysics Data System (ADS)

    Burns, Jack

    Galaxy clusters are assembled through large and small mergers which are the most energetic events ( bangs ) since the Big Bang. Cluster mergers stir the ICM creating shocks and turbulence which are illuminated by Mpc-sized radio features called relics and halos. These shocks heat the ICM and are detected in x-rays via thermal emission. Disturbed morphologies in x-ray surface brightness and temperatures are direct evidence for cluster mergers. In the radio, relics (in the outskirts of the clusters) and halos (located near the cluster core) are clear signposts of recent mergers. Our recent cosmological simulations suggest that around a merger event, radio emission peaks very sharply (and briefly) while the x-ray emission rises and decays slowly. Hence, a sample of galaxy clusters that shows both luminous x-ray and radio relics/halos are clear candidates for very recent mergers. We propose to analyze a unique sample of 48 galaxy clusters with (i) known radio relics and/or halos and (ii) significant archival x-ray observations (e 50 ksec) from Chandra and/or XMM. We will use a new x-ray data analysis pipeline, implemented on a parallelprocessor supercomputer, to create x-ray surface brightness, high fidelity temperature, and pressure maps of these clusters in order to study merging activity. In addition, we will use a control sample of clusters from the HIFLUGCS catalog which do not show radio relics/halos or any significant x-ray surface brightness substructure, thus devoid of recent mergers. The temperature maps will be made using 3 different map-making techniques: Weighted Voronoi Tessellation, Adaptive Circular Binning, and Contour Binning. We also plan to use archival Suzaku data for 22 clusters in our sample and study the x-ray temperatures at the outskirts of the clusters. All 48 clusters have archival radio data at d1.4 GHz which will be re-analyzed using advanced algorithms in NRAO s CASA software. We also have new radio data on a subset of these clusters and

  20. The Early Growth of the First Black Holes

    NASA Astrophysics Data System (ADS)

    Johnson, Jarrett L.; Haardt, Francesco

    2016-03-01

    With detections of quasars powered by increasingly massive black holes at increasingly early times in cosmic history over the past decade, there has been correspondingly rapid progress made on the theory of early black hole formation and growth. Here, we review the emerging picture of how the first massive black holes formed from the primordial gas and then grew to supermassive scales. We discuss the initial conditions for the formation of the progenitors of these seed black holes, the factors dictating the initial masses with which they form, and their initial stages of growth via accretion, which may occur at super-Eddington rates. Finally, we briefly discuss how these results connect to large-scale simulations of the growth of supermassive black holes in the first billion years after the Big Bang.

  1. A case study of an extremely luminous, highly spatially extended starburst only 1.7Gyr after the Big Bang

    NASA Astrophysics Data System (ADS)

    Farrah, Duncan

    2017-08-01

    Luminous starbursts, systems with SFRs exceeding 1000Msun yr-1, are predicted to be extremely rare at z>3. However, recent observations find such systems at rates of tens to hundreds above predictions. This discrepancy is extremely difficult to explain. Case studies of such luminous starbursts are thus of profound importance to understand how star formation is triggered and quenched at z > 3, and help reconcile models with observations. Our group has been intensively studying the quasar SDSS J160705.16, at z = 3.65 (or 1.7Gyr after the Big Bang). This quasar is an excellent case study of luminous star formation at z > 3, and how AGN activity may affect such star formation. SDSS J160705.16 harbors both a broad-line, luminous quasar and an extremely high star formation rate, with an AGN luminosity of 10^47 ergs s-1 and an SFR of 2000 Msol yr-1. Sub-mm interferometry has further revealed that the star formation is highly spatially extended on scales up to 40kpc. Furthermore, VLA observations show an emerging 4kpc radio jet.We here propose WFC3 imaging with the following goals: (1) to set precise constraints on any lensing magnification, (2) to determine the morphology and color structure of the extended star formation, (3) to compare the optical morphology of the star formation to that seen in the sub-mm data, and (4) to search for evidence that SDSS J160705.16 resides in a protocluster.

  2. Reaction of the French population to the supersonic bang

    NASA Technical Reports Server (NTRS)

    Bremond, J.

    1980-01-01

    A discussion of a survey dealing with the supersonic bang is presented. Topics include the position the bang has in today's pollution, annoyance caused by the bang and its dependence on sociological and psychological variables, and whether or not the perception of the ban is objective. Other questions raised are whether the frequency of exposure to the bang has an influence on attitudes and does the sensitivity to or annoyance from the bang have a linear increase with the frequency.

  3. Big angiotensin-25: a novel glycosylated angiotensin-related peptide isolated from human urine.

    PubMed

    Nagata, Sayaka; Hatakeyama, Kinta; Asami, Maki; Tokashiki, Mariko; Hibino, Hajime; Nishiuchi, Yuji; Kuwasako, Kenji; Kato, Johji; Asada, Yujiro; Kitamura, Kazuo

    2013-11-29

    The renin-angiotensin system (RAS), including angiotensin II (Ang II), plays an important role in the regulation of blood pressure and body fluid balance. Consequently, the RAS has emerged as a key target for treatment of kidney and cardiovascular disease. In a search for bioactive peptides using an antibody against the N-terminal portion of Ang II, we identified and characterized a novel angiotensin-related peptide from human urine as a major molecular form. We named the peptide Big angiotensin-25 (Bang-25) because it consists of 25 amino acids with a glycosyl chain and added cysteine. Bang-25 is rapidly cleaved by chymase to Ang II, but is resistant to cleavage by renin. The peptide is abundant in human urine and is present in a wide range of organs and tissues. In particular, immunostaining of Bang-25 in the kidney is specifically localized to podocytes. Although the physiological function of Bang-25 remains uncertain, our findings suggest it is processed from angiotensinogen and may represent an alternative, renin-independent path for Ang II synthesis in tissue. Copyright © 2013. Published by Elsevier Inc.

  4. X-ray Emission from Early Universe Analog Galaxies

    NASA Astrophysics Data System (ADS)

    Brorby, Matthew; Kaaret, Philip; Prestwich, Andrea H.; Mirabel, I. Felix; Feng, Hua

    2016-01-01

    Around 300,000 years after the Big Bang, the Universe had cooled enough to combine and form neutral atoms. This signified the beginning of a time known as the Dark Ages. Neutral matter began to fall into the dark matter gravitational wells that were seeded after the initial moments of the Big Bang. As the first stars and galaxies formed within these gravitational wells, the surrounding baryonic matter was heated and started to ionize. The source of energetic photons that heated and reionized the early Universe remains uncertain. Early galaxies had low metallicity and recent population synthesis calculations suggest that the number and luminosity of high-mass X-ray binaries are enhanced in star-forming galaxies with low metallicity, offering a potentially important and previously overlooked source of heating and reionization. Here we examine two types of local galaxies that have been shown to be good analogs to the early galaxies in the Universe: Blue compact dwarf galaxies (BCDs) and Lyman Break Analogs (LBAs).A BCD is defined by its blue optical colors, low metallicities, and physically small size. This makes BCDs the best available local analogs for early star formation. We analyzed data from a sample of 25 metal-poor BCDs and compared our results with those of near-solar metallicity galaxies. Using a Bayesian approach, we showed that the X-ray luminosity function for the low-metallicity BCDs is significantly elevated relative to the XLF for near-solar metallicity galaxies.Larger, gas-rich galaxies may have formed shortly after these first galaxies. These larger galaxies would be similar in their properties to the high-redshift Lyman break galaxies (LBGs). LBAs provide the best local comparison to the LBGs. We studied a sample of 10 LBAs in order to measure the relation between star formation rate and X-ray luminosity for these galaxies. We found that for LBAs with intermediate sub-solar metallicities, there is enhanced X-ray emission relative to the expected

  5. Cross-section measurement of 7Be + d and 7Li + d with ANASEN* and its implication in the Big Bang Nucleosynthesis

    NASA Astrophysics Data System (ADS)

    Rijal, Nabin; Wiedenhover, Ingo; Baby, L. T.; Blackmon, J. C.; Rogachev, G.

    2017-09-01

    Astrophysically observed 7Li is 3 -4 times less than predicted amount by current models of Standard Big Bang Nucleosynthesis (SBBN). The nuclear reaction 7Be + d at energies relevant to SBBN, has been discussed as a possible means to destroy mass-7 nuclei. We investigated the 7Be + d and it's mirror nuclear reaction 7Li + d at SBBN energies using a radioactive 7Be and stable 7Li beam both in deuterium gas target inside ANASEN at Florida State University. ANASEN is an active target detector system which tracks the charged particles using a position sensitive proportional counter and 24-SX3 and 4-QQQ position sensitive Silicon detectors, all backed up by CsI detectors. ANASEN has wide angular coverage. The experiment measures a continuous excitation function by slowing down the beam in the target gas down to zero energy by using a single beam energy. Our set-up provides a high detection efficiency for all relevant reaction channels including (d , p) , (d , α) and/or direct breakup that can destroy mass-7 nuclei in contrast to previous measurements. The preliminary results of these experiments along with details of ANASEN detector will be presented. *ANASEN: Array for Nuclear Astrophysics and Structure with Exotic Nuclei. This work is supported by the US NSF MRI program, Grant No. PHY-0821308 and NSF Grant PHY-1401574.

  6. Protostar formation in the early universe.

    PubMed

    Yoshida, Naoki; Omukai, Kazuyuki; Hernquist, Lars

    2008-08-01

    The nature of the first generation of stars in the universe remains largely unknown. Observations imply the existence of massive primordial stars early in the history of the universe, and the standard theory for the growth of cosmic structure predicts that structures grow hierarchically through gravitational instability. We have developed an ab initio computer simulation of the formation of primordial stars that follows the relevant atomic and molecular processes in a primordial gas in an expanding universe. The results show that primeval density fluctuations left over from the Big Bang can drive the formation of a tiny protostar with a mass 1% that of the Sun. The protostar is a seed for the subsequent formation of a massive primordial star.

  7. Shocks in the Early Universe.

    PubMed

    Pen, Ue-Li; Turok, Neil

    2016-09-23

    We point out a surprising consequence of the usually assumed initial conditions for cosmological perturbations. Namely, a spectrum of Gaussian, linear, adiabatic, scalar, growing mode perturbations not only creates acoustic oscillations of the kind observed on very large scales today, it also leads to the production of shocks in the radiation fluid of the very early Universe. Shocks cause departures from local thermal equilibrium as well as create vorticity and gravitational waves. For a scale-invariant spectrum and standard model physics, shocks form for temperatures 1  GeVearly as 10^{-30}  sec after the big bang.

  8. The early growth of the first black holes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Johnson, Jarrett L.; Haardt, Francesco

    With detections of quasars powered by increasingly massive black holes at increasingly early times in cosmic history over the past decade, there has been correspondingly rapid progress made on the theory of early black hole formation and growth. Here, we review the emerging picture of how the first massive black holes formed from the primordial gas and then grew to supermassive scales. We discuss the initial conditions for the formation of the progenitors of these seed black holes, the factors dictating the initial masses with which they form, and their initial stages of growth via accretion, which may occur atmore » super-Eddington rates. Lastly, we briefly discuss how these results connect to large-scale simulations of the growth of supermassive black holes in the first billion years after the Big Bang.« less

  9. The early growth of the first black holes

    DOE PAGES

    Johnson, Jarrett L.; Haardt, Francesco

    2016-03-04

    With detections of quasars powered by increasingly massive black holes at increasingly early times in cosmic history over the past decade, there has been correspondingly rapid progress made on the theory of early black hole formation and growth. Here, we review the emerging picture of how the first massive black holes formed from the primordial gas and then grew to supermassive scales. We discuss the initial conditions for the formation of the progenitors of these seed black holes, the factors dictating the initial masses with which they form, and their initial stages of growth via accretion, which may occur atmore » super-Eddington rates. Lastly, we briefly discuss how these results connect to large-scale simulations of the growth of supermassive black holes in the first billion years after the Big Bang.« less

  10. Big Bang and context-driven collapse.

    PubMed

    Robertson-Tessi, Mark; Anderson, Alexander R A

    2015-03-01

    Heterogeneity is the single most important factor driving cancer progression and treatment failure, yet little is understood about how and when this heterogeneity arises. A new study shows that colorectal cancers acquire their dominant mutations early in development and that subsequent mutations, even if they confer greater fitness, are unlikely to sweep through the tumor.

  11. Characterization of big bang, a novel gene encoding for PDZ domain-containing proteins that are dynamically expressed throughout Drosophila development.

    PubMed

    Kim, Sabrina Y; Renihan, Maia K; Boulianne, Gabrielle L

    2006-06-01

    PDZ (PSD-95, Discs-large, ZO-1) domain proteins often function as scaffolding proteins and have been shown to play important roles in diverse cellular processes such as the establishment and maintenance of cell polarity, and signal transduction. Here, we report the identification and cloning of a novel Drosophila melanogaster gene that is predicted to produce several different PDZ domain-containing proteins through alternative promoter usage and alternative splicing. This gene, that we have named big bang (bbg), was first identified as C96-GAL4, a GAL4 enhancer trap line that was generated in our lab. To further characterize bbg, its expression pattern was examined in ovaries, embryos, and late third instar larvae using UAS reporter gene constructs, in situ hybridization, or immunocytochemistry. In addition, the expression of alternatively spliced transcripts was examined in more detail using in situ hybridization. We find that during embryogenesis bbg is predominantly expressed in the developing gut, but it is also expressed in external sensory organs found in the epidermis. In the late third instar larva, bbg is expressed along the presumptive wing margin in the wing disc, broadly in the eye disc, and in other imaginal discs as well as in the brain. The expression patterns observed are dynamic and specific during development, suggesting that like other genes that encode for several different PDZ domain protein isoforms, bbg likely plays important roles in multiple developmental processes.

  12. Enhancing Teachers' Awareness About Relations Between Science and Religion. The Debate Between Steady State and Big Bang Theories

    NASA Astrophysics Data System (ADS)

    Bagdonas, Alexandre; Silva, Cibelle Celestino

    2015-11-01

    Educators advocate that science education can help the development of more responsible worldviews when students learn not only scientific concepts, but also about science, or "nature of science". Cosmology can help the formation of worldviews because this topic is embedded in socio-cultural and religious issues. Indeed, during the Cold War period, the cosmological controversy between Big Bang and Steady State theory was tied up with political and religious arguments. The present paper discusses a didactic sequence developed for and applied in a pre-service science teacher-training course on history of science. After studying the historical case, pre-service science teachers discussed how to deal with possible conflicts between scientific views and students' personal worldviews related to religion. The course focused on the study of primary and secondary sources about cosmology and religion written by cosmologists such as Georges Lemaître, Fred Hoyle and the Pope Pius XII. We used didactic strategies such as short seminars given by groups of pre-service teachers, videos, computer simulations, role-play, debates and preparation of written essays. Along the course, most pre-service teachers emphasized differences between science and religion and pointed out that they do not feel prepared to conduct classroom discussions about this topic. Discussing the relations between science and religion using the history of cosmology turned into an effective way to teach not only science concepts but also to stimulate reflections about nature of science. This topic may contribute to increasing students' critical stance on controversial issues, without the need to explicitly defend certain positions, or disapprove students' cultural traditions. Moreover, pre-service teachers practiced didactic strategies to deal with this kind of unusual content.

  13. Analysis of BigFoot HDC SymCap experiment N161205 on NIF

    NASA Astrophysics Data System (ADS)

    Dittrich, T. R.; Baker, K. L.; Thomas, C. A.; Berzak Hopkins, L. F.; Harte, J. A.; Zimmerman, G. B.; Woods, D. T.; Kritcher, A. L.; Ho, D. D.; Weber, C. R.; Kyrala, G.

    2017-10-01

    Analysis of NIF implosion experiment N161205 provides insight into both hohlraum and capsule performance. This experiment used an undoped High Density Carbon (HDC) ablator driven by a BigFoot x-ray profile in a Au hohlraum. Observations from this experiment include DT fusion yield, bang time, DSR, Tion and time-resolved x-ray emission images around bang time. These observations are all consistent with an x-ray spectrum having significantly reduced Au m-band emission that is present in a standard hohlraum simulation. Attempts to justify the observations using several other simulation modifications will be presented. This work was performed under the auspices of the Department of Energy by Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344.

  14. Particle physics in the very early universe

    NASA Technical Reports Server (NTRS)

    Schramm, D. N.

    1981-01-01

    Events in the very early big bang universe in which elementary particle physics effects may have been dominant are discussed, with attention to the generation of a net baryon number by way of grand unification theory, and emphasis on the possible role of massive neutrinos in increasing current understanding of various cosmological properties and of the constraints placed on neutrino properties by cosmology. It is noted that when grand unification theories are used to describe very early universe interactions, an initially baryon-symmetrical universe can evolve a net baryon excess of 10 to the -9th to 10 to the -11th per photon, given reasonable parameters. If neutrinos have mass, the bulk of the mass of the universe may be in the form of leptons, implying that the form of matter most familiar to physical science may not be the dominant form of matter in the universe.

  15. The Growth of Early Galaxies and Reionization of Hydrogen

    NASA Astrophysics Data System (ADS)

    Chary, Ranga Ram

    2012-07-01

    The reionization of the intergalactic medium about a billion years after the Big Bang was an important event which occurred due to the release of ionizing photons from the growth of stellar mass and black holes in the early Universe. By leveraging the benefits of field galaxy surveys, I will present some recent breakthroughs in our understanding of how the earliest galaxies in the Universe evolved. I will present evidence that unlike in the local Universe where galaxy growth occurs through intermittent cannibalism, star-formation in the distant Universe is a more continuous if violent process with an overabundance of massive stars. Implications for the reionization history of the Universe will also be discussed.

  16. Adult head-banging and stereotypic movement disorders.

    PubMed

    Mendez, M F; Mirea, A

    1998-09-01

    Stereotypic movement disorders (SMD) such as head-banging, which are common among children with mental retardation or pervasive developmental disorders, may also occur in intellectually normal adults. We report a 27-year history of daily head-banging with self-injury in a 49-year-old man with normal cognition. The patient had no personal or family history of Tourette's syndrome, tic disorder, obsessive-compulsive disorder (OCD), or mental retardation. The frequency of his stereotypical head-banging increased with anxiety, loud noises with startle, and boredom. He reported a sense of pleasure from his head-banging, and the frequency of this behavior decreased when he was treated with the opioid antagonist naltrexone. Although not diagnostic, the self-stimulatory or pleasurable component of head-banging, body-rocking, thumb-sucking, and other SMD may help distinguish them from tics, Tourette's syndrome, OCD, and deliberate self-harming behavior. This report reviews the disorders associated with SMD and discusses the potential mechanisms for these behaviors. The treatment of SMD includes drugs that work through opioid, serotonergic, or dopaminergic systems.

  17. Early Childhood Education and Care as a Community Service or Big Business?

    ERIC Educational Resources Information Center

    Kilderry, Anna

    2006-01-01

    This colloquium discusses recent trends where early childhood education and care has shifted from being a community service to that of big business. Years of neo-liberal reform have created market conditions favourable for large corporations to provide childcare within Australia. This situation raises some issues and concerns, particularly in…

  18. Thermal equilibrium control by frequent bang-bang modulation.

    PubMed

    Yang, Cheng-Xi; Wang, Xiang-Bin

    2010-05-01

    In this paper, we investigate the non-Markovian heat transfer between a weakly damped harmonic oscillator (system) and a thermal bath. When the system is initially in a thermal state and not correlated with the environment, the mean energy of the system always first increases, then oscillates, and finally reaches equilibrium with the bath, no matter what the initial temperature of the system is. Moreover, the heat transfer between the system and the bath can be controlled by fast bang-bang modulation. This modulation does work on the system, and temporarily inverts the direction of heat flow. In this case, the common sense that heat always transfers from hot to cold does not hold any more. At the long time scale, a new dynamic equilibrium is established between the system and the bath. At this equilibrium, the energy of the system can be either higher or lower than its normal equilibrium value. A comprehensive analysis of the relationship between the dynamic equilibrium and the parameters of the modulation as well as the environment is presented.

  19. Black hole growth in the early Universe is self-regulated and largely hidden from view.

    PubMed

    Treister, Ezequiel; Schawinski, Kevin; Volonteri, Marta; Natarajan, Priyamvada; Gawiser, Eric

    2011-06-15

    The formation of the first massive objects in the infant Universe remains impossible to observe directly and yet it sets the stage for the subsequent evolution of galaxies. Although some black holes with masses more than 10(9) times that of the Sun have been detected in luminous quasars less than one billion years after the Big Bang, these individual extreme objects have limited utility in constraining the channels of formation of the earliest black holes; this is because the initial conditions of black hole seed properties are quickly erased during the growth process. Here we report a measurement of the amount of black hole growth in galaxies at redshift z = 6-8 (0.95-0.7 billion years after the Big Bang), based on optimally stacked, archival X-ray observations. Our results imply that black holes grow in tandem with their host galaxies throughout cosmic history, starting from the earliest times. We find that most copiously accreting black holes at these epochs are buried in significant amounts of gas and dust that absorb most radiation except for the highest-energy X-rays. This suggests that black holes grew significantly more during these early bursts than was previously thought, but because of the obscuration of their ultraviolet emission they did not contribute to the re-ionization of the Universe.

  20. Note: Neutron bang time diagnostic system on Shenguang-III prototype

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Tang, Qi; Chen, Jiabin; Liu, Zhongjie

    A neutron bang time (NBT) diagnostic system has been implemented on Shenguang-III prototype. The bang time diagnostic system is based on a sensitive fusion neutron detector, which consists of a plastic scintillator and a micro-channel plate photomultiplier tube (PMT). An optical fiber bundle is used to couple the scintillator and the PMT. The bang time system is able to measure bang time above a neutron yield of 10{sup 7}. Bang times and start time of laser were related by probing x-ray pulses produced by 200 ps laser irradiating golden targets. Timing accuracy of the NBT is better than 60 ps.

  1. The Big Bang left a permanent scare in the cosmic background, 5 billion light-years from Earth

    NASA Image and Video Library

    2017-12-08

    The events surrounding the Big Bang were so cataclysmic that they left an indelible imprint on the fabric of the cosmos. We can detect these scars today by observing the oldest light in the universe. As it was created nearly 14 billion years ago, this light — which exists now as weak microwave radiation and is thus named the cosmic microwave background (CMB) — permeates the entire cosmos, filling it with detectable photons. The CMB can be used to probe the cosmos via something known as the Sunyaev-Zel’dovich (SZ) effect, which was first observed over 30 years ago. We detect the CMB here on Earth when its constituent microwave photons travel to us through space. On their journey to us, they can pass through galaxy clusters that contain high-energy electrons. These electrons give the photons a tiny boost of energy. Detecting these boosted photons through our telescopes is challenging but important — they can help astronomers to understand some of the fundamental properties of the universe, such as the location and distribution of dense galaxy clusters. The NASA/ESA (European Space Agency) Hubble Space Telescope observed one of most massive known galaxy clusters, RX J1347.5–1145, seen in this Picture of the Week, as part of the Cluster Lensing And Supernova survey with Hubble (CLASH). This observation of the cluster, 5 billion light-years from Earth, helped the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile to study the cosmic microwave background using the thermal Sunyaev-Zel’dovich effect. The observations made with ALMA are visible as the blue-purple hues. Image credit: ESA/Hubble & NASA, T. Kitayama (Toho University, Japan)/ESA/Hubble & NASA NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to

  2. Supersonic gas streams enhance the formation of massive black holes in the early universe.

    PubMed

    Hirano, Shingo; Hosokawa, Takashi; Yoshida, Naoki; Kuiper, Rolf

    2017-09-29

    The origin of super-massive black holes in the early universe remains poorly understood. Gravitational collapse of a massive primordial gas cloud is a promising initial process, but theoretical studies have difficulty growing the black hole fast enough. We report numerical simulations of early black hole formation starting from realistic cosmological conditions. Supersonic gas motions left over from the Big Bang prevent early gas cloud formation until rapid gas condensation is triggered in a protogalactic halo. A protostar is formed in the dense, turbulent gas cloud, and it grows by sporadic mass accretion until it acquires 34,000 solar masses. The massive star ends its life with a catastrophic collapse to leave a black hole-a promising seed for the formation of a monstrous black hole. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  3. DMR 'Map of the Early Universe.'

    NASA Technical Reports Server (NTRS)

    2002-01-01

    DMR 'Map of the Early Universe.' This false-color image shows tiny variations in the intensity of the cosmic microwave background measured in four years of observations by the Differential Microwave Radiometers on NASA's Cosmic Background Explorer (COBE). The cosmic microwave background is widely believed to be a remnant of the Big Bang; the blue and red spots correspond to regions of greater or lesser density in the early Universe. These 'fossilized' relics record the distribution of matter and energy in the early Universe before the matter became organized into stars and galaxies. While the initial discovery of variations in the intensity of the CMB (made by COBE in 1992) was based on a mathematical examination of the data, this picture of the sky from the full four-year mission gives an accurate visual impression of the data. The features traced in this map stretch across the visible Universe: the largest features seen by optical telescopes, such as the 'Great Wall' of galaxies, would fit neatly within the smallest feature in this map. (See Bennett et al. 1996, ApJ, 464, L1 and references therein for details.)

  4. Destructions of {sup 7}Be and {sup 7}Li in Big Bang nucleosynthesis through reactions with exotic long-lived sub-strongly interacting massive particles

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kusakabe, Motohiko; Kawasaki, Masahiro; Institute for Cosmic Ray Research, University of Tokyo, Kashiwa, Chiba 277-8582, Japan and Institute for the Physics and Mathematics of the Universe, University of Tokyo, Kashiwa, Chiba 277-8582

    An observed plateau abundance of {sup 7}Li in metal-poor halo stars indicates its primordial origin. The {sup 7}Li abundances are about a factor of three smaller than that predicted in standard big bang nucleosynthesis (BBN) model. In addition, some of the stars possibly contain {sup 6}Li in abundances larger than standard BBN prediction. Particle models sometimes include heavy longlived colored particles which are confined in exotic strongly interacting massive particles (SIMPs). We have found reactions which destroy {sup 7}Be and {sup 7}Li during BBN in the scenario of BBN affected by a long-lived sub-strongly interactingmassive particle (sub-SIMP, X). The reactionsmore » are non radiative X captures of {sup 7}Be and {sup 7}Li which can operate if the X particle interacts with nuclei strongly enough to drive {sup 7}Be destruction but not strongly enough to form a bound state with {sup 4}He of relative angular momentum L = 1. The processes can be a cause of the {sup 7}Li problem. In this paper we suggest new possible reactions for {sup 6}Li production. Especially, a {sup 6}Li production through the deuteron capture of {sup 4}He bound to X can operate in the parameter region solving the {sup 7}Li problem.« less

  5. What is the Universe made of?

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Paris, Mark

    A team of physicists and astrophysicists at Los Alamos National Laboratory, in collaboration with leading universities around the country, are using the Laboratory’s supercomputers to simulate the Big Bang nucleosynthesis and the early universe to unprecedented precision. These researchers developed a code, called BURST that describes the universe from a time of a few seconds after the Big Bang to several hundred thousand years later. BURST allows physicists to study the microscopic, quantum nature of fundamental particles — like nuclei and the ghostly, weakly interacting neutrinos — by simulating the universe at its largest, cosmological scale. BURST simultaneously describes allmore » the particles present in the early universe as they develop, tracking their evolution, particularly the amounts of light nuclei fused in the cosmic soup.« less

  6. Big data from electronic health records for early and late translational cardiovascular research: challenges and potential.

    PubMed

    Hemingway, Harry; Asselbergs, Folkert W; Danesh, John; Dobson, Richard; Maniadakis, Nikolaos; Maggioni, Aldo; van Thiel, Ghislaine J M; Cronin, Maureen; Brobert, Gunnar; Vardas, Panos; Anker, Stefan D; Grobbee, Diederick E; Denaxas, Spiros

    2018-04-21

    Cohorts of millions of people's health records, whole genome sequencing, imaging, sensor, societal and publicly available data present a rapidly expanding digital trace of health. We aimed to critically review, for the first time, the challenges and potential of big data across early and late stages of translational cardiovascular disease research. We sought exemplars based on literature reviews and expertise across the BigData@Heart Consortium. We identified formidable challenges including: data quality, knowing what data exist, the legal and ethical framework for their use, data sharing, building and maintaining public trust, developing standards for defining disease, developing tools for scalable, replicable science and equipping the clinical and scientific work force with new inter-disciplinary skills. Opportunities claimed for big health record data include: richer profiles of health and disease from birth to death and from the molecular to the societal scale; accelerated understanding of disease causation and progression, discovery of new mechanisms and treatment-relevant disease sub-phenotypes, understanding health and diseases in whole populations and whole health systems and returning actionable feedback loops to improve (and potentially disrupt) existing models of research and care, with greater efficiency. In early translational research we identified exemplars including: discovery of fundamental biological processes e.g. linking exome sequences to lifelong electronic health records (EHR) (e.g. human knockout experiments); drug development: genomic approaches to drug target validation; precision medicine: e.g. DNA integrated into hospital EHR for pre-emptive pharmacogenomics. In late translational research we identified exemplars including: learning health systems with outcome trials integrated into clinical care; citizen driven health with 24/7 multi-parameter patient monitoring to improve outcomes and population-based linkages of multiple EHR sources

  7. Cosmic Microwave Background Timeline

    Science.gov Websites

    about 2.3 K 1948: George Gamow, Ralph Alpher, and Robert Herman predict that a Big Bang universe perfect blackbody spectrum and thereby strongly supporting the hot big bang model, the thermal history of anisotropy in the cosmic microwave background, this strongly supports the big bang model with gravitational

  8. Magnetized strange quark model with Big Rip singularity in f(R, T) gravity

    NASA Astrophysics Data System (ADS)

    Sahoo, P. K.; Sahoo, Parbati; Bishi, Binaya K.; Aygün, S.

    2017-07-01

    Locally rotationally symmetric (LRS) Bianchi type-I magnetized strange quark matter (SQM) cosmological model has been studied based on f(R, T) gravity. The exact solutions of the field equations are derived with linearly time varying deceleration parameter, which is consistent with observational data (from SNIa, BAO and CMB) of standard cosmology. It is observed that the model begins with big bang and ends with a Big Rip. The transition of the deceleration parameter from decelerating phase to accelerating phase with respect to redshift obtained in our model fits with the recent observational data obtained by Farook et al. [Astrophys. J. 835, 26 (2017)]. The well-known Hubble parameter H(z) and distance modulus μ(z) are discussed with redshift.

  9. Nonsingular, big-bounce cosmology from spinor-torsion coupling

    NASA Astrophysics Data System (ADS)

    Popławski, Nikodem

    2012-05-01

    The Einstein-Cartan-Sciama-Kibble theory of gravity removes the constraint of general relativity that the affine connection be symmetric by regarding its antisymmetric part, the torsion tensor, as a dynamical variable. The minimal coupling between the torsion tensor and Dirac spinors generates a spin-spin interaction which is significant in fermionic matter at extremely high densities. We show that such an interaction averts the unphysical big-bang singularity, replacing it with a cusp-like bounce at a finite minimum scale factor, before which the Universe was contracting. This scenario also explains why the present Universe at largest scales appears spatially flat, homogeneous and isotropic.

  10. Taking the Measure of the Universe

    NASA Technical Reports Server (NTRS)

    Hinshaw, Gary

    2009-01-01

    The cosmic microwave background (CMB) radiation is the oldest light in the universe - it is literally the remnant heat left over from the Big Bang. This fossil relic has survived largely intact and it provides us with a unique probe of conditions in the early universe, long before any stars or galaxies had formed. NASA has now flown two satellites devoted to studying the CMB: 'COBE' and 'WMAP'. In this lecture I will describe what we have learned from these missions including: evidence for the Big Bang itself; new measurements of the age, shape, and content of the universe; and new evidence that all structure in the universe emerged from microscopic quantum fluctuations in the primordial soup.

  11. Elementary particles in the early Universe

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gromov, N.A., E-mail: gromov@dm.komisc.ru

    The high-temperature limit of the Standard Model generated by the contractions of gauge groups is discussed. Contraction parameters of gauge group SU(2) of the Electroweak Model and gauge group SU(3) of Quantum Chromodynamics are taken identical and tending to zero when the temperature increases. Properties of the elementary particles change drastically at the infinite temperature limit: all particles lose masses, all quarks are monochromatic. Electroweak interactions become long-range and are mediated by neutral currents. Particles of different kind do not interact. It looks like some stratification with only one sort of particles in each stratum. The Standard Model passes inmore » this limit through several stages, which are distinguished by the powers of the contraction parameter. For any stage intermediate models are constructed and the exact expressions for the respective Lagrangians are presented. The developed approach describes the evolution of the Standard Model in the early Universe from the Big Bang up to the end of several nanoseconds.« less

  12. Lyman-α Emission from an Infant Black Hole in the Early Universe

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wiggins, Brandon Kerry; Smidt, Joseph Michael; Johnson, Jarrett L.

    The COSMOS survey recently discovered an exotic young galaxy, COSMOS Redshift 7 (CR7), in the early universe (1 billion years after the Big Bang), which is devoid of evidence of elements heavier than hydrogen and helium. Whereas some believe this might be the first galaxy discovered with stars made only from these elements, others think CR7 may be powered by a newborn supermassive black hole. In this paper, we summarize for a general academic audience our efforts to model the creation of this galaxy through cosmological simulations. These state-of-the-art calculations include primordial chemistry and cooling and the interaction of x-raysmore » from the black hole with surrounding gas. We simulate the process of light escaping this object with Monte Carlo Lyman-α transfer and compare our calculations with observations of CR7. Our work demonstrates the viability of the black hole interpretation for this intriguing object in the early universe.« less

  13. Lyman-α Emission from an Infant Black Hole in the Early Universe

    DOE PAGES

    Wiggins, Brandon Kerry; Smidt, Joseph Michael; Johnson, Jarrett L.

