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

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.

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.

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

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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 ideas, that we are led to try and reconstruct the past and predict the future evolution of our universe. Just that. Sound science turns out to be much more attractive when we tell the truth of what we really know.

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.

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.

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) successfully predicts a lower abundance of the beryllium isotope which eventually decays into lithium relative to the classical Maxwell-Boltzmann distribution (solid lines), without changing the predicted abundances of deuterium or helium. [Hou et al. 2017]Questioning StatisticsHou and collaborators questioned a key assumption in Big Bang nucleosynthesis theory: that the nuclei involved in the process are all in thermodynamic equilibrium, and their velocities which determine the thermonuclear reaction rates are described by the classical Maxwell-Boltzmann distribution.But do nuclei still obey this classical distribution in the extremely complex, fast-expanding Big Bang hot plasma? Hou and collaborators propose that the lithium nuclei dont, and that they must instead be described by a slightly modified version of the classical distribution, accounted for using whats known as non-extensive statistics.The authors show that using the modified velocity distributions described by these statistics, they can successfully predict the observed primordial abundances of deuterium, helium, and lithium simultaneously. If this solution to the cosmological lithium problem is correct, the Big Bang theory is now one step closer to fully describing the formation of our universe.CitationS. Q. Hou et al 2017 ApJ 834 165. doi:10.3847/1538-4357/834/2/165

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...

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.

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.

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.

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.

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.

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…

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.

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.

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.

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

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

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.

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.

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

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…

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.

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…

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)

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…

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.

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.

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.

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…

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.

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

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.

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.

James Webb Space Telescope (JWST): The First Light Machine

NASA Technical Reports Server (NTRS)

Stahl, Philip

2009-01-01

This slide presentation review the mission objective, the organization of the mission planning, the design, and testing of the James Webb Space Telescope (JWST). There is also information about the orbit, in comparison to the Hubble Space Telescope, the mirror design, and the science instruments. Pictures of the full scale mockup of the JWST are given. A brief history of the universe is also presented from the big bang through the formation of galaxies, and the planets, to life itself. One of the goals of the JWST is to search for extra solar planets and then to search for signs of life.

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.

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.

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.

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.

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) \

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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

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

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.

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.

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.

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…

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

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.

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.

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.

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.

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.

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.

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.

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.

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)

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.

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.

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.

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.

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

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.

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

Dealing with doomsday

NASA Astrophysics Data System (ADS)

Crease, Robert P.

2010-04-01

There is a classic episode of the US political-satire TV programme The Daily Show about the Relativistic Heavy Ion Collider (RHIC) at the Brookhaven National Laboratory (BNL) in the US. The show was filmed in June 2000, just as scientists were firing up the collider to smash gold nuclei into each other for the first time. The quest of the machine was to recreate the hot, dense soup of free quarks, antiquarks and gluons - the "quark-gluon plasma" - that had previously only ever existed in the first few microseconds after the Big Bang. What had attracted the attention of the programme-makers, however, was not the science but rumours that RHIC would create a world-destroying black hole.

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.

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.

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

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.

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

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.

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.

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.

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.

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

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.

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.

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.

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.

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 show a completely successful r-process. In this work it is shown that general relativistic effects associated with a more compact supernova core can provide more suitable conditions for the r-process. As a step towards analyzing the effects of neutrino mixing in such a relativistic environment, neutrino oscillations in curved spacetime are studied.

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.

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.

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.

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.

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.

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.

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.

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

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.

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.

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).

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.

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.

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

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.

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.

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

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

``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.

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.

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.

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...

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...

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 contracts to another regular null hypersurface.

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

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.

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.

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

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.

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.

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.

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.

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

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.

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.

`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.

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.

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.

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).

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.

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

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

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.

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.

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).

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.

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).

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.

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.

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.

Amino acid "little Big Bang": representing amino acid substitution matrices as dot products of Euclidian vectors.

PubMed

Zimmermann, Karel; Gibrat, Jean-François

2010-01-04

Sequence comparisons make use of a one-letter representation for amino acids, the necessary quantitative information being supplied by the substitution matrices. This paper deals with the problem of finding a representation that provides a comprehensive description of amino acid intrinsic properties consistent with the substitution matrices. We present a Euclidian vector representation of the amino acids, obtained by the singular value decomposition of the substitution matrices. The substitution matrix entries correspond to the dot product of amino acid vectors. We apply this vector encoding to the study of the relative importance of various amino acid physicochemical properties upon the substitution matrices. We also characterize and compare the PAM and BLOSUM series substitution matrices. This vector encoding introduces a Euclidian metric in the amino acid space, consistent with substitution matrices. Such a numerical description of the amino acid is useful when intrinsic properties of amino acids are necessary, for instance, building sequence profiles or finding consensus sequences, using machine learning algorithms such as Support Vector Machine and Neural Networks algorithms.

Fire in the Sky--From Big Bang to Big Money: Outdoor Education and Sustainable Development. Part One.

ERIC Educational Resources Information Center

Walker, Rod

1998-01-01

Within diverse outdoor educational activities, a core experience of connection with the earth balances self, others, and nature with elements of ritual. Most effective when experiential, integrated, and technologically simple, the core experience's educative power lies in awakening awareness of interconnectedness between human and nonhuman life.…

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…

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

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. )

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.

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.

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

Nuclear constraints on the age of the universe

NASA Technical Reports Server (NTRS)

Schramm, D. N.

1982-01-01

A review is made of how one can use nuclear physics to put rather stringent limits on the age of the universe and thus the cosmic distance scale. The age can be estimated to a fair degree of accuracy. No single measurement of the time since the Big Bang gives a specific, unambiguous age. There are several methods that together fix the age with surprising precision. In particular, there are three totally independent techniques for estimating an age and a fourth technique which involves finding consistency of the other three in the framework of the standard Big Bang cosmological model. The three independent methods are: cosmological dynamics, the age of the oldest stars, and radioactive dating. This paper concentrates on the third of the three methods, and the consistency technique.

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.