    2016-01-01

    The COSMOS survey recently discovered an exotic young galaxy, COSMOS Redshift 7 (CR7), in the early universe (1 billion years after the Big Bang), which is devoid of evidence of elements heavier than hydrogen and helium. Whereas some believe this might be the first galaxy discovered with stars made only from these elements, others think CR7 may be powered by a newborn supermassive black hole. In this paper, we summarize for a general academic audience our efforts to model the creation of this galaxy through cosmological simulations. These state-of-the-art calculations include primordial chemistry and cooling and the interaction of x-raysmore » from the black hole with surrounding gas. We simulate the process of light escaping this object with Monte Carlo Lyman-α transfer and compare our calculations with observations of CR7. Our work demonstrates the viability of the black hole interpretation for this intriguing object in the early universe.« less

  14. Early prediction of movie box office success based on Wikipedia activity big data.

    PubMed

    Mestyán, Márton; Yasseri, Taha; Kertész, János

    2013-01-01

    Use of socially generated "big data" to access information about collective states of the minds in human societies has become a new paradigm in the emerging field of computational social science. A natural application of this would be the prediction of the society's reaction to a new product in the sense of popularity and adoption rate. However, bridging the gap between "real time monitoring" and "early predicting" remains a big challenge. Here we report on an endeavor to build a minimalistic predictive model for the financial success of movies based on collective activity data of online users. We show that the popularity of a movie can be predicted much before its release by measuring and analyzing the activity level of editors and viewers of the corresponding entry to the movie in Wikipedia, the well-known online encyclopedia.

  15. Early Prediction of Movie Box Office Success Based on Wikipedia Activity Big Data

    PubMed Central

    Mestyán, Márton; Yasseri, Taha; Kertész, János

    2013-01-01

    Use of socially generated “big data” to access information about collective states of the minds in human societies has become a new paradigm in the emerging field of computational social science. A natural application of this would be the prediction of the society's reaction to a new product in the sense of popularity and adoption rate. However, bridging the gap between “real time monitoring” and “early predicting” remains a big challenge. Here we report on an endeavor to build a minimalistic predictive model for the financial success of movies based on collective activity data of online users. We show that the popularity of a movie can be predicted much before its release by measuring and analyzing the activity level of editors and viewers of the corresponding entry to the movie in Wikipedia, the well-known online encyclopedia. PMID:23990938

  16. Hints of a Fundamental Misconception in Cosmology

    NASA Astrophysics Data System (ADS)

    Prather, Edward E.; Slater, Timothy F.; Offerdahl, Erika G.

    To explore the frequency and range of student ideas regarding the Big Bang, nearly 1,000 students from middle school, secondary school, and college were surveyed and asked if they had heard of the Big Bang and, if so, to describe it. In analyzing their responses, we uncovered an unexpected result that more than half of the students who stated that they had heard of the Big Bang also provided responses that suggest they believe that the Big Bang was a phenomenon that organized pre-existing matter. To further examine this result, a second group of college students was asked specifically to describe what existed or occurred before, during, and after the Big Bang. Nearly 70% gave responses clearly stating that matter existed prior to the Big Bang. These results are interpreted as strongly suggesting that most students are answering these questions by employing an internally consistent element of knowledge or reasoning (often referred to as a phenomenological primitive, or p-prim), consistent with the idea that "you can't make something from nothing." These results inform the debate about the extent to which college students have pre-existing notions that are poised to interfere with instructional efforts about contemporary physics and astronomy topics.

  17. Matter Under Extreme Conditions: The Early Years

    NASA Astrophysics Data System (ADS)

    Keeler, R. Norris; Gibson, Carl H.

    2012-03-01

    Extreme conditions in natural flows are examined, starting with a turbulent big bang. A hydro-gravitational-dynamics cosmology model is adopted. Planck-Kerr turbulence instability causes Planck-particle turbulent combustion. Inertial-vortex forces induce a non-turbulent ki- netic energy cascade to Planck-Kolmogorov scales where vorticity is produced, overcoming 10113 Pa Planck-Fortov pressures. The spinning, expanding fireball has a slight deficit of Planck antiparticles. Space and mass-energy powered by gluon viscous stresses expand exponentially at speeds >1025 c. Turbulent temperature and spin fluctuations fossilize at scales larger than ct, where c is light speed and t is time. Because "dark-energy" antigravity forces vanish when infla- tion ceases, and because turbulence produces entropy, the universe is closed and will collapse and rebound. Density and spin fossils of big bang turbulent mixing trigger structure formation in the plasma epoch. Fragmenting protosuperclustervoids and protoclustervoids produce weak tur- bulence until the plasma-gas transition give chains of protogalaxies with the morphology of tur- bulence. Chain galaxy clusters observed at large redshifts ~8.6 support this interpretation. Pro- togalaxies fragment into clumps, each with a trillion Earth-mass H-He gas planets. These make stars, supernovae, the first chemicals, the first oceans and the first life soon after the cosmologi- cal event.

  18. The early universe as a probe of new physics

    NASA Astrophysics Data System (ADS)

    Bird, Christopher Shane

    The Standard Model of Particle Physics has been verified to unprecedented precision in the last few decades. However there are still phenomena in nature which cannot be explained, and as such new theories will be required. Since terrestrial experiments are limited in both the energy and precision that can be probed, new methods are required to search for signs of physics beyond the Standard Model. In this dissertation, I demonstrate how these theories can be probed by searching for remnants of their effects in the early Universe. In particular I focus on three possible extensions of the Standard Model: the addition of massive neutral particles as dark matter, the addition of charged massive particles, and the existence of higher dimensions. For each new model, I review the existing experimental bounds and the potential for discovering new physics in the next generation of experiments. For dark matter, I introduce six simple models which I have developed, and which involve a minimum amount of new physics, as well as reviewing one existing model of dark matter. For each model I calculate the latest constraints from astrophysics experiments, nuclear recoil experiments, and collider experiments. I also provide motivations for studying sub-GeV mass dark matter, and propose the possibility of searching for light WIMPs in the decay of B-mesons and other heavy particles. For charged massive relics, I introduce and review the recently proposed model of catalyzed Big Bang nucleosynthesis. In particular I review the production of 6Li by this mechanism, and calculate the abundance of 7Li after destruction of 7Be by charged relics. The result is that for certain natural relics CBBN is capable of removing tensions between the predicted and observed 6Li and 7Li abundances which are present in the standard model of BBN. For extra dimensions, I review the constraints on the ADD model from both astrophysics and collider experiments. I then calculate the constraints on this model

  19. The Age of Precision Cosmology

    NASA Technical Reports Server (NTRS)

    Chuss, David T.

    2012-01-01

    In the past two decades, our understanding of the evolution and fate of the universe has increased dramatically. This "Age of Precision Cosmology" has been ushered in by measurements that have both elucidated the details of the Big Bang cosmology and set the direction for future lines of inquiry. Our universe appears to consist of 5% baryonic matter; 23% of the universe's energy content is dark matter which is responsible for the observed structure in the universe; and 72% of the energy density is so-called "dark energy" that is currently accelerating the expansion of the universe. In addition, our universe has been measured to be geometrically flat to 1 %. These observations and related details of the Big Bang paradigm have hinted that the universe underwent an epoch of accelerated expansion known as Uinflation" early in its history. In this talk, I will review the highlights of modern cosmology, focusing on the contributions made by measurements of the cosmic microwave background, the faint afterglow of the Big Bang. I will also describe new instruments designed to measure the polarization of the cosmic microwave background in order to search for evidence of cosmic inflation.

  20. Contracting for Agile Software Development in the Department of Defense: An Introduction

    DTIC Science & Technology

    2015-08-01

    Requirements are fixed at a more granular level; reviews of the work product happen more frequently and assess each individual increment rather than a “ big bang ...boundaries than “ big - bang ” development. The implementation of incremental or progressive reviews enables just that—any issues identified at the time of the...the contract needs to support the delivery of deployable software at defined increments/intervals, rather than incentivizing “ big - bang ” efforts or

  1. Exploring nuclear reactions relevant to Stellar and Big-Bang Nucleosynthesis using High-Energy-Density plasmas at OMEGA and the NIF

    NASA Astrophysics Data System (ADS)

    Gatu Johnson, M.

    2017-10-01

    Thermonuclear reaction rates and nuclear processes have been explored traditionally by means of accelerator experiments, which are difficult to execute at conditions relevant to Stellar Nucleosynthesis (SN) and Big Bang Nucleosynthesis (BBN). High-Energy-Density (HED) plasmas closely mimic astrophysical environments and are an excellent complement to accelerator experiments in exploring SN and BBN-relevant nuclear reactions. To date, our work using HED plasmas at OMEGA and NIF has focused on the complementary 3He+3He, T+3He and T +T reactions. First studies of the T +T reaction indicated the significance of the 5He ground-state resonance in the T +T neutron spectrum. Subsequent T +T experiments showed that the strength of this resonance varies with center-of-mass (c-m) energy in the range of 16-50 keV, a variation that is not fundamentally understood. Studies of the 3He+3He and T+3He reactions have also been conducted at OMEGA at c-m energies of 165 keV and 80 keV, respectively, and the results revealed three things. First, a large cross section for the T+3He- γ branch can be ruled out as an explanation for the anomalously high abundance of 6Li in primordial material. Second, the results contrasted to theoretical modeling indicate that the mirror-symmetry assumption is not enough to capture the differences between T +T and 3He+3He reactions. Third, the elliptical spectrum assumed in the analysis of 3He+3He data obtained in accelerator experiments is incorrect. Preliminary data from recent experiments at the NIF exploring the 3He+3He reaction at c-m energies of 60 keV and 100 keV also indicate that the underlying physics changes with c-m energy. In this talk, we describe these findings and future directions for exploring light-ion reactions at OMEGA and the NIF. The work was supported in part by the US DOE, LLE, and LLNL.

  2. FLRW Cosmology with Horava-Lifshitz Gravity: Impacts of Equations of State

    NASA Astrophysics Data System (ADS)

    Tawfik, A.; Abou El Dahab, E.

    2017-07-01

    Inspired by Lifshitz theory for quantum critical phenomena in condensed matter, Horava proposed a theory for quantum gravity with an anisotropic scaling in ultraviolet. In Horava-Lifshitz gravity (HLG), we have studied the impacts of six types of equations of state on the evolution of various cosmological parameters such as Hubble parameters and scale factor. From the comparison of the general relativity gravity with the HLG with detailed and without with non-detailed balance conditions, remarkable differences are found. Also, a noticeable dependence of singular and non-singular Big Bang on the equations of state is observed. We conclude that HLG explains various epochs in the early universe and might be able to reproduce the entire cosmic history with and without singular Big Bang.

  3. Early assembly of the most massive galaxies.

    PubMed

    Collins, Chris A; Stott, John P; Hilton, Matt; Kay, Scott T; Stanford, S Adam; Davidson, Michael; Hosmer, Mark; Hoyle, Ben; Liddle, Andrew; Lloyd-Davies, Ed; Mann, Robert G; Mehrtens, Nicola; Miller, Christopher J; Nichol, Robert C; Romer, A Kathy; Sahlén, Martin; Viana, Pedro T P; West, Michael J

    2009-04-02

    The current consensus is that galaxies begin as small density fluctuations in the early Universe and grow by in situ star formation and hierarchical merging. Stars begin to form relatively quickly in sub-galactic-sized building blocks called haloes which are subsequently assembled into galaxies. However, exactly when this assembly takes place is a matter of some debate. Here we report that the stellar masses of brightest cluster galaxies, which are the most luminous objects emitting stellar light, some 9 billion years ago are not significantly different from their stellar masses today. Brightest cluster galaxies are almost fully assembled 4-5 billion years after the Big Bang, having grown to more than 90 per cent of their final stellar mass by this time. Our data conflict with the most recent galaxy formation models based on the largest simulations of dark-matter halo development. These models predict protracted formation of brightest cluster galaxies over a Hubble time, with only 22 per cent of the stellar mass assembled at the epoch probed by our sample. Our findings suggest a new picture in which brightest cluster galaxies experience an early period of rapid growth rather than prolonged hierarchical assembly.

  4. The physics and early history of the intergalactic medium

    NASA Astrophysics Data System (ADS)

    Barkana, Rennan; Loeb, Abraham

    2007-04-01

    The intergalactic medium—the cosmic gas that fills the great spaces between the galaxies—is affected by processes ranging from quantum fluctuations in the very early Universe to radiative emission from newly formed stars. This gives the intergalactic medium a dual role as a powerful probe both of fundamental physics and of astrophysics. The heading of fundamental physics includes conditions in the very early Universe and cosmological parameters that determine the age of the Universe and its matter content. The astrophysics refers to chapters of the long cosmic history of stars and galaxies that are being revealed through the effects of stellar feedback on the cosmic gas. This review describes the physics of the intergalactic medium, focusing on recent theoretical and observational developments in understanding early cosmic history. In particular, the earliest generation of stars is thought to have transformed the Universe from darkness to light and to have had an enormous impact on the intergalactic medium. Half a million years after the Big Bang the Universe was filled with atomic hydrogen. As gravity pulled gas clouds together, the first stars ignited and their radiation turned the surrounding atoms back into free electrons and ions. From the observed spectral absorption signatures of the gas between us and distant sources, we know that the process of reionization pervaded most of space a billion years after the Big Bang, so that only a small fraction of the primordial hydrogen atoms remained between galaxies. Knowing exactly when and how the reionization process happened is a primary goal of cosmologists, because this would tell us when the early stars and black holes formed and in what kinds of galaxies. The distribution and clustering of these galaxies is particularly interesting since it is driven by primordial density fluctuations in the dark matter. Cosmic reionization is beginning to be understood with the help of theoretical models and computer

  5. Scale factor duality for conformal cyclic cosmologies

    NASA Astrophysics Data System (ADS)

    Camara da Silva, U.; Alves Lima, A. L.; Sotkov, G. M.

    2016-11-01

    The scale factor duality is a symmetry of dilaton gravity which is known to lead to pre-big-bang cosmologies. A conformal time version of the scale factor duality (SFD) was recently implemented as a UV/IR symmetry between decelerated and accelerated phases of the post-big-bang evolution within Einstein gravity coupled to a scalar field. The problem investigated in the present paper concerns the employment of the conformal time SFD methods to the construction of pre-big-bang and cyclic extensions of these models. We demonstrate that each big-bang model gives rise to two qualitatively different pre-big-bang evolutions: a contraction/expansion SFD model and Penrose's Conformal Cyclic Cosmology (CCC). A few examples of SFD symmetric cyclic universes involving certain gauged Kähler sigma models minimally coupled to Einstein gravity are studied. We also describe the specific SFD features of the thermodynamics and the conditions for validity of the generalized second law in the case of Gauss-Bonnet (GB) extension of these selected CCC models.

  6. Emerging Methane Sources: A Bang or Whimper? (Invited)

    NASA Astrophysics Data System (ADS)

    Harriss, R. C.

    2013-12-01

    In this presentation we examine two emerging methane emission sources that may further accelerate climate change in the 21st century: 1) Will fugitive methane emissions associated with the development of unconventional natural gas resources pose a significant threat of accelerating climate change? 2) Will continued warming of Arctic regions destabilize permafrost and methane hydrates rapidly increasing global atmospheric methane that results in a catastrophic climate change emergency? These risks are currently described in two different guises, with unconventional gas as persistent and gradually unfolding threat and Arctic rapid warming and release of methane as a low-probability event that could in an instant change everything. Current research is far from answering the question of whether these emerging methane sources will lead to a climate change bang or whimper. Both issues reflect the need to understand complex environmental and engineered systems as they interact with social and economic forces. While the evolution of energy systems favors methane as a contemporary transition fuel, researchers and practitioners need to address the fugitive methane leakage, reliability, and safety of natural gas systems. The concept of a methane bridge as a viable direction to decarbonization is appealing; it's just not as big or fast a step as many scientists want.

  7. 77 FR 35625 - Statement of General Policy on the Sequencing of the Compliance Dates for Final Rules Applicable...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-14

    ... a ``big bang'' approach where all of the rules to be adopted under Title VII go into effect... `big bang' approach to implementation would be too disruptive to the marketplace--particularly given...

  8. Revised thermonuclear rate of 7Be(n ,α ) 4He relevant to Big-Bang nucleosynthesis

    NASA Astrophysics Data System (ADS)

    Hou, S. Q.; He, J. J.; Kubono, S.; Chen, Y. S.

    2015-05-01

    In the standard Big-Bang nucleosynthesis (BBN) model, the primordial 7Li abundance is overestimated by about a factor of 2 to 3 compared to astronomical observations; this is the so-called pending cosmological lithium problem. The 7Be(n ,α )4He reaction was regarded as the secondary important reaction in affecting the 7Li abundance by destructing the 7Be nucleus in BBN. However, the reaction rate of 7Be(n ,α )4He has not been well studied so far. This reaction rate was first estimated by Wagoner in 1969, which has been primarily adopted in the current BBN simulations. This simple estimate involved only a direct reaction contribution, but the resonant component should also be considered according to the later experimental results. In the present work, we revised this rate based on the indirect cross-section data available for the 4He(α ,n )7Be and 4He(α ,p )7Li reactions by applying the charge symmetry and the principle of detailed balance. Our new result shows that the previous rate (acting as an upper limit) is overestimated by about a factor of ten. The BBN simulation shows that the present rate leads to a 1.2% increase in the final 7Li abundance compared with the result using the Wagoner rate and, hence, the present rate even worsens the 7Li problem. By the present estimation, the role of 7Be(n ,α )4He in destroying 7Be is weakened from the second most importance to the third and, in turn, the

  9. Jupiter's Big Bang.

    ERIC Educational Resources Information Center

    McDonald, Kim A.

    1994-01-01

    Collision of a comet with Jupiter beginning July 16, 1994 will be observed by astronomers worldwide, with computerized information relayed to a center at the University of Maryland, financed by the National Aeronautics and Space Administration and National Science Foundation. Geologists and paleontologists also hope to learn more about earth's…

  10. The origin of the Universe by the Big Bang theory applied in the classroom, following the proposal of the school curriculum of the State of São Paulo

    NASA Astrophysics Data System (ADS)

    Oliveira, J. F. dos R.

    2017-07-01

    The purpose of this work is show to a bibliographic study based on the analysis made to the content applied in the first year of High School, through the booklet primer of the educational curriculum of the state of São Paulo, as predicted: "Natural Sciences and their Technologies" (São Paulo, 2010), implemented since 2008 in the public education network. The analysis made compares from the content addressed by the "Student Notebook" versus "Teacher's Notebook", an indispensable tool in the teaching network on the approach of theory of the emergence of the universe. An essential theme for educational knowledge in this cycle, revealing a hypothetical model of the Big Bang, and also curved space and cosmic inflation. Possibly this model may still be a controversial subject for some groups, because it involves belief, religion, science or another perspective of universe. The field of research was carried out in a group of 40 first year students of the High School, at the State School "Professor Rômulo Pero", in the city of São Paulo, supervised by the State Board of Education - Central Region. The completion of this task presents an important tool to be used by the teacher, a Conceptual Map, in order to raise previous knowledge and probing for the established topic, in the teaching of Physics.

  11. Comment from the Editor to the Special Issue: “Big Data and Precision Medicine Series I: Lung Cancer Early Diagnosis”

    PubMed Central

    Spaggiari, Lorenzo

    2018-01-01

    With this Editorial we want to present the Special Issue “Big Data and Precision Medicine Series I: Lung Cancer Early Diagnosis” to the scientific community, which aims to gather experts on the early detection of lung cancer in order to implement common efforts in the fight against cancer. PMID:29425180

  12. Portfolio Acquisition - How the DoD Can Leverage the Commercial Product Line Model

    DTIC Science & Technology

    2015-04-30

    canceled (Harrison, 2011). A major contributing factor common to these failures is that the programs tried to do too much at once: they used a big - bang ...requirements in a single, big - bang approach. MDAPs take 10 to 15 years from Milestone A to initial operational capability, with many of the largest...2013). The block upgrade model for B-52, F-15, and F-16 proved successful over decades, yet with its big - bang structure the F-35 program is

  13. Non-minimally coupled varying constants quantum cosmologies

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Balcerzak, Adam, E-mail: abalcerz@wmf.univ.szczecin.pl

    We consider gravity theory with varying speed of light and varying gravitational constant. Both constants are represented by non-minimally coupled scalar fields. We examine the cosmological evolution in the near curvature singularity regime. We find that at the curvature singularity the speed of light goes to infinity while the gravitational constant vanishes. This corresponds to the Newton's Mechanics limit represented by one of the vertex of the Bronshtein-Zelmanov-Okun cube [1,2]. The cosmological evolution includes both the pre-big-bang and post-big-bang phases separated by the curvature singularity. We also investigate the quantum counterpart of the considered theory and find the probability ofmore » transition of the universe from the collapsing pre-big-bang phase to the expanding post-big-bang phase.« less

  14. Reviews Book: Nucleus Book: The Wonderful World of Relativity Book: Head Shot Book: Cosmos Close-Up Places to Visit: Physics DemoLab Book: Quarks, Leptons and the Big Bang EBook: Shooting Stars Equipment: Victor 70C USB Digital Multimeter Web Watch

    NASA Astrophysics Data System (ADS)

    2012-09-01

    WE RECOMMEND Nucleus: A Trip into the Heart of Matter A coffee-table book for everyone to dip into and learn from The Wonderful World of Relativity A charming, stand-out introduction to relativity The Physics DemoLab, National University of Singapore A treasure trove of physics for hands-on science experiences Quarks, Leptons and the Big Bang Perfect to polish up on particle physics for older students Victor 70C USB Digital Multimeter Equipment impresses for usability and value WORTH A LOOK Cosmos Close-Up Weighty tour of the galaxy that would make a good display Shooting Stars Encourage students to try astrophotography with this ebook HANDLE WITH CARE Head Shot: The Science Behind the JKF Assassination Exploration of the science behind the crime fails to impress WEB WATCH App-lied science for education: a selection of free Android apps are reviewed and iPhone app options are listed

  15. Big data managing in a landslide early warning system: experience from a ground-based interferometric radar application

    NASA Astrophysics Data System (ADS)

    Intrieri, Emanuele; Bardi, Federica; Fanti, Riccardo; Gigli, Giovanni; Fidolini, Francesco; Casagli, Nicola; Costanzo, Sandra; Raffo, Antonio; Di Massa, Giuseppe; Capparelli, Giovanna; Versace, Pasquale

    2017-10-01

    A big challenge in terms or landslide risk mitigation is represented by increasing the resiliency of society exposed to the risk. Among the possible strategies with which to reach this goal, there is the implementation of early warning systems. This paper describes a procedure to improve early warning activities in areas affected by high landslide risk, such as those classified as critical infrastructures for their central role in society. This research is part of the project LEWIS (Landslides Early Warning Integrated System): An Integrated System for Landslide Monitoring, Early Warning and Risk Mitigation along Lifelines. LEWIS is composed of a susceptibility assessment methodology providing information for single points and areal monitoring systems, a data transmission network and a data collecting and processing center (DCPC), where readings from all monitoring systems and mathematical models converge and which sets the basis for warning and intervention activities. The aim of this paper is to show how logistic issues linked to advanced monitoring techniques, such as big data transfer and storing, can be dealt with compatibly with an early warning system. Therefore, we focus on the interaction between an areal monitoring tool (a ground-based interferometric radar) and the DCPC. By converting complex data into ASCII strings and through appropriate data cropping and average, and by implementing an algorithm for line-of-sight correction, we managed to reduce the data daily output without compromising the capability for performing.

  16. Quantum Gravity in Cyclic (ekpyrotic) and Multiple (anthropic) Universes with Strings And/or Loops

    NASA Astrophysics Data System (ADS)

    Chung, T. J.

    2008-09-01

    This paper addresses a hypothetical extension of ekpyrotic and anthropic principles, implying cyclic and multiple universes, respectively. Under these hypotheses, from time immemorial (t = -∞), a universe undergoes a big bang from a singularity, initially expanding and eventually contracting to another singularity (big crunch). This is to prepare for the next big bang, repeating these cycles toward eternity (t = +∞), every 30 billion years apart. Infinity in time backward and forward (t = ±∞) is paralleled with infinity in space (Xi = ±∞), allowing multiple universes to prevail, each undergoing big bangs and big crunches similarly as our own universe. It is postulated that either string theory and /or loop quantum gravity might be able to substantiate these hypotheses.

  17. The evolution of modern cosmology as seen through a personal walk across six decades

    NASA Astrophysics Data System (ADS)

    Narlikar, Jayant V.

    2018-02-01

    This highly personal account of evolution of cosmology spans a period of approximately six decades 1959-2017. It begins when in 1959 the author, as an undergraduate at Cambridge, was attracted to the subject by the thought provoking lectures by Fred Hoyle as well as by his popular books The Nature of Universe and The Frontiers of Astronomy. The result was that after a successful performance at the Mathematical Tripos (Part III) examination, he enrolled as a research student of Hoyle. In this article the author describes the interesting works in cosmology that kept him busy both in Cambridge and in India. The issues pertinent to cosmological research in the 1960s and 1970s included the Mach's principle, the Wheeler-Feynman theory relating the local electromagnetic arrow of time to the cosmological one, the observational tests of specific expanding universe models, and issues like singularity in quantum cosmology. However, post-1965, the nature of cosmological research changed dramatically with the discovery of the cosmic microwave background radiation (CMBR). Given the assumption that the CMBR is a relic of big bang there has been a host of papers on the early universe, going as close to the big bang as the very early universe would permit: around just 10-36 s. The author argues that despite the popularity of the standard hot big bang cosmology (SBBC) it rests on rather shaky foundations. On the theoretical side there is no well established physical framework to support the SBBC; nor is there independent observational support for its assumptions like the nonbaryonic dark matter, inflation and dark energy. While technological progress has made it possible to explore the universe in greater detail with open mind, today's cosmologists seem caught in a range of speculations in support of the big bang dogma. Thus, in modern times cosmology appears to have lost the Camelot spirit encouraging adventurous studies of the unknown. A spirit of openness is advocated to restore

  18. The evolution of modern cosmology as seen through a personal walk across six decades

    NASA Astrophysics Data System (ADS)

    Narlikar, Jayant V.

    2018-05-01

    This highly personal account of evolution of cosmology spans a period of approximately six decades 1959-2017. It begins when in 1959 the author, as an undergraduate at Cambridge, was attracted to the subject by the thought provoking lectures by Fred Hoyle as well as by his popular books The Nature of Universe and The Frontiers of Astronomy. The result was that after a successful performance at the Mathematical Tripos (Part III) examination, he enrolled as a research student of Hoyle. In this article the author describes the interesting works in cosmology that kept him busy both in Cambridge and in India. The issues pertinent to cosmological research in the 1960s and 1970s included the Mach's principle, the Wheeler-Feynman theory relating the local electromagnetic arrow of time to the cosmological one, the observational tests of specific expanding universe models, and issues like singularity in quantum cosmology. However, post-1965, the nature of cosmological research changed dramatically with the discovery of the cosmic microwave background radiation (CMBR). Given the assumption that the CMBR is a relic of big bang there has been a host of papers on the early universe, going as close to the big bang as the very early universe would permit: around just 10-36 s. The author argues that despite the popularity of the standard hot big bang cosmology (SBBC) it rests on rather shaky foundations. On the theoretical side there is no well established physical framework to support the SBBC; nor is there independent observational support for its assumptions like the nonbaryonic dark matter, inflation and dark energy. While technological progress has made it possible to explore the universe in greater detail with open mind, today's cosmologists seem caught in a range of speculations in support of the big bang dogma. Thus, in modern times cosmology appears to have lost the Camelot spirit encouraging adventurous studies of the unknown. A spirit of openness is advocated to restore

  19. Infinite derivative gravity: non-singular cosmology & blackhole solutions

    NASA Astrophysics Data System (ADS)

    Mazumdar, A.

    Both Einstein’s theory of General Relativity and Newton’s theory of gravity possess a short distance and small time scale catastrophe. The blackhole singularity and cosmological Big Bang singularity problems highlight that current theories of gravity are incomplete description at early times and small distances. I will discuss how one can potentially resolve these fundamental problems at a classical level and quantum level. In particular, I will discuss infinite derivative theories of gravity, where gravitational interactions become weaker in the ultraviolet, and therefore resolving some of the classical singularities, such as Big Bang and Schwarzschild singularity for compact non-singular objects with mass up to 1025 grams. In this lecture, I will discuss quantum aspects of infinite derivative gravity and discuss few aspects which can make the theory asymptotically free in the UV.

  20. Big data analytics for early detection of breast cancer based on machine learning

    NASA Astrophysics Data System (ADS)

    Ivanova, Desislava

    2017-12-01

    This paper presents the concept and the modern advances in personalized medicine that rely on technology and review the existing tools for early detection of breast cancer. The breast cancer types and distribution worldwide is discussed. It is spent time to explain the importance of identifying the normality and to specify the main classes in breast cancer, benign or malignant. The main purpose of the paper is to propose a conceptual model for early detection of breast cancer based on machine learning for processing and analysis of medical big dataand further knowledge discovery for personalized treatment. The proposed conceptual model is realized by using Naive Bayes classifier. The software is written in python programming language and for the experiments the Wisconsin breast cancer database is used. Finally, the experimental results are presented and discussed.

  1. The Cosmic Microwave Background Radiation - A Unique Window on the Early Universe

    NASA Technical Reports Server (NTRS)

    Hinshaw, Gary F.

    2009-01-01

    The cosmic microwave background radiation is the remnant heat from the Big Bang. It provides us with a unique probe of conditions in the early universe, long before any organized structures had yet formed. The anisotropy in the radiation's brightness yields important clues about primordial structure and additionally provides a wealth of information about the physics of the early universe. Within the framework of inflationary dark matter models, observations of the anisotropy on sub-degree angular scales reveals the signatures of acoustic oscillations of the photon-baryon fluid at a redshift of approx. 1100. Data from the first five years of operation of the Wilkinson Microwave Anisotropy Probe (WMAP) satellite provide detailed full-sky maps of the cosmic microwave background temperature and polarization anisotropy. Together, the data provide a wealth of cosmological information, including the age of the universe, the epoch when the first stars formed, and the overall composition of baryonic matter, dark matter, and dark energy. The results also provide constraints on the period of inflationary expansion in the very first moments of time.

  2. Does loop quantum cosmology replace the big rip singularity by a non-singular bounce?

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Haro, Jaume de, E-mail: jaime.haro@upc.edu

    It is stated that holonomy corrections in loop quantum cosmology introduce a modification in Friedmann's equation which prevent the big rip singularity. Recently in [1] it has been proved that this modified Friedmann equation is obtained in an inconsistent way, what means that the results deduced from it, in particular the big rip singularity avoidance, are not justified. The problem is that holonomy corrections modify the gravitational part of the Hamiltonian of the system leading, after Legendre's transformation, to a non covariant Lagrangian which is in contradiction with one of the main principles of General Relativity. A more consistent waymore » to deal with the big rip singularity avoidance is to disregard modification in the gravitational part of the Hamiltonian, and only consider inverse volume effects [2]. In this case we will see that, not like the big bang singularity, the big rip singularity survives in loop quantum cosmology. Another way to deal with the big rip avoidance is to take into account geometric quantum effects given by the the Wheeler-De Witt equation. In that case, even though the wave packets spread, the expectation values satisfy the same equations as their classical analogues. Then, following the viewpoint adopted in loop quantum cosmology, one can conclude that the big rip singularity survives when one takes into account these quantum effects. However, the spreading of the wave packets prevents the recover of the semiclassical time, and thus, one might conclude that the classical evolution of the universe come to and end before the big rip is reached. This is not conclusive because. as we will see, it always exists other external times that allows us to define the classical and quantum evolution of the universe up to the big rip singularity.« less

  3. Helium-3 in Milky Way Reveals Abundance of Matter in Early Universe

    NASA Astrophysics Data System (ADS)

    2002-01-01

    Astronomers using the National Science Foundation's 140 Foot Radio Telescope in Green Bank, West Virginia, were able to infer the amount of matter created by the Big Bang, and confirmed that it accounts for only a small portion of the effects of gravity observed in the Universe. The scientists were able to make these conclusions by determining the abundance of the rare element helium-3 (helium with only one neutron and two protons in its nucleus) in the Milky Way Galaxy. The NRAO 140 Foot Radio Telescope The NRAO 140-Foot Radio Telescope "Moments after the Big Bang, protons and neutrons began to combine to form helium-3 and other basic elements," said Robert Rood of the University of Virginia. "By accurately measuring the abundance of this primordial element in our Galaxy today, we were able infer just how much matter was created when the Universe was only a few minutes old." Rood and his colleagues, Thomas Bania from Boston University and Dana Balser from the National Radio Astronomy Observatory (NRAO), report their findings in the January 3 edition of the scientific journal Nature. Rood began searching for helium-3 in the Milky Way Galaxy in 1978. At that time, scientists believed that stars like our Sun synthesized helium-3 in their nuclear furnaces. Surprisingly, Rood's observations indicated that there was far less of this element in the Galaxy than the current models predicted. "If stars were indeed producing helium-3, as scientists believed, then we should have detected this element in much greater concentrations," he said. This unexpected discovery prompted Rood and his colleagues to broaden their search, and to look throughout the Milky Way for signs of stellar production of helium-3. Over the course of two decades, the researchers discovered that regardless of where they looked -- whether in the areas of sparse star formation like the outer edges of the Galaxy, or in areas of intense star formation near center of the Galaxy -- the relative abundance of

  4. From the Big Bang to the life in the primitive seas. (Spanish Title: Desde la Gran Explosión hasta la vida en los mares primitivos)

    NASA Astrophysics Data System (ADS)

    Esteban, S. B.

    Man has always wondered about the origins of humanity, life, and the world around him. The Earth crust is a vast and natural archive, and its rocks represent the pages of the most documented events in the geological past. These rocks hold large amounts of information about the Earth history, whose age is estimated to be 4,600 million years. Historical Geology seeks to bring together the knowledge of the origin of the Universe as well as the origin of Earth as a member of the Solar System. The Big Bang theory supposes that the Universe began with a huge explosion. In the Earth's history it is possible to differentiate the biological events from the physical ones. The physical events are geographical and environmental transformations. The biological events are related to life on Earth. There are evidences of biological processes back to 3,500 million years ago. At the beginning, the conditions on Earth were catastrophic and unstable. At this stage, the first signs of life were the molecules that started to take energy from the sunlight and the chemical products. It was not a simple accumulation of gradual biological forms, but was accompanied by episodic innovations that allowed increasing complexity and greater use of ecospace. Some of these innovations are shown by certain groups of primitive arthropods adapted to live in oxygen-poor, deep marine environments. These arthropods have been found in 500 million-year-old rocks in northwestern Argentina (provinces of Jujuy and La Rioja), indicating the presence of oxygen-poor seas in that region.

  5. The Breast International Group 1-98 trial: big results for women with hormone-sensitive early breast cancer.

    PubMed

    Monnier, Alain M

    2007-05-01

    As there is a risk for relapse in early breast cancer, especially at 1-3 years post surgery, the need for adjuvant therapy is clear. In terms of disease-free survival, aromatase inhibitors have emerged as superior to tamoxifen for the adjuvant treatment of hormone-sensitive breast cancer in several Phase III clinical trials. Of these trials, the Breast International Group (BIG) 1-98 trial stands out as unique in design, as it is the only trial to address whether an aromatase inhibitor is more effective as initial adjuvant therapy or as sequential therapy with an aromatase inhibitor and tamoxifen in either order and in rigor of end points and safety evaluations. When compared with tamoxifen, letrozole has been shown to significantly reduce recurrence risk in the overall population by 19% and also significantly reduced recurrence risk in the patient subgroups at increased risk: node-positive and previously chemotherapy-treated patients. Letrozole is the only aromatase inhibitor to demonstrate a significant 27% reduction in the risk of distant metastases (p = 0.001) in the clinically relevant, hormone receptor-positive population in the initial adjuvant setting. Recent results also suggest that letrozole in particular reduces the risk of distant metastases early on after initial surgery for breast cancer. This is important, as early distant metastatic events compose the majority of early recurrences and are a well-recognized predictor of breast cancer death. Letrozole has been found to be well tolerated in the initial adjuvant treatment setting, and these data have been confirmed by long-term safety data from the monotherapy analysis in the BIG 1-98 study. Thus far, the results from the BIG 1-98 trial provide clear support for the use of letrozole in the initial adjuvant treatment of breast cancer. Future studies will provide the definitive answer to questions of which initial adjuvant therapy is superior (i.e., anastrozole or letrozole) and information as to the

  6. Big bounce with finite-time singularity: The F(R) gravity description

    NASA Astrophysics Data System (ADS)

    Odintsov, S. D.; Oikonomou, V. K.

    An alternative to the Big Bang cosmologies is obtained by the Big Bounce cosmologies. In this paper, we study a bounce cosmology with a Type IV singularity occurring at the bouncing point in the context of F(R) modified gravity. We investigate the evolution of the Hubble radius and we examine the issue of primordial cosmological perturbations in detail. As we demonstrate, for the singular bounce, the primordial perturbations originating from the cosmological era near the bounce do not produce a scale-invariant spectrum and also the short wavelength modes after these exit the horizon, do not freeze, but grow linearly with time. After presenting the cosmological perturbations study, we discuss the viability of the singular bounce model, and our results indicate that the singular bounce must be combined with another cosmological scenario, or should be modified appropriately, in order that it leads to a viable cosmology. The study of the slow-roll parameters leads to the same result indicating that the singular bounce theory is unstable at the singularity point for certain values of the parameters. We also conformally transform the Jordan frame singular bounce, and as we demonstrate, the Einstein frame metric leads to a Big Rip singularity. Therefore, the Type IV singularity in the Jordan frame becomes a Big Rip singularity in the Einstein frame. Finally, we briefly study a generalized singular cosmological model, which contains two Type IV singularities, with quite appealing features.

  7. Early experiences with big data at an academic medical center.

    PubMed

    Halamka, John D

    2014-07-01

    Beth Israel Deaconess Medical Center (BIDMC), an academic health care institution affiliated with Harvard University, has been an early adopter of electronic applications since the 1970s. Various departments of the medical center and the physician practice groups affiliated with it have implemented electronic health records, filmless imaging, and networked medical devices to such an extent that data storage at BIDMC now amounts to three petabytes and continues to grow at a rate of 25 percent a year. Initially, the greatest technical challenge was the cost and complexity of data storage. However, today the major focus is on transforming raw data into information, knowledge, and wisdom. This article discusses the data growth, increasing importance of analytics, and changing user requirements that have shaped the management of big data at BIDMC. Project HOPE—The People-to-People Health Foundation, Inc.

  8. The boron-to-beryllium ratio in halo stars - A signature of cosmic-ray nucleosynthesis in the early Galaxy

    NASA Technical Reports Server (NTRS)

    Walker, T. P.; Steigman, G.; Schramm, D. N.; Olive, K. A.; Fields, B.

    1993-01-01

    We discuss Galactic cosmic-ray (GCR) spallation production of Li, Be, and B in the early Galaxy with particular attention to the uncertainties in the predictions of this model. The observed correlation between the Be abundance and the metallicity in metal-poor Population II stars requires that Be was synthesized in the early Galaxy. We show that the observations and such Population II GCR synthesis of Be are quantitatively consistent with the big bang nucleosynthesis production of Li-7. We find that there is a nearly model independent lower bound to B/Be of about 7 for GCR synthesis. Recent measurements of B/Be about 10 in HD 140283 are in excellent agreement with the predictions of Population II GCR nucleosynthesis. Measurements of the boron abundance in additional metal-poor halo stars is a key diagnostic of the GCR spallation mechanism. We also show that Population II GCR synthesis can produce amounts of Li-6 which may be observed in the hottest halo stars.

  9. Age distribution of human gene families shows significant roles of both large- and small-scale duplications in vertebrate evolution.

    PubMed

    Gu, Xun; Wang, Yufeng; Gu, Jianying

    2002-06-01

    The classical (two-round) hypothesis of vertebrate genome duplication proposes two successive whole-genome duplication(s) (polyploidizations) predating the origin of fishes, a view now being seriously challenged. As the debate largely concerns the relative merits of the 'big-bang mode' theory (large-scale duplication) and the 'continuous mode' theory (constant creation by small-scale duplications), we tested whether a significant proportion of paralogous genes in the contemporary human genome was indeed generated in the early stage of vertebrate evolution. After an extensive search of major databases, we dated 1,739 gene duplication events from the phylogenetic analysis of 749 vertebrate gene families. We found a pattern characterized by two waves (I, II) and an ancient component. Wave I represents a recent gene family expansion by tandem or segmental duplications, whereas wave II, a rapid paralogous gene increase in the early stage of vertebrate evolution, supports the idea of genome duplication(s) (the big-bang mode). Further analysis indicated that large- and small-scale gene duplications both make a significant contribution during the early stage of vertebrate evolution to build the current hierarchy of the human proteome.

  10. Inflation in the early universe.

    NASA Astrophysics Data System (ADS)

    Carmeli, M.

    1998-04-01

    In this talk it will be assumed that gravitation is negligible. Under this assumption, the receding velocities of galaxies and the distances between them in the Hubble expansion are united into a four-dimensional pseudo-Euclidean manifold, similarly to space and time in ordinary special relativity. The Hubble law is assumed and is written in an invariant way that enables one to derive a four-dimensional transformation which is similar to the Lorentz transformation. The parameter in the new transformation is the ratio between the cosmic time to the Hubble time. Accordingly, the new transformation relates physical quantities at different cosmic times in the limit of weak or negligible gravitation. The transformation is then applied to the problem of the expansion of the Universe at the very early stage when gravity was negligible and thus the transformation is applicable. The author calculates the ratio of the volumes of the Universe at two different times T1 and T2 after the big bang. The result conforms with the standard inflationary universe theory, but now it is obtained without assuming that the Universe is propelled by antigravity.

  11. Abbreviated right-sided heart echocardiogram and the STOP-Bang questionnaire-a useful relationship for preoperative patient evaluation?

    PubMed

    Evans, Rebecca E; Zimmerman, Joshua; Shishido, Sonia; Heath, Elise; Bledsoe, Amber; Johnson, Ken

    2016-05-01

    The aims of this study were to (1) explore the incidence of right-sided heart dysfunction (RHD) and STOP-Bang questionnaire responses consistent with obstructive sleep apnea (OSA) and (2) assess the relationship between patients with STOP-Bang questionnaire responses consistent with OSA and echocardiographic findings suggestive of RHD. Observational study. Tertiary academic center preoperative clinic. Two hundred patients presenting for elective surgery to the University of Utah preoperative clinic. Abbreviated transthoracic right-sided echocardiogram and STOP-Bang questionnaire. Tricuspid annular plane systolic excursion, tissue Doppler-derived tricuspid lateral annular systolic velocity (S'), and the tricuspid inflow E wave to tricuspid annular tissue Doppler e' wave ratio (E/e') for the presence of RHD, as well as responses to STOP-Bang questionnaire. A total of 140 echocardiograms were analyzed after exclusion of participants with incomplete STOP-Bang questionnaires and inadequate images. Thirty-five patients (25%) reported 5 or more positive responses to the STOP-Bang questionnaire. Forty-six patients (35%) had abnormal right-sided heart measurements. Of the 35 patients with STOP-Bang scores 5 or greater, 11 (31%) had evidence of RHD. No correlation was observed between STOP-Bang scores and the echocardiography metrics of RHD. This preliminary study suggests that there are numerous sources of RHD, among one of which is sleep apnea, and/or the STOP-Bang questionnaire is not a sensitive tool for predicting RHD. We conclude that although the STOP-Bang questionnaire is easy to implement in a preoperative clinical setting, it is not useful in identifying patients at risk for RHD. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Big Bang Day : The Great Big Particle Adventure - 2. Who Ordered That?

    ScienceCinema

    None

    2017-12-09

    In this series, comedian and physicist Ben Miller asks the CERN scientists what they hope to find. The atoms that make up our material world are important to us, but it turns out they aren't so significant on the cosmic stage. In fact early in the search for the stuff of atoms, researchers discovered particles that played no part in Earthly chemistry - for example particles in cosmic rays that resemble electrons (the stuff of electricity and the chemical glue in molecules) in almost all respects except that they weigh 140 times more. "Who ordered that?" one Nobel laureate demanded. They also discovered antimatter - the destructive mirror-image particles at obliterate all matter they come into contact with. In fact, the Universe is mostly made up of particles that could never make atoms, so that we are just the flotsam of the cosmos. But the main constituent of the Universe, what makes 80% of creation, has never been seen in the lab. Researchers at CERN believe they can create samples of it, down here on Earth.

  13. Inflation and late-time acceleration from a double-well potential with cosmological constant

    NASA Astrophysics Data System (ADS)

    de Haro, Jaume; Elizalde, Emilio

    2016-06-01

    A model of a universe without big bang singularity is presented, which displays an early inflationary period ending just before a phase transition to a kination epoch. The model produces enough heavy particles so as to reheat the universe at temperatures in the MeV regime. After the reheating, it smoothly matches the standard Λ CDM scenario.

  14. On the Weyl curvature hypothesis

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Stoica, Ovidiu Cristinel, E-mail: holotronix@gmail.com

    2013-11-15

    The Weyl curvature hypothesis of Penrose attempts to explain the high homogeneity and isotropy, and the very low entropy of the early universe, by conjecturing the vanishing of the Weyl tensor at the Big-Bang singularity. In previous papers it has been proposed an equivalent form of Einstein’s equation, which extends it and remains valid at an important class of singularities (including in particular the Schwarzschild, FLRW, and isotropic singularities). Here it is shown that if the Big-Bang singularity is from this class, it also satisfies the Weyl curvature hypothesis. As an application, we study a very general example of cosmologicalmore » models, which generalizes the FLRW model by dropping the isotropy and homogeneity constraints. This model also generalizes isotropic singularities, and a class of singularities occurring in Bianchi cosmologies. We show that the Big-Bang singularity of this model is of the type under consideration, and satisfies therefore the Weyl curvature hypothesis. -- Highlights: •The singularities we introduce are described by finite geometric/physical objects. •Our singularities have smooth Riemann and Weyl curvatures. •We show they satisfy Penrose’s Weyl curvature hypothesis (Weyl=0 at singularities). •Examples: FLRW, isotropic singularities, an extension of Schwarzschild’s metric. •Example: a large class of singularities which may be anisotropic and inhomogeneous.« less

  15. Cosmological element production.

    PubMed

    Wagoner, R V

    1967-03-17

    Two recent observations appear to have provided critical information about the past history of the universe. The thermal character of the microwave background radiation suggests that the universe has expanded from a state of high temperature and density, and places constraints on such a big-bang cosmology. The observations of very weak helium lines in the spectra of certain stars in the halo of our galaxy are possibly due to a low primeval abundance of this element. However, the simplest model of a big-bang cosmology leads to much higher helium abundances, such as are observed in the solar system and in many stars. The production of helium can be reduced either by altering the early expansion rate or by introducing degenerate electron neutrinos. Observations of interstellar and intergalactic deuterium and He(4), and possibly even He(3) and Li(7), are needed to test the various models.

  16. Was the Universe actually radiation dominated prior to nucleosynthesis?

    NASA Astrophysics Data System (ADS)

    Giblin, John T.; Kane, Gordon; Nesbit, Eva; Watson, Scott; Zhao, Yue

    2017-08-01

    Maybe not. String theory approaches to both beyond the Standard Model and inflationary model building generically predict the existence of scalars (moduli) that are light compared to the scale of quantum gravity. These moduli become displaced from their low energy minima in the early Universe and lead to a prolonged matter-dominated epoch prior to big bang nucleosynthesis (BBN). In this paper, we examine whether nonperturbative effects such as parametric resonance or tachyonic instabilities can shorten, or even eliminate, the moduli condensate and matter-dominated epoch. Such effects depend crucially on the strength of the couplings, and we find that unless the moduli become strongly coupled, the matter-dominated epoch is unavoidable. In particular, we find that in string and M-theory compactifications where the lightest moduli are near the TeV scale, a matter-dominated epoch will persist until the time of big bang nucleosynthesis.

  17. Initial conditions for cosmological perturbations

    NASA Astrophysics Data System (ADS)

    Ashtekar, Abhay; Gupt, Brajesh

    2017-02-01

    Penrose proposed that the big bang singularity should be constrained by requiring that the Weyl curvature vanishes there. The idea behind this past hypothesis is attractive because it constrains the initial conditions for the universe in geometric terms and is not confined to a specific early universe paradigm. However, the precise statement of Penrose’s hypothesis is tied to classical space-times and furthermore restricts only the gravitational degrees of freedom. These are encapsulated only in the tensor modes of the commonly used cosmological perturbation theory. Drawing inspiration from the underlying idea, we propose a quantum generalization of Penrose’s hypothesis using the Planck regime in place of the big bang, and simultaneously incorporating tensor as well as scalar modes. Initial conditions selected by this generalization constrain the universe to be as homogeneous and isotropic in the Planck regime as permitted by the Heisenberg uncertainty relations.

  18. NovaCare's big bang.

    PubMed

    Speer, T L

    1997-10-05

    The no. 2 rehab provider took a dose of its own medicine--therapy that boosted productivity, slashed costs, and pushed the company into new markets. Now a consensus of analysts sees growth soaring by 20 percent a year.

  19. Finding the Big Bang

    NASA Astrophysics Data System (ADS)

    Peebles, P. James E.; Page, Lyman A., Jr.; Partridge, R. Bruce

    2009-03-01

    1. Introduction; 2. A guide to modern cosmology; 3. Origins of the cosmology of the 1960s; 4. Recollections of the 1960s Dave Hogg, Neville Woolf, George B. Field, Patrick Thaddeus, Donald E. Osterbrock, Yuri Nikolaevich Smirnov, Igor Dmitriyevich Novikov, Andrei Georgievich Doroshkevich, Rashid Alievich Sunyaev, Malcolm S. Longair, Arno Penzias, Robert W. Wilson, Bernard F. Burke, Kenneth C. Turner, P. James E. Peebles, David T. Wilkinson, Peter G. Roll, R. Bruce Partridge, Malcolm S. Longair, John Faulkner, Robert V. Wagoner, Martin Rees, Geoffrey R. Burbidge, Jayant V. Narlikar, David Layzer, Michele Kaufman, Jasper V. Wall, John Shakeshaft, William Welch, Kazimir S. Stankevich, Paul Boynton, Robert A. Stokes, Martin Harwit, Judith L. Pipher, Kandiah Shivanandan, Rainer Weiss, Jer-tsang Yu, Rainer K. Sachs, Arthur M. Wolfe, Joe Silk, George F. R. Ellis, Ronald N. Bracewell, Edward K. Conklin, Stephen Boughn, Karl C. Davis, Paul S. Henry; 5. Cosmology and the CMBR since the 1960s Dick Bond; Appendixes; Glossary; References; Index.

  20. Pop science's big bang

    NASA Astrophysics Data System (ADS)

    Barrow, John D.

    2008-10-01

    Physicists have a long history of writing books for outsiders - often to enlighten, sometimes to persuade and occasionally to assuage. Galileo's Dialogues bypassed the conventional channels of scholarly debate and addressed the general public directly; Newton was happy for others to use his work in the public arena and to see the Newtonian "system of the world", as outlined in his Principia, extend far beyond physics. Few people could read Newton, but everyone read about him. In a similar vein, Einstein's public reputation rose steadily upwards, enhanced, ironically, by a reputation for his work being stratospherically difficult to comprehend. This reassured people that they really did not need to make the effort to understand it, merely know that it was very important. Even his own elegant efforts at popularization with co-author Leopold Infeld in 1938, The Evolution of Physics, were unable to sweep away this myth.

  1. The MHC big bang.

    PubMed

    Abi Rached, L; McDermott, M F; Pontarotti, P

    1999-02-01

    The human Major Histocompatibility Complex (MHC) shares similarities with three other chromosome regions in human. This could be the vestige of ancestral large scale duplications. We discuss here the possibility i) that these duplications occurred during two rounds of tetraploidization supposed to have taken place during chordate evolution before the jawed vertebrate radiation, and ii) that one of the quadruplicate regions, relaxed of functional constraints, gave rise to the vertebrate MHC by a quick round of gene cis-duplication and cis-exon shuffling. These different rounds of cis-duplications and exon shufflings allowed the emergence of new genes participating in novel biological functions i.e. adaptive immune responses. Cis-duplications and cis-exon shufflings are ongoing processes in the evolution of some of these genes in this region as they have occurred and were fixed at different times and in different lineages during vertebrate evolution. In contrast, other genes within the MHC have remained stable since the emergence of jawed vertebrates.

  2. Light element production in the big bang and the synthesis of heavy elements in 3D MHD jets from core-collapse supernovae

    NASA Astrophysics Data System (ADS)

    Winteler, Christian

    2014-02-01

    In this dissertation we present the main features of a new nuclear reaction network evolution code. This new code allows nucleosynthesis calculations for large numbers of nuclides. The main results in this dissertation are all obtained using this new code. The strength of standard big bang nucleosynthesis is, that all primordial abundances are determined by only one free parameter, the baryon-to-photon ratio η. We perform self consistent nucleosynthesis calculations for the latest WMAP value η = (6.16±0.15)×10^-10 . We predict primordial light element abundances: D/H = (2.84 ± 0.23)×10^-5, 3He/H = (1.07 ± 0.09)×10^-5, Yp = 0.2490±0.0005 and 7Li/H = (4.57 ± 0.55)×10^-10, in agreement with current observations and other predictions. We investigate the influence of the main production rate on the 6 Li abundance, but find no significant increase of the predicted value, which is known to be orders of magnitude lower than the observed. The r-process is responsible for the formation of about half of the elements heavier than iron in our solar system. This neutron capture process requires explosive environments with large neutron densities. The exact astrophysical site where the r-process occurs has not yet been identified. We explore jets from magnetorotational core collapse supernovae (MHD jets) as possible r-process site. In a parametric study, assuming adiabatic expansion, we find good agreement with solar system abundances for a superposition of components with different electron fraction (Ye ), ranging from Ye = 0.1 to Ye = 0.3. Fission is found to be important only for Ye ≤ 0.17. The first postprocessing calculations with data from 3D MHD core collapse supernova simulations are performed for two different simulations. Calculations are based on two different methods to extract data from the simulation: tracer particles and a two dimensional, mass weighted histogram. Both results yield almost identical results. We find that both simulations can

  3. Incorporating body-type (apple vs. pear) in STOP-BANG questionnaire improves its validity to detect OSA.

    PubMed

    Sangkum, Lisa; Klair, Ikrita; Limsuwat, Chok; Bent, Sabrina; Myers, Leann; Thammasitboon, Supat

    2017-09-01

    The aim of this study is to evaluate whether adding the item of "apple body type" to the STOP-BANG questionnaire enhances diagnostic performance of the questionnaire for detecting obstructive sleep apnea (OSA). Cross-sectional study. Sleep center setting. Two hundred and eight subjects who were referred for an evaluation of possible OSA at Tulane Comprehensive Sleep Center. The exclusion criteria were age<18years old, incomplete or absent questionnaire, incomplete body type identification, polysomnography (PSG) refusal, and pregnant women. STOP-BANG items and body type data were collected on the initial clinic visit. An overnight PSG was performed on every participant. Descriptive analyses of the demographic data and PSG variables were performed. The predictive parameters of STOP and STOP-BANG without and with body type score (STOP-Apple and STOPBANG-Apple) were compared. The STOP questionnaire's sensitivity/specificity/positive likelihood ratio (+LR) (cut-off=2) was 96%/11%/1.1, respectively whereas the STOP-Apple questionnaire (cut-off=3) was 88%/39%/1.5. The STOP-BANG's sensitivity/specificity/+LR (cut-off=3) was 96%/19%/1.2, respectively whereas the STOP-BANG-Apple questionnaire (cut-off=4) was 90%/39%/1.5. The area under the Receiver Operating Characteristic (ROC) curve of STOP-Apple was comparable to the STOP-BANG (P=0.25). The addition of the apple body type item to the STOP-BANG questionnaire in participants with a score≥3 led to increased specificity (67.4%), increased the odds ratio of having OSA of 2.5 (95% CI, 1.2-5.3) and odds ratio of having moderate-severe OSA of 4.7 (95% CI, 2.5-8.7). In the sleep center setting, adding the body type item to the STOP-BANG questionnaire improves not only clinical prediction for PSG confirmed OSA but also predicts moderate to severe of OSA. Published by Elsevier Inc.

  4. The cosmic web and microwave background fossilize the first turbulent combustion

    NASA Astrophysics Data System (ADS)

    Gibson, Carl H.; Keeler, R. Norris

    2016-10-01

    Collisional fluid mechanics theory predicts a turbulent hot big bang at Planck conditions from large, negative, turbulence stresses below the Fortov-Kerr limit (< -10113 Pa). Big bang turbulence fossilized when quarks formed, extracting the mass energy of the universe by extreme negative viscous stresses of inflation, expanding to length scales larger than the horizon scale ct. Viscous-gravitational structure formation by fragmentation was triggered at big bang fossil vorticity turbulence vortex lines during the plasma epoch, as observed by the Planck space telescope. A cosmic web of protogalaxies, protogalaxyclusters, and protogalaxysuperclusters that formed in turbulent boundary layers of the spinning voids are hereby identified as expanding turbulence fossils that falsify CDMHC cosmology.

  5. CHAIRMAN'S PREFACE: Nobel Symposium 79: The Birth and Early Evolution of Our Universe

    NASA Astrophysics Data System (ADS)

    Gustafsson, Bengt; Nilsson, Jan S.; Skagerstam, Bo-Sture

    1991-01-01

    It was in 1986 that we submitted a proposal to organize a Nobel Symposium on the topic "The Birth and Early Evolution of Our Universe", a subject not previously discussed at such a meeting. Our feeling at the time was that it would be appropriate to gather together international expertise on the deep and exciting connections between elementary physics and astrophysics/cosmology. In both these scientific disciplines there are wellknown "standard models"—the Glashow-Weinberg-Salam model of electroweak interactions and the Big-Bang cosmological model. The former model has now been tested to a very high accuracy. Progress in observational cosmology and astrophysics has on the other hand given strong support to the standard Big-Bang model as a realistic framework of cosmological evolution. The interesting fact, of course, is that the two standard models are not independent, and their predictions become interlinked when one considers the early, hot universe. It is now a wonderfully accepted piece of history that the constraint on the number of light neutrinos as obtained from the Big-Bang primordial nucleosynthesis agree very well with recent high-energy laboratory experiments. When our proposal was approved in 1989 we were very happy and honoured to invite a large number of internationally outstanding contributors to take part in the Symposium, almost all of whom were able to participate. It was, however, with deep regret and shock that their sudden deaths prevented us from inviting A Sakharov and Y Zeldovich. Their presence and wisdom was sadly missed. By choosing the beautiful village of Gräftåvallen, outside the town of Östesund, as the location of the Symposium, we hoped to provide a relaxing and stimulating atmosphere and also, possibly, almost twenty hours of sunlight a day for a week. The hosts of Gräftåvallen, Annika and Tommy Hagström, have to be thanked for making our stay both extremely successful and to a memorable experience. Our thanks also go to

  6. Rapid growth of seed black holes in the early universe by supra-exponential accretion.

    PubMed

    Alexander, Tal; Natarajan, Priyamvada

    2014-09-12

    Mass accretion by black holes (BHs) is typically capped at the Eddington rate, when radiation's push balances gravity's pull. However, even exponential growth at the Eddington-limited e-folding time t(E) ~ few × 0.01 billion years is too slow to grow stellar-mass BH seeds into the supermassive luminous quasars that are observed when the universe is 1 billion years old. We propose a dynamical mechanism that can trigger supra-exponential accretion in the early universe, when a BH seed is bound in a star cluster fed by the ubiquitous dense cold gas flows. The high gas opacity traps the accretion radiation, while the low-mass BH's random motions suppress the formation of a slowly draining accretion disk. Supra-exponential growth can thus explain the puzzling emergence of supermassive BHs that power luminous quasars so soon after the Big Bang. Copyright © 2014, American Association for the Advancement of Science.

  7. Cosmology and the early universe

    NASA Astrophysics Data System (ADS)

    Joshi, Abhigna

    2017-01-01

    In the beginning the universe was in a hot dense state nearly 13.8 billion years ago. The thermal history of the universe was traced back to an era when the temperature was about 1012K. At this early time, the universe was filled with particles-mostly photons and leptons- whose interactions are hopefully weak enough to allow this medium to be treated as a more or less ideal gas. However, if we look back a little further, into the first 0.0001 second of cosmic history when the temperature was above 1012K. At such temperatures, there will be present in thermal equilibrium copious numbers of strongly interacting particles-mostly masons and baryons-with a mean interparticle distance less than a Compton wavelength. These particles will be in a state of continual mutual interaction, and cannot reasonably be expected to obey any simple equation of state. The inflationary epoch lasted from 10-36seconds after the Big Bang to sometime between 10-33and 10-32seconds. Matter and energy created in this time. Right after that space expanded exponentially with enormous rate of 74.3 +/-2.1Km per second per Mpc. Undergraduate student and researcher of the string theory, quantum gravity, cosmology and quantum biology.

  8. A massive protocluster of galaxies at a redshift of z ≈ 5.3.

    PubMed

    Capak, Peter L; Riechers, Dominik; Scoville, Nick Z; Carilli, Chris; Cox, Pierre; Neri, Roberto; Robertson, Brant; Salvato, Mara; Schinnerer, Eva; Yan, Lin; Wilson, Grant W; Yun, Min; Civano, Francesca; Elvis, Martin; Karim, Alexander; Mobasher, Bahram; Staguhn, Johannes G

    2011-02-10

    Massive clusters of galaxies have been found that date from as early as 3.9 billion years (3.9 Gyr; z = 1.62) after the Big Bang, containing stars that formed at even earlier epochs. Cosmological simulations using the current cold dark matter model predict that these systems should descend from 'protoclusters'-early overdensities of massive galaxies that merge hierarchically to form a cluster. These protocluster regions themselves are built up hierarchically and so are expected to contain extremely massive galaxies that can be observed as luminous quasars and starbursts. Observational evidence for this picture, however, is sparse because high-redshift protoclusters are rare and difficult to observe. Here we report a protocluster region that dates from 1 Gyr (z = 5.3) after the Big Bang. This cluster of massive galaxies extends over more than 13 megaparsecs and contains a luminous quasar as well as a system rich in molecular gas. These massive galaxies place a lower limit of more than 4 × 10(11) solar masses of dark and luminous matter in this region, consistent with that expected from cosmological simulations for the earliest galaxy clusters.

  9. Unified field theories, the early big bang, and the microwave background paradox

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.

    1979-01-01

    It is suggested that a superunified field theory incorporating gravity and possessing asymptotic freedom could provide a solution to the paradox of the isotropy of the universal 3K background radiation. Thermal equilibrium could be established in this context through interactions occurring in a temporally indefinite preplanckian era.

  10. The first three minutes - 1990 version. [of early universe after Big Bang

    NASA Technical Reports Server (NTRS)

    Schramm, David N.

    1991-01-01

    The present state of understanding of what occurred in the universe's first three minutes is reviewed. Emphasis is on the events that lead to potentially observable consequences and that are model-independent or at least generic to broad classes of models. Inflation, phase transitions, dark matter, and nucleosynthesis are summarized.

  11. L. V. Al'tshuler, and High Energy Density Research

    NASA Astrophysics Data System (ADS)

    Gibson, Carl H.; Krikorian, Nerses H.; Keeler, R. Norris

    2012-03-01

    Knowledge of high energy densities critical to cosmology and astrophysics was achieved and exchanged among a very few scientists at a time when science was even more constrained by political considerations that it is today. Resources for the early studies necessarily involved atomic weaponry. A history of L. V. Al'tshuler and some others in his science is given in cosmological context. In the beginning of cosmology and the Universe, negative Fortov-Planck1 pressures c7h-1G-2 of 4.6 10115 Pa are overcome by inertial-vortex anti-gravity (dark energy) pressures to achieve a turbulent big bang and the first turbulent combustion with power 1066 watts at the Kolmogorov-Planck scale 10-35 meters. The big bang event ceased when negative- pressure gluon-viscous-forces extracted 10100 kg of mass-energy from the vacuum to produce the observed fossil vorticity turbulence Universe and its inflation with power 10145 watts.

  12. Lithium-6: A probe of the early universe

    PubMed

    Jedamzik

    2000-04-10

    I consider the synthesis of 6Li due to the decay of relic particles, such as gravitinos or moduli, after the epoch of big bang nucleosynthesis. The synthesized 6Li/H ratio may be compared to 6Li/H in metal-poor stars which, in the absence of stellar depletion of 6Li, yields significantly stronger constraints on relic particle densities than the usual consideration of overproduction of 3He. Production of 6Li during such an era of nonthermal nucleosynthesis may also be regarded as a possible explanation for the relatively high 6Li/H ratios observed in metal-poor halo stars.

  13. Big Opportunities and Big Concerns of Big Data in Education

    ERIC Educational Resources Information Center

    Wang, Yinying

    2016-01-01

    Against the backdrop of the ever-increasing influx of big data, this article examines the opportunities and concerns over big data in education. Specifically, this article first introduces big data, followed by delineating the potential opportunities of using big data in education in two areas: learning analytics and educational policy. Then, the…

  14. Observing the Cosmic Microwave Background Radiation: A Unique Window on the Early Universe

    NASA Technical Reports Server (NTRS)

    Hinshaw, Gary; Fisher, Richard R. (Technical Monitor)

    2001-01-01

    The cosmic microwave background radiation is the remnant heat from the Big Bang. It provides us with a unique probe of conditions in the early universe, long before any organized structures had yet formed. The anisotropy in the radiation's brightness yields important clues about primordial structure and additionally provides a wealth of information about the physics,of the early universe. Within the framework of inflationary dark matter models observations of the anisotropy on sub-degree angular scales will reveal the signatures of acoustic oscillations of the photon-baryon fluid at a redshift of approx. 1100. The validity of inflationary models will be tested and, if agreement is found, accurate values for most of the key cosmological parameters will result. If disagreement is found, we will need to rethink our basic ideas about the physics of the early universe. I will present an overview of the physical processes at work in forming the anisotropy and discuss what we have already learned from current observations. I will conclude with a brief overview of the recently launched Microwave Anisotropy Probe (MAP) mission which will observe the anisotropy over the full sky with 0.21 degree angular resolution. At the time of this meeting, MAP will have just arrived at the L2 Lagrange point, marking the start of its observing campaign. The MAP hardware is being produced by Goddard in partnership with Princeton University.