Scalar field cosmologies with inverted potentials

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

Boisseau, B.; Giacomini, H.; Polarski, D., E-mail: bruno.boisseau@lmpt.univ-tours.fr, E-mail: hector.giacomini@lmpt.univ-tours.fr, E-mail: david.polarski@umontpellier.fr

Regular bouncing solutions in the framework of a scalar-tensor gravity model were found in a recent work. We reconsider the problem in the Einstein frame (EF) in the present work. Singularities arising at the limit of physical viability of the model in the Jordan frame (JF) are either of the Big Bang or of the Big Crunch type in the EF. As a result we obtain integrable scalar field cosmological models in general relativity (GR) with inverted double-well potentials unbounded from below which possess solutions regular in the future, tending to a de Sitter space, and starting with a Bigmore » Bang. The existence of the two fixed points for the field dynamics at late times found earlier in the JF becomes transparent in the EF.« less

The cosmological lithium problem revisited

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

Bertulani, C. A., E-mail: carlos.bertulani@tamuc.edu; Department of Physics and Astronomy, Texas A&M University, College Station, TX 75429; Mukhamedzhanov, A. M., E-mail: akram@comp.tamu.edu

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 ourmore » 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.« less

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.

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 cosmology to its rightful position as the flagship of astronomy.

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 cosmology to its rightful position as the flagship of astronomy.

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.

Smoot Cosmology Group

Science.gov Websites

Fuzz, FORBES ASAP article on the Arrow of Time by George Smoot. Lecture Archives: The relic radiation from the big bang begining of the Universe. Antimatter in the Universe (Physics 24 Lecture by George

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)

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.

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.

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

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 |

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.

Nuclear constraints on the age of the universe

NASA Technical Reports Server (NTRS)

Schramm, D. N.

1983-01-01

A review is made of how one can use nuclear physics to put rather stringent limits on the age of the universe and thus the cosmic distance scale. The age can be estimated to a fair degree of accuracy. No single measurement of the time since the Big Bang gives a specific, unambiguous age. There are several methods that together fix the age with surprising precision. In particular, there are three totally independent techniques for estimating an age and a fourth technique which involves finding consistency of the other three in the framework of the standard Big Bang cosmological model. The three independent methods are: cosmological dynamics, the age of the oldest stars, and radioactive dating. This paper concentrates on the third of the three methods, and the consistency technique. Previously announced in STAR as N83-34868

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.

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.

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

The NASA Beyond Einstein Program

NASA Technical Reports Server (NTRS)

White, Nicholas E.

2006-01-01

Einstein's legacy is incomplete, his theory of General relativity 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 towards shared science goals. The Beyond Einstein program has three linked elements which advance science and technology towards two visions; to detect directly gravitational wave signals from the earliest possible moments of the BIg Bang, and to image the event horizon of a black hole. The central element is a pair of Einstein Great Observatories, Constellation-X and LISA. Constellation-X is a powerful new X-ray observatory dedicated to X-Ray Spectroscopy. LISA is the first spaced based gravitational wave detector. These powerful facilities will blaze new paths to the questions about black holes, the Big Bang and dark energy. The second element is a series of competitively selected Einstein Probes, each focused on one of the science questions and includes a mission dedicated resolving the Dark Energy mystery. The third element is a program of technology development, theoretical studies and education. The Beyond Einstein program is a new element in the proposed NASA budget for 2004. This talk will give an overview of the program and the missions contained within it.

The Universe Comes into Sharper Focus

NASA Image and Video Library

2013-03-21

This graphic illustrates the evolution of satellites designed to measure ancient light leftover from the big bang that created our universe 13.8 billion years ago; NASA COBE Explorer left and WMAP middle, and ESA Planck right.

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.

Hawking's acting roles

NASA Astrophysics Data System (ADS)

Castell, Stephen

2012-06-01

In the wake of Stephen Hawking's appearance on the TV show The Big Bang Theory, last month's "Quanta" page (May p3), included a request: "If you think Hawking should appear in any other TV shows, then let us know".

Possible antigravity regions in F(R) theory?

NASA Astrophysics Data System (ADS)

Bamba, Kazuharu; Nojiri, Shin'ichi; Odintsov, Sergei D.; Sáez-Gómez, Diego

2014-03-01

We construct an F(R) gravity theory corresponding to the Weyl invariant two scalar field theory. We investigate whether such F(R) gravity can have the antigravity regions where the Weyl curvature invariant does not diverge at the Big Bang and Big Crunch singularities. It is revealed that the divergence cannot be evaded completely but can be much milder than that in the original Weyl invariant two scalar field theory.

Use of Automated Testing to Facilitate Affordable Design of Military Systems

DTIC Science & Technology

2015-04-30

momentum across the Navy and DoD. This initiative is no new big bang /silver bullet; it simply focuses on lowering the cost and risk of government...University of Minnesota. He has developed several specification languages, software tools for computer-aided software design, and fundamental theory ...review of lessons learned and recommendations for further enhancements are discussed. Overview: The Testing Challenge Infinity Is a Big Place The

Bouncing cosmologies from quantum gravity condensates

NASA Astrophysics Data System (ADS)

Oriti, Daniele; Sindoni, Lorenzo; Wilson-Ewing, Edward

2017-02-01

We show how the large-scale cosmological dynamics can be obtained from the hydrodynamics of isotropic group field theory condensate states in the Gross-Pitaevskii approximation. The correct Friedmann equations are recovered in the classical limit for some choices of the parameters in the action for the group field theory, and quantum gravity corrections arise in the high-curvature regime causing a bounce which generically resolves the big-bang and big-crunch singularities.

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.

The Future of the Universe.

ERIC Educational Resources Information Center

Pasachoff, Jay M.

1979-01-01

Discusses some of the basic theories in cosmology, such as Hubble's laws and the big-bang theories, and looks at some of the ideas of astronomers and scientists with respect to their evaluation of the future of the universe. (GA)

Big Bang Day: The Making of CERN (Episode 1)

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

None

2009-10-06

A two-part history of the CERN project. Quentin Cooper explores the fifty-year history of CERN, the European particle physics laboratory in Switzerland. The institution was created to bring scientists together after WW2 .......

Distant galaxy formed stars only 250 million years after the Big Bang

NASA Astrophysics Data System (ADS)

Bouwens, Rychard

2018-05-01

Little is known about the star-birth activity of the earliest galaxies. Observations of a particularly distant galaxy provide evidence for such activity when the Universe was just 2% of its current age.

Big Bang Day: The Making of CERN (Episode 1)

ScienceCinema

None

2017-12-09

A two-part history of the CERN project. Quentin Cooper explores the fifty-year history of CERN, the European particle physics laboratory in Switzerland. The institution was created to bring scientists together after WW2 .......

Distant Galaxies in Goods North

NASA Image and Video Library

2014-01-07

The view is a composite of images taken in visible and near-infrared light by NASA Hubble Space Telescope. Researchers have circled four unusually red objects that appear as they existed just 500 million years after the big bang.