  15. Big bang or continuous creation: does life have multiple origins?

    NASA Astrophysics Data System (ADS)

    Konesky, Gregory A.

    2012-10-01

    The generally accepted notion of a single origin of life from a primordial soup on the early Earth has been challenged recently by the suggestion of a "second life," "shadow life," and even "biological dark matter." The problem in classifying these microorganisms is in the difficulty or complete failure of the 16s genetic fingerprinting process, suggesting a different underlying biochemistry resulting from at least a second origin of life. We consider an extension of this concept to include continuous origination of life throughout Earth's history, up to the present. The consequences for interpreting the "tree of life" are also considered.

  16. What is your Cosmic Connection to the Elements?

    NASA Technical Reports Server (NTRS)

    White, Nicholas E. (Technical Monitor); Lochner, James; Rohrbach, Gail; Cochrane, Kim

    2003-01-01

    This information and activity booklet describes the roles of the Big Bang, types of stars, supernovae, cosmic ray interactions, and radioactive decay in the formation of the elements. The booklet includes instructions for the following classroom activities, intended for students in Grades 9-12: Grandma's Apple Pie; Cosmic Shuffle; Nickel-odeon; Kinesthetic Big Bang; Elemental Haiku; Cosmic Ray Collisions; Cosmic Abundances; and What's Out There.

  17. The STOP-BANG questionnaire shows an insufficient specificity for detecting obstructive sleep apnea in patients with atrial fibrillation.

    PubMed

    Abumuamar, Asmaa M; Dorian, Paul; Newman, David; Shapiro, Colin M

    2018-04-22

    Obstructive sleep apnea (OSA) is a sleep disorder associated with significant cardiovascular comorbidities, including cardiac arrhythmia. The STOP-BANG questionnaire is an eight-item self-report questionnaire designed to screen patients for OSA and was validated in preoperative surgical patients. The STOP items are snoring, daytime tiredness, observed apneas and high blood pressure. The BANG items are body mass index >35 kg/m 2 , age >50 years, neck circumference >40 cm and male gender. We aimed to determine the screening properties of the STOP-BANG questionnaire in patients with arrhythmia. Non-selected consecutive patients were recruited from arrhythmia clinics. Patients with previously diagnosed and/or treated OSA were excluded. The STOP-BANG questionnaire was self-administered. Patients underwent two consecutive nights of home sleep recording. OSA was defined as an apnea-hypopnea index score of ≥5/hr of sleep. The screening properties of the STOP-BANG questionnaire were analysed compared with the objective diagnosis of OSA by ambulatory testing. Ninety-five patients were included in the final analysis. Eighty-five percent were found to have OSA. The STOP-BANG score of ≥3 was 89% sensitive and 36% specific for diagnosis of OSA. The STOP-BANG questionnaire had fair performance, as indicated by an area under the curve of 0.74 (p = .004). In conclusion, the STOP-BANG questionnaire is sensitive; however, it has a low specificity with a high false positive rate. Given that a large number of atrial fibrillation patients need testing for OSA, we recommend the use of a level II sleep study regardless of the results of the screening questionnaire. This approach accurately identifies OSA and may limit the cost of unnecessary level-I sleep studies. © 2018 European Sleep Research Society.

  18. Big Data and the Global Public Health Intelligence Network (GPHIN)

    PubMed Central

    Dion, M; AbdelMalik, P; Mawudeku, A

    2015-01-01

    Background Globalization and the potential for rapid spread of emerging infectious diseases have heightened the need for ongoing surveillance and early detection. The Global Public Health Intelligence Network (GPHIN) was established to increase situational awareness and capacity for the early detection of emerging public health events. Objective To describe how the GPHIN has used Big Data as an effective early detection technique for infectious disease outbreaks worldwide and to identify potential future directions for the GPHIN. Findings Every day the GPHIN analyzes over more than 20,000 online news reports (over 30,000 sources) in nine languages worldwide. A web-based program aggregates data based on an algorithm that provides potential signals of emerging public health events which are then reviewed by a multilingual, multidisciplinary team. An alert is sent out if a potential risk is identified. This process proved useful during the Severe Acute Respiratory Syndrome (SARS) outbreak and was adopted shortly after by a number of countries to meet new International Health Regulations that require each country to have the capacity for early detection and reporting. The GPHIN identified the early SARS outbreak in China, was credited with the first alert on MERS-CoV and has played a significant role in the monitoring of the Ebola outbreak in West Africa. Future developments are being considered to advance the GPHIN’s capacity in light of other Big Data sources such as social media and its analytical capacity in terms of algorithm development. Conclusion The GPHIN’s early adoption of Big Data has increased global capacity to detect international infectious disease outbreaks and other public health events. Integration of additional Big Data sources and advances in analytical capacity could further strengthen the GPHIN’s capability for timely detection and early warning. PMID:29769954

  19. Gravitational Physics: the birth of a new era

    NASA Astrophysics Data System (ADS)

    Sakellariadou, Mairi

    2017-11-01

    We live the golden age of cosmology, while the era of gravitational astronomy has finally begun. Still, fundamental puzzles remain. Standard cosmology is formulated within the framework of Einstein's General theory of Relativity. Notwithstanding, General Relativity is not adequate to explain the earliest stages of cosmic existence, and cannot provide an explanation for the Big Bang itself. Modern early universe cosmology is in need of a rigorous underpinning in Quantum Gravity.

  20. A dust-obscured massive maximum-starburst galaxy at a redshift of 6.34.

    PubMed

    Riechers, Dominik A; Bradford, C M; Clements, D L; Dowell, C D; Pérez-Fournon, I; Ivison, R J; Bridge, C; Conley, A; Fu, Hai; Vieira, J D; Wardlow, J; Calanog, J; Cooray, A; Hurley, P; Neri, R; Kamenetzky, J; Aguirre, J E; Altieri, B; Arumugam, V; Benford, D J; Béthermin, M; Bock, J; Burgarella, D; Cabrera-Lavers, A; Chapman, S C; Cox, P; Dunlop, J S; Earle, L; Farrah, D; Ferrero, P; Franceschini, A; Gavazzi, R; Glenn, J; Solares, E A Gonzalez; Gurwell, M A; Halpern, M; Hatziminaoglou, E; Hyde, A; Ibar, E; Kovács, A; Krips, M; Lupu, R E; Maloney, P R; Martinez-Navajas, P; Matsuhara, H; Murphy, E J; Naylor, B J; Nguyen, H T; Oliver, S J; Omont, A; Page, M J; Petitpas, G; Rangwala, N; Roseboom, I G; Scott, D; Smith, A J; Staguhn, J G; Streblyanska, A; Thomson, A P; Valtchanov, I; Viero, M; Wang, L; Zemcov, M; Zmuidzinas, J

    2013-04-18

    Massive present-day early-type (elliptical and lenticular) galaxies probably gained the bulk of their stellar mass and heavy elements through intense, dust-enshrouded starbursts--that is, increased rates of star formation--in the most massive dark-matter haloes at early epochs. However, it remains unknown how soon after the Big Bang massive starburst progenitors exist. The measured redshift (z) distribution of dusty, massive starbursts has long been suspected to be biased low in z owing to selection effects, as confirmed by recent findings of systems with redshifts as high as ~5 (refs 2-4). Here we report the identification of a massive starburst galaxy at z = 6.34 through a submillimetre colour-selection technique. We unambiguously determined the redshift from a suite of molecular and atomic fine-structure cooling lines. These measurements reveal a hundred billion solar masses of highly excited, chemically evolved interstellar medium in this galaxy, which constitutes at least 40 per cent of the baryonic mass. A 'maximum starburst' converts the gas into stars at a rate more than 2,000 times that of the Milky Way, a rate among the highest observed at any epoch. Despite the overall downturn in cosmic star formation towards the highest redshifts, it seems that environments mature enough to form the most massive, intense starbursts existed at least as early as 880 million years after the Big Bang.

  1. Big Numbers Hypothesis

    NASA Astrophysics Data System (ADS)

    Goradia, Shantilal

    2006-10-01

    The dark matter predicted by the quantum field theory has a value of force 10^120 greater than indicated by observations. The product of 10^80 nucleons and the surface area 10^40 of each nucleon is 10^120. The surface area of the universe taken as a single particle is 10^120. The coupling constant between inter universes calculable, as square of D (Hubble time) as done in [1] is 10^120. The ratio of Hubble time to nucleon diameter is the same as the ratio of nucleon surface area to Planck length, both equal to 10^40, raising a question: Are they both inflating at the same time or is it the Planck length that is shrinking since the big bang, and impacting evolution? The universe looks inflationary looking inside out. We are taking Doppler effect as scale invariant, while the fundamental constants of nature are changing. The 2002 publication of the English translation of Einstein's 1919 paper by Hawking reveals clearly that he retracted the 1917 introduction of the cosmological constant. He might have informally uttered to Gamow about his blunder made in 1917 without clarifying his correction in 1919. His 1919 paper and his 1935 paper, both connect particles to normal spacetime implying he held the same view the rest of his life. I connect them too in physics/0210040 and will present more details. [1] S. G. Goradia gr-qc/0507130 (Indian Journal of Theoretical Physics 52 143 2004)

  2. The cosmic web and microwave background fossilize the first turbulent combustion

    NASA Astrophysics Data System (ADS)

    Gibson, Carl H.

    2015-09-01

    The weblike structure of the cosmic microwave background CMB temperature fluctuations are interpreted as fossils of the first turbulent combustion that drives the big bang1,2,3. Modern turbulence theory3 requires that inertial vortex forces cause turbulence to always cascade from small scales to large, contrary to the standard turbulence model where the cascade is reversed. Assuming that the universe begins at Planck length 10-35 m and temperature 1032 K, the mechanism of the big bang is a powerful turbulent combustion instability, where turbulence forms at the Kolmogorov scale and mass-energy is extracted by < -10113 Pa negative stresses from big bang turbulence working against gravity. Prograde accretion of a Planck antiparticle on a spinning particle-antiparticle pair releases 42% of a particle rest mass from the Kerr metric, producing a spinning gas of turbulent Planck particles that cascades to larger scales at smaller temperatures (10-27 m, 1027 K) retaining the Planck density 1097 kg m-3, where quarks form and gluon viscosity fossilizes the turbulence. Viscous stress powers inflation to ~ 10 m and ~ 10100 kg. The CMB shows signatures of both plasma and big bang turbulence. Direct numerical simulations support the new turbulence theory6.

  3. Multiverse Space-Antispace Dual Calabi-Yau `Exciplex-Zitterbewegung' Particle Creation

    NASA Astrophysics Data System (ADS)

    Amoroso, Richard L.

    Modeling the `creation/emergence' of matter from spacetime is as old as modern cosmology itself and not without controversy within each model such as Static, Steady-state, Big Bang or Multiverse Continuous-State. In this paper we present only a brief primitive introduction to a new form of `Exciplex-Zitterbewegung' dual space-antispace vacuum Particle Creation applicable especially to Big Bang alternatives which are well-known but ignored; Hubble discovered `Redshift' not a Doppler expansion of the universe which remains the currently popular interpretation. Holographic Anthropic Multiverse cosmology provides viable alternatives to all seemingly sacrosanct pillars of the Big Bang. A model for Multiverse Space-Antispace Dual Calabi-Yau `Exciplex-Zitterbewegung' particle creation has only become possible by incorporating the additional degrees of freedom provided by the capacity complex dimensional extended Yang-Mills Kaluza-Klein correspondence provides.

  4. Helium synthesis, neutrino flavors, and cosmological implications

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.

    1979-01-01

    The problem of the production of helium in big bang cosmology is re-examined in the light of several recent astrophysical observations. These data, and theoretical particle physics considerations, lead to some important inconsistencies in the standard big bang model and suggest that a more complicated picture is needed. Thus, recent constraints on the number of neutrino flavors, as well as constraints on the mean density (openness) of the universe, need not be valid.

  5. Supply Chain Management Model for Modular or Flexible Optimally Manned Ships

    DTIC Science & Technology

    2014-03-01

    Navy’s New Class of Warships: Big Bucks, Little Bang .” Battleland. Accessed October 3, 2013. http://nation.time.com/2012/10/05/the-navys-new-class-of...warships- big -bucks- little- bang /. Strauch, F. C. n.d. ARROWS Model Evaluation. Project Number N9324-B11-4135, Mechanicsburg, PA: Navy Fleet Material...existing models to determine which one could be suitable for altering to meet the stakeholders’ requirements. Modeling and simulation was used to

  6. The natural science underlying big history.

    PubMed

    Chaisson, Eric J

    2014-01-01

    Nature's many varied complex systems-including galaxies, stars, planets, life, and society-are islands of order within the increasingly disordered Universe. All organized systems are subject to physical, biological, or cultural evolution, which together comprise the grander interdisciplinary subject of cosmic evolution. A wealth of observational data supports the hypothesis that increasingly complex systems evolve unceasingly, uncaringly, and unpredictably from big bang to humankind. These are global history greatly extended, big history with a scientific basis, and natural history broadly portrayed across ∼14 billion years of time. Human beings and our cultural inventions are not special, unique, or apart from Nature; rather, we are an integral part of a universal evolutionary process connecting all such complex systems throughout space and time. Such evolution writ large has significant potential to unify the natural sciences into a holistic understanding of who we are and whence we came. No new science (beyond frontier, nonequilibrium thermodynamics) is needed to describe cosmic evolution's major milestones at a deep and empirical level. Quantitative models and experimental tests imply that a remarkable simplicity underlies the emergence and growth of complexity for a wide spectrum of known and diverse systems. Energy is a principal facilitator of the rising complexity of ordered systems within the expanding Universe; energy flows are as central to life and society as they are to stars and galaxies. In particular, energy rate density-contrasting with information content or entropy production-is an objective metric suitable to gauge relative degrees of complexity among a hierarchy of widely assorted systems observed throughout the material Universe. Operationally, those systems capable of utilizing optimum amounts of energy tend to survive, and those that cannot are nonrandomly eliminated.

  7. The Natural Science Underlying Big History

    PubMed Central

    Chaisson, Eric J.

    2014-01-01

    Nature's many varied complex systems—including galaxies, stars, planets, life, and society—are islands of order within the increasingly disordered Universe. All organized systems are subject to physical, biological, or cultural evolution, which together comprise the grander interdisciplinary subject of cosmic evolution. A wealth of observational data supports the hypothesis that increasingly complex systems evolve unceasingly, uncaringly, and unpredictably from big bang to humankind. These are global history greatly extended, big history with a scientific basis, and natural history broadly portrayed across ∼14 billion years of time. Human beings and our cultural inventions are not special, unique, or apart from Nature; rather, we are an integral part of a universal evolutionary process connecting all such complex systems throughout space and time. Such evolution writ large has significant potential to unify the natural sciences into a holistic understanding of who we are and whence we came. No new science (beyond frontier, nonequilibrium thermodynamics) is needed to describe cosmic evolution's major milestones at a deep and empirical level. Quantitative models and experimental tests imply that a remarkable simplicity underlies the emergence and growth of complexity for a wide spectrum of known and diverse systems. Energy is a principal facilitator of the rising complexity of ordered systems within the expanding Universe; energy flows are as central to life and society as they are to stars and galaxies. In particular, energy rate density—contrasting with information content or entropy production—is an objective metric suitable to gauge relative degrees of complexity among a hierarchy of widely assorted systems observed throughout the material Universe. Operationally, those systems capable of utilizing optimum amounts of energy tend to survive, and those that cannot are nonrandomly eliminated. PMID:25032228

  8. REVISED BIG BANG NUCLEOSYNTHESIS WITH LONG-LIVED, NEGATIVELY CHARGED MASSIVE PARTICLES: UPDATED RECOMBINATION RATES, PRIMORDIAL {sup 9}Be NUCLEOSYNTHESIS, AND IMPACT OF NEW {sup 6}Li LIMITS

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kusakabe, Motohiko; Kim, K. S.; Cheoun, Myung-Ki

    We extensively reanalyze the effects of a long-lived, negatively charged massive particle, X {sup –}, on big bang nucleosynthesis (BBN). The BBN model with an X {sup –} particle was originally motivated by the discrepancy between the {sup 6,} {sup 7}Li abundances predicted in the standard BBN model and those inferred from observations of metal-poor stars. In this model, {sup 7}Be is destroyed via the recombination with an X {sup –} particle followed by radiative proton capture. We calculate precise rates for the radiative recombinations of {sup 7}Be, {sup 7}Li, {sup 9}Be, and {sup 4}He with X {sup –}. Inmore » nonresonant rates, we take into account respective partial waves of scattering states and respective bound states. The finite sizes of nuclear charge distributions cause deviations in wave functions from those of point-charge nuclei. For a heavy X {sup –} mass, m{sub X} ≳ 100 GeV, the d-wave → 2P transition is most important for {sup 7}Li and {sup 7,} {sup 9}Be, unlike recombination with electrons. Our new nonresonant rate of the {sup 7}Be recombination for m{sub X} = 1000 GeV is more than six times larger than the existing rate. Moreover, we suggest a new important reaction for {sup 9}Be production: the recombination of {sup 7}Li and X {sup –} followed by deuteron capture. We derive binding energies of X nuclei along with reaction rates and Q values. We then calculate BBN and find that the amount of {sup 7}Be destruction depends significantly on the charge distribution of {sup 7}Be. Finally, updated constraints on the initial abundance and the lifetime of the X {sup –} are derived in the context of revised upper limits to the primordial {sup 6}Li abundance. Parameter regions for the solution to the {sup 7}Li problem and the primordial {sup 9}Be abundances are revised.« less

  9. Cosmological singularity resolution from quantum gravity: The emergent-bouncing universe

    NASA Astrophysics Data System (ADS)

    Alesci, Emanuele; Botta, Gioele; Cianfrani, Francesco; Liberati, Stefano

    2017-08-01

    Alternative scenarios to the big bang singularity have been subject of intense research for several decades by now. Most popular in this sense have been frameworks were such singularity is replaced by a bounce around some minimal cosmological volume or by some early quantum phase. This latter scenario was devised a long time ago and referred as an "emergent universe" (in the sense that our universe emerged from a constant volume quantum phase). We show here that within an improved framework of canonical quantum gravity (the so-called quantum reduced loop gravity) the Friedmann equations for cosmology are modified in such a way to replace the big bang singularity with a short bounce preceded by a metastable quantum phase in which the volume of the universe oscillates between a series of local maxima and minima. We call this hybrid scenario an "emergent-bouncing universe" since after a pure oscillating quantum phase the classical Friedmann spacetime emerges. Perspective developments and possible tests of this scenario are discussed in the end.

  10. Cosmological baryon number domain structure from symmetry-breaking in grand unified field theories

    NASA Technical Reports Server (NTRS)

    Brown, R. W.; Stecker, F. W.

    1979-01-01

    It is suggested that grand unified field theories with spontaneous symmetry breaking in the very early big-bang can lead more naturally to a baryon symmetric cosmology with a domain structure than to a totally baryon asymmetric cosmology. The symmetry is broken in a randomized manner in causally independent domains, favoring neither a baryon nor an antibaryon excess on a universal scale. Arguments in favor of this cosmology and observational tests are discussed.

  11. Cosmological baryon-number domain structure from symmetry breaking in grand unified field theories

    NASA Technical Reports Server (NTRS)

    Brown, R. W.; Stecker, F. W.

    1979-01-01

    It is suggested that grand unified field theories with spontaneous symmetry breaking in the very early big bang can lead more naturally to a baryon-symmetric cosmology with a domain structure than to a totally baryon-asymmetric cosmology. The symmetry is broken in a randomized manner in causally independent domains, favoring neither a baryon nor an antibaryon excess on a universal scale. Arguments in favor of this cosmology and observational tests are discussed.

  12. Nonsingular universe in massive gravity's rainbow

    NASA Astrophysics Data System (ADS)

    Hendi, S. H.; Momennia, M.; Eslam Panah, B.; Panahiyan, S.

    2017-06-01

    One of the fundamental open questions in cosmology is whether we can regard the universe evolution without singularity like a Big Bang or a Big Rip. This challenging subject stimulates one to regard a nonsingular universe in the far past with an arbitrarily large vacuum energy. Considering the high energy regime in the cosmic history, it is believed that Einstein gravity should be corrected to an effective energy dependent theory which could be acquired by gravity's rainbow. On the other hand, employing massive gravity provided us with solutions to some of the long standing fundamental problems of cosmology such as cosmological constant problem and self acceleration of the universe. Considering these aspects of gravity's rainbow and massive gravity, in this paper, we initiate studying FRW cosmology in the massive gravity's rainbow formalism. At first, we show that although massive gravity modifies the FRW cosmology, but it does not itself remove the big bang singularity. Then, we generalize the massive gravity to the case of energy dependent spacetime and find that massive gravity's rainbow can remove the early universe singularity. We bring together all the essential conditions for having a nonsingular universe and the effects of both gravity's rainbow and massive gravity generalizations on such criteria are determined.

  13. Big Bang Day : Physics Rocks

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    None

    2009-10-07

    Is particle physics the new rock 'n' roll? The fundamental questions about the nature of the universe that particle physics hopes to answer have attracted the attention of some very high profile and unusual fans. Alan Alda, Ben Miller, Eddie Izzard, Dara O'Briain and John Barrowman all have interests in this branch of physics. Brian Cox - CERN physicist, and former member of 90's band D:Ream, tracks down some very well known celebrity enthusiasts and takes a light-hearted look at why this subject can appeal to all of us.

  14. Big Bang Day: Engineering Solutions

    ScienceCinema

    None

    2017-12-09

    CERN's Large Hadron Collider is the most complicated scientific apparatus ever built. Many of the technologies it uses hadn't even been invented when scientists started building it. Adam Hart-Davis discovers what it takes to build the world's most intricate discovery machine.

  15. The meta-analytic big bang.

    PubMed

    Shadish, William R; Lecy, Jesse D

    2015-09-01

    This article looks at the impact of meta-analysis and then explores why meta-analysis was developed at the time and by the scholars it did in the social sciences in the 1970s. For the first problem, impact, it examines the impact of meta-analysis using citation network analysis. The impact is seen in the sciences, arts and humanities, and on such contemporaneous developments as multilevel modeling, medical statistics, qualitative methods, program evaluation, and single-case design. Using a constrained snowball sample of citations, we highlight key articles that are either most highly cited or most central to the systematic review network. Then, the article examines why meta-analysis came to be in the 1970s in the social sciences through the work of Gene Glass, Robert Rosenthal, and Frank Schmidt, each of whom developed similar theories of meta-analysis at about the same time. The article ends by explaining how Simonton's chance configuration theory and Campbell's evolutionary epistemology can illuminate why meta-analysis occurred with these scholars when it did and not in medical sciences. Copyright © 2015 John Wiley & Sons, Ltd.

  16. The Meta-Analytic Big Bang

    ERIC Educational Resources Information Center

    Shadish, William R.; Lecy, Jesse D.

    2015-01-01

    This article looks at the impact of meta-analysis and then explores why meta-analysis was developed at the time and by the scholars it did in the social sciences in the 1970s. For the first problem, impact, it examines the impact of meta-analysis using citation network analysis. The impact is seen in the sciences, arts and humanities, and on such…

  17. Gauging away a big bang

    NASA Astrophysics Data System (ADS)

    Krishnan, Chethan; Raju, Avinash

    2017-08-01

    We argue that in the tensionless phase of string theory where the stringy gauge symmetries are unbroken, (at least some) cosmological singularities can be understood as gauge artefacts. We present two conceptually related, but distinct, pieces of evidence: one relying on spacetime and the other on worldsheet.

  18. Big Bang Day : Physics Rocks

    ScienceCinema

    None

    2017-12-09

    Is particle physics the new rock 'n' roll? The fundamental questions about the nature of the universe that particle physics hopes to answer have attracted the attention of some very high profile and unusual fans. Alan Alda, Ben Miller, Eddie Izzard, Dara O'Briain and John Barrowman all have interests in this branch of physics. Brian Cox - CERN physicist, and former member of 90's band D:Ream, tracks down some very well known celebrity enthusiasts and takes a light-hearted look at why this subject can appeal to all of us.

  19. Metallicities and Nucleosynthesis Patterns in Early Generation Halo Stars

    NASA Astrophysics Data System (ADS)

    Beers, T.

    2004-05-01

    I review our present knowledge of the Metallicity Distribution Function of stars in the low-metallicity tail of the halo population of the Galaxy, and the variety of observed elemental signatures that might be associated with particular astrophysical origins in the early Universe. Such signatures include stars that exhibit (a) highly and mildly enhanced r-process element ratios, as compared to the solar ratios, (b) highly s-process enriched stars, (c) stars showing large enrichments of both the r- and and s-process elements, and (d) stars that are greatly enhanced in the light element species, such as CNO, and (in some cases) the alpha elements. Because the stars in which these characteristics are observed all have metallicity [Fe/H] ≤ -2.5, they are inferred to have formed no more than 0.5-1 Gyrs after the Big Bang, prior to the final assemblage of the Milky Way. As such, they provide our best available probes of the nature of early element producers, such as Type II SN and hypernovae, as well as binaries that included (now deceased) stars of intermediate (1.5 - 3 Mo) masses. I outline ongoing and future plans for dramatically accelerating the pace of discovery of these rare, but clearly important, objects. Partial support for this work has been received from NSF grants AST 00-98508 and AST 00-98549, and from JINA, the Joint Institute for Nuclear Astrophysics, an NSF Physics Frontier Center.

  20. Analogues of primeval galaxies two billion years after the Big Bang

    NASA Astrophysics Data System (ADS)

    Amorín, Ricardo; Fontana, Adriano; Pérez-Montero, Enrique; Castellano, Marco; Guaita, Lucia; Grazian, Andrea; Le Fèvre, Olivier; Ribeiro, Bruno; Schaerer, Daniel; Tasca, Lidia A. M.; Thomas, Romain; Bardelli, Sandro; Cassarà, Letizia; Cassata, Paolo; Cimatti, Andrea; Contini, Thierry; de Barros, Stephane; Garilli, Bianca; Giavalisco, Mauro; Hathi, Nimish; Koekemoer, Anton; Le Brun, Vincent; Lemaux, Brian C.; Maccagni, Dario; Pentericci, Laura; Pforr, Janine; Talia, Margherita; Tresse, Laurence; Vanzella, Eros; Vergani, Daniela; Zamorani, Giovanni; Zucca, Elena; Merlin, Emiliano

    2017-03-01

    Deep observations are revealing a growing number of young galaxies in the first billion years of cosmic time1. Compared to typical galaxies at later times, they show more extreme emission-line properties2, higher star formation rates3, lower masses4, and smaller sizes5. However, their faintness precludes studies of their chemical abundances and ionization conditions, strongly limiting our understanding of the physics driving early galaxy build-up and metal enrichment. Here we study a rare population of ultraviolet-selected, low-luminosity galaxies at redshift 2.4 < z < 3.5 that exhibit all the rest-frame properties expected from primeval galaxies. These low-mass, highly compact systems are rapidly forming galaxies able to double their stellar mass in only a few tens of millions of years. They are characterized by very blue ultraviolet spectra with weak absorption features and bright nebular emission lines, which imply hard radiation fields from young hot massive stars6,7. Their highly ionized gas phase has strongly sub-solar carbon and oxygen abundances, with metallicities more than a factor of two lower than that found in typical galaxies of similar mass and star formation rate at z≤2.58. These young galaxies reveal an early and short stage in the assembly of their galactic structures and their chemical evolution, a vigorous phase that is likely to be dominated by the effects of gas-rich mergers, accretion of metal-poor gas and strong outflows.

  1. Big Five personality stability, change, and codevelopment across adolescence and early adulthood.

    PubMed

    Borghuis, Jeroen; Denissen, Jaap J A; Oberski, Daniel; Sijtsma, Klaas; Meeus, Wim H J; Branje, Susan; Koot, Hans M; Bleidorn, Wiebke

    2017-10-01

    Using data from 2 large and overlapping cohorts of Dutch adolescents, containing up to 7 waves of longitudinal data each (N = 2,230), the present study examined Big Five personality trait stability, change, and codevelopment in friendship and sibling dyads from age 12 to 22. Four findings stand out. First, the 1-year rank-order stability of personality traits was already substantial at age 12, increased strongly from early through middle adolescence, and remained rather stable during late adolescence and early adulthood. Second, we found linear mean-level increases in girls' conscientiousness, in both genders' agreeableness, and in boys' openness. We also found temporal dips (i.e., U-shaped mean-level change) in boys' conscientiousness and in girls' emotional stability and extraversion. We did not find a mean-level change in boys' emotional stability and extraversion, and we found an increase followed by a decrease in girls' openness. Third, adolescents showed substantial individual differences in the degree and direction of personality trait changes, especially with respect to conscientiousness, extraversion, and emotional stability. Fourth, we found no evidence for personality trait convergence, for correlated change, or for time-lagged partner effects in dyadic friendship and sibling relationships. This lack of evidence for dyadic codevelopment suggests that adolescent friends and siblings tend to change independently from each other and that their shared experiences do not have uniform influences on their personality traits. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  2. Black hole formation in the early Universe

    NASA Astrophysics Data System (ADS)

    Latif, M. A.; Schleicher, D. R. G.; Schmidt, W.; Niemeyer, J.

    2013-08-01

    Supermassive black holes with up to a 109 M⊙ dwell in the centres of present-day galaxies, and their presence has been confirmed at z ≥ 6. Their formation at such early epochs is still an enigma. Different pathways have been suggested to assemble supermassive black holes in the first billion years after the big bang. Direct collapse has emerged as a highly plausible scenario to form black holes as it provides seed masses of 105-106 M⊙. Gravitational collapse in atomic cooling haloes with virial temperatures Tvir ≥ 104 K may lead to the formation of massive seed black holes in the presence of an intense background ultraviolet flux. Turbulence plays a central role in regulating accretion and transporting angular momentum. We present here the highest resolution cosmological large eddy simulations to date which track the evolution of high-density regions on scales of 0.25 au beyond the formation of the first peak, and study the impact of subgrid-scale turbulence. The peak density reached in these simulations is 1.2 × 10-8 g cm-3. Our findings show that while fragmentation occasionally occurs, it does not prevent the growth of a central massive object resulting from turbulent accretion and occasional mergers. The central object reaches ˜1000 M⊙ within four free-fall times, and we expect further growth up to 106 M⊙ through accretion in about 1 Myr. The direct collapse model thus provides a viable pathway of forming high-mass black holes at early cosmic times.

  3. Priming the Pump for Big Data at Sentara Healthcare.

    PubMed

    Kern, Howard P; Reagin, Michael J; Reese, Bertram S

    2016-01-01

    Today's healthcare organizations are facing significant demands with respect to managing population health, demonstrating value, and accepting risk for clinical outcomes across the continuum of care. The patient's environment outside the walls of the hospital and physician's office-and outside the electronic health record (EHR)-has a substantial impact on clinical care outcomes. The use of big data is key to understanding factors that affect the patient's health status and enhancing clinicians' ability to anticipate how the patient will respond to various therapies. Big data is essential to delivering sustainable, highquality, value-based healthcare, as well as to the success of new models of care such as clinically integrated networks (CINs) and accountable care organizations.Sentara Healthcare, based in Norfolk, Virginia, has been an early adopter of the technologies that have readied us for our big data journey: EHRs, telehealth-supported electronic intensive care units, and telehealth primary care support through MDLIVE. Although we would not say Sentara is at the cutting edge of the big data trend, it certainly is among the fast followers. Use of big data in healthcare is still at an early stage compared with other industries. Tools for data analytics are maturing, but traditional challenges such as heightened data security and limited human resources remain the primary focus for regional health systems to improve care and reduce costs. Sentara primarily makes actionable use of big data in our CIN, Sentara Quality Care Network, and at our health plan, Optima Health. Big data projects can be expensive, and justifying the expense organizationally has often been easier in times of crisis. We have developed an analytics strategic plan separate from but aligned with corporate system goals to ensure optimal investment and management of this essential asset.

  4. [Blood pressure and sleep apnoea hypopnoea syndrome in workers. STOP-Bang test versus Epworth test].

    PubMed

    Vicente-Herrero, M T; Capdevila-García, L; Bellido-Cambrón, M C; Ramírez-Iñiguez de la Torre, M V; Lladosa-Marco, S

    OSAHS is associated with an increased risk of cardiovascular disease and stroke. Arterial hypertension is a key risk factor to consider due to its impact on health. Cross-sectional study carried out on Spanish public service workers. The nocturnal apnoea risk using the Epworth and STOP-Bang questionnaires and their influence on the mean values of blood pressure are assessed. The detection of OSAHS using the Epworth test and, particularly with the STOP-Bang shows a significant relationship with the mean values of blood pressure, with differences between both questionnaires. The Epworth and STOP-Bang questionnaires are useful for the initial detection of OSAHS and a higher prevalence of high blood pressure. Both can be used in screening procedures in occupational health. Copyright © 2017 SEH-LELHA. Publicado por Elsevier España, S.L.U. All rights reserved.

  5. How Big Are "Martin's Big Words"? Thinking Big about the Future.

    ERIC Educational Resources Information Center

    Gardner, Traci

    "Martin's Big Words: The Life of Dr. Martin Luther King, Jr." tells of King's childhood determination to use "big words" through biographical information and quotations. In this lesson, students in grades 3 to 5 explore information on Dr. King to think about his "big" words, then they write about their own…

  6. BigData as a Driver for Capacity Building in Astrophysics

    NASA Astrophysics Data System (ADS)

    Shastri, Prajval

    2015-08-01

    Exciting public interest in astrophysics acquires new significance in the era of Big Data. Since Big Data involves advanced technologies of both software and hardware, astrophysics with Big Data has the potential to inspire young minds with diverse inclinations - i.e., not just those attracted to physics but also those pursuing engineering careers. Digital technologies have become steadily cheaper, which can enable expansion of the Big Data user pool considerably, especially to communities that may not yet be in the astrophysics mainstream, but have high potential because of access to thesetechnologies. For success, however, capacity building at the early stages becomes key. The development of on-line pedagogical resources in astrophysics, astrostatistics, data-mining and data visualisation that are designed around the big facilities of the future can be an important effort that drives such capacity building, especially if facilitated by the IAU.

  7. Formation of the First Stars and Blackholes

    NASA Astrophysics Data System (ADS)

    Yoshida, Naoki

    2018-05-01

    Cosmic reionization is thought to be initiated by the first generation of stars and blackholes. We review recent progress in theoretical studies of early structure formation. Cosmic structure formation is driven by gravitational instability of primeval density fluctuations left over from Big Bang. At early epochs, there are baryonic streaming motions with significant relative velocity with respect to dark matter. The formation of primordial gas clouds is typically delayed by the streaming motions, but then physical conditions for the so-called direct collapse blackhole formation are realized in proto-galactic halos. We present a promising model in which intermediate mass blackholes are formed as early as z = 30.

  8. Einstein's equations and a cosmology with finite matter

    NASA Astrophysics Data System (ADS)

    Clavelli, L.; Goldstein, Gary R.

    2015-05-01

    We discuss various space-time metrics which are compatible with Einstein's equations and a previously suggested cosmology with a finite total mass.1 In this alternative cosmology, the matter density was postulated to be a spatial delta function at the time of the big bang thereafter diffusing outward with constant total mass. This proposal explores a departure from standard assumptions that the big bang occurred everywhere at once or was just one of an infinite number of previous and later transitions.

  9. BBN constraints on MeV-scale dark sectors. Part I. Sterile decays

    NASA Astrophysics Data System (ADS)

    Hufnagel, Marco; Schmidt-Hoberg, Kai; Wild, Sebastian

    2018-02-01

    We study constraints from Big Bang Nucleosynthesis on inert particles in a dark sector which contribute to the Hubble rate and therefore change the predictions of the primordial nuclear abundances. We pay special attention to the case of MeV-scale particles decaying into dark radiation, which are neither fully relativistic nor non-relativistic during all temperatures relevant to Big Bang Nucleosynthesis. As an application we discuss the implications of our general results for models of self-interacting dark matter with light mediators.

  10. Trojan Horse Method for neutrons-induced reaction studies

    NASA Astrophysics Data System (ADS)

    Gulino, M.; Asfin Collaboration

    2017-09-01

    Neutron-induced reactions play an important role in nuclear astrophysics in several scenario, such as primordial Big Bang Nucleosynthesis, Inhomogeneous Big Bang Nucleosynthesis, heavy-element production during the weak component of the s-process, explosive stellar nucleosynthesis. To overcome the experimental problems arising from the production of a neutron beam, the possibility to use the Trojan Horse Method to study neutron-induced reactions has been investigated. The application is of particular interest for reactions involving radioactive nuclei having short lifetime.

  11. Big Data, Big Problems: A Healthcare Perspective.

    PubMed

    Househ, Mowafa S; Aldosari, Bakheet; Alanazi, Abdullah; Kushniruk, Andre W; Borycki, Elizabeth M

    2017-01-01

    Much has been written on the benefits of big data for healthcare such as improving patient outcomes, public health surveillance, and healthcare policy decisions. Over the past five years, Big Data, and the data sciences field in general, has been hyped as the "Holy Grail" for the healthcare industry promising a more efficient healthcare system with the promise of improved healthcare outcomes. However, more recently, healthcare researchers are exposing the potential and harmful effects Big Data can have on patient care associating it with increased medical costs, patient mortality, and misguided decision making by clinicians and healthcare policy makers. In this paper, we review the current Big Data trends with a specific focus on the inadvertent negative impacts that Big Data could have on healthcare, in general, and specifically, as it relates to patient and clinical care. Our study results show that although Big Data is built up to be as a the "Holy Grail" for healthcare, small data techniques using traditional statistical methods are, in many cases, more accurate and can lead to more improved healthcare outcomes than Big Data methods. In sum, Big Data for healthcare may cause more problems for the healthcare industry than solutions, and in short, when it comes to the use of data in healthcare, "size isn't everything."

  12. Status of the GroundBIRD Telescope

    NASA Astrophysics Data System (ADS)

    Choi, J.; Génova-Santos, R.; Hattori, M.; Hazumi, M.; Ishitsuka, H.; Kanno, F.; Karatsu, K.; Kiuchi, K.; Koyano, R.; Kutsuma, H.; Lee, K.; Mima, S.; Minowa, M.; Nagai, M.; Nagasaki, T.; Naruse, M.; Oguri, S.; Okada, T.; Otani, C.; Rebolo, R.; Rubiño-Martín, J.; Sekimoto, Y.; Suzuki, J.; Taino, T.; Tajima, O.; Tomita, N.; Uchida, T.; Won, E.; Yoshida, M.

    2018-01-01

    Our understanding of physics at very early Universe, as early as 10-35 s after the Big Bang, relies on the scenario known as the inflationary cosmology. Inflation predicts a particular polarization pattern in the cosmic microwave background, known as the B-mode yet the strength of such polarization pattern is extremely weak. To search for the B-mode of the polarization in the cosmic microwave background, we are constructing an off-axis rotating telescope to mitigate systematic effects as well as to maximize the sky coverage of the observation. We will discuss the present status of the GroundBIRD telescope.

  13. 1976 Big Thompson flood, Colorado

    USGS Publications Warehouse

    Jarrett, R. D.; Vandas, S.J.

    2006-01-01

    In the early evening of July 31, 1976, a large stationary thunderstorm released as much as 7.5 inches of rainfall in about an hour (about 12 inches in a few hours) in the upper reaches of the Big Thompson River drainage. This large amount of rainfall in such a short period of time produced a flash flood that caught residents and tourists by surprise. The immense volume of water that churned down the narrow Big Thompson Canyon scoured the river channel and destroyed everything in its path, including 418 homes, 52 businesses, numerous bridges, paved and unpaved roads, power and telephone lines, and many other structures. The tragedy claimed the lives of 144 people. Scores of other people narrowly escaped with their lives. The Big Thompson flood ranks among the deadliest of Colorado's recorded floods. It is one of several destructive floods in the United States that has shown the necessity of conducting research to determine the causes and effects of floods. The U.S. Geological Survey (USGS) conducts research and operates a Nationwide streamgage network to help understand and predict the magnitude and likelihood of large streamflow events such as the Big Thompson Flood. Such research and streamgage information are part of an ongoing USGS effort to reduce flood hazards and to increase public awareness.

  14. [Big data approaches in psychiatry: examples in depression research].

    PubMed

    Bzdok, D; Karrer, T M; Habel, U; Schneider, F

    2017-11-29

    The exploration and therapy of depression is aggravated by heterogeneous etiological mechanisms and various comorbidities. With the growing trend towards big data in psychiatry, research and therapy can increasingly target the individual patient. This novel objective requires special methods of analysis. The possibilities and challenges of the application of big data approaches in depression are examined in closer detail. Examples are given to illustrate the possibilities of big data approaches in depression research. Modern machine learning methods are compared to traditional statistical methods in terms of their potential in applications to depression. Big data approaches are particularly suited to the analysis of detailed observational data, the prediction of single data points or several clinical variables and the identification of endophenotypes. A current challenge lies in the transfer of results into the clinical treatment of patients with depression. Big data approaches enable biological subtypes in depression to be identified and predictions in individual patients to be made. They have enormous potential for prevention, early diagnosis, treatment choice and prognosis of depression as well as for treatment development.

  15. 33 CFR 165.801 - Annual fireworks displays and other events in the Eighth Coast Guard District requiring safety...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... July Big Bang Fireworks USS LEXINGTON/Corpus Christi, TX All waters contained within a 1,000-ft radius... down river from the Ashland bridge. 24 27 July 4th Big Sandy Superstore Arena/Dawg Dazzle Fireworks...

  16. 33 CFR 165.801 - Annual fireworks displays and other events in the Eighth Coast Guard District requiring safety...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... July Big Bang Fireworks USS LEXINGTON/Corpus Christi, TX All waters contained within a 1,000-ft radius... down river from the Ashland bridge. 24 27 July 4th Big Sandy Superstore Arena/Dawg Dazzle Fireworks...

  17. The Cosmic Microwave Background Radiation - A Unique Window on the Early Universe

    NASA Technical Reports Server (NTRS)

    Hinshaw, Gary F.

    2009-01-01

    The cosmic microwave background radiation is the remnant heat from the Big Bang. It provides us with a unique probe of conditions in the early universe, long before any organized structures had yet formed. The anisotropy in the radiation's brightness yields important clues about primordial structure and additionally provides a wealth of information about the physics of the early universe. Within the framework of inflationary dark matter models, observations of the anisotropy on sub-degree angular scales reveals the signatures of acoustic oscillations of the photon-baryon fluid at a redshift of approximately 1100. Data from the first five years of operation of the Wilkinson Microwave Anisotropy Probe (WMAP) satellite provide detailed full-sky maps of the cosmic microwave background temperature and polarization anisotropy. Together, the data provide a wealth of cosmological information, including the age of the universe, the epoch when the first stars formed, and the overall composition of baryonic matter, dark matter, and dark energy. The results also provide constraints on the period of inflationary expansion in the very first moments of time. WMAP, part of NASA's Explorers program, was launched on June 30, 2001. The WMAP satellite was produced in a partnership between the Goddard Space Flight Center and Princeton University. The WMAP team also includes researchers at the Johns Hopkins University; the Canadian Institute of Theoretical Astrophysics; University of Texas; Oxford University; University of Chicago; Brown University; University of British Columbia; and University of California, Los Angeles.

  18. The Cosmic Microwave Background Radiation - A Unique Window on the Early Universe

    NASA Technical Reports Server (NTRS)

    Hinshaw, Gary F.

    2008-01-01

    The cosmic microwave background radiation is the remnant heat from the Big Bang. It provides us with a unique probe of conditions in the early universe, long before any organized structures had yet formed. The anisotropy in the radiation's brightness yields important clues about primordial structure and additionally provides a wealth of information about the physics of the early universe. Within the framework of inflationary dark matter models, observations of the anisotropy on sub-degree angular scales reveals the signatures of acoustic oscillations of the photon-baryon fluid at a redshift of approximately 1100. Data from the first five years of operation of the Wilkinson Microwave Anisotropy Probe (WMAP) satellite provide detailed full-sky maps of the cosmic microwave background temperature and polarization anisotropy. Together, the data provide a wealth of cosmological information, including the age of the universe, the epoch when the first stars formed, and the overall composition of baryonic matter, dark matter, and dark energy. The results also provide constraints on the period of inflationary expansion in the very first moments of time. WMAP, part of NASA's Explorers program, was launched on June 30, 2001. The WMAP satellite was produced in a partnership between the Goddard Space Flight Center and Princeton University. The WMAP team also includes researchers at Johns Hopkins University; the Canadian Institute of Theoretical Astrophysics; University of Texas; Oxford University; University of Chicago; Brown university; University of British Columbia; and University of California, Los Angeles.

  19. The Cosmic Microwave Background Radiation-A Unique Window on the Early Universe

    NASA Technical Reports Server (NTRS)

    Hinshaw, Gary

    2010-01-01

    The cosmic microwave background radiation is the remnant heat from the Big Bang. It provides us with a unique probe of conditions in the early universe, long before any organized structures had yet formed. The anisotropy in the radiation's brightness yields important clues about primordial structure and additionally provides a wealth of information about the physics of the early universe. Within the framework of inflationary dark matter models, observations of the anisotropy on sub-degree angular scales reveals the signatures of acoustic oscillations of the photon-baryon fluid at a redshift of 11 00. Data from the first seven years of operation of the Wilkinson Microwave Anisotropy Probe (WMAP) satellite provide detailed full-sky maps of the cosmic microwave background temperature and polarization anisotropy. Together, the data provide a wealth of cosmological information, including the age of the universe, the epoch when the first stars formed, and the overall composition of baryonic matter, dark matter, and dark energy. The results also provide constraints on the period of inflationary expansion in the very first moments of time. WMAP, part of NASA's Explorers program, was launched on June 30, 2001. The WMAP satellite was produced in a partnership between the Goddard Space Flight Center and Princeton University. The WMAP team also includes researchers at the Johns Hopkins University; the Canadian Institute of Theoretical Astrophysics; University of Texas; Oxford University; University of Chicago; Brown University; University of British Columbia; and University of California, Los Angeles.

  20. Big Results From a Smaller Gearbox

    NASA Technical Reports Server (NTRS)

    2005-01-01

    Many people will be sad to see the Hubble Space Telescope go, as it was the first instrument of its kind to provide us with such a wealth of imagery and information about the galaxy. The telescope has served us well since its launch in spring of 1990, but it is nearly time for its retirement. The science, however, will continue, as NASA plans the launch of a new, more modern orbiting telescope, the James Webb Space Telescope. Named after the man who ran NASA from 1961 to 1968, years fraught with the anxiety and uncertainty of the Space Race, the scope is scheduled for launch in fall of 2011. It is designed to study the earliest galaxies and some of the first stars formed after the Big Bang. NASA scientists at the Goddard Space Flight Center are busy developing the technologies to build this new machine. Many of the new technologies are available for commercial licensing and development. For example, the NASA Planetary Gear System technology developed to give precise nanometer positioning capabilities for the James Webb Space Telescope is now being employed by Turnkey Design Services, LLC (TDS), of Blue Island, Illinois, to improve electric motors. This revolutionary piece of technology allows more efficient operation of the motors, and is more cost- effective than traditional gearbox designs.

  1. Cosmology and the weak interaction

    NASA Technical Reports Server (NTRS)

    Schramm, David N.

    1989-01-01

    The weak interaction plays a critical role in modern Big Bang cosmology. Two of its most publicized comological connections are emphasized: big bang nucleosynthesis and dark matter. The first of these is connected to the cosmological prediction of neutrine flavors, N(sub nu) is approximately 3 which in now being confirmed. The second is interrelated to the whole problem of galacty and structure formation in the universe. The role of the weak interaction both for dark matter candidates and for the problem of generating seeds to form structure is demonstrated.

  2. Combination of STOP-Bang Score with Mallampati Score fails to improve specificity in the prediction of sleep-disordered breathing.

    PubMed

    Dette, Frank G; Graf, Juergen; Cassel, Werner; Lloyd-Jones, Carla; Boehm, Stefan; Zoremba, Martin; Schramm, Patrick; Pestel, Gunther; Thal, Serge C

    2016-06-01

    Sleep-disordered breathing (SDB) is closely associated with perioperative complications. STOP-Bang score was validated for preoperative screening of SDB. However, STOP-Bang Score lacks adequately high specificity. We aimed to improve it by combining it with the Mallampati Score. The study included 347 patients, in which we assessed both STOP-Bang and Mallampati scores. Overnight oxygen saturation was measured to calculate ODI4%. We calculated the sensitivity and specificity for AHI and ODI4% of both scores separately and in combination. We found that STOP-Bang Score ≥3 was present in 71%, ODI≥5/h (AHI ≥5/h) in 42.6% (39.3%) and ODI≥15/h (AHI ≥15/h) in 13.5% (17.8%). For ODI4%≥5/h (AHI ≥5/h) we observed in men a response rate for sensitivity and specificity of STOP-Bang of 94.5% and 17.1% (90.9% and 12.5%) and in women 66% and 51% (57.8% and 46.9%). For ODI4%≥15/h (AHI≥15/h) it was 92% and 12% (84.6% and 10.3%) and 93% and 49% (75% and 49.2%). For ODI4%≥5 (AHI≥5) sensitivity and specificity of Mallampati score were in men 38.4% and 78.6% (27.3% and 68.2%) and in women 25% and 82.7% (21.9% and 81.3%), for ODI≥15 (AHI ≥15/h) 38.5% and 71.8% (26.9% and 69.2%) and 33.3% and 81.4% (17.9% and 79.6%). In combination, for ODI4%≥15/h, we found sensitivity in men to be 92.3% and in women 93.3%, specificity 10.3% and 41.4%. STOP-Bang Score combined with Mallampati Score fails to increase specificity. Low specificity should be considered when using both scores for preoperative screening of SDB.

  3. The Intricate Role of Cold Gas and Dust in Galaxy Evolution at Early Cosmic Epochs

    NASA Astrophysics Data System (ADS)

    Riechers, Dominik A.; Capak, Peter L.; Carilli, Christopher L.

    Cold molecular and atomic gas plays a central role in our understanding of early galaxy formation and evolution. It represents the component of the interstellar medium (ISM) that stars form out of, and its mass, distribution, excitation, and dynamics provide crucial insight into the physical processes that support the ongoing star formation and stellar mass buildup. We here present results that demonstrate the capability of the Atacama Large (sub-)Millimeter Array (ALMA) to detect the cold ISM and dust in ``normal'' galaxies at redshifts z=5-6. We also show detailed studies of the ISM in massive, dust-obscured starburst galaxies out to z>6 with ALMA, the Combined Array for Research in Millimeter-wave Astronomy (CARMA), the Plateau de Bure Interferometer (PdBI), and the Karl G. Jansky Very Large Array (VLA). These observations place some of the most direct constraints on the dust-obscured fraction of the star formation history of the universe at z>5 to date, showing that ``typical'' galaxies at these epochs have low dust content, but also that highly-enriched, dusty starbursts already exist within the first billion years after the Big Bang.

  4. A first-principles model of early evolution: emergence of gene families, species, and preferred protein folds.

    PubMed

    Zeldovich, Konstantin B; Chen, Peiqiu; Shakhnovich, Boris E; Shakhnovich, Eugene I

    2007-07-01

    In this work we develop a microscopic physical model of early evolution where phenotype--organism life expectancy--is directly related to genotype--the stability of its proteins in their native conformations-which can be determined exactly in the model. Simulating the model on a computer, we consistently observe the "Big Bang" scenario whereby exponential population growth ensues as soon as favorable sequence-structure combinations (precursors of stable proteins) are discovered. Upon that, random diversity of the structural space abruptly collapses into a small set of preferred proteins. We observe that protein folds remain stable and abundant in the population at timescales much greater than mutation or organism lifetime, and the distribution of the lifetimes of dominant folds in a population approximately follows a power law. The separation of evolutionary timescales between discovery of new folds and generation of new sequences gives rise to emergence of protein families and superfamilies whose sizes are power-law distributed, closely matching the same distributions for real proteins. On the population level we observe emergence of species--subpopulations that carry similar genomes. Further, we present a simple theory that relates stability of evolving proteins to the sizes of emerging genomes. Together, these results provide a microscopic first-principles picture of how first-gene families developed in the course of early evolution.

  5. How Big Is Too Big?

    ERIC Educational Resources Information Center

    Cibes, Margaret; Greenwood, James

    2016-01-01

    Media Clips appears in every issue of Mathematics Teacher, offering readers contemporary, authentic applications of quantitative reasoning based on print or electronic media. This issue features "How Big is Too Big?" (Margaret Cibes and James Greenwood) in which students are asked to analyze the data and tables provided and answer a…

  6. Big data in food safety: An overview.

    PubMed

    Marvin, Hans J P; Janssen, Esmée M; Bouzembrak, Yamine; Hendriksen, Peter J M; Staats, Martijn

    2017-07-24

    Technology is now being developed that is able to handle vast amounts of structured and unstructured data from diverse sources and origins. These technologies are often referred to as big data, and open new areas of research and applications that will have an increasing impact in all sectors of our society. In this paper we assessed to which extent big data is being applied in the food safety domain and identified several promising trends. In several parts of the world, governments stimulate the publication on internet of all data generated in public funded research projects. This policy opens new opportunities for stakeholders dealing with food safety to address issues which were not possible before. Application of mobile phones as detection devices for food safety and the use of social media as early warning of food safety problems are a few examples of the new developments that are possible due to big data.

  7. Interpreting Breast International Group (BIG) 1-98: a randomized, double-blind, phase III trial comparing letrozole and tamoxifen as adjuvant endocrine therapy for postmenopausal women with hormone receptor-positive, early breast cancer.

    PubMed

    Regan, Meredith M; Price, Karen N; Giobbie-Hurder, Anita; Thürlimann, Beat; Gelber, Richard D

    2011-05-26

    The Breast International Group (BIG) 1-98 study is a four-arm trial comparing 5 years of monotherapy with tamoxifen or with letrozole or with sequences of 2 years of one followed by 3 years of the other for postmenopausal women with endocrine-responsive early invasive breast cancer. From 1998 to 2003, BIG -98 enrolled 8,010 women. The enhanced design f the trial enabled two complementary analyses of efficacy and safety. Collection of tumor specimens further enabled treatment comparisons based on tumor biology. Reports of BIG 1-98 should be interpreted in relation to each individual patient as she weighs the costs and benefits of available treatments. Clinicaltrials.gov ID: NCT00004205.

  8. Interpreting breast international group (BIG) 1-98: a randomized, double-blind, phase III trial comparing letrozole and tamoxifen as adjuvant endocrine therapy for postmenopausal women with hormone receptor-positive, early breast cancer

    PubMed Central

    2011-01-01

    The Breast International Group (BIG) 1-98 study is a four-arm trial comparing 5 years of monotherapy with tamoxifen or with letrozole or with sequences of 2 years of one followed by 3 years of the other for postmenopausal women with endocrine-responsive early invasive breast cancer. From 1998 to 2003, BIG -98 enrolled 8,010 women. The enhanced design f the trial enabled two complementary analyses of efficacy and safety. Collection of tumor specimens further enabled treatment comparisons based on tumor biology. Reports of BIG 1-98 should be interpreted in relation to each individual patient as she weighs the costs and benefits of available treatments. Clinicaltrials.gov ID: NCT00004205. PMID:21635709

  9. BigDog

    NASA Astrophysics Data System (ADS)

    Playter, R.; Buehler, M.; Raibert, M.

    2006-05-01

    BigDog's goal is to be the world's most advanced quadruped robot for outdoor applications. BigDog is aimed at the mission of a mechanical mule - a category with few competitors to date: power autonomous quadrupeds capable of carrying significant payloads, operating outdoors, with static and dynamic mobility, and fully integrated sensing. BigDog is about 1 m tall, 1 m long and 0.3 m wide, and weighs about 90 kg. BigDog has demonstrated walking and trotting gaits, as well as standing up and sitting down. Since its creation in the fall of 2004, BigDog has logged tens of hours of walking, climbing and running time. It has walked up and down 25 & 35 degree inclines and trotted at speeds up to 1.8 m/s. BigDog has walked at 0.7 m/s over loose rock beds and carried over 50 kg of payload. We are currently working to expand BigDog's rough terrain mobility through the creation of robust locomotion strategies and terrain sensing capabilities.

  10. Activation measurement of the 3He(alpha,gamma)7Be cross section at low energy.

    PubMed

    Bemmerer, D; Confortola, F; Costantini, H; Formicola, A; Gyürky, Gy; Bonetti, R; Broggini, C; Corvisiero, P; Elekes, Z; Fülöp, Zs; Gervino, G; Guglielmetti, A; Gustavino, C; Imbriani, G; Junker, M; Laubenstein, M; Lemut, A; Limata, B; Lozza, V; Marta, M; Menegazzo, R; Prati, P; Roca, V; Rolfs, C; Alvarez, C Rossi; Somorjai, E; Straniero, O; Strieder, F; Terrasi, F; Trautvetter, H P

    2006-09-22

    The nuclear physics input from the 3He(alpha,gamma)7Be cross section is a major uncertainty in the fluxes of 7Be and 8B neutrinos from the Sun predicted by solar models and in the 7Li abundance obtained in big-bang nucleosynthesis calculations. The present work reports on a new precision experiment using the activation technique at energies directly relevant to big-bang nucleosynthesis. Previously such low energies had been reached experimentally only by the prompt-gamma technique and with inferior precision. Using a windowless gas target, high beam intensity, and low background gamma-counting facilities, the 3He(alpha,gamma)7Be cross section has been determined at 127, 148, and 169 keV center-of-mass energy with a total uncertainty of 4%. The sources of systematic uncertainty are discussed in detail. The present data can be used in big-bang nucleosynthesis calculations and to constrain the extrapolation of the 3He(alpha,gamma)7Be astrophysical S factor to solar energies.

  11. New trends in cosmology

    NASA Technical Reports Server (NTRS)

    Canuto, V. M.

    1978-01-01

    A review of big-bang cosmology is presented, emphasizing the big-bang model, hypotheses on the origin of galaxies, observational tests of the big-bang model that may be possible with the Large Space Telescope, and the scale-covariant theory of gravitation. Detailed attention is given to the equations of general relativity, the redshift-distance relation for extragalactic objects, expansion of the universe, the initial singularity, the discovery of the 3-K blackbody radiation, and measurements of the amount of deuterium in the universe. The curvature of the expanding universe is examined along with the magnitude-redshift relation for quasars and galaxies. Several models for the origin of galaxies are evaluated, and it is suggested that a model of galaxy formation via the formation of black holes is consistent with the model of an expanding universe. Scale covariance is discussed, a scale-covariant theory is developed which contains invariance under scale transformation, and it is shown that Dirac's (1937) large-numbers hypothesis finds a natural role in this theory by relating the atomic and Einstein units.

  12. Nursing Needs Big Data and Big Data Needs Nursing.

    PubMed

    Brennan, Patricia Flatley; Bakken, Suzanne

    2015-09-01

    Contemporary big data initiatives in health care will benefit from greater integration with nursing science and nursing practice; in turn, nursing science and nursing practice has much to gain from the data science initiatives. Big data arises secondary to scholarly inquiry (e.g., -omics) and everyday observations like cardiac flow sensors or Twitter feeds. Data science methods that are emerging ensure that these data be leveraged to improve patient care. Big data encompasses data that exceed human comprehension, that exist at a volume unmanageable by standard computer systems, that arrive at a velocity not under the control of the investigator and possess a level of imprecision not found in traditional inquiry. Data science methods are emerging to manage and gain insights from big data. The primary methods included investigation of emerging federal big data initiatives, and exploration of exemplars from nursing informatics research to benchmark where nursing is already poised to participate in the big data revolution. We provide observations and reflections on experiences in the emerging big data initiatives. Existing approaches to large data set analysis provide a necessary but not sufficient foundation for nursing to participate in the big data revolution. Nursing's Social Policy Statement guides a principled, ethical perspective on big data and data science. There are implications for basic and advanced practice clinical nurses in practice, for the nurse scientist who collaborates with data scientists, and for the nurse data scientist. Big data and data science has the potential to provide greater richness in understanding patient phenomena and in tailoring interventional strategies that are personalized to the patient. © 2015 Sigma Theta Tau International.

  13. KSC-01pp1030

    NASA Image and Video Library

    2001-05-25

    KENNEDY SPACE CENTER, FLA. -- A second solid rocket booster is lifted up the gantry at Launch Complex 17-B, Cape Canaveral Air Force Station. The SRBs will be mated to the Delta II rocket that will launch the MAP instrument into a lunar-assisted trajectory to the Sun-Earth for a 27-month mission. The MAP mission will examine conditions in the early universe by measuring temperature differences in cosmic microwave background radiation, which is the radiant heat left over from the Big Bang. The properties of this radiation directly reflect conditions in the early universe. MAP is scheduled to launch June 30 at 3:46:46 p.m. EDT

  14. KSC-01pp1029

    NASA Image and Video Library

    2001-05-25

    KENNEDY SPACE CENTER, FLA. -- A solid rocket booster is lifted up the gantry at Launch Complex 17-B, Cape Canaveral Air Force Station. The SRB will be mated to the Delta II rocket that will launch the MAP instrument into a lunar-assisted trajectory to the Sun-Earth for a 27-month mission. The MAP mission will examine conditions in the early universe by measuring temperature differences in cosmic microwave background radiation, which is the radiant heat left over from the Big Bang. The properties of this radiation directly reflect conditions in the early universe. MAP is scheduled to launch June 30 at 3:46:46 p.m. EDT

  15. KSC-01pp1032

    NASA Image and Video Library

    2001-05-25

    KENNEDY SPACE CENTER, FLA. -- On Launch Complex 17-B, Cape Canaveral Air Force Station, the Delta II rocket waits to be mated to four solid rocket boosters (behind the Delta). The rocket will launch the MAP instrument into a lunar-assisted trajectory to the Sun-Earth for a 27-month mission. The MAP mission will examine conditions in the early universe by measuring temperature differences in cosmic microwave background radiation, which is the radiant heat left over from the Big Bang. The properties of this radiation directly reflect conditions in the early universe. MAP is scheduled to launch June 30 at 3:46:46 p.m. EDT

  16. Inflation in the Early Universe

    NASA Astrophysics Data System (ADS)

    Carmeli, Moshe

    In this talk it will be assumed that gravitation is negligible. Under this assumption, the receding velocities of galaxies and the distances between them in the Hubble expansion are united into a four-dimensional pseudo-Euclidean manifold, similarly to space and time in ordinary special relativity. The Hubble law is assumed and is written in an invariant way that enables one to derive a four-dimensional transformation which is similar to the Lorentz transformation. The parameter in the new transformation is the ratio between the cosmic time to the Hubble time (in which the cosmic time is measured backward with respect to the present time). Accordingly, the new transformation relates physical quantities at different cosmic times in the limit of weak or negligible gravitation. The transformation is then applied to the problem of the expansion of the Universe at the very early stage when gravity was negligible and thus the transformation is applicable. We calculate the ratio of the volumes of the Universe at two different times T1 and T2 after the Big Bang. Under the assumptions that T2 - T1 ≈ 10-32 sec and T2 ≪ 1 sec, we find that V_{2}/V_{1} = 10^{-16}/√{T_{1}}. For T1 ≈ 10-132 sec we obtain V2/V1 ≈ 1050. This result conforms with the standard inflationary universe theory, but now it is obtained without assuming that the Universe is propelled by antigravity.

  17. A philosophy for big-bang cosmology.

    PubMed

    McCrea, W H

    1970-10-03

    According to recent developments in cosmology we seem bound to find a model universe like the observed universe, almost independently of how we suppose it started. Such ideas, if valid, provide fresh justification for the procedures of current cosmological theory.

  18. Supersymmetric relics from the big bang

    DOE PAGES

    Ellis, John; Hagelin, J. S.; Nanopoulos, D. V.; ...

    1984-06-01

    In this paper, we consider the cosmological constraints on supersymmetric theories with a new, stable particle. Circumstantial evidence points to a neutral gauge/Higgs fermion as the best candidate for this particle, and we derive bounds on the parameters in the lagrangian which govern its mass and couplings. One favored possibility is that the lightest neutral supersymmetric particle is predominantly a photino ~γ with mass above 12 GeV, while another is that the lightest neutral supersymmetric particle is a Higgs fermion with mass above 5 GeV or less than O(100) eV. We also point out that a gravitino mass of 10more » to 100 GeV implies that the temperature after completion of an inflationary phase cannot be above 10 14 GeV, and probably not above 3 × 10 12 GeV. Finally, this imposes constraints on mechanisms for generating the baryon number of the universe.« less

  19. Tracking Back to the Big Bang.

    ERIC Educational Resources Information Center

    Peat, David

    1983-01-01

    Traces some astronomical history and considers how astronomers have arrived at their current knowledge of distance, size, and time as it applies to objects in the night sky. The information is provided as background to a discussion of the Hubble constant and its relationship to the age of the universe. (JN)

  20. Quasars at Cosmic Dawn: Discoveries and Probes of the Early Universe

    NASA Astrophysics Data System (ADS)

    Wang, Feige; Wu, Xue-Bing; Fan, Xiaohui; Yang, Jinyi; Bian, Fuyan; McGreer, Ian D.; Green, Richard F.; Yang, Qian; Jiang, Linhua; Wang, Ran; DECaLS Team; UHS Team

    2017-01-01

    High redshift quasars, as the most luminous non-transient objects in the early universe, are the most promising tracers to address the history of cosmic reionization and how the origins of super-massive black hole (SMBH) are linked to galaxy formation and evolution. Over the last fifteen years, more than 100 quasars within the first billion years after the Big Bang have been discovered with the highest redshift at 7.1. We have developed a new method to select z>~6 quasars with both high efficiency and high completeness by combing optical and mid-IR Wide-field Infrared Survey Explorer (WISE) photometric data. We have applied this method to SDSS footprint and resulted in the discovery of the most luminous z>6 quasar ever discovered, which hosts a twelve billion solar mass black hole. I will present detailed follow-up observations of the host galaxies and environment of the most luminous quasars using HST, LBT and ALMA, in order to constrain early black hole growth and black hole/galaxy co-evolution at the highest redshift. I will also present initial results from a new quasar survey, which utilizes optical data from DECaLS, which is imaging 6700 deg^2 of sky down to z_AB˜23.0, and neaar-IR data from UHS and UKIDSS, which maps the whole northern sky at Decl.<+60deg. The combination of these datasets allows us to discover quasars at redshift z>~7 and to conduct a complete census of the faint quasar population at z~6.