Black Holes: The making of a monster

NASA Astrophysics Data System (ADS)

Mayer, Lucio

2017-04-01

The biggest black holes in the Universe were in place soon after the Big Bang. Explaining how they formed so rapidly is a daunting challenge, but the latest simulations give clues to how this may have occurred.

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.

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.

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.

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

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

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.

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.

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.

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.

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

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.

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

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

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.

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

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.

"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".

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

The Path of the Blind Watchmaker: A Model of Evolution

DTIC Science & Technology

2011-04-06

computational biology has now reached the point that astronomy reached when it began to look backward in time to the Big Bang. Our goal is look backward in...treatment. We claim that computational biology has now reached the point that astronomy reached when it began to look backward in time to the Big...evolutionary process itself, in fact, created it. When astronomy reached a critical mass of theory, technology, and observational data, astronomers

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.

Hilltop Supernatural Inflation

NASA Astrophysics Data System (ADS)

Lin, C.

In this talk, I will explain how to reduce the spectral index to be n_s = 0.96 for supernatural inflation. I will also show the constraint to the reheating temperature from Big Bang Nucleosynthesis of both thermal and non-thermal gravitino production.

Planetarium Show on Dark Matter

DOE PAGES

Barnett, R. Michael

2016-05-31

We describe a new planetarium show about Dark Matter entitled “Phantom of the Universe”. When completed in late 2014, it will feature the exciting story of dark matter, from the Big Bang to its anticipated discovery at the Large Hadron Collider.

To Your Health: NLM update transcript - NIH MedlinePlus magazine Winter 2018

MedlinePlus

... who is a star of 'The Big Bang Theory' television show, and the producer/narrator of a ... trials, NIH MedlinePlus magazine reports the current life expectancy of a person with sickle cell disease is ...

Distant Galaxy Bursts with Stars

NASA Image and Video Library

2011-12-21

This image from NASA Hubble telescope shows one of the most distant galaxies known, called GN-108036, dating back to 750 million years after the Big Bang that created our universe. The galaxy light took 12.9 billion years to reach us.

Tested Demonstrations.

ERIC Educational Resources Information Center

Gilbert, George L., Ed.

1983-01-01

Describes a lecture demonstration of a solid state phase transition using a thermodynamic material which changes state at room temperature. Also describes a demonstration on kinetics using a "Big Bang" (trade mark) calcium carbide cannon. Indicates that the cannon is safe to use. (JN)

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.

Texas Symposium on Relativistic Astrophysics, 11th, Austin, TX, December 12-17, 1982, Proceedings

NASA Technical Reports Server (NTRS)

Evans, D. S. (Editor)

1984-01-01

Various papers on relativistic astrophysics are presented. The general subjects addressed include: particle physics and astrophysics, general relativity, large-scale structure, big bang cosmology, new-generation telescopes, pulsars, supernovae, high-energy astrophysics, and active galaxies.

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.

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.

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.'

Journeys through antigravity?

NASA Astrophysics Data System (ADS)

Carrasco, John Joseph M.; Chemissany, Wissam; Kallosh, Renata

2014-01-01

A possibility of journeys through antigravity has recently been proposed, with the suggestion that Weyl-invariant extension of scalars coupled to Einstein gravity allows for an unambiguous classical evolution through cosmological singularities in anisotropic spacetimes. We compute the Weyl invariant curvature squared and find that it blows up for the proposed anisotropic solution both at the Big Crunch as well as at the Big Bang. Therefore the cosmological singularities are not resolved by uplifting Einstein theory to a Weyl invariant model.

The New Cosmos

ERIC Educational Resources Information Center

McCray, Richard A.

1970-01-01

Discusses areas of modern astronomy that owe their development largely to nonoptical radiation: radio, infrared, ultraviolet, and x-ray radiation. Indicates new observations favor the big-bang" model of the universe, for it is now established that the earth is expanding at a measurable rate. Annotated bibliography. (LS)

Open and Distance Learning Today. Routledge Studies in Distance Education Series.

ERIC Educational Resources Information Center

Lockwood, Fred, Ed.

This book contains the following papers on open and distance learning today: "Preface" (Daniel); "Big Bang Theory in Distance Education" (Hawkridge); "Practical Agenda for Theorists of Distance Education" (Perraton); "Trends, Directions and Needs: A View from Developing Countries" (Koul); "American…

MLBCD: a machine learning tool for big clinical data.

PubMed

Luo, Gang

2015-01-01

Predictive modeling is fundamental for extracting value from large clinical data sets, or "big clinical data," advancing clinical research, and improving healthcare. Machine learning is a powerful approach to predictive modeling. Two factors make machine learning challenging for healthcare researchers. First, before training a machine learning model, the values of one or more model parameters called hyper-parameters must typically be specified. Due to their inexperience with machine learning, it is hard for healthcare researchers to choose an appropriate algorithm and hyper-parameter values. Second, many clinical data are stored in a special format. These data must be iteratively transformed into the relational table format before conducting predictive modeling. This transformation is time-consuming and requires computing expertise. This paper presents our vision for and design of MLBCD (Machine Learning for Big Clinical Data), a new software system aiming to address these challenges and facilitate building machine learning predictive models using big clinical data. The paper describes MLBCD's design in detail. By making machine learning accessible to healthcare researchers, MLBCD will open the use of big clinical data and increase the ability to foster biomedical discovery and improve care.

A Universe of Questions.

ERIC Educational Resources Information Center

Zeldovich, Yakov

1992-01-01

Reprinted from the original Russian manuscript of Yakov Zeldovich, this article chronicles his studies of the universe and his attempts to construct a theory of its evolution. He provides the high school student with compelling cosmological discussions about uniformity, galactic clusters, radiation, evolution, the big bang, and gravitational…

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.

Neutrino Masses and Mixings and Astrophysics

NASA Astrophysics Data System (ADS)

Fuller, George M.

1998-10-01

Here we discuss the implications of light neutrino masses and neutrino flavor/type mixing for dark matter, big bang nucleosynthesis, and models of heavy element nucleosynthesis in super novae. We will also argue the other way and discuss possible constraints on neutrino physics from these astrophysical considerations.