  1. Primordial lithium and the standard model(s)

    NASA Technical Reports Server (NTRS)

    Deliyannis, Constantine P.; Demarque, Pierre; Kawaler, Steven D.; Romanelli, Paul; Krauss, Lawrence M.

    1989-01-01

    The results of new theoretical work on surface Li-7 and Li-6 evolution in the oldest halo stars are presented, along with a new and refined analysis of the predicted primordial Li abundance resulting from big-bang nucleosynthesis. This makes it possible to determine the constraints which can be imposed on cosmology using primordial Li and both standard big-bang and stellar-evolution models. This leads to limits on the baryon density today of 0.0044-0.025 (where the Hubble constant is 100h km/sec Mpc) and imposes limitations on alternative nucleosynthesis scenarios.

  2. Cosmic alternatives?

    NASA Astrophysics Data System (ADS)

    Gregory, Ruth

    2009-04-01

    "Cosmologists are often in error but never in doubt." This pithy characterization by the Soviet physicist Lev Landau sums up the raison d'être of Facts and Speculations in Cosmology. Authors Jayant Narlikar and Geoffrey Burbidge are proponents of a "steady state" theory of cosmology, and they argue that the cosmological community has become fixated on a "Big Bang" dogma, suppressing alternative viewpoints. This book very much does what it says on the tin: it sets out what is known in cosmology, and puts forward the authors' point of view on an alternative to the Big Bang.

  3. DYZ1 copy number variation, Y chromosome polymorphism and early recurrent spontaneous abortion/early embryo growth arrest.

    PubMed

    Yan, Junhao; Fan, Lingling; Zhao, Yueran; You, Li; Wang, Laicheng; Zhao, Han; Li, Yuan; Chen, Zi-Jiang

    2011-12-01

    To find the association between recurrent spontaneous abortion (RSA)/early embryo growth arrest and Y chromosome polymorphism. Peripheral blood samples of the male patients of big Y chromosome, small Y chromosome and other male patients whose partners suffered from unexplained RSA/early embryo growth arrest were collected. PCR and real-time fluorescent quantitative PCR were used to test the deletion and the copy number variation of DYZ1 region in Y chromosome of the patients. A total of 79 big Y chromosome patients (48 of whose partners suffered from RSA or early embryo growth arrest), 7 small Y chromosome patients, 106 other male patients whose partners had suffered from unexplained RSA or early embryo growth arrest, and 100 normal male controls were enrolled. There was no fraction deletion of DYZ1 detected both in big Y patients and in normal men. Of RSA patients, 1 case showed deletion of 266bp from the gene locus 25-290bp, and 2 cases showed deletion of 773bp from 1347 to 2119bp. Of only 7 small Y chromosome patients, 2 cases showed deletion of 266bp from 25 to 290bp, and 4 cases showed deletion of 773bp from 1347 to 2119bp and 275bp from 3128 to 3420bp. The mean of DYZ1 copies was 3900 in normal control men; the mean in big Y patients was 5571, in RSA patients was 2655, and in small Y patients was 1059. All of the others were significantly different (P<0.01) compared with normal control men, which meant that DYZ1 copy number in normal control men was less than that of big Y chromosome patients, and was more than that of unexplained early RSA patients and small Y patients. The integrity and copy number variation of DYZ1 are closely related to the Y chromosome length under microscope. The cause of RSA/early embryo growth arrest in some couples may be the increase (big Y patients) or decrease of DYZ1 copy number in the husbands' Y chromosome. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  4. More on the holographic Ricci dark energy model: smoothing Rips through interaction effects?

    PubMed

    Bouhmadi-López, Mariam; Errahmani, Ahmed; Ouali, Taoufik; Tavakoli, Yaser

    2018-01-01

    The background cosmological dynamics of the late Universe is analysed on the framework of a dark energy model described by an holographic Ricci dark energy component. Several kind of interactions between the dark energy and the dark matter components are considered herein. We solve the background cosmological dynamics for the different choices of interactions with the aim to analyse not only the current evolution of the universe but also its asymptotic behaviour and, in particular, possible future singularities removal. We show that in most of the cases, the Big Rip singularity, a finger print of this model in absence of an interaction between the dark sectors, is substituted by a de Sitter or a Minkowski state. Most importantly, we found two new future bouncing solutions leading to two possible asymptotic behaviours, we named Little Bang and Little Sibling of the Big Bang. At a Little Bang, as the size of the universe shrinks to zero in an infinite cosmic time, the Hubble rate and its cosmic time derivative blow up. In addition, at a Little sibling of the Big Bang, as the size of the universe shrinks to zero in an infinite cosmic time, the Hubble rate blows up but its cosmic time derivative is finite. These two abrupt events can happen as well in the past.

  5. More on the holographic Ricci dark energy model: smoothing Rips through interaction effects?

    NASA Astrophysics Data System (ADS)

    Bouhmadi-López, Mariam; Errahmani, Ahmed; Ouali, Taoufik; Tavakoli, Yaser

    2018-04-01

    The background cosmological dynamics of the late Universe is analysed on the framework of a dark energy model described by an holographic Ricci dark energy component. Several kind of interactions between the dark energy and the dark matter components are considered herein. We solve the background cosmological dynamics for the different choices of interactions with the aim to analyse not only the current evolution of the universe but also its asymptotic behaviour and, in particular, possible future singularities removal. We show that in most of the cases, the Big Rip singularity, a finger print of this model in absence of an interaction between the dark sectors, is substituted by a de Sitter or a Minkowski state. Most importantly, we found two new future bouncing solutions leading to two possible asymptotic behaviours, we named Little Bang and Little Sibling of the Big Bang. At a Little Bang, as the size of the universe shrinks to zero in an infinite cosmic time, the Hubble rate and its cosmic time derivative blow up. In addition, at a Little sibling of the Big Bang, as the size of the universe shrinks to zero in an infinite cosmic time, the Hubble rate blows up but its cosmic time derivative is finite. These two abrupt events can happen as well in the past.

  6. Final Scientific/Technical Report-Quantum Field Theories for Cosmology

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Nicolis, Alberto

    The research funded by this award spanned a wide range of subjects in theoretical cosmology and in field theory. In the first part, the PI and his collaborators applied effective field theory techniques to the study of macroscopic media and of cosmological perturbations. Such an approach—now standard in particle physics—is quite unconventional for theoretical cosmology. They addressed several concrete questions where this formalism proved valuable, both within and outside the cosmological context, concerning for instance macroscopic physical phenomena for fluids, superfluids, and solids, and their relationship to the dynamics of cosmological perturbations. A particularly successful outcome of this line ofmore » research has been the development of “solid inflation”: a cosmological model for primordial inflation where the expansion of the universe is driven by an exotic solid substance. In the second part, the PI and his collaborators investigated more fundamental questions and ideas, for the present universe as well as for the very early one, using quantum field theory as a guide. The questions addressed include: Is the present cosmic acceleration due to a new, ‘dark’ form of energy, or are we instead observing a breakdown of Einstein’s general relativity at cosmological distances? Is the cosmic acceleration accelerating? Is the Big Bang unavoidable? Related to this, is early inflation the only sensible cure for the shortcomings of the standard Big Bang model, and the only possible source for the observed scale-invariant cosmological perturbations?« less

  7. GLINT. Gravitational-wave laser INterferometry triangle

    NASA Astrophysics Data System (ADS)

    Aria, Shafa; Azevedo, Rui; Burow, Rick; Cahill, Fiachra; Ducheckova, Lada; Holroyd, Alexa; Huarcaya, Victor; Järvelä, Emilia; Koßagk, Martin; Moeckel, Chris; Rodriguez, Ana; Royer, Fabien; Sypniewski, Richard; Vittori, Edoardo; Yttergren, Madeleine

    2017-11-01

    When the universe was roughly one billion years old, supermassive black holes (103-106 solar masses) already existed. The occurrence of supermassive black holes on such short time scales are poorly understood in terms of their physical or evolutionary processes. Our current understanding is limited by the lack of observational data due the limits of electromagnetic radiation. Gravitational waves as predicted by the theory of general relativity have provided us with the means to probe deeper into the history of the universe. During the ESA Alpach Summer School of 2015, a group of science and engineering students devised GLINT (Gravitational-wave Laser INterferometry Triangle), a space mission concept capable of measuring gravitational waves emitted by black holes that have formed at the early periods after the big bang. Morespecifically at redshifts of 15 < z < 30(˜ 0.1 - 0.3× 109 years after the big bang) in the frequency range 0.01 - 1 Hz. GLINT design strain sensitivity of 5× 10^{-24} 1/√ { {Hz}} will theoretically allow the study of early black holes formations as well as merging events and collapses. The laser interferometry, the technology used for measuring gravitational waves, monitors the separation of test masses in free-fall, where a change of separation indicates the passage of a gravitational wave. The test masses will be shielded from disturbing forces in a constellation of three geocentric orbiting satellites.

  8. Biography of Professor Hayashi

    NASA Astrophysics Data System (ADS)

    Sato, Humitaka

    2012-09-01

    Biography of Chushiro Hayashi(1920-2010) is described with an emphasis on his early career as a theoretical physicist. In spite of his well-recognized achievements in theoretical astrophysics, such as Hayashi phase, p/n-ratio at Big Bang, stellar evolution and nucleosynthesis and Kyoto Model on the origin of solar system, Hayashi had once wished to devote in study of non-local field theory of particle physics. However, the various changes of situation around Hideki Yukawa(Nobel prize laureate in 1949) had guided him to the study of astrophysics.

  9. Supernovae at the cosmic dawn

    NASA Astrophysics Data System (ADS)

    Chen, Ke-Jung

    2014-03-01

    Modern cosmological simulations predict that the first generation of stars formed with a mass scale around 100 M⊙ about 300-400 million years after the Big Bang. When the first stars reached the end of their lives, many of them might have died as energetic supernovae (SNe) that could have significantly affected the early Universe via injecting large amounts of energy and metals into the primordial intergalactic medium. In this paper, we review the current models of the first SNe by discussing on the relevant background physics, computational methods and the latest results.

  10. Big Data in Drug Discovery.

    PubMed

    Brown, Nathan; Cambruzzi, Jean; Cox, Peter J; Davies, Mark; Dunbar, James; Plumbley, Dean; Sellwood, Matthew A; Sim, Aaron; Williams-Jones, Bryn I; Zwierzyna, Magdalena; Sheppard, David W

    2018-01-01

    Interpretation of Big Data in the drug discovery community should enhance project timelines and reduce clinical attrition through improved early decision making. The issues we encounter start with the sheer volume of data and how we first ingest it before building an infrastructure to house it to make use of the data in an efficient and productive way. There are many problems associated with the data itself including general reproducibility, but often, it is the context surrounding an experiment that is critical to success. Help, in the form of artificial intelligence (AI), is required to understand and translate the context. On the back of natural language processing pipelines, AI is also used to prospectively generate new hypotheses by linking data together. We explain Big Data from the context of biology, chemistry and clinical trials, showcasing some of the impressive public domain sources and initiatives now available for interrogation. © 2018 Elsevier B.V. All rights reserved.

  11. Identification of Patients with Sleep Disordered Breathing: Comparing the Four-Variable Screening Tool, STOP, STOP-Bang, and Epworth Sleepiness Scales

    PubMed Central

    Silva, Graciela E.; Vana, Kimberly D.; Goodwin, James L.; Sherrill, Duane L.; Quan, Stuart F.

    2011-01-01

    Study Objective: The Epworth Sleepiness Scale (ESS) has been used to detect patients with potential sleep disordered breathing (SDB). Recently, a 4-Variable screening tool was proposed to identify patients with SDB, in addition to the STOP and STOP-Bang questionnaires. This study evaluated the abilities of the 4-Variable screening tool, STOP, STOP-Bang, and ESS questionnaires in identifying subjects at risk for SDB. Methods: A total of 4,770 participants who completed polysomnograms in the baseline evaluation of the Sleep Heart Health Study (SHHS) were included. Subjects with RDIs ≥ 15 and ≥ 30 were considered to have moderate-to-severe or severe SDB, respectively. Variables were constructed to approximate those in the questionnaires. The risk of SDB was calculated by the 4-Variable screening tool according to Takegami et al. The STOP and STOP-Bang questionnaires were evaluated including variables for snoring, tiredness/sleepiness, observed apnea, blood pressure, body mass index, age, neck circumference, and gender. Sleepiness was evaluated using the ESS questionnaire and scores were dichotomized into < 11 and ≥ 11. Results: The STOP-Bang questionnaire had higher sensitivity to predict moderate-to-severe (87.0%) and severe (70.4%) SDB, while the 4-Variable screening tool had higher specificity to predict moderate-to-severe and severe SDB (93.2% for both). Conclusions: In community populations such as the SHHS, high specificities may be more useful in excluding low-risk patients, while avoiding false positives. However, sleep clinicians may prefer to use screening tools with high sensitivities, like the STOP-Bang, in order to avoid missing cases that may lead to adverse health consequences and increased healthcare costs. Citation: Silva GE; Vana KD; Goodwin JL; Sherrill DL; Quan SF. Identification of patients with sleep disordered breathing: comparing the Four-Variable screening tool, STOP, STOP-Bang, and Epworth Sleepiness Scales. J Clin Sleep Med 2011

  12. Big Bang Day : The Great Big Particle Adventure - 1. Atom

    ScienceCinema

    None

    2017-12-09

    In this series, comedian and physicist Ben Miller asks the CERN scientists what they hope to find. The notion of atoms dates back to Greek philosophers who sought a natural mechanical explanation of the Universe, as opposed to a divine one. The existence what we call chemical atoms, the constituents of all we see around us, wasn't proved until a hundred years ago, but almost simultaneously it was realised these weren't the indivisible constituents the Greeks envisaged. Much of the story of physics since then has been the ever-deeper probing of matter until, at the end of the 20th century, a complete list of fundamental ingredients had been identified, apart from one, the much discussed Higgs particle. In this programme, Ben finds out why this last particle is so pivotal, not just to atomic theory, but to our very existence - and how hopeful the scientists are of proving its existence.

  13. Big Bang Day : The Great Big Particle Adventure - 1. Atom

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    None

    2009-10-08

    In this series, comedian and physicist Ben Miller asks the CERN scientists what they hope to find. The notion of atoms dates back to Greek philosophers who sought a natural mechanical explanation of the Universe, as opposed to a divine one. The existence what we call chemical atoms, the constituents of all we see around us, wasn't proved until a hundred years ago, but almost simultaneously it was realised these weren't the indivisible constituents the Greeks envisaged. Much of the story of physics since then has been the ever-deeper probing of matter until, at the end of the 20th century,more » a complete list of fundamental ingredients had been identified, apart from one, the much discussed Higgs particle. In this programme, Ben finds out why this last particle is so pivotal, not just to atomic theory, but to our very existence - and how hopeful the scientists are of proving its existence.« less

  14. BigBWA: approaching the Burrows-Wheeler aligner to Big Data technologies.

    PubMed

    Abuín, José M; Pichel, Juan C; Pena, Tomás F; Amigo, Jorge

    2015-12-15

    BigBWA is a new tool that uses the Big Data technology Hadoop to boost the performance of the Burrows-Wheeler aligner (BWA). Important reductions in the execution times were observed when using this tool. In addition, BigBWA is fault tolerant and it does not require any modification of the original BWA source code. BigBWA is available at the project GitHub repository: https://github.com/citiususc/BigBWA. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  15. An Ancient Revisits Cosmology

    NASA Astrophysics Data System (ADS)

    Greenstein, Jesse L.

    1993-06-01

    In this after-dinner speech, a somewhat light-hearted attempt is made to view the observational side of physical cosmology as a subdiscipline of astrophysics, still in an early stage of sophistication and in need of more theoretical understanding. The theoretical side of cosmology, in contrast, has its deep base in general relativity. A major result of observational cosmology is that an expansion of the Universe arose from a singularity some 15 billion years ago. This has had an enormous impact on the public's view of both astronomy and theology. It places on cosmologists an extra responsibility for clear thinking and interpretation. Recently, gravitational physics caused another crisis from an unexpected observational result that nonbaryonic matter appears to dominate. Will obtaining information about this massive nonbaryonic component require that astronomers cease to rely on measurement of photons? But 40 years ago after radio astronomical techniques uncovered the high-energy universe, we happily introduced new subfields, with techniques from physics and engineering still tied to photon detection. Another historical example shows how a subfield of cosmology, big bang nucleosynthesis, grew in complexity from its spectroscopic astrophysics beginning 40 years ago. Determination of primordial abundances of lighter nuclei does illuminate conditions in the Big Bang, but the observational results faced and overcame many hurdles on the way.

  16. From Mars to the Multiverse

    NASA Astrophysics Data System (ADS)

    Martin Rees, Lord

    2017-01-01

    Lord Martin Rees will discuss questions including: What does the long-range future hold? Should we be surprised that the physical laws permitted the emergence of complexity? Is physical reality even more extensive than the domain that our telescopes can probe? Are there many `big bangs'? Powerful instruments have led to astonishing progress in tracing the emergence of atoms, galaxies, stars and planets from a mysterious `beginning' nearly 14 billion years ago. Unmanned spacecraft have visited the other planets of our Solar System (and some of their moons), beaming back pictures of varied and distinctive worlds. An exciting development in the last two decades has been the realization that many other stars are orbited by retinues of planets - some resembling our Earth (and capable of harboring life). Looking further afield, observers can probe galaxies and the massive back holes at their centers and can check models of their evolution by detecting objects all the way back to an epoch only a billion years after the Big Bang. Indeed we can trace pre-galactic history with some confidence back to a nanosecond after the Big Bang. But the key parameters of our expanding universe - the expansion rate, the geometry and the content - were established far earlier still, when the physics is still conjectural but is being constrained, especially by precision measurements of the cosmic microwave background. These advances pose new questions: What does the long-range future hold? Should we be surprised that the physical laws permitted the emergence of complexity? Is physical reality even more extensive than the domain that our telescopes can probe? Are there many `big bangs'? This illustrated lecture will attempt to address such issues.

  17. Loop quantum cosmology and singularities.

    PubMed

    Struyve, Ward

    2017-08-15

    Loop quantum gravity is believed to eliminate singularities such as the big bang and big crunch singularity. This belief is based on studies of so-called loop quantum cosmology which concerns symmetry-reduced models of quantum gravity. In this paper, the problem of singularities is analysed in the context of the Bohmian formulation of loop quantum cosmology. In this formulation there is an actual metric in addition to the wave function, which evolves stochastically (rather than deterministically as the case of the particle evolution in non-relativistic Bohmian mechanics). Thus a singularity occurs whenever this actual metric is singular. It is shown that in the loop quantum cosmology for a homogeneous and isotropic Friedmann-Lemaître-Robertson-Walker space-time with arbitrary constant spatial curvature and cosmological constant, coupled to a massless homogeneous scalar field, a big bang or big crunch singularity is never obtained. This should be contrasted with the fact that in the Bohmian formulation of the Wheeler-DeWitt theory singularities may exist.

  18. A quasi-steady state cosmological model with creation of matter

    NASA Technical Reports Server (NTRS)

    Hoyle, F.; Burbidge, G.; Narlikar, J. V.

    1993-01-01

    A universe is envisioned in which there was a major creation episode when the mean universal density was about 10 to the -27 g/cu cm. Explicit equations are given for the creation of matter; in a cosmological approximation, these equations lead to expressions for the time-dependence of the cosmological scale factor S(t), but do not entail, as big bang cosmology does, that S(t) tend to zero at some finite time t. The equations therefore possess a universality that is absent from big bang cosmology. Creation occurs when certain conservation equations involving the gradient of a scalar field C(i) are satisfied.

  19. GI Stromal Tumors: 15 Years of Lessons From a Rare Cancer.

    PubMed

    Cioffi, Angela; Maki, Robert G

    2015-06-01

    A confluence of factors, most prominently the recognition of GI stromal tumor (GIST) as a specific sarcoma subtype and the availability of imatinib, led to the "Big Bang" of GIST therapy (ie, the successful treatment of the first patient with GIST with imatinib in 2000). The trail blazed by imatinib for chronic myelogenous leukemia and GIST has become a desired route to regulatory approval of an increasing number of oral kinase inhibitors and other novel therapeutics. In this review, the status of GIST management before and after GIST's "Big Bang" and new steps being taken to further improve on therapy are reviewed. © 2015 by American Society of Clinical Oncology.

  20. The Cosmic Background Explorer

    NASA Technical Reports Server (NTRS)

    Gulkis, Samuel; Lubin, Philip M.; Meyer, Stephan S.; Silverberg, Robert F.

    1990-01-01

    The Cosmic Background Explorer (CBE), NASA's cosmological satellite which will observe a radiative relic of the big bang, is discussed. The major questions connected to the big bang theory which may be clarified using the CBE are reviewed. The satellite instruments and experiments are described, including the Differential Microwave Radiometer, which measures the difference between microwave radiation emitted from two points on the sky, the Far-Infrared Absolute Spectrophotometer, which compares the spectrum of radiation from the sky at wavelengths from 100 microns to one cm with that from an internal blackbody, and the Diffuse Infrared Background Experiment, which searches for the radiation from the earliest generation of stars.

  1. Benchmarking Big Data Systems and the BigData Top100 List.

    PubMed

    Baru, Chaitanya; Bhandarkar, Milind; Nambiar, Raghunath; Poess, Meikel; Rabl, Tilmann

    2013-03-01

    "Big data" has become a major force of innovation across enterprises of all sizes. New platforms with increasingly more features for managing big datasets are being announced almost on a weekly basis. Yet, there is currently a lack of any means of comparability among such platforms. While the performance of traditional database systems is well understood and measured by long-established institutions such as the Transaction Processing Performance Council (TCP), there is neither a clear definition of the performance of big data systems nor a generally agreed upon metric for comparing these systems. In this article, we describe a community-based effort for defining a big data benchmark. Over the past year, a Big Data Benchmarking Community has become established in order to fill this void. The effort focuses on defining an end-to-end application-layer benchmark for measuring the performance of big data applications, with the ability to easily adapt the benchmark specification to evolving challenges in the big data space. This article describes the efforts that have been undertaken thus far toward the definition of a BigData Top100 List. While highlighting the major technical as well as organizational challenges, through this article, we also solicit community input into this process.

  2. Big data, big knowledge: big data for personalized healthcare.

    PubMed

    Viceconti, Marco; Hunter, Peter; Hose, Rod

    2015-07-01

    The idea that the purely phenomenological knowledge that we can extract by analyzing large amounts of data can be useful in healthcare seems to contradict the desire of VPH researchers to build detailed mechanistic models for individual patients. But in practice no model is ever entirely phenomenological or entirely mechanistic. We propose in this position paper that big data analytics can be successfully combined with VPH technologies to produce robust and effective in silico medicine solutions. In order to do this, big data technologies must be further developed to cope with some specific requirements that emerge from this application. Such requirements are: working with sensitive data; analytics of complex and heterogeneous data spaces, including nontextual information; distributed data management under security and performance constraints; specialized analytics to integrate bioinformatics and systems biology information with clinical observations at tissue, organ and organisms scales; and specialized analytics to define the "physiological envelope" during the daily life of each patient. These domain-specific requirements suggest a need for targeted funding, in which big data technologies for in silico medicine becomes the research priority.

  3. Asymptotic freedom in the early big-bang and the isotropy of the cosmic microwave background

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.

    1979-01-01

    The isotropy of the universal 3K background radiation is discussed and a superunified field theory incorporating gravity and possessing asymptotic freedom is suggested to provide a solution to the problem. Thermal equilibrium is established in this context through interactions occurring in a temporally indefinite preplanckian era.

  4. Asymptotic freedom in the early big bang and the isotropy of the cosmic microwave background

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.

    1980-01-01

    It is suggested that a superunified field theory incorporating gravity and possessing asymptotic freedom could provide a solution to the problem of the isotropy of the universal 3 K background radiation. Thermal equilibrium could be established in this context through interactions occurring in a temporally indefinite pre-Planckian era.

  5. Complete conformal classification of the Friedmann–Lemaître–Robertson–Walker solutions with a linear equation of state

    NASA Astrophysics Data System (ADS)

    Harada, Tomohiro; Carr, B. J.; Igata, Takahisa

    2018-05-01

    We completely classify Friedmann–Lemaître–Robertson–Walker solutions with spatial curvature and equation of state , according to their conformal structure, singularities and trapping horizons. We do not assume any energy conditions and allow , thereby going beyond the usual well-known solutions. For each spatial curvature, there is an initial spacelike big-bang singularity for w  >  ‑1/3 and , while there is no big-bang singularity for w  <  ‑1 and . For K  =  0 or  ‑1, ‑1  <  w  <  ‑1/3 and , there is an initial null big-bang singularity. For each spatial curvature, there is a final spacelike future big-rip singularity for w  <  ‑1 and , with null geodesics being future complete for but incomplete for w  <  ‑5/3. For w  =  ‑1/3, the expansion speed is constant. For  ‑1  <  w  <  ‑1/3 and K  =  1, the universe contracts from infinity, then bounces and expands back to infinity. For K  =  0, the past boundary consists of timelike infinity and a regular null hypersurface for  ‑5/3  <  w  <  ‑1, while it consists of past timelike and past null infinities for . For w  <  ‑1 and K  =  1, the spacetime contracts from an initial spacelike past big-rip singularity, then bounces and blows up at a final spacelike future big-rip singularity. For w  <  ‑1 and K  =  ‑1, the past boundary consists of a regular null hypersurface. The trapping horizons are timelike, null and spacelike for , and , respectively. A negative energy density () is possible only for K  =  ‑1. In this case, for w  >  ‑1/3, the universe contracts from infinity, then bounces and expands to infinity; for  ‑1  <  w  <  ‑1/3, it starts from a big-bang singularity and contracts to a big-crunch singularity; for w  <  ‑1, it expands from a regular null hypersurface and

  6. Visualizing the knowledge structure and evolution of big data research in healthcare informatics.

    PubMed

    Gu, Dongxiao; Li, Jingjing; Li, Xingguo; Liang, Changyong

    2017-02-01

    In recent years, the literature associated with healthcare big data has grown rapidly, but few studies have used bibliometrics and a visualization approach to conduct deep mining and reveal a panorama of the healthcare big data field. To explore the foundational knowledge and research hotspots of big data research in the field of healthcare informatics, this study conducted a series of bibliometric analyses on the related literature, including papers' production trends in the field and the trend of each paper's co-author number, the distribution of core institutions and countries, the core literature distribution, the related information of prolific authors and innovation paths in the field, a keyword co-occurrence analysis, and research hotspots and trends for the future. By conducting a literature content analysis and structure analysis, we found the following: (a) In the early stage, researchers from the United States, the People's Republic of China, the United Kingdom, and Germany made the most contributions to the literature associated with healthcare big data research and the innovation path in this field. (b) The innovation path in healthcare big data consists of three stages: the disease early detection, diagnosis, treatment, and prognosis phase, the life and health promotion phase, and the nursing phase. (c) Research hotspots are mainly concentrated in three dimensions: the disease dimension (e.g., epidemiology, breast cancer, obesity, and diabetes), the technical dimension (e.g., data mining and machine learning), and the health service dimension (e.g., customized service and elderly nursing). This study will provide scholars in the healthcare informatics community with panoramic knowledge of healthcare big data research, as well as research hotspots and future research directions. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  7. Challenges and Opportunities of Big Data in Health Care: A Systematic Review

    PubMed Central

    Goswamy, Rishi; Raval, Yesha; Marawi, Sarah

    2016-01-01

    Background Big data analytics offers promise in many business sectors, and health care is looking at big data to provide answers to many age-related issues, particularly dementia and chronic disease management. Objective The purpose of this review was to summarize the challenges faced by big data analytics and the opportunities that big data opens in health care. Methods A total of 3 searches were performed for publications between January 1, 2010 and January 1, 2016 (PubMed/MEDLINE, CINAHL, and Google Scholar), and an assessment was made on content germane to big data in health care. From the results of the searches in research databases and Google Scholar (N=28), the authors summarized content and identified 9 and 14 themes under the categories Challenges and Opportunities, respectively. We rank-ordered and analyzed the themes based on the frequency of occurrence. Results The top challenges were issues of data structure, security, data standardization, storage and transfers, and managerial skills such as data governance. The top opportunities revealed were quality improvement, population management and health, early detection of disease, data quality, structure, and accessibility, improved decision making, and cost reduction. Conclusions Big data analytics has the potential for positive impact and global implications; however, it must overcome some legitimate obstacles. PMID:27872036

  8. Big data uncertainties.

    PubMed

    Maugis, Pierre-André G

    2018-07-01

    Big data-the idea that an always-larger volume of information is being constantly recorded-suggests that new problems can now be subjected to scientific scrutiny. However, can classical statistical methods be used directly on big data? We analyze the problem by looking at two known pitfalls of big datasets. First, that they are biased, in the sense that they do not offer a complete view of the populations under consideration. Second, that they present a weak but pervasive level of dependence between all their components. In both cases we observe that the uncertainty of the conclusion obtained by statistical methods is increased when used on big data, either because of a systematic error (bias), or because of a larger degree of randomness (increased variance). We argue that the key challenge raised by big data is not only how to use big data to tackle new problems, but to develop tools and methods able to rigorously articulate the new risks therein. Copyright © 2016. Published by Elsevier Ltd.

  9. The Origin of the Elements

    ScienceCinema

    Murphy, Edward

    2018-01-23

    The world around us is made of atoms. Did you ever wonder where these atoms came from? How was the gold in our jewelry, the carbon in our bodies, and the iron in our cars made? In this lecture, we will trace the origin of a gold atom from the Big Bang to the present day, and beyond. You will learn how the elements were forged in the nuclear furnaces inside stars, and how, when they die, these massive stars spread the elements into space. You will learn about the origin of the building blocks of matter in the Big Bang, and we will speculate on the future of the atoms around us today.

  10. Stability of Einstein static universe in gravity theory with a non-minimal derivative coupling

    NASA Astrophysics Data System (ADS)

    Huang, Qihong; Wu, Puxun; Yu, Hongwei

    2018-01-01

    The emergent mechanism provides a possible way to resolve the big-bang singularity problem by assuming that our universe originates from the Einstein static (ES) state. Thus, the existence of a stable ES solution becomes a very crucial prerequisite for the emergent scenario. In this paper, we study the stability of an ES universe in gravity theory with a non-minimal coupling between the kinetic term of a scalar field and the Einstein tensor. We find that the ES solution is stable under both scalar and tensor perturbations when the model parameters satisfy certain conditions, which indicates that the big-bang singularity can be avoided successfully by the emergent mechanism in the non-minimally kinetic coupled gravity.

  11. The formation of the first stars and galaxies.

    PubMed

    Bromm, Volker; Yoshida, Naoki; Hernquist, Lars; McKee, Christopher F

    2009-05-07

    Observations made using large ground-based and space-borne telescopes have probed cosmic history from the present day to a time when the Universe was less than one-tenth of its present age. Earlier still lies the remaining frontier, where the first stars, galaxies and massive black holes formed. They fundamentally transformed the early Universe by endowing it with the first sources of light and chemical elements beyond the primordial hydrogen and helium produced in the Big Bang. The interplay of theory and upcoming observations promises to answer the key open questions in this emerging field.

  12. Sterile neutrino dark matter with supersymmetry

    NASA Astrophysics Data System (ADS)

    Shakya, Bibhushan; Wells, James D.

    2017-08-01

    Sterile neutrino dark matter, a popular alternative to the WIMP paradigm, has generally been studied in non-supersymmetric setups. If the underlying theory is supersymmetric, we find that several interesting and novel dark matter features can arise. In particular, in scenarios of freeze-in production of sterile neutrino dark matter, its superpartner, the sterile sneutrino, can play a crucial role in early Universe cosmology as the dominant source of cold, warm, or hot dark matter, or of a subdominant relativistic population of sterile neutrinos that can contribute to the effective number of relativistic degrees of freedom Neff during big bang nucleosynthesis.

  13. Status of the BL2 beam measurement of the neutron lifetime

    NASA Astrophysics Data System (ADS)

    Hoogerheide, Shannon Fogwell; BL2 Collaboration

    2017-09-01

    Neutron beta decay is the simplest example of nuclear beta decay and a precise value of the neutron lifetime is important for consistency tests of the Standard Model and Big Bang Nucleosynthesis models. A new measurement of the neutron lifetime, utilizing the beam method, is underway at the National Institute of Standards and Technology Center for Neutron Research with a projected uncertainty of 1 s. A review of the beam method and the technical improvements in this experiment will be presented. The status of the experiment, as well as preliminary measurements, beam characteristics, and early data will be discussed.

  14. Quantum Gravity and Cosmology: an intimate interplay

    NASA Astrophysics Data System (ADS)

    Sakellariadou, Mairi

    2017-08-01

    I will briefly discuss three cosmological models built upon three distinct quantum gravity proposals. I will first highlight the cosmological rôle of a vector field in the framework of a string/brane cosmological model. I will then present the resolution of the big bang singularity and the occurrence of an early era of accelerated expansion of a geometric origin, in the framework of group field theory condensate cosmology. I will then summarise results from an extended gravitational model based on non-commutative spectral geometry, a model that offers a purely geometric explanation for the standard model of particle physics.