Copper vs. Copper at the Relativistic Heavy Ion Collider (2005)

ScienceCinema

Brookhaven Lab - Fulvia Pilat

2017-12-09

To investigate a new form of matter not seen since the Big Bang, scientists are using a new experimental probe: collisions between two beams of copper ions. The use of intermediate size nuclei is expected to result in intermediate energy density - not as

Non-singular and cyclic universe from the modified GUP

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

Salah, Maha; Hammad, Fayçal; Faizal, Mir

In this paper, we investigate the effects of a new version of the generalized uncertainty principle (modified GUP) on the dynamics of the Universe. As the modified GUP will modify the relation between the entropy and area of the apparent horizon, it will also deform the Friedmann equations within Jacobson's approach. We explicitly find these deformed Friedmann equations governing the modified GUP-corrected dynamics of such a Universe. It is shown that the modified GUP-deformed Jacobson's approach implies an upper bound for the density of such a Universe. The Big Bang singularity can therefore also be avoided using the modified GUP-correctionsmore » to horizons' thermodynamics. In fact, we are able to analyze the pre Big Bang state of the Universe. Furthermore, the equations imply that the expansion of the Universe will come to a halt and then will immediately be followed by a contracting phase. When the equations are extrapolated beyond the maximum rate of contraction, a cyclic Universe scenario emerges.« less

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.

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

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.

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.

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.

Space Science

NASA Image and Video Library

2003-07-10

NASA's Hubble Space Telescope (HST) precisely measured the mass of the oldest known planet in our Milky Way Galaxy bringing closure to a decade of speculation. Scientists weren't sure if the object was a planet or a brown dwarf. Hubble's analysis shows that the object is 2.5 times the mass of Jupiter, confirming that it is indeed a planet. At an estimated age of 13 billion years, the planet is more than twice the age of Earth's 4.5 billion years. It formed around a young, sun-like star barely 1 million years after our universe's birth in the Big Bang. The ancient planet resides in an unlikely, rough neighborhood. It orbits a peculiar pair of burned-out stars in the crowded core cluster of more than 100,000 stars. Its very existence provides evidence that the first planets formed rapidly, within a billion years of the Big Bang, and leads astronomers to conclude that planets may be very abundant in our galaxy. This artist's concept depicts the planet with a view of a rich star filled sky.

The evolving Planck mass in classically scale-invariant theories

NASA Astrophysics Data System (ADS)

Kannike, K.; Raidal, M.; Spethmann, C.; Veermäe, H.

2017-04-01

We consider classically scale-invariant theories with non-minimally coupled scalar fields, where the Planck mass and the hierarchy of physical scales are dynamically generated. The classical theories possess a fixed point, where scale invariance is spontaneously broken. In these theories, however, the Planck mass becomes unstable in the presence of explicit sources of scale invariance breaking, such as non-relativistic matter and cosmological constant terms. We quantify the constraints on such classical models from Big Bang Nucleosynthesis that lead to an upper bound on the non-minimal coupling and require trans-Planckian field values. We show that quantum corrections to the scalar potential can stabilise the fixed point close to the minimum of the Coleman-Weinberg potential. The time-averaged motion of the evolving fixed point is strongly suppressed, thus the limits on the evolving gravitational constant from Big Bang Nucleosynthesis and other measurements do not presently constrain this class of theories. Field oscillations around the fixed point, if not damped, contribute to the dark matter density of the Universe.

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.

7Be(n,α) and 7Be(n,p) cross-section measurement for the cosmological lithium problem at the n_TOF facility at CERN

NASA Astrophysics Data System (ADS)

Barbagallo, M.; Colonna, N.; Aberle, O.; Andrzejewski, J.; Audouin, L.; Bécares, V.; Bacak, M.; Balibrea, J.; Barros, S.; Bečvář, F.; Beinrucker, C.; Berthoumieux, E.; Billowes, J.; Bosnar, D.; Brugger, M.; Caamaño, M.; Calviño, F.; Calviani, M.; Cano-Ott, D.; Cardella, R.; Casanovas, A.; Castelluccio, D. M.; Cerutti, F.; Chen, Y. H.; Chiaveri, E.; Cortés, G.; Cortés-Giraldo, M. A.; Cosentino, L.; Damone, L. A.; Diakaki, M.; Domingo-Pardo, C.; Dressler, R.; Dupont, E.; Durán, I.; Fernández-Domínguez, B.; Ferrari, A.; Ferreira, P.; Finocchiaro, P.; Furman, V.; Göbel, K.; García, A. R.; Gawlik, A.; Glodariu, T.; Gonçalves, I. F.; González, E.; Goverdovski, A.; Griesmayer, E.; Guerrero, C.; Gunsing, F.; Harada, H.; Heftrich, T.; Heinitz, S.; Heyse, J.; Jenkins, D. G.; Jericha, E.; Käppeler, F.; Kadi, Y.; Katabuchi, T.; Kavrigin, P.; Ketlerov, V.; Khryachkov, V.; Kimura, A.; Kivel, N.; Kokkoris, M.; Krtička, M.; Leal-Cidoncha, E.; Lederer, C.; Leeb, H.; Lerendegui-Marco, J.; Meo, S. Lo; Lonsdale, S. J.; Losito, R.; Macina, D.; Marganiec, J.; Martínez, T.; Massimi, C.; Mastinu, P.; Mastromarco, M.; Matteucci, F.; Maugeri, E. A.; Mendoza, E.; Mengoni, A.; Milazzo, P. M.; Mingrone, F.; Mirea, M.; Montesano, S.; Musumarra, A.; Nolte, R.; Oprea, A.; Patronis, N.; Pavlik, A.; Perkowski, J.; Porras, J. I.; Praena, J.; Quesada, J. M.; Rajeev, K.; Rauscher, T.; Reifarth, R.; Riego-Perez, A.; Rout, P. C.; Rubbia, C.; Ryan, J. A.; Sabaté-Gilarte, M.; Saxena, A.; Schillebeeckx, P.; Schmidt, S.; Schumann, D.; Sedyshev, P.; Smith, A. G.; Stamatopoulos, A.; Tagliente, G.; Tain, J. L.; Tarifeño-Saldivia, A.; Tassan-Got, L.; Tsinganis, A.; Valenta, S.; Vannini, G.; Variale, V.; Vaz, P.; Ventura, A.; Vlachoudis, V.; Vlastou, R.; Wallner, A.; Warren, S.; Weigand, M.; Weiss, C.; Wolf, C.; Woods, P. J.; Wright, T.; Žugec, P.