  15. Five Big Ideas

    ERIC Educational Resources Information Center

    Morgan, Debbie

    2012-01-01

    Designing quality continuing professional development (CPD) for those teaching mathematics in primary schools is a challenge. If the CPD is to be built on the scaffold of five big ideas in mathematics, what might be these five big ideas? Might it just be a case of, if you tell me your five big ideas, then I'll tell you mine? Here, there is…

  16. Foul weather friends: big business and health care reform in the 1990s in historical perspective.

    PubMed

    Swenson, Peter; Greer, Scott

    2002-08-01

    Existing accounts of the Clinton health reform efforts of the early 1990s neglect to examine how the change in big business reform interests during the short period between the late 1980s and 1994 might have altered the trajectory of compulsory health insurance legislation in Congress. This article explores evidence that big employers lost their early interest in reform because they believed their private remedies for bringing down health cost inflation were finally beginning to work. This had a discouraging effect on reform efforts. Historical analysis shows how hard times during the Great Depression also aligned big business interests with those of reformers seeking compulsory social insurance. Unlike the present case, however, the economic climate did not quickly improve, and the social insurance reform of the New Deal succeeded. The article speculates, therefore, that had employer health expenditures not flattened out, continuing and even growing big business support might have neutralized small business and other opposition that contributed heavily to the failure of reform. Thus in light of the Clinton administration's demonstrated willingness to compromise with business on details of its plan, some kind of major reform might have succeeded.

  17. A study on specialist or special disease clinics based on big data.

    PubMed

    Fang, Zhuyuan; Fan, Xiaowei; Chen, Gong

    2014-09-01

    Correlation analysis and processing of massive medical information can be implemented through big data technology to find the relevance of different factors in the life cycle of a disease and to provide the basis for scientific research and clinical practice. This paper explores the concept of constructing a big medical data platform and introduces the clinical model construction. Medical data can be collected and consolidated by distributed computing technology. Through analysis technology, such as artificial neural network and grey model, a medical model can be built. Big data analysis, such as Hadoop, can be used to construct early prediction and intervention models as well as clinical decision-making model for specialist and special disease clinics. It establishes a new model for common clinical research for specialist and special disease clinics.

  18. A magnetic particle time-of-flight (MagPTOF) diagnostic for measurements of shock- and compression-bang time at the NIF (invited).

    PubMed

    Rinderknecht, H G; Sio, H; Frenje, J A; Magoon, J; Agliata, A; Shoup, M; Ayers, S; Bailey, C G; Gatu Johnson, M; Zylstra, A B; Sinenian, N; Rosenberg, M J; Li, C K; Sèguin, F H; Petrasso, R D; Rygg, J R; Kimbrough, J R; Mackinnon, A; Bell, P; Bionta, R; Clancy, T; Zacharias, R; House, A; Döppner, T; Park, H S; LePape, S; Landen, O; Meezan, N; Robey, H; Glebov, V U; Hohenberger, M; Stoeckl, C; Sangster, T C; Li, C; Parat, J; Olson, R; Kline, J; Kilkenny, J

    2014-11-01

    A magnetic particle time-of-flight (MagPTOF) diagnostic has been designed to measure shock- and compression-bang time using D(3)He-fusion protons and DD-fusion neutrons, respectively, at the National Ignition Facility (NIF). This capability, in combination with shock-burn weighted areal density measurements, will significantly constrain the modeling of the implosion dynamics. This design is an upgrade to the existing particle time-of-flight (pTOF) diagnostic, which records bang times using DD or DT neutrons with an accuracy better than ±70 ps [H. G. Rinderknecht et al., Rev. Sci. Instrum. 83, 10D902 (2012)]. The inclusion of a deflecting magnet will increase D(3)He-proton signal-to-background by a factor of 1000, allowing for the first time simultaneous measurements of shock- and compression-bang times in D(3)He-filled surrogate implosions at the NIF.

  19. Sleep-disordered breathing in patients with cardiovascular diseases cannot be detected by ESS, STOP-BANG, and Berlin questionnaires.

    PubMed

    Reuter, Hannes; Herkenrath, Simon; Treml, Marcel; Halbach, Marcel; Steven, Daniel; Frank, Konrad; Castrogiovanni, Alessandra; Kietzmann, Ilona; Baldus, Stephan; Randerath, Winfried J

    2018-05-29

    Sleep-disordered breathing (SDB) is highly prevalent in patients with cardiovascular diseases (CVD) and associated with poor outcome. At least 50% of heart failure (HF) patients present with SDB, equally divided in obstructive sleep apnea (OSA) and central sleep apnea (CSA). CVD patients with SDB do not always present with typical SDB symptoms. Therefore, we asked whether established questionnaires allow for the reliable detection of SDB. In this prospective cohort study, 89 CVD patients (54 male, 59 ± 15 years, BMI 30 ± 6 kg/m 2 ) in stable clinical state underwent an ambulatory polygraphy. SDB was defined as an apnea-hypopnea index (AHI) ≥ 15/h. We evaluated the Epworth Sleepiness Scale (ESS), STOP-BANG and Berlin questionnaires as well as anthropometric data and comorbidities regarding their ability to predict SDB. The ESS showed no correlation with SDB. The sensitivity of the Berlin Questionnaire to detect SDB was 73%, specificity was 42%. The STOP-BANG questionnaire showed a sensitivity of 97% while specificity was 13%. Coronary heart disease and/or history of myocardial infarction, hyperuricemia and age significantly contributed to a logistic regression model predicting presence of SDB. However, our regression model explains only 36% of the variance regarding the presence or absence of SDB. The approach to find variables, which would allow an early and reliable differentiation between patients with CVD and coexistence or absence of SDB, failed. Thus, as CVD patients show a high SDB prevalence and poor outcome, only a systematic screening based on measures of respiration-related parameters (i.e., respiratory flow, blood oxygen saturation, etc.) allows for a reliable SDB assessment.

  20. A probable stellar solution to the cosmological lithium discrepancy.

    PubMed

    Korn, A J; Grundahl, F; Richard, O; Barklem, P S; Mashonkina, L; Collet, R; Piskunov, N; Gustafsson, B

    2006-08-10

    The measurement of the cosmic microwave background has strongly constrained the cosmological parameters of the Universe. When the measured density of baryons (ordinary matter) is combined with standard Big Bang nucleosynthesis calculations, the amounts of hydrogen, helium and lithium produced shortly after the Big Bang can be predicted with unprecedented precision. The predicted primordial lithium abundance is a factor of two to three higher than the value measured in the atmospheres of old stars. With estimated errors of 10 to 25%, this cosmological lithium discrepancy seriously challenges our understanding of stellar physics, Big Bang nucleosynthesis or both. Certain modifications to nucleosynthesis have been proposed, but found experimentally not to be viable. Diffusion theory, however, predicts atmospheric abundances of stars to vary with time, which offers a possible explanation of the discrepancy. Here we report spectroscopic observations of stars in the metal-poor globular cluster NGC 6397 that reveal trends of atmospheric abundance with evolutionary stage for various elements. These element-specific trends are reproduced by stellar-evolution models with diffusion and turbulent mixing. We thus conclude that diffusion is predominantly responsible for the low apparent stellar lithium abundance in the atmospheres of old stars by transporting the lithium deep into the star.

  1. `The Wildest Speculation of All': Lemaître and the Primeval-Atom Universe

    NASA Astrophysics Data System (ADS)

    Kragh, Helge

    Although there is no logical connection between the expanding universe and the idea of a big bang, from a historical perspective the two concepts were intimately connected. Four years after his pioneering work on the expanding universe, Lemaître suggested that the entire universe had originated in a kind of explosive act from what he called a primeval atom and which he likened to a huge atomic nucleus. His theory of 1931 was the first realistic finite-age model based upon relativistic cosmology, but it presupposed a material proto-universe and thus avoided an initial singularity. What were the sources of Lemaître's daring proposal? Well aware that his new cosmological model needed to have testable consequences, he argued that the cosmic rays were fossils of the original radioactive explosion. However, this hypothesis turned out to be untenable. The first big-bang model ever was received with a mixture of indifference and hostility. Why? The answer is not that contemporary cosmologists failed to recognize Lemaître's genius, but rather that his model was scientifically unconvincing. Although Lemaître was indeed the father of big-bang cosmology, his brilliant idea was only turned into a viable cosmological theory by later physicists.

  2. Nuclear physics and cosmology

    NASA Technical Reports Server (NTRS)

    Schramm, David N.

    1989-01-01

    Nuclear physics has provided one of two critical observational tests of all Big Bang cosmology, namely Big Bang Nucleosynthesis. Furthermore, this same nuclear physics input enables a prediction to be made about one of the most fundamental physics questions of all, the number of elementary particle families. The standard Big Bang Nucleosynthesis arguments are reviewed. The primordial He abundance is inferred from He-C and He-N and He-O correlations. The strengthened Li constraint as well as D-2 plus He-3 are used to limit the baryon density. This limit is the key argument behind the need for non-baryonic dark matter. The allowed number of neutrino families, N(nu), is delineated using the new neutron lifetime value of tau(n) = 890 + or - 4s (tau(1/2) = 10.3 min). The formal statistical result is N(nu) = 2.6 + or - 0.3 (1 sigma), providing a reasonable fit (1.3 sigma) to three families but making a fourth light (m(nu) less than or equal to 10 MeV) neutrino family exceedly unlikely (approx. greater than 4.7 sigma). It is also shown that uncertainties induced by postulating a first-order quark-baryon phase transition do not seriously affect the conclusions.

  3. Cell Phones ≠ Self and Other Problems with Big Data Detection and Containment during Epidemics.

    PubMed

    Erikson, Susan L

    2018-03-08

    Evidence from Sierra Leone reveals the significant limitations of big data in disease detection and containment efforts. Early in the 2014-2016 Ebola epidemic in West Africa, media heralded HealthMap's ability to detect the outbreak from newsfeeds. Later, big data-specifically, call detail record data collected from millions of cell phones-was hyped as useful for stopping the disease by tracking contagious people. It did not work. In this article, I trace the causes of big data's containment failures. During epidemics, big data experiments can have opportunity costs: namely, forestalling urgent response. Finally, what counts as data during epidemics must include that coming from anthropological technologies because they are so useful for detection and containment. © 2018 The Authors Medical Anthropology Quarterly published by Wiley Periodicals, Inc. on behalf of American Anthropological Association.

  4. Generation of large coherent states by bang–bang control of a trapped-ion oscillator

    PubMed Central

    Alonso, J.; Leupold, F. M.; Solèr, Z. U.; Fadel, M.; Marinelli, M.; Keitch, B. C.; Negnevitsky, V.; Home, J. P.

    2016-01-01

    Fast control of quantum systems is essential to make use of quantum properties before they degrade by decoherence. This is important for quantum-enhanced information processing, as well as for pushing quantum systems towards the boundary between quantum and classical physics. ‘Bang–bang' control attains the ultimate speed limit by making large changes to control fields much faster than the system can respond, but is often challenging to implement experimentally. Here we demonstrate bang–bang control of a trapped-ion oscillator using nanosecond switching of the trapping potentials. We perform controlled displacements with which we realize coherent states with up to 10,000 quanta of energy. We use these displaced states to verify the form of the ion-light interaction at high excitations far outside the usual regime of operation. These methods provide new possibilities for quantum-state manipulation and generation, alongside the potential for a significant increase in operational clock speed for trapped-ion quantum information processing. PMID:27046513

  5. Challenges and Opportunities of Big Data in Health Care: A Systematic Review.

    PubMed

    Kruse, Clemens Scott; Goswamy, Rishi; Raval, Yesha; Marawi, Sarah

    2016-11-21

    Big data analytics offers promise in many business sectors, and health care is looking at big data to provide answers to many age-related issues, particularly dementia and chronic disease management. The purpose of this review was to summarize the challenges faced by big data analytics and the opportunities that big data opens in health care. A total of 3 searches were performed for publications between January 1, 2010 and January 1, 2016 (PubMed/MEDLINE, CINAHL, and Google Scholar), and an assessment was made on content germane to big data in health care. From the results of the searches in research databases and Google Scholar (N=28), the authors summarized content and identified 9 and 14 themes under the categories Challenges and Opportunities, respectively. We rank-ordered and analyzed the themes based on the frequency of occurrence. The top challenges were issues of data structure, security, data standardization, storage and transfers, and managerial skills such as data governance. The top opportunities revealed were quality improvement, population management and health, early detection of disease, data quality, structure, and accessibility, improved decision making, and cost reduction. Big data analytics has the potential for positive impact and global implications; however, it must overcome some legitimate obstacles. ©Clemens Scott Kruse, Rishi Goswamy, Yesha Raval, Sarah Marawi. Originally published in JMIR Medical Informatics (http://medinform.jmir.org), 21.11.2016.

  6. LHC, le Big Bang en éprouvette

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    None

    Notre compréhension de l’Univers est en train de changer… Bar des Sciences - Tout public Débat modéré par Marie-Odile Montchicourt, journaliste de France Info. Evenement en vidéoconférence entre le Globe de la science et de l’innovation, le bar le Baloard de Montpellier et la Maison des Métallos à Paris. Intervenants au CERN : Philippe Charpentier et Daniel Froideveaux, physiciens au CERN. Intervenants à Paris : Vincent Bontemps, philosophe et chercheur au CEA ; Jacques Arnould, philosophe, historien des sciences et théologien, Jean-Jacques Beineix, réalisateur, producteur, scénariste de cinéma. Intervenants à Montpellier (LPTA) : André Neveu, physicien théoricien et directeur demore » recherche au CNRS ; Gilbert Moultaka, physicien théoricien et chargé de recherche au CNRS. Partenariat : CERN, CEA, IN2P3, Université MPL2 (LPTA) Dans le cadre de la Fête de la science 2008.« less

  7. From the Big Bang to sustainable societies.

    PubMed

    Eriksson, K E; Robèrt, K H

    1991-01-01

    A series of events in the history of cosmos has created the prerequisites for life on Earth. With respect to matter, the earth is a closed system. However, it receives light from the sun and emits infrared radiation into space. The difference in thermodynamic potential between these two flows has provided the physical conditions for self-organization. The transformation of lifeless matter into modern life forms, with their high degree of order and complexity, has occurred in the context of the earth's natural cycles, including the water cycle and the biochemical cycles between plants and animals. Primary production units, the cells of green plants, can use the thermodynamic potential of the energy balance in a very direct way, i.e. in photosynthesis. Plant cells are unique in their ability to synthesize more structure than is broken down elsewhere in the biosphere. The perpetuation of this process requires the recycling of wastes. However, modern industrial societies are obsessed with the supply side, ignoring the principle of matter's conservation and neglecting to plan for the entire material flow. As a result there has been an accumulation of both visible and invisible garbage (pollution), which disturbs the biosphere and reduces stocks of natural resources. Furthermore, due to complexity and delay mechanisms, we usually cannot predict time parameters for the resulting socio-economic consequences or the development of disease. To continue along this path of folly is not compatible with the maintenance of wealth, nor with the health of humans or the biosphere. Rather than address the millions of environmental problems one at a time, we need to approach them at the systemic level. It is essential to convert to human life-styles and forms of societal organization that are based on cyclic processes compatible with the earth's natural cycles. The challenge to the developed countries is not only to decrease their own emissions of pollutants but to develop the cyclic technology and life styles needed by the entire human community.

  8. The big-bang-for-your-buck theory.

    PubMed

    Lucas, H C; Weill, P; Cox, S

    1993-01-01

    Do it right, and your investment in information technology can have all sorts of strategic payoffs. Do it wrong, and you'll be paying, dearly, for nothing. Here's a guide to evaluating IT and measuring its impact.

  9. From the Big Bang to the Brain.

    ERIC Educational Resources Information Center

    Boliek, Carol A.; Lohmeier, Heather

    1999-01-01

    Summarizes research findings that challenge long-standing theories of infant cognition and motor development and proposes alternative theoretical models to describe skill acquisition during the first several years of life. Findings are discussed with respect to research in the area of infant speech physiology and production. (Author/CR)

  10. From the big bang to the brain.

    PubMed

    Boliek, C A; Lohmeier, H

    1999-01-01

    Current research on the capacities of the infant has lead to a better understanding of developmental processes underlying cognition and motor skill acquisition. ASHA's Eighth Annual Research Symposium on Infant-Toddler Development, in November 1998, included a presentation on developmental cognitive science by Dr. Andrew Meltzoff and a presentation on motor skill acquisition by Dr. Esther Thelen. The theoretical constructs and data presented served to broaden our current perspectives on infant abilities. The data reported by Meltzoff and Thelen challenged several long-standing theories of infant cognition and motor development. Alternative theoretical models were used to describe skill acquisition during the first several years of life. Our response will include a brief summary of each investigator's presentation, discuss their findings with respect to research in the area of infant speech physiology and production, and provide possible future directions and challenges for individuals conducting developmental research.

  11. Primordial beryllium as a big bang calorimeter.

    PubMed

    Pospelov, Maxim; Pradler, Josef

    2011-03-25

    Many models of new physics including variants of supersymmetry predict metastable long-lived particles that can decay during or after primordial nucleosynthesis, releasing significant amounts of nonthermal energy. The hadronic energy injection in these decays leads to the formation of ⁹Be via the chain of nonequilibrium transformations: Energy(h)→T, ³He→⁶He, ⁶Li→⁹Be. We calculate the efficiency of this transformation and show that if the injection happens at cosmic times of a few hours the release of O(10 MeV) per baryon can be sufficient for obtaining a sizable ⁹Be abundance. The absence of a plateau structure in the ⁹Be/H abundance down to a O(10⁻¹⁴) level allows one to use beryllium as a robust constraint on new physics models with decaying or annihilating particles.

  12. Oceanic turbulence - Big bangs or continuous creation?

    NASA Technical Reports Server (NTRS)

    Caldwell, D. R.

    1983-01-01

    A hypothesis concerning the turbulence characteristics of 'microstructure' patches in the ocean is proposed in which a turbulence field is driven at the same time and scale at which it is observed. The driving energy is converted into turbulence kinetic energy in such a way that the observed overturning thickness scale is linearly related to the length scale. This hypothesis is contrasted with that of Gibson (1982), in which the 'patches' are produced by rare, powerful turbulence generators that have 'fossilized' prior to their observation. Careful attention is given to the sampling process and its assumptions.

  13. 'Big bang' of B-cell development revealed.

    PubMed

    Murre, Cornelis

    2018-01-15

    Earlier studies have identified transcription factors that specify B-cell fate, but the underlying mechanisms remain to be revealed. Two new studies by Miyai and colleagues (pp. 112-126) and Li and colleagues (pp. 96-111) in this issue of Genes & Development provide new and unprecedented insights into the genetic and epigenetic mechanisms that establish B-cell identity. © 2018 Murre; Published by Cold Spring Harbor Laboratory Press.

  14. Motivating Reluctant Learners with a Big Bang

    NASA Technical Reports Server (NTRS)

    Lochner, James C.; Cvetic, Geraldine A.; Hall, Jonathan B.

    2007-01-01

    We present results of a collaboration between a media specialist, a science teacher, and an astronomer to bring a modern astronomy topic to at-risk, emotionally disabled students who have experienced little success. These normally unengaged students became highly motivated because they were given an authentic task of presenting research on an intriguing science topic, and because they witnessed a collaboration brought together on their behalf This experience demonstrates that sophisticated astronomy topics can be used to motivate at-risk students.

  15. The quark-hadron transition in cosmology and astrophysics.

    PubMed

    Olive, K A

    1991-03-08

    A transition from normal hadronic matter (such as protons and neutrons) to quark-gluon matter is expected at both high temperatures and densities. In physical situations, this transition may occur in heavy ion collisions, the early universe, and in the cores of neutron stars. Astrophysics and cosmology can be greatly affected by such a phase transition. With regard to the early universe, big bang nucleosynthesis, the theory describing the primordial origin of the light elements, can be affected by inhomogeneities produced during the transition. A transition to quark matter in the interior by neutron stars further enhances our uncertainties regarding the equation of state of dense nuclear matter and neutron star properties such as the maximum mass and rotation frequencies.

  16. Evolution of hydromagnetic turbulence from the electroweak phase transition

    NASA Astrophysics Data System (ADS)

    Brandenburg, Axel; Kahniashvili, Tina; Mandal, Sayan; Pol, Alberto Roper; Tevzadze, Alexander G.; Vachaspati, Tanmay

    2017-12-01

    We present new simulations of decaying hydromagnetic turbulence for a relativistic equation of state relevant to the early Universe. We compare helical and nonhelical cases either with kinetically or magnetically dominated initial fields. Both kinetic and magnetic initial helicities lead to maximally helical magnetic fields after some time, but with different temporal decay laws. Both are relevant to the early Universe, although no mechanisms have yet been identified that produce magnetic helicity with strengths comparable to the big bang nucleosynthesis limit at scales comparable to the Hubble horizon at the electroweak phase transition. Nonhelical magnetically dominated fields could still produce picoGauss magnetic fields under most optimistic conditions. Only helical magnetic fields can potentially have nanoGauss strengths at scales up to 30 kpc today.

  17. The Cosmic Microwave Background: Detection and Interpretation of the First Light

    NASA Technical Reports Server (NTRS)

    Wollack, Edward J.

    2016-01-01

    A host of astrophysical observations suggest the early Universe was incredibly hot, dense, and homogeneous. A powerful and useful probe of this epoch is provided by the relic radiation, which we refer to today as the Cosmic Microwave Background (CMB). Precision maps of this light contain the earliest glimpse of the Universe after the Big Bang and signatures of the evolution of its contents. By exploiting these clues, constraints on the age, mass density, detailed composition, and geometry of the Universe can be made. A brief survey of the evolution of the radiometric and polarimetric imaging systems used in advancing our understanding of the early Universe will be reviewed. A survey of detector technologies, instrumentation techniques, and experimental challenges encountered in these efforts will be presented.

  18. An ancient revisits cosmology.

    PubMed Central

    Greenstein, J L

    1993-01-01

    In this after-dinner speech, a somewhat light-hearted attempt is made to view the observational side of physical cosmology as a subdiscipline of astrophysics, still in an early stage of sophistication and in need of more theoretical understanding. The theoretical side of cosmology, in contrast, has its deep base in general relativity. A major result of observational cosmology is that an expansion of the Universe arose from a singularity some 15 billion years ago. This has had an enormous impact on the public's view of both astronomy and theology. It places on cosmologists an extra responsibility for clear thinking and interpretation. Recently, gravitational physics caused another crisis from an unexpected observational result that nonbaryonic matter appears to dominate. Will obtaining information about this massive nonbaryonic component require that astronomers cease to rely on measurement of photons? But 40 years ago after radio astronomical techniques uncovered the high-energy universe, we happily introduced new subfields, with techniques from physics and engineering still tied to photon detection. Another historical example shows how a subfield of cosmology, big bang nucleosynthesis, grew in complexity from its spectroscopic astrophysics beginning 40 years ago. Determination of primordial abundances of lighter nuclei does illuminate conditions in the Big Bang, but the observational results faced and overcame many hurdles on the way. PMID:11607403

  19. Artist's Concept of Early Universe

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This is an artist's impression of how the very early universe (less than one billion years old) might have looked when it went through a voracious onset of star formation, converting primordial hydrogen into myriad stars at an unprecedented rate. The deepest views of the cosmos from the Hubble Space Telescope (HST) yield clues that the very first stars may have burst into the universe as brilliantly and spectacularly as a firework finale. Except in this case, the finale came first, long before Earth, the Sun ,and the Milky Way Galaxy formed. Studies of HST's deepest views of the heavens lead to the preliminary conclusion that the universe made a significant portion of its stars in a torrential firestorm of star birth, which abruptly lit up the pitch-dark heavens just a few hundred million years after the 'big bang,' the tremendous explosion that created the cosmos. Within the starburst galaxies, bright knots of hot blue stars come and go like bursting fireworks shells. Regions of new starbirth glow intensely red under torrent of ultraviolet radiation. The most massive stars self-detonate as supernovas, which explode across the sky like a string of firecrackers. A foreground starburst galaxy at lower right is sculpted with hot bubbles from supernova explosions and torrential stellar winds. Unlike today there is very little dust in these galaxies, because the heavier elements have not yet been cooked up through nucleosynthesis in stars. Recent analysis of HST deep sky images supports the theory that the first stars in the universe appeared in an abrupt eruption of star formation, rather than at a gradual pace. Science Credit: NASA and K. Lanzetta (SUNY). Artwork Credit: Adolf Schaller for STScI.

  20. A magnetic particle time-of-flight (MagPTOF) diagnostic for measurements of shock- and compression-bang time at the NIF (invited)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rinderknecht, H. G., E-mail: hgr@mit.edu; Sio, H.; Frenje, J. A.

    A magnetic particle time-of-flight (MagPTOF) diagnostic has been designed to measure shock- and compression-bang time using D{sup 3}He-fusion protons and DD-fusion neutrons, respectively, at the National Ignition Facility (NIF). This capability, in combination with shock-burn weighted areal density measurements, will significantly constrain the modeling of the implosion dynamics. This design is an upgrade to the existing particle time-of-flight (pTOF) diagnostic, which records bang times using DD or DT neutrons with an accuracy better than ±70 ps [H. G. Rinderknecht et al., Rev. Sci. Instrum. 83, 10D902 (2012)]. The inclusion of a deflecting magnet will increase D{sup 3}He-proton signal-to-background by amore » factor of 1000, allowing for the first time simultaneous measurements of shock- and compression-bang times in D{sup 3}He-filled surrogate implosions at the NIF.« less

  1. Circulating big endothelin-1: an active role in pulmonary thromboendarterectomy?

    PubMed

    Langer, Frank; Bauer, Michael; Tscholl, Dietmar; Schramm, Rene; Kunihara, Takashi; Lausberg, Henning; Georg, Thomas; Wilkens, Heinrike; Schäfers, Hans-Joachim

    2005-11-01

    Pulmonary thromboendarterectomy is an effective treatment for patients with chronic thromboembolic pulmonary hypertension. The early postoperative course may be associated with pulmonary vasoconstriction and profound systemic vasodilation. We investigated the potential involvement of endothelins in these hemodynamic alterations. Seventeen patients with chronic thromboembolic pulmonary hypertension (pulmonary vascular resistance, 1015 +/- 402 dyne x s x cm(-5) [mean +/- SD]) underwent pulmonary thromboendarterectomy with cardiopulmonary bypass and deep hypothermic circulatory arrest. Peripheral arterial blood samples were drawn before sternotomy, during cardiopulmonary bypass before and after deep hypothermic circulatory arrest, and 0, 8, 16, and 24 hours after surgery and were analyzed for big endothelin-1. The patients were divided into 2 groups according to whether their preoperative big endothelin-1 plasma level was above or below the cutoff point of 2.1 pg/mL, as determined by receiver operating characteristic curve analysis (group A, big endothelin-1 <2.1 pg/mL, n = 8; group B, big endothelin-1 > or =2.1 pg/mL, n = 9). Patients in group B, with higher preoperative big endothelin-1 levels (3.2 +/- 1.0 pg/mL vs 1.5 +/- 0.4 pg/mL; P < .001), were poorer operative candidates (preoperative mean pulmonary artery pressure, 51.3 +/- 7.1 mm Hg vs 43.6 +/- 6.2 mm Hg; P = .006) and had a poorer outcome (mean pulmonary artery pressure 24 hours after surgery, 32.6 +/- 9.5 mm Hg vs 21.8 +/- 6.2 mm Hg; P < .001). Positive correlations were found between preoperative big endothelin-1 levels and preoperative mean pulmonary artery pressure (r = 0.56; P = .02) as well as postoperative mean pulmonary artery pressure at 0 hours (r = 0.70; P = .002) and 24 hours (r = 0.63; P = .006) after surgery. Preoperative big endothelin-1 levels predicted outcome (postoperative mean pulmonary artery pressure at 24 hours after surgery) after pulmonary thromboendarterectomy (area under the

  2. Native Perennial Forb Variation Between Mountain Big Sagebrush and Wyoming Big Sagebrush Plant Communities

    NASA Astrophysics Data System (ADS)

    Davies, Kirk W.; Bates, Jon D.

    2010-09-01

    Big sagebrush ( Artemisia tridentata Nutt.) occupies large portions of the western United States and provides valuable wildlife habitat. However, information is lacking quantifying differences in native perennial forb characteristics between mountain big sagebrush [ A. tridentata spp. vaseyana (Rydb.) Beetle] and Wyoming big sagebrush [ A. tridentata spp. wyomingensis (Beetle & A. Young) S.L. Welsh] plant communities. This information is critical to accurately evaluate the quality of habitat and forage that these communities can produce because many wildlife species consume large quantities of native perennial forbs and depend on them for hiding cover. To compare native perennial forb characteristics on sites dominated by these two subspecies of big sagebrush, we sampled 106 intact big sagebrush plant communities. Mountain big sagebrush plant communities produced almost 4.5-fold more native perennial forb biomass and had greater native perennial forb species richness and diversity compared to Wyoming big sagebrush plant communities ( P < 0.001). Nonmetric multidimensional scaling (NMS) and the multiple-response permutation procedure (MRPP) demonstrated that native perennial forb composition varied between these plant communities ( P < 0.001). Native perennial forb composition was more similar within plant communities grouped by big sagebrush subspecies than expected by chance ( A = 0.112) and composition varied between community groups ( P < 0.001). Indicator analysis did not identify any perennial forbs that were completely exclusive and faithful, but did identify several perennial forbs that were relatively good indicators of either mountain big sagebrush or Wyoming big sagebrush plant communities. Our results suggest that management plans and habitat guidelines should recognize differences in native perennial forb characteristics between mountain and Wyoming big sagebrush plant communities.

  3. Seeing the big picture in nursing: a source of human and professional pride.

    PubMed

    Sørensen, Erik E; Hall, Elisabeth O C

    2011-10-01

    This article presents a discussion of the meaning of the phenomenon of seeing the big picture in nursing. Seeing the big picture is a frequent expression among Danish nurses. It is used when trying to understand a situation in its wider context. However, it has a rather imprecise meaning that might lead to misunderstandings. This paper draws on studies undertaken in the mid 1990s and the early 2000s, but with the current discussion developed in the context of contemporary nursing. Seeing the big picture indicates a desire to do good for patients' and staff. This desire expressed through saying 'I need to see the big picture' is discussed to be a backbone in nursing and nursing leadership and a source of human and professional pride. There is, however, a dilemma if nurses overlook needs of patients that require immediate actions and if a nurse leader does not intercept staff members in crisis. The pride is oscillating between seeing the here-and-now and seeing the long-term in the big picture. We assumed seeing the big picture had to do with practical knowledge. Wonder and reasoning, however, brought us to virtues. Seeing the big picture as mentioned among nursing leaders and clinical nurses demonstrates human and professional pride. The study is useful in organizational, clinical and educational settings in updating policies for nursing, enlarging nurses understanding of practice and training students in understanding nursing practice. © 2011 Blackwell Publishing Ltd.

  4. Big Data and Neuroimaging.

    PubMed

    Webb-Vargas, Yenny; Chen, Shaojie; Fisher, Aaron; Mejia, Amanda; Xu, Yuting; Crainiceanu, Ciprian; Caffo, Brian; Lindquist, Martin A

    2017-12-01

    Big Data are of increasing importance in a variety of areas, especially in the biosciences. There is an emerging critical need for Big Data tools and methods, because of the potential impact of advancements in these areas. Importantly, statisticians and statistical thinking have a major role to play in creating meaningful progress in this arena. We would like to emphasize this point in this special issue, as it highlights both the dramatic need for statistical input for Big Data analysis and for a greater number of statisticians working on Big Data problems. We use the field of statistical neuroimaging to demonstrate these points. As such, this paper covers several applications and novel methodological developments of Big Data tools applied to neuroimaging data.

  5. The cosmological lithium problem revisited

    NASA Astrophysics Data System (ADS)

    Bertulani, C. A.; Mukhamedzhanov, A. M.; Shubhchintak

    2016-07-01

    After a brief review of the cosmological lithium problem, we report a few recent attempts to find theoretical solutions by our group at Texas A&M University (Commerce & College Station). We will discuss our studies on the theoretical description of electron screening, the possible existence of parallel universes of dark matter, and the use of non-extensive statistics during the Big Bang nucleosynthesis epoch. Last but not least, we discuss possible solutions within nuclear physics realm. The impact of recent measurements of relevant nuclear reaction cross sections for the Big Bang nucleosynthesis based on indirect methods is also assessed. Although our attempts may not able to explain the observed discrepancies between theory and observations, they suggest theoretical developments that can be useful also for stellar nucleosynthesis.

  6. Tachyon field in loop quantum cosmology: An example of traversable singularity

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Li Lifang; Zhu Jianyang

    2009-06-15

    Loop quantum cosmology (LQC) predicts a nonsingular evolution of the universe through a bounce in the high energy region. But LQC has an ambiguity about the quantization scheme. Recently, the authors in [Phys. Rev. D 77, 124008 (2008)] proposed a new quantization scheme. Similar to others, this new quantization scheme also replaces the big bang singularity with the quantum bounce. More interestingly, it introduces a quantum singularity, which is traversable. We investigate this novel dynamics quantitatively with a tachyon scalar field, which gives us a concrete example. Our result shows that our universe can evolve through the quantum singularity regularly,more » which is different from the classical big bang singularity. So this singularity is only a weak singularity.« less

  7. Cryptography for Big Data Security

    DTIC Science & Technology

    2015-07-13

    Cryptography for Big Data Security Book Chapter for Big Data: Storage, Sharing, and Security (3S) Distribution A: Public Release Ariel Hamlin1 Nabil...Email: arkady@ll.mit.edu ii Contents 1 Cryptography for Big Data Security 1 1.1 Introduction...48 Chapter 1 Cryptography for Big Data Security 1.1 Introduction With the amount

  8. Data: Big and Small.

    PubMed

    Jones-Schenk, Jan

    2017-02-01

    Big data is a big topic in all leadership circles. Leaders in professional development must develop an understanding of what data are available across the organization that can inform effective planning for forecasting. Collaborating with others to integrate data sets can increase the power of prediction. Big data alone is insufficient to make big decisions. Leaders must find ways to access small data and triangulate multiple types of data to ensure the best decision making. J Contin Educ Nurs. 2017;48(2):60-61. Copyright 2017, SLACK Incorporated.