2017-09-01

The Cosmological Lithium Problem refers to the large discrepancy between the abundance of primordial 7Li predicted by the standard theory of Big Bang Nucleosynthesis and the value inferred from the so-called "Spite plateau" in halo stars. A possible explanation for this longstanding puzzle in Nuclear Astrophysics is related to the incorrect estimation of the destruction rate of 7Be, which is responsible for the production of 95% of primordial Lithium. While charged-particle induced reactions have mostly been ruled out, data on the 7Be(n,α) and 7Be(n,p) reactions are scarce or completely missing, so that a large uncertainty still affects the abundance of 7Li predicted by the standard theory of Big Bang Nucleosynthesis. Both reactions have been measured at the n_TOF facility at CERN, providing for the first time data in a wide neutron energy range.

Non-singular and cyclic universe from the modified GUP

NASA Astrophysics Data System (ADS)

Salah, Maha; Hammad, Fayçal; Faizal, Mir; Farag Ali, Ahmed

2017-02-01

In this paper, we investigate the effects of a new version of the generalized uncertainty principle (modified GUP) on the dynamics of the Universe. As the modified GUP will modify the relation between the entropy and area of the apparent horizon, it will also deform the Friedmann equations within Jacobson's approach. We explicitly find these deformed Friedmann equations governing the modified GUP-corrected dynamics of such a Universe. It is shown that the modified GUP-deformed Jacobson's approach implies an upper bound for the density of such a Universe. The Big Bang singularity can therefore also be avoided using the modified GUP-corrections to horizons' thermodynamics. In fact, we are able to analyze the pre Big Bang state of the Universe. Furthermore, the equations imply that the expansion of the Universe will come to a halt and then will immediately be followed by a contracting phase. When the equations are extrapolated beyond the maximum rate of contraction, a cyclic Universe scenario emerges.

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.

Cosmological Implications of the Electron-Positron Aether

NASA Astrophysics Data System (ADS)

Rothwarf, Allen

1997-04-01

An aether is not prohibited on theoretical nor experimental grounds; only a credible physical model for it is lacking.By assuming that the particles and anti-particles created during the "big-bang" origin of the universe have not annihilated one another, but instead, form a bound state plasma, we have a model for a real aether.This aether is dominated by electron-positron pairs at very high density(10**30/cm3),in close analogy with electron-hole droplets formed in laser irradiated semiconductors. The Fermi velocity of this plasma is the speed of light, and the plasma expands at this speed. This gives results for the expanding universe in agreement with the Einstein-deSitter result for a universe dominated by radiation.The speed of light varies with time as do the other fundamental constants.This leads to an alternate explanation for cosmological redshifts. Independent,mini big bangs can occur and account for observed anomalous redshifts. The model can be tested using LIGO apparatus.

Machine learning for Big Data analytics in plants.

PubMed

Ma, Chuang; Zhang, Hao Helen; Wang, Xiangfeng

2014-12-01

Rapid advances in high-throughput genomic technology have enabled biology to enter the era of 'Big Data' (large datasets). The plant science community not only needs to build its own Big-Data-compatible parallel computing and data management infrastructures, but also to seek novel analytical paradigms to extract information from the overwhelming amounts of data. Machine learning offers promising computational and analytical solutions for the integrative analysis of large, heterogeneous and unstructured datasets on the Big-Data scale, and is gradually gaining popularity in biology. This review introduces the basic concepts and procedures of machine-learning applications and envisages how machine learning could interface with Big Data technology to facilitate basic research and biotechnology in the plant sciences. Copyright © 2014 Elsevier Ltd. All rights reserved.

Ricci time in the Lemaître-Tolman model and the block universe

NASA Astrophysics Data System (ADS)

Elmahalawy, Yasser; Hellaby, Charles; Ellis, George F. R.

2015-10-01

It is common to think of our universe according to the "block universe" concept, which says that spacetime consists of many "stacked" three-surfaces, labelled by some kind of proper time, . Standard ideas do not distinguish past and future, but Ellis' "evolving block universe" tries to make a fundamental distinction. One proposal for this proper time is the proper time measured along the timelike Ricci eigenlines, starting from the big bang. This work investigates the shape of the "Ricci time" surfaces relative to the the null surfaces. We use the Lemaître-Tolman metric as our inhomogeneous spacetime model, and we find the necessary and sufficient conditions for these constant surfaces, , to be spacelike or timelike. Furthermore, we look at the effect of strong gravity domains by determining the location of timelike S regions relative to apparent horizons. We find that constant Ricci time surfaces are always spacelike near the big bang, while at late times (near the crunch or the extreme far future), they are only timelike under special circumstances. At intermediate times, timelike S regions are common unless the variation of the bang time is restricted. The regions where these surfaces become timelike are often adjacent to apparent horizons, but always outside them, and in particular timelike S regions do not occur inside the horizons of black-hole-like models.

From Pinholes to Black Holes

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

Fenimore, Edward E.

2014-10-06

Pinhole photography has made major contributions to astrophysics through the use of “coded apertures”. Coded apertures were instrumental in locating gamma-ray bursts and proving that they originate in faraway galaxies, some from the birth of black holes from the first stars that formed just after the big bang.

The Role of Antimatter in Big-Bang Cosmology

ERIC Educational Resources Information Center

Stecker, Floyd W.

1974-01-01

Discusses theories underlying man's conceptions of the universe, including Omnes' repulsive separation mechanism, the turbulence theory of galaxy formation, and the author's idea about gamma ray spectra in cosmological matter-antimatter annihilation. Indicates that the Apollo data provide encouraging evidence by fitting well with his theoretical…

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)

--No Title--

Science.gov Websites

time. It is usually measured in radians per second. Anisotropy- Physical property values that vary when negative charge. When an antimatter particle collides with its normal-matter counterpart, both particles neutrons. Big Bang- The violent cosmic explosion of an incredibly small amount of matter at high

What Happens at the ‘House of Hope’? Discovery CHannel Series | NIH MedlinePlus the Magazine

MedlinePlus

... work. “Big Bang Theory” and “Hidden Figures” actor Jim Parsons narrates the series, which was filmed over ... part in clinical trials,” said NIH Director Francis Collins. “Not only do clinical trials offer sick people ...

Cosmology and Prehistory: Imagination on the Rise. Spotlight: Montessori Potpourri.

ERIC Educational Resources Information Center

Hallenberg, Harvey

2001-01-01

Presents the Maori cosmological perspective and the modern theory of evolution. Explains how these two creation stories can coexist. Discusses life on earth during its first 3 billion years, including concepts of singularity, Big Bang, time, space, matter, gravity, stars, planets, seas, and life. (DLH)

Supernovae, an accelerating universe and the cosmological constant

PubMed Central

Kirshner, Robert P.

1999-01-01

Observations of supernova explosions halfway back to the Big Bang give plausible evidence that the expansion of the universe has been accelerating since that epoch, approximately 8 billion years ago and suggest that energy associated with the vacuum itself may be responsible for the acceleration. PMID:10200242

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…

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 based on a physical vacuum made of superbradyons with the spinorial space-time (SST) geometry we introduced in 1996-97. In particular, the SST automatically generates a local privileged space direction (PSD) for earch comoving observer and such a signature may have been confirmed by Planck data. Both superluminal preons and the existence of the PSD would have strong cosmological implications. Planck 2016 results will be particularly relevant as a step in the study of present open questions. This paper is dedicated to the memory of Yoichiro Nambu

Reviews

NASA Astrophysics Data System (ADS)

2002-11-01

CD-ROM REVIEW (551) Essential Physics BOOK REVIEWS (551) Collins Advanced Science: Physics, 2nd edition Quarks, Leptons and the Big Bang, 2nd edition Do Brilliantly: A2 Physics IGCSE Physics Geophysics in the UK Synoptic Skills in Advanced Physics Flash! The hunt for the biggest explosions in the universe Materials Maths for Advanced Physics

Evolution: Don't Debate, Educate.

ERIC Educational Resources Information Center

Bybee, Rodger W.

2000-01-01

Discusses controversy over the teaching of biological evolution and other scientific ideas such as Big Bang theory. Recommends that teachers avoid debating creationists, help students develop a greater understanding and appreciation for science as a way of explaining the natural world, and emphasize inquiry and the nature of science. (Contains 19…

How Cosmology Became a Science.

ERIC Educational Resources Information Center

Brush, Stephen G.

1992-01-01

Describes the origin of the science of cosmology and the competing theories to explain the beginning of the universe. The big bang theory for the creation of the universe is contrasted with the steady state theory. The author details discoveries that led to the demise of the steady state theory. (PR)

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)

Waves in Nature, Lasers to Tsumanis and Beyond

ScienceCinema

LLNL - University of California Television

2017-12-09

Waves are everywhere. Microwaves, laser beams, music, tsunamis. Electromagnetic waves emanating from the Big Bang fill the universe. Learn about the similarities and difference in all of these wavy phenomena with Ed Moses and Rick Sawicki, Lawrence Livermore National Laboratory scientists Series: Science on Saturday [10/2006] [Science] [Show ID: 11541

Science 101: What, Exactly, Is the Heisenberg Uncertainty Principle?

ERIC Educational Resources Information Center

Robertson, Bill

2016-01-01

Bill Robertson is the author of the NSTA Press book series, "Stop Faking It! Finally Understanding Science So You Can Teach It." In this month's issue, Robertson describes and explains the Heisenberg Uncertainty Principle. The Heisenberg Uncertainty Principle was discussed on "The Big Bang Theory," the lead character in…

Waves in Nature, Lasers to Tsumanis and Beyond

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

LLNL - University of California Television

2008-05-01

Waves are everywhere. Microwaves, laser beams, music, tsunamis. Electromagnetic waves emanating from the Big Bang fill the universe. Learn about the similarities and difference in all of these wavy phenomena with Ed Moses and Rick Sawicki, Lawrence Livermore National Laboratory scientists Series: Science on Saturday [10/2006] [Science] [Show ID: 11541

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.

Singularity Crossing, Transformation of Matter Properties and the Problem of Parametrization in Field Theories

NASA Astrophysics Data System (ADS)

Kamenshchik, A. Yu.

2018-03-01

We investigate particular cosmological models, based either on tachyon fields or on perfect fluids, for which soft future singularities arise in a natural way. Our main result is the description of a smooth crossing of the soft singularity in models with an anti-Chaplygin gas or with a particular tachyon field in the presence of dust. Such a crossing is made possible by certain transformations of matter properties. We discuss and compare also different approaches to the problem of crossing of the Big Bang-Big Crunch singularities.

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 helium-3 remained constant. By concurrently measuring the amount of hydrogen (also created by the Big Bang) in the same areas, the scientists were able to determine the relative abundance of helium-3. "Since stellar processes appear to have little or no impact on the amount of helium-3 in the Galaxy, we were able to deduce two very important things," said Bania. "First, since our current models predict stellar production of helium-3, then we will need to rethink our understanding of the internal workings of stars like our Sun. Second, since helium-3 has not been created or destroyed in our Galaxy in any appreciable amounts, then what we detected is most likely equal to the abundance of primordial helium-3 created by the Big Bang." The scientists were able to use this discovery to calculate how much "normal" matter was created during the Big Bang. (Normal matter is anything made of baryons, subatomic particles that include neutrons and protons.) The researchers made these calculations by taking what they know of the composition of the Universe today, and essentially running time in reverse. In this case, the ratio of helium-3 to hydrogen gives the ratio of baryons to photons (the density of radiation) just after the Big Bang. By using the rate of expansion of the Universe, given by the Hubble Constant, the scientists could then infer just how much normal matter was produced during the Big Bang. "Our findings for helium-3 in fact support other studies that also constrain the amount of matter in the Universe," said Balser. "Taken together, these studies show that the matter that makes up stars, planets, and the visible Universe can only account for a small fraction of what we observe as the effects of gravity in the Universe." Dark matter, which can be both baryonic (dead stars, rocks, etc.) and non-baryonic, and other as-yet-unidentified forces appear to be the primary sources of the gravity that holds galaxies, and the larger structures of the Universe, together. "The fact that most of the matter in the Universe is non-baryonic, that is to say not made of any particle we've ever seen on Earth, is a very exciting concept," commented Rood. The astronomers conducted their research using measurements at a frequency of 8.665 GHz (3.46 cm), which is emitted naturally by ionized helium-3. The 140 Foot Radio Telescope at the NRAO in Green Bank now is decommissioned after a long and highly productive career. "Though the 140 Foot Telescope enabled us to make remarkable observations," commented Rood, "we anticipate that the new Robert C. Byrd Green Bank Telescope will greatly increase our ability to continue this research." The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

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.

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.

Dark Energy Survey Year 1 Results: A Precise H0 Measurement from DES Y1, BAO, and D/H Data

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

Abbott, T.M.C.; et al.