  9. Big Data in industry

    NASA Astrophysics Data System (ADS)

    Latinović, T. S.; Preradović, D. M.; Barz, C. R.; Latinović, M. T.; Petrica, P. P.; Pop-Vadean, A.

    2016-08-01

    The amount of data at the global level has grown exponentially. Along with this phenomena, we have a need for a new unit of measure like exabyte, zettabyte, and yottabyte as the last unit measures the amount of data. The growth of data gives a situation where the classic systems for the collection, storage, processing, and visualization of data losing the battle with a large amount, speed, and variety of data that is generated continuously. Many of data that is created by the Internet of Things, IoT (cameras, satellites, cars, GPS navigation, etc.). It is our challenge to come up with new technologies and tools for the management and exploitation of these large amounts of data. Big Data is a hot topic in recent years in IT circles. However, Big Data is recognized in the business world, and increasingly in the public administration. This paper proposes an ontology of big data analytics and examines how to enhance business intelligence through big data analytics as a service by presenting a big data analytics services-oriented architecture. This paper also discusses the interrelationship between business intelligence and big data analytics. The proposed approach in this paper might facilitate the research and development of business analytics, big data analytics, and business intelligence as well as intelligent agents.

  10. k-essence in the DGP brane-world cosmology

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bouhmadi-Lopez, Mariam; Chimento, Luis P.

    We analyze a Dvali-Gabadadze-Porrati (DGP) brane filled with a k-essence field and assume the k field evolving linearly with the cosmic time of the brane. We then solve analytically the Friedmann equation and deduce the different behavior of the brane at the low- and the high-energy regimes. The asymptotic behavior can be quite different involving accelerating branes, big bangs, big crunches, big rips, or quiescent singularities. The latter correspond to a type of sudden singularity.

  11. The big data-big model (BDBM) challenges in ecological research

    NASA Astrophysics Data System (ADS)

    Luo, Y.

    2015-12-01

    The field of ecology has become a big-data science in the past decades due to development of new sensors used in numerous studies in the ecological community. Many sensor networks have been established to collect data. For example, satellites, such as Terra and OCO-2 among others, have collected data relevant on global carbon cycle. Thousands of field manipulative experiments have been conducted to examine feedback of terrestrial carbon cycle to global changes. Networks of observations, such as FLUXNET, have measured land processes. In particular, the implementation of the National Ecological Observatory Network (NEON), which is designed to network different kinds of sensors at many locations over the nation, will generate large volumes of ecological data every day. The raw data from sensors from those networks offer an unprecedented opportunity for accelerating advances in our knowledge of ecological processes, educating teachers and students, supporting decision-making, testing ecological theory, and forecasting changes in ecosystem services. Currently, ecologists do not have the infrastructure in place to synthesize massive yet heterogeneous data into resources for decision support. It is urgent to develop an ecological forecasting system that can make the best use of multiple sources of data to assess long-term biosphere change and anticipate future states of ecosystem services at regional and continental scales. Forecasting relies on big models that describe major processes that underlie complex system dynamics. Ecological system models, despite great simplification of the real systems, are still complex in order to address real-world problems. For example, Community Land Model (CLM) incorporates thousands of processes related to energy balance, hydrology, and biogeochemistry. Integration of massive data from multiple big data sources with complex models has to tackle Big Data-Big Model (BDBM) challenges. Those challenges include interoperability of multiple

  12. Science and Technology Review, January-February 1997

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    NONE

    Table of contents: accelerators at Livermore; the B-Factory and the Big Bang; assessing exposure to radiation; next generation of computer storage; and a powerful new tool to detect clandestine nuclear tests.

  13. Big Machines and Big Science: 80 Years of Accelerators at Stanford

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Loew, Gregory

    2008-12-16

    Longtime SLAC physicist Greg Loew will present a trip through SLAC's origins, highlighting its scientific achievements, and provide a glimpse of the lab's future in 'Big Machines and Big Science: 80 Years of Accelerators at Stanford.'

  14. Himalayan fossils of the oldest known pantherine establish ancient origin of big cats

    PubMed Central

    Tseng, Z. Jack; Wang, Xiaoming; Slater, Graham J.; Takeuchi, Gary T.; Li, Qiang; Liu, Juan; Xie, Guangpu

    2014-01-01

    Pantherine felids (‘big cats’) include the largest living cats, apex predators in their respective ecosystems. They are also the earliest diverging living cat lineage, and thus are important for understanding the evolution of all subsequent felid groups. Although the oldest pantherine fossils occur in Africa, molecular phylogenies point to Asia as their region of origin. This paradox cannot be reconciled using current knowledge, mainly because early big cat fossils are exceedingly rare and fragmentary. Here, we report the discovery of a fossil pantherine from the Tibetan Himalaya, with an age of Late Miocene–Early Pliocene, replacing African records as the oldest pantherine. A ‘total evidence’ phylogenetic analysis of pantherines indicates that the new cat is closely related to the snow leopard and exhibits intermediate characteristics on the evolutionary line to the largest cats. Historical biogeographic models provide robust support for the Asian origin of pantherines. The combined analyses indicate that 75% of the divergence events in the pantherine lineage extended back to the Miocene, up to 7 Myr earlier than previously estimated. The deeper evolutionary origin of big cats revealed by the new fossils and analyses indicate a close association between Tibetan Plateau uplift and diversification of the earliest living cats. PMID:24225466

  15. Himalayan fossils of the oldest known pantherine establish ancient origin of big cats.

    PubMed

    Tseng, Z Jack; Wang, Xiaoming; Slater, Graham J; Takeuchi, Gary T; Li, Qiang; Liu, Juan; Xie, Guangpu

    2014-01-07

    Pantherine felids ('big cats') include the largest living cats, apex predators in their respective ecosystems. They are also the earliest diverging living cat lineage, and thus are important for understanding the evolution of all subsequent felid groups. Although the oldest pantherine fossils occur in Africa, molecular phylogenies point to Asia as their region of origin. This paradox cannot be reconciled using current knowledge, mainly because early big cat fossils are exceedingly rare and fragmentary. Here, we report the discovery of a fossil pantherine from the Tibetan Himalaya, with an age of Late Miocene-Early Pliocene, replacing African records as the oldest pantherine. A 'total evidence' phylogenetic analysis of pantherines indicates that the new cat is closely related to the snow leopard and exhibits intermediate characteristics on the evolutionary line to the largest cats. Historical biogeographic models provide robust support for the Asian origin of pantherines. The combined analyses indicate that 75% of the divergence events in the pantherine lineage extended back to the Miocene, up to 7 Myr earlier than previously estimated. The deeper evolutionary origin of big cats revealed by the new fossils and analyses indicate a close association between Tibetan Plateau uplift and diversification of the earliest living cats.

  16. The Prospect of Internet of Things and Big Data Analytics in Transportation System

    NASA Astrophysics Data System (ADS)

    Noori Hussein, Waleed; Kamarudin, L. M.; Hussain, Haider N.; Zakaria, A.; Badlishah Ahmed, R.; Zahri, N. A. H.

    2018-05-01

    Internet of Things (IoT); the new dawn technology that describes how data, people and interconnected physical objects act based on communicated information, and big data analytics have been adopted by diverse domains for varying purposes. Manufacturing, agriculture, banks, oil and gas, healthcare, retail, hospitality, and food services are few of the sectors that have adopted and massively utilized IoT and big data analytics. The transportation industry is also an early adopter, with significant attendant effects on its processes of tracking shipment, freight monitoring, and transparent warehousing. This is recorded in countries like England, Singapore, Portugal, and Germany, while Malaysia is currently assessing the potentials and researching a purpose-driven adoption and implementation. This paper, based on review of related literature, presents a summary of the inherent prospects in adopting IoT and big data analytics in the Malaysia transportation system. Efficient and safe port environment, predictive maintenance and remote management, boundary-less software platform and connected ecosystem, among others, are the inherent benefits in the IoT and big data analytics for the Malaysia transportation system.

  17. An investigation of Taiwanese early adolescents' self-evaluations concerning the Big 6 information problem-solving approach.

    PubMed

    Chang, Chiung-Sui

    2007-01-01

    The study developed a Big 6 Information Problem-Solving Scale (B61PS), including the subscales of task definition and information-seeking strategies, information access and synthesis, and evaluation. More than 1,500 fifth and sixth graders in Taiwan responded. The study revealed that the scale showed adequate reliability in assessing the adolescents' perceptions about the Big 6 information problem-solving approach. In addition, the adolescents had quite different responses toward different subscales of the approach. Moreover, females tended to have higher quality information-searching skills than their male counterparts. The adolescents of different grades also displayed varying views toward the approach. Other results are also provided.

  18. Update of the BIG 1-98 Trial: where do we stand?

    PubMed

    Joerger, Markus; Thürlimann, Beat

    2009-10-01

    There is accumulating data on the clinical benefit of aromatase inhibitors in the adjuvant treatment of early-stage breast cancer in postmenopausal women. The Breast International Group (BIG) 1-98 study is a randomized, phase 3, double-blind trial comparing four adjuvant endocrine treatments of 5 years duration in postmenopausal women with hormone-receptor-positive breast cancer: letrozole or tamoxifen monotherapy, sequential treatment with tamoxifen followed by letrozole, or vice versa. This article summarizes data presented at the 2009 St. Gallen early breast cancer conference: an update on the monotherapy arms of the BIG 1-98 study, and results from the sequential treatment arms. Implications for daily practice from BIG 1-98 and from other adjuvant trials will be discussed. Despite cross-over from tamoxifen to letrozole by 25% of the patients after unblinding of the tamoxifen monotherapy arm, the improvement of disease-free survival (HR 0.88, 0.78-0.99, p = 0.03) and time to distant recurrence (HR 0.85, 0.72-1.00, p = 0.05) for letrozole monotherapy as compared to tamoxifen monotherapy remained significant in the intention-to-treat (ITT) analysis. A trend for an overall survival advantage for letrozole was seen in the ITT analysis (HR 0.87, 0.75-1.02, p = 0.08). No statistically significant differences were found for the sequential treatment arms versus letrozole monotherapy, with respect to disease-free survival, time to distant recurrence or overall survival. Cumulative incidence analysis of breast cancer recurrence favors the initiation of adjuvant endocrine treatment with letrozole instead of tamoxifen, especially in patients at higher risk for early recurrence. Similarly, data suggest that patients commenced on letrozole can be switched to tamoxifen after 2 years, if required. The BIG 1-98 study update with median follow up of 76 months confirms a significant reduction in the risk of breast cancer recurrence and a trend towards improved overall survival

  19. Analytical review based on statistics on good and poor financial performance of LPD in Bangli regency.

    NASA Astrophysics Data System (ADS)

    Yasa, I. B. A.; Parnata, I. K.; Susilawati, N. L. N. A. S.

    2018-01-01

    This study aims to apply analytical review model to analyze the influence of GCG, accounting conservatism, financial distress models and company size on good and poor financial performance of LPD in Bangli Regency. Ordinal regression analysis is used to perform analytical review, so that obtained the influence and relationship between variables to be considered further audit. Respondents in this study were LPDs in Bangli Regency, which amounted to 159 LPDs of that number 100 LPDs were determined as randomly selected samples. The test results found GCG and company size have a significant effect on both the good and poor financial performance, while the conservatism and financial distress model has no significant effect. The influence of the four variables on the overall financial performance of 58.8%, while the remaining 41.2% influenced by other variables. Size, FDM and accounting conservatism are variables, which are further recommended to be audited.

  20. High-redshift galaxy populations.

    PubMed

    Hu, Esther M; Cowie, Lennox L

    2006-04-27

    We now see many galaxies as they were only 800 million years after the Big Bang, and that limit may soon be exceeded when wide-field infrared detectors are widely available. Multi-wavelength studies show that there was relatively little star formation at very early times and that star formation was at its maximum at about half the age of the Universe. A small number of high-redshift objects have been found by targeting X-ray and radio sources and most recently, gamma-ray bursts. The gamma-ray burst sources may provide a way to reach even higher-redshift galaxies in the future, and to probe the first generation of stars.

  1. Eddington's theory of gravity and its progeny.

    PubMed

    Bañados, Máximo; Ferreira, Pedro G

    2010-07-02

    We resurrect Eddington's proposal for the gravitational action in the presence of a cosmological constant and extend it to include matter fields. We show that the Newton-Poisson equation is modified in the presence of sources and that charged black holes show great similarities with those arising in Born-Infeld electrodynamics coupled to gravity. When we consider homogeneous and isotropic space-times, we find that there is a minimum length (and maximum density) at early times, clearly pointing to an alternative theory of the big bang. We thus argue that the modern formulation of Eddington's theory, Born-Infeld gravity, presents us with a novel, nonsingular description of the Universe.

  2. Stellar nucleosynthesis and chemical evolution of the solar neighborhood

    NASA Technical Reports Server (NTRS)

    Clayton, Donald D.

    1988-01-01

    Current theoretical models of nucleosynthesis (N) in stars are reviewed, with an emphasis on their implications for Galactic chemical evolution. Topics addressed include the Galactic population II red giants and early N; N in the big bang; star formation, stellar evolution, and the ejection of thermonuclearly evolved debris; the chemical evolution of an idealized disk galaxy; analytical solutions for a closed-box model with continuous infall; and nuclear burning processes and yields. Consideration is given to shell N in massive stars, N related to degenerate cores, and the types of observational data used to constrain N models. Extensive diagrams, graphs, and tables of numerical data are provided.

  3. Dissipative universe-inflation with soft singularity

    NASA Astrophysics Data System (ADS)

    Brevik, Iver; Timoshkin, Alexander V.

    We investigate the early-time accelerated universe after the Big Bang. We pay attention to the dissipative properties of the inflationary universe in the presence of a soft type singularity, making use of the parameters of the generalized equation of state of the fluid. Flat Friedmann-Robertson-Walker metric is being used. We consider cosmological models leading to the so-called type IV singular inflation. Our obtained theoretical results are compared with observational data from the Planck satellite. The theoretical predictions for the spectral index turn out to be in agreement with the data, while for the scalar-to-tensor ratio, there are minor deviations.

  4. Astrophysical and cosmological constraints to neutrino properties

    NASA Technical Reports Server (NTRS)

    Kolb, Edward W.; Schramm, David N.; Turner, Michael S.

    1989-01-01

    The astrophysical and cosmological constraints on neutrino properties (masses, lifetimes, numbers of flavors, etc.) are reviewed. The freeze out of neutrinos in the early Universe are discussed and then the cosmological limits on masses for stable neutrinos are derived. The freeze out argument coupled with observational limits is then used to constrain decaying neutrinos as well. The limits to neutrino properties which follow from SN1987A are then reviewed. The constraint from the big bang nucleosynthesis on the number of neutrino flavors is also considered. Astrophysical constraints on neutrino-mixing as well as future observations of relevance to neutrino physics are briefly discussed.

  5. Quark Matter and Nuclear Collisions a Brief History of Strong Interaction Thermodynamics

    NASA Astrophysics Data System (ADS)

    Satz, Helmut

    2012-08-01

    The past 50 years have seen the emergence of a new field of research in physics, the study of matter at extreme temperatures and densities. The theory of strong interactions, quantum chromodynamics (QCD), predicts that in this limit, matter will become a plasma of deconfined quarks and gluons — the medium which made up the early universe in the first 10 microseconds after the Big Bang. High energy nuclear collisions are expected to produce short-lived bubbles of such a medium in the laboratory. I survey the merger of statistical QCD and nuclear collision studies for the analysis of strongly interacting matter in theory and experiment.

  6. On Gauge Invariant Cosmological Perturbations in UV-modified Hořava Gravity: A Brief Introduction

    NASA Astrophysics Data System (ADS)

    Park, Mu-In

    2018-01-01

    We revisit gauge invariant cosmological perturbations in UV-modified, z = 3 Hořava gravity with one scalar matter field, which has been proposed as a renormalizable gravity theory without the ghost problem in four dimensions. We confirm that there is no extra graviton modes and general relativity is recovered in IR, which achieves the consistency of the model. From the UV-modification terms which break the detailed balance condition in UV, we obtain scale-invariant power spectrums for non-inflationary backgrounds, like the power-law expansions, without knowing the details of early expansion history of Universe. This could provide a new framework for the Big Bang cosmology.

  7. Computational Cosmology: From the Early Universe to the Large Scale Structure.

    PubMed

    Anninos, Peter

    2001-01-01

    In order to account for the observable Universe, any comprehensive theory or model of cosmology must draw from many disciplines of physics, including gauge theories of strong and weak interactions, the hydrodynamics and microphysics of baryonic matter, electromagnetic fields, and spacetime curvature, for example. Although it is difficult to incorporate all these physical elements into a single complete model of our Universe, advances in computing methods and technologies have contributed significantly towards our understanding of cosmological models, the Universe, and astrophysical processes within them. A sample of numerical calculations (and numerical methods applied to specific issues in cosmology are reviewed in this article: from the Big Bang singularity dynamics to the fundamental interactions of gravitational waves; from the quark-hadron phase transition to the large scale structure of the Universe. The emphasis, although not exclusively, is on those calculations designed to test different models of cosmology against the observed Universe.

  8. Computational Cosmology: from the Early Universe to the Large Scale Structure.

    PubMed

    Anninos, Peter

    1998-01-01

    In order to account for the observable Universe, any comprehensive theory or model of cosmology must draw from many disciplines of physics, including gauge theories of strong and weak interactions, the hydrodynamics and microphysics of baryonic matter, electromagnetic fields, and spacetime curvature, for example. Although it is difficult to incorporate all these physical elements into a single complete model of our Universe, advances in computing methods and technologies have contributed significantly towards our understanding of cosmological models, the Universe, and astrophysical processes within them. A sample of numerical calculations addressing specific issues in cosmology are reviewed in this article: from the Big Bang singularity dynamics to the fundamental interactions of gravitational waves; from the quark-hadron phase transition to the large scale structure of the Universe. The emphasis, although not exclusively, is on those calculations designed to test different models of cosmology against the observed Universe.

  9. Model of a Negatively Curved Two-Dimensional Space.

    ERIC Educational Resources Information Center

    Eckroth, Charles A.

    1995-01-01

    Describes the construction of models of two-dimensional surfaces with negative curvature that are used to illustrate differences in the triangle sum rule for the various Big Bang Theories of the universe. (JRH)

  10. On the cosmological gravitational waves and cosmological distances

    NASA Astrophysics Data System (ADS)

    Belinski, V. A.; Vereshchagin, G. V.

    2018-03-01

    We show that solitonic cosmological gravitational waves propagated through the Friedmann universe and generated by the inhomogeneities of the gravitational field near the Big Bang can be responsible for increase of cosmological distances.

  11. Faint Compact Galaxy in the Early Universe

    NASA Image and Video Library

    2015-12-03

    This is a Hubble Space Telescope view of a very massive cluster of galaxies, MACS J0416.1-2403, located roughly 4 billion light-years away and weighing as much as a million billion suns. The cluster's immense gravitational field magnifies the image of galaxies far behind it, in a phenomenon called gravitational lensing. The inset is an image of an extremely faint and distant galaxy that existed only 400 million years after the big bang. It was discovered by Hubble and NASA's Spitzer Space Telescope. The gravitational lens makes the galaxy appear 20 times brighter than normal. The galaxy is comparable in size to the Large Magellanic Cloud (LMC), a diminutive satellite galaxy of our Milky Way. It is rapidly making stars at a rate ten times faster than the LMC. This might be the growing core of what was to eventually evolve into a full-sized galaxy. The research team has nicknamed the object Tayna, which means "first-born" in Aymara, a language spoken in the Andes and Altiplano regions of South America. http://photojournal.jpl.nasa.gov/catalog/PIA20054

  12. Big data need big theory too

    PubMed Central

    Dougherty, Edward R.; Highfield, Roger R.

    2016-01-01

    The current interest in big data, machine learning and data analytics has generated the widespread impression that such methods are capable of solving most problems without the need for conventional scientific methods of inquiry. Interest in these methods is intensifying, accelerated by the ease with which digitized data can be acquired in virtually all fields of endeavour, from science, healthcare and cybersecurity to economics, social sciences and the humanities. In multiscale modelling, machine learning appears to provide a shortcut to reveal correlations of arbitrary complexity between processes at the atomic, molecular, meso- and macroscales. Here, we point out the weaknesses of pure big data approaches with particular focus on biology and medicine, which fail to provide conceptual accounts for the processes to which they are applied. No matter their ‘depth’ and the sophistication of data-driven methods, such as artificial neural nets, in the end they merely fit curves to existing data. Not only do these methods invariably require far larger quantities of data than anticipated by big data aficionados in order to produce statistically reliable results, but they can also fail in circumstances beyond the range of the data used to train them because they are not designed to model the structural characteristics of the underlying system. We argue that it is vital to use theory as a guide to experimental design for maximal efficiency of data collection and to produce reliable predictive models and conceptual knowledge. Rather than continuing to fund, pursue and promote ‘blind’ big data projects with massive budgets, we call for more funding to be allocated to the elucidation of the multiscale and stochastic processes controlling the behaviour of complex systems, including those of life, medicine and healthcare. This article is part of the themed issue ‘Multiscale modelling at the physics–chemistry–biology interface’. PMID:27698035

  13. Big data need big theory too.

    PubMed

    Coveney, Peter V; Dougherty, Edward R; Highfield, Roger R

    2016-11-13

    The current interest in big data, machine learning and data analytics has generated the widespread impression that such methods are capable of solving most problems without the need for conventional scientific methods of inquiry. Interest in these methods is intensifying, accelerated by the ease with which digitized data can be acquired in virtually all fields of endeavour, from science, healthcare and cybersecurity to economics, social sciences and the humanities. In multiscale modelling, machine learning appears to provide a shortcut to reveal correlations of arbitrary complexity between processes at the atomic, molecular, meso- and macroscales. Here, we point out the weaknesses of pure big data approaches with particular focus on biology and medicine, which fail to provide conceptual accounts for the processes to which they are applied. No matter their 'depth' and the sophistication of data-driven methods, such as artificial neural nets, in the end they merely fit curves to existing data. Not only do these methods invariably require far larger quantities of data than anticipated by big data aficionados in order to produce statistically reliable results, but they can also fail in circumstances beyond the range of the data used to train them because they are not designed to model the structural characteristics of the underlying system. We argue that it is vital to use theory as a guide to experimental design for maximal efficiency of data collection and to produce reliable predictive models and conceptual knowledge. Rather than continuing to fund, pursue and promote 'blind' big data projects with massive budgets, we call for more funding to be allocated to the elucidation of the multiscale and stochastic processes controlling the behaviour of complex systems, including those of life, medicine and healthcare.This article is part of the themed issue 'Multiscale modelling at the physics-chemistry-biology interface'. © 2015 The Authors.

  14. Increased plasma levels of big-endothelin-2 and big-endothelin-3 in patients with end-stage renal disease.

    PubMed

    Miyauchi, Yumi; Sakai, Satoshi; Maeda, Seiji; Shimojo, Nobutake; Watanabe, Shigeyuki; Honma, Satoshi; Kuga, Keisuke; Aonuma, Kazutaka; Miyauchi, Takashi

    2012-10-15

    Big endothelins (pro-endothelin; inactive-precursor) are converted to biologically active endothelins (ETs). Mammals and humans produce three ET family members: ET-1, ET-2 and ET-3, from three different genes. Although ET-1 is produced by vascular endothelial cells, these cells do not produce ET-3, which is produced by neuronal cells and organs such as the thyroid, salivary gland and the kidney. In patients with end-stage renal disease, abnormal vascular endothelial cell function and elevated plasma ET-1 and big ET-1 levels have been reported. It is unknown whether big ET-2 and big ET-3 plasma levels are altered in these patients. The purpose of the present study was to determine whether endogenous ET-1, ET-2, and ET-3 systems including big ETs are altered in patients with end-stage renal disease. We measured plasma levels of ET-1, ET-3 and big ET-1, big ET-2, and big ET-3 in patients on chronic hemodialysis (n=23) and age-matched healthy subjects (n=17). In patients on hemodialysis, plasma levels (measured just before hemodialysis) of both ET-1 and ET-3 and big ET-1, big ET-2, and big ET-3 were markedly elevated, and the increase was higher for big ETs (Big ET-1, 4-fold; big ET-2, 6-fold; big ET-3: 5-fold) than for ETs (ET-1, 1.7-fold; ET-3, 2-fold). In hemodialysis patients, plasma levels of the inactive precursors big ET-1, big ET-2, and big ET-3 levels are markedly increased, yet there is only a moderate increase in plasma levels of the active products, ET-1 and ET-3. This suggests that the activity of endothelin converting enzyme contributing to circulating levels of ET-1 and ET-3 may be decreased in patients on chronic hemodialysis. Copyright © 2012 Elsevier Inc. All rights reserved.

  15. A Quality Improvement Project: Using the STOP-BANG Tool in a Military Population to Improve Equity in Preoperative Screening.

    PubMed

    Dixon, Samuel E; Haas, Shelia A; Klopp, Audrey; Carlson, Judy

    2016-10-01

    The lack of a preoperative screening tool to detect obstructive sleep apnea (OSA) may lead to an increase in postoperative complications. The aim of the study was to implement a prescreening tool to identify diagnosed or undiagnosed OSA before a surgical procedure. The study was conducted in the surgical admission center and postanesthesia care unit at a military treatment facility in Hawaii. Participants of the study included military personnel, military family members, veterans, and veteran beneficiaries. The STOP-BANG (snore/tired/obstruction/pressure-body mass index/age/neck/gender) tool was used between April and June 2013 to identify and stratify 1,625 patients into low-risk, intermediate-risk, high-risk, and known OSA categories. The STOP-BANG tool confirmed the diagnosed OSA rate to be 13.48%, and increased at-risk OSA detection by 24.69%. Hawaiians/Pacific Islanders were more frequently found to be at risk with known OSA, likely to have complications, and be transferred to PACU 23-hour extended stay compared to other races and intermediate-risk and high-risk categories. The STOP-BANG tool identified and stratified surgical patients at risk for OSA and standardized OSA assessments. Copyright © 2016 American Society of PeriAnesthesia Nurses. Published by Elsevier Inc. All rights reserved.

  16. Big Data and medicine: a big deal?

    PubMed

    Mayer-Schönberger, V; Ingelsson, E

    2018-05-01

    Big Data promises huge benefits for medical research. Looking beyond superficial increases in the amount of data collected, we identify three key areas where Big Data differs from conventional analyses of data samples: (i) data are captured more comprehensively relative to the phenomenon under study; this reduces some bias but surfaces important trade-offs, such as between data quantity and data quality; (ii) data are often analysed using machine learning tools, such as neural networks rather than conventional statistical methods resulting in systems that over time capture insights implicit in data, but remain black boxes, rarely revealing causal connections; and (iii) the purpose of the analyses of data is no longer simply answering existing questions, but hinting at novel ones and generating promising new hypotheses. As a consequence, when performed right, Big Data analyses can accelerate research. Because Big Data approaches differ so fundamentally from small data ones, research structures, processes and mindsets need to adjust. The latent value of data is being reaped through repeated reuse of data, which runs counter to existing practices not only regarding data privacy, but data management more generally. Consequently, we suggest a number of adjustments such as boards reviewing responsible data use, and incentives to facilitate comprehensive data sharing. As data's role changes to a resource of insight, we also need to acknowledge the importance of collecting and making data available as a crucial part of our research endeavours, and reassess our formal processes from career advancement to treatment approval. © 2017 The Association for the Publication of the Journal of Internal Medicine.

  17. Untapped Potential: Fulfilling the Promise of Big Brothers Big Sisters and the Bigs and Littles They Represent

    ERIC Educational Resources Information Center

    Bridgeland, John M.; Moore, Laura A.

    2010-01-01

    American children represent a great untapped potential in our country. For many young people, choices are limited and the goal of a productive adulthood is a remote one. This report paints a picture of who these children are, shares their insights and reflections about the barriers they face, and offers ways forward for Big Brothers Big Sisters as…

  18. Comparative validity of brief to medium-length Big Five and Big Six Personality Questionnaires.

    PubMed

    Thalmayer, Amber Gayle; Saucier, Gerard; Eigenhuis, Annemarie

    2011-12-01

    A general consensus on the Big Five model of personality attributes has been highly generative for the field of personality psychology. Many important psychological and life outcome correlates with Big Five trait dimensions have been established. But researchers must choose between multiple Big Five inventories when conducting a study and are faced with a variety of options as to inventory length. Furthermore, a 6-factor model has been proposed to extend and update the Big Five model, in part by adding a dimension of Honesty/Humility or Honesty/Propriety. In this study, 3 popular brief to medium-length Big Five measures (NEO Five Factor Inventory, Big Five Inventory [BFI], and International Personality Item Pool), and 3 six-factor measures (HEXACO Personality Inventory, Questionnaire Big Six Scales, and a 6-factor version of the BFI) were placed in competition to best predict important student life outcomes. The effect of test length was investigated by comparing brief versions of most measures (subsets of items) with original versions. Personality questionnaires were administered to undergraduate students (N = 227). Participants' college transcripts and student conduct records were obtained 6-9 months after data was collected. Six-factor inventories demonstrated better predictive ability for life outcomes than did some Big Five inventories. Additional behavioral observations made on participants, including their Facebook profiles and cell-phone text usage, were predicted similarly by Big Five and 6-factor measures. A brief version of the BFI performed surprisingly well; across inventory platforms, increasing test length had little effect on predictive validity. Comparative validity of the models and measures in terms of outcome prediction and parsimony is discussed.

  19. Bone fractures among postmenopausal patients with endocrine-responsive early breast cancer treated with 5 years of letrozole or tamoxifen in the BIG 1-98 trial.

    PubMed

    Rabaglio, M; Sun, Z; Price, K N; Castiglione-Gertsch, M; Hawle, H; Thürlimann, B; Mouridsen, H; Campone, M; Forbes, J F; Paridaens, R J; Colleoni, M; Pienkowski, T; Nogaret, J-M; Láng, I; Smith, I; Gelber, R D; Goldhirsch, A; Coates, A S

    2009-09-01

    To compare the incidence and timing of bone fractures in postmenopausal women treated with 5 years of adjuvant tamoxifen or letrozole for endocrine-responsive early breast cancer in the Breast International Group (BIG) 1-98 trial. We evaluated 4895 patients allocated to 5 years of letrozole or tamoxifen in the BIG 1-98 trial who received at least some study medication (median follow-up 60.3 months). Bone fracture information (grade, cause, site) was collected every 6 months during trial treatment. The incidence of bone fractures was higher among patients treated with letrozole [228 of 2448 women (9.3%)] versus tamoxifen [160 of 2447 women (6.5%)]. The wrist was the most common site of fracture in both treatment groups. Statistically significant risk factors for bone fractures during treatment included age, smoking history, osteoporosis at baseline, previous bone fracture, and previous hormone replacement therapy. Consistent with other trials comparing aromatase inhibitors to tamoxifen, letrozole was associated with an increase in bone fractures. Benefits of superior disease control associated with letrozole and lower incidence of fracture with tamoxifen should be considered with the risk profile for individual patients.

  20. Bone fractures among postmenopausal patients with endocrine-responsive early breast cancer treated with 5 years of letrozole or tamoxifen in the BIG 1-98 trial

    PubMed Central

    Rabaglio, M.; Sun, Z.; Castiglione-Gertsch, M.; Hawle, H.; Thürlimann, B.; Mouridsen, H.; Campone, M.; Forbes, J. F.; Paridaens, R. J.; Colleoni, M.; Pienkowski, T.; Nogaret, J.-M.; Láng, I.; Smith, I.; Gelber, R. D.; Goldhirsch, A.; Coates, A. S.

    2009-01-01

    Background: To compare the incidence and timing of bone fractures in postmenopausal women treated with 5 years of adjuvant tamoxifen or letrozole for endocrine-responsive early breast cancer in the Breast International Group (BIG) 1-98 trial. Methods: We evaluated 4895 patients allocated to 5 years of letrozole or tamoxifen in the BIG 1-98 trial who received at least some study medication (median follow-up 60.3 months). Bone fracture information (grade, cause, site) was collected every 6 months during trial treatment. Results: The incidence of bone fractures was higher among patients treated with letrozole [228 of 2448 women (9.3%)] versus tamoxifen [160 of 2447 women (6.5%)]. The wrist was the most common site of fracture in both treatment groups. Statistically significant risk factors for bone fractures during treatment included age, smoking history, osteoporosis at baseline, previous bone fracture, and previous hormone replacement therapy. Conclusions: Consistent with other trials comparing aromatase inhibitors to tamoxifen, letrozole was associated with an increase in bone fractures. Benefits of superior disease control associated with letrozole and lower incidence of fracture with tamoxifen should be considered with the risk profile for individual patients. PMID:19474112