We combine Dark Energy Survey Year 1 clustering and weak lensing data with Baryon Acoustic Oscillations (BAO) and Big Bang Nucleosynthesis (BBN) experiments to constrain the Hubble constant. Assuming a flatmore » $$\\Lambda$$CDM model with minimal neutrino mass ($$\\sum m_\

The Universe Adventure - Feedback

Science.gov Websites

like to hear back from us): How can we contact you? Occupation (high school student, physics teacher , cosmologist, et cetera): What is your occupation? Type: Type of Feedback Organization/Format Content Fundamentals of Cosmology Evidence for the Big Bang Eras of the Cosmos The Final Frontier Glossary Other

A Polarized Universe

NASA Technical Reports Server (NTRS)

Wanjek, Christopher

2003-01-01

The CMB polarization was produced as light scattered off a primordial cloud of protons and electrons nearly 14 billion years ago, about 400,000 years after the Big Bang. This marks the moment of recombination, when the universe finally cooled enough to allow electrons to join protons. The CMB is the light that broke through the fog.

Visualizing Cosmological Concepts Using the Analog of a Hot Liquid

ERIC Educational Resources Information Center

Yusofi, E.; Mohsenzadeh, M.

2010-01-01

We have used the expansion process of hot milk, which has similarities with the cosmic expansion, to facilitate easier and better visualization and teaching of cosmological concepts. Observations of milk are used to illustrate phenomena related to the Planck era, the standard hot big bang model, cosmic inflation, problems with the formation of…

The Higgs boson and cosmology

PubMed Central

Shaposhnikov, Mikhail

2015-01-01

I will discuss how the Higgs field of the Standard Model may have played an important role in cosmology, leading to the homogeneity, isotropy and flatness of the Universe; producing the quantum fluctuations that seed structure formation; triggering the radiation-dominated era of the hot Big Bang; and contributing to the processes of baryogenesis and dark matter production.

A Brief Glossary of Commonly Used Astronomical Terms.

ERIC Educational Resources Information Center

Harrington, Sherwood

A glossary of 50 astronimical terms is presented. Among terms included are: Asteroid; Big Bang; Binary Star; Black Hole; Comet; Constellation; Eclipse; Equinox; Galaxy; Globular Cluster; Local Group; Magellanic Clouds; Nebula; Neutron Star; Nova; Parsec; Quasar; Radio Astronomy; Red Giant; Red Shift; S.E.T.I.; Solstice; Supernova; and White Dwarf.…

Are Schools Getting a Big Enough Bang for Their Education Technology Buck?

ERIC Educational Resources Information Center

Boser, Ulrich

2013-01-01

Far too often, school leaders fail to consider how technology might dramatically improve teaching and learning, and schools frequently acquire digital devices without discrete learning goals and ultimately use these devices in ways that fail to adequately serve students, schools, or taxpayers. Because of a growing debate concerning spending on…

Ex-Nihilo II: Examination Syllabi and the Sequencing of Cosmology Education

ERIC Educational Resources Information Center

Pimbblet, Kevin A.; Newman, John C.

2003-01-01

Cosmology education has become an integral part of modern physics courses. Directed by National Curricula, major UK examination boards have developed syllabi that contain explicit statements about the model of the Big Bang and the strong observational evidence that supports it. This work examines the similarities and differences in these…

The Redshifts in Relativity

ERIC Educational Resources Information Center

Singh, Satya Pal; Singh, Apoorva; Hareet, Prabhav

2011-01-01

The progress of modern cosmology took off in 1917 when A. Einstein published his paper on general theory of relativity extending his work of special theory of relativity (1905). In 1922 Alexander Friedmann constructed a mathematical model for expanding Universe that had a big bang in remote past. The experimental evidences could come in 1929 by…

The Higgs boson and cosmology.

PubMed

Shaposhnikov, Mikhail

2015-01-13

I will discuss how the Higgs field of the Standard Model may have played an important role in cosmology, leading to the homogeneity, isotropy and flatness of the Universe; producing the quantum fluctuations that seed structure formation; triggering the radiation-dominated era of the hot Big Bang; and contributing to the processes of baryogenesis and dark matter production.

Fermilab Library

Science.gov Websites

Book Newsroom Newsroom News and features Press releases Photo gallery Fact sheets and brochures Media Big Bang. Featured New eBooks The Black Book of Quantum Chromodynamics This book by Fermilab author at the LHC This book aims to give a broad organizational and strategic understanding of the nature of

A recipe for primordial soup

NASA Technical Reports Server (NTRS)

Kolb, E.

2001-01-01

If the universe emerged from a state of high temperature and high density, we can study the origin of the universe by recreating those conditions in the laboratory. While we can not reproduce the Big Bang, we can recreate its conditions and study the physical processes responsible for producing the rich and varied universe we observe today.

Navigating Deep Time: Landmarks for Time from the Big Bang to the Present

ERIC Educational Resources Information Center

Delgado, Cesar

2013-01-01

People make sense of the world by comparing and relating new information to their existing landmarks. Each individual may have different landmarks, developed through idiosyncratic experiences. Identifying specific events that constitute landmarks for a group of learners may help instructors in gauging students' prior knowledge and in planning…

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.

Big Bang Technology: What's Next in Design Education, Radical Innovation or Incremental Change?

ERIC Educational Resources Information Center

Fleischmann, Katja

2013-01-01

Since the introduction of digital media, design education has been challenged by the ongoing advancement of technology. Technological change has created unprecedented possibilities for designers to engage in the broadening realm of interactive digital media. The increasing sophistication of interactivity has brought a complexity which needs to be…

Papier-Mache Urns

ERIC Educational Resources Information Center

Kleinman, Marla

2010-01-01

Even in the best of economic times, most art teachers are subsidizing their artroom budgets with their own money and dumpster diving to provide the kind of art experience their students deserve. Green is in and art teachers have years of experience recycling trash into treasures. This urn project gives art teachers a big bang for their buck. They…

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.

Georges Lemaître and Fred Hoyle: Contrasting Characters in Science and Religion

NASA Astrophysics Data System (ADS)

Holder, Rodney D.

Georges Lemaître was a jocular Roman Catholic priest and Fred Hoyle a bluff Yorkshireman who despised organized religion. Both were giants of twentieth century cosmology but espoused diametrically opposed cosmological models. This paper explores the extent to which ideology, and particularly religion, played a part in the controversies over the big bang and steady-state theories. A particular problem for many cosmologists, including Hoyle, was posed by the idea that the universe had a temporal beginning: an eternal, unchanging universe seemed metaphysically preferable. And Hoyle was highly polemical about religion in his popular writings. In contrast, Lemaître saw no theological import from the big bang, and never entered a debate about its theological implications until, perhaps unexpectedly, he took issue with an address given by the Pope. Hoyle's seminal work on stellar nucleosynthesis led him to speak of a `superintellect monkeying with physics' though this was never identified with the God of classical theism. The work of both Lemaître and Hoyle resonates with more recent debates concerning cosmology.

Alternative explanations of the cosmic microwave background: A historical and an epistemological perspective

NASA Astrophysics Data System (ADS)

Ćirković, Milan M.; Perović, Slobodan

2018-05-01

We historically trace various non-conventional explanations for the origin of the cosmic microwave background and discuss their merit, while analyzing the dynamics of their rejection, as well as the relevant physical and methodological reasons for it. It turns out that there have been many such unorthodox interpretations; not only those developed in the context of theories rejecting the relativistic ("Big Bang") paradigm entirely (e.g., by Alfvén, Hoyle and Narlikar) but also those coming from the camp of original thinkers firmly entrenched in the relativistic milieu (e.g., by Rees, Ellis, Rowan-Robinson, Layzer and Hively). In fact, the orthodox interpretation has only incrementally won out against the alternatives over the course of the three decades of its multi-stage development. While on the whole, none of the alternatives to the hot Big Bang scenario is persuasive today, we discuss the epistemic ramifications of establishing orthodoxy and eliminating alternatives in science, an issue recently discussed by philosophers and historians of science for other areas of physics. Finally, we single out some plausible and possibly fruitful ideas offered by the alternatives.

Artist's Concept of Hubble-Discovered Ancient Gas-Giant Planet

NASA Technical Reports Server (NTRS)

2003-01-01

NASA's Hubble Space Telescope (HST) precisely measured the mass of the oldest known planet in our Milky Way Galaxy bringing closure to a decade of speculation. Scientists weren't sure if the object was a planet or a brown dwarf. Hubble's analysis shows that the object is 2.5 times the mass of Jupiter, confirming that it is indeed a planet. At an estimated age of 13 billion years, the planet is more than twice the age of Earth's 4.5 billion years. It formed around a young, sun-like star barely 1 million years after our universe's birth in the Big Bang. The ancient planet resides in an unlikely, rough neighborhood. It orbits a peculiar pair of burned-out stars in the crowded core cluster of more than 100,000 stars. Its very existence provides evidence that the first planets formed rapidly, within a billion years of the Big Bang, and leads astronomers to conclude that planets may be very abundant in our galaxy. This artist's concept depicts the planet with a view of a rich star filled sky.

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.

Vacuum low-temperature superconductivity is the essence of superconductivity - Atomic New Theory

NASA Astrophysics Data System (ADS)

Yongquan, Han

2010-10-01

The universe when the temperature closest to the Big Bang the temperature should be nuclear. Because, after the big bang, instant formation of atoms, nuclei and electrons between the absolute vacuum, the nucleus can not emit energy. (Radioactive elements, except in fact, radiation Yuan Su limited power emitted) which causes atomic nuclei and external temperature difference are so enormous that a large temperature difference reasons, all external particles became closer to the nucleus, affect the motion of electrons. When the conductor conductivity and thus affect the conductivity, the formation of resistance. Assumption that no particles affect the motion of electrons (except outside the nucleus) to form a potential difference will not change after the vector form, is now talking about the phenomenon of superconductivity, and then to introduce general, the gap between atoms in molecules or between small, valence electron number of high temperature superconducting conductors. This theory of atomic nuclei, but also explain the atomic and hydrogen bombs can remain after an explosion Why can release enormous energy reasons. Can also explain the ``super flow'' phenomenon. natural world. Tel 13241375685

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.

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.

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.

A New Viewpoint (The expanding universe, Dark energy and Dark matter)

NASA Astrophysics Data System (ADS)

Cwele, Daniel

2011-10-01

Just as the relativity paradox once threatened the validity of physics in Albert Einstein's days, the cosmos paradox, the galaxy rotation paradox and the experimental invalidity of the theory of dark matter and dark energy threaten the stability and validity of physics today. These theories and ideas and many others, including the Big Bang theory, all depend almost entirely on the notion of the expanding universe, Edwin Hubble's observations and reports and the observational inconsistencies of modern day theoretical Physics and Astrophysics on related subjects. However, much of the evidence collected in experimental Physics and Astronomy aimed at proving many of these ideas and theories is ambiguous, and can be used to prove other theories, given a different interpretation of its implications. The argument offered here is aimed at providing one such interpretation, attacking the present day theories of dark energy, dark matter and the Big Bang, and proposing a new Cosmological theory based on a modification of Isaac Newton's laws and an expansion on Albert Einstein's theories, without assuming any invalidity or questionability on present day cosmological data and astronomical observations.

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

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"?

Ultralight gravitons with tiny electric dipole moment are seeping from the vacuum

NASA Astrophysics Data System (ADS)

Novikov, Evgeny A.

2016-05-01

Mass and electric dipole moment (EDM) of graviton, which is identified as dark matter particle (DMP), are estimated. This change the concept of dark matter and can help to explain the baryon asymmetry of the universe. The calculations are based on quantum modification of the general relativity (Qmoger) with two additional terms in the Einstein equations, which takes into account production/absorption of gravitons. In this theory, there are no Big Bang in the beginning (some local bangs during the evolution of the universe are probable), no critical density of the universe, no dark energy (no need in cosmological constant) and no inflation. The theory (without fitting) is in good quantitative agreement with cosmic data.

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

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 in the nuclear physics for the case of deuterium and are potentially significant for the error budget of helium in upcoming cosmological observations.« less

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 physics for the case of deuterium and are potentially signi↓cant for the error budget of helium in upcoming cosmological observations.

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 in the nuclear physics for the case of deuterium and are potentially significant for the error budget of helium in upcoming cosmological observations.« less

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 probed the T+3He reaction, possibly relevant to Big Bang nucleosynthesis.

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

The Shape and Flow of Heavy Ion Collisions (490th Brookhaven Lecture)

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

Schenke, Bjoern

2014-12-18

The sun can’t do it, but colossal machines like the Relativistic Heavy Ion Collider (RHIC) at Brookhaven Lab and Large Hadron Collider (LHC) in Europe sure can. Quarks and gluons make up protons and neutrons found in the nucleus of every atom in the universe. At heavy ion colliders like RHIC and the LHC, scientists can create matter more than 100,000 times hotter than the center of the sun—so hot that protons and neutrons melt into a plasma of quarks and gluons. The particle collisions and emerging quark-gluon plasma hold keys to understanding how these fundamental particles interact with eachmore » other, which helps explain how everything is held together—from atomic nuclei to human beings to the biggest stars—how all matter has mass, and what the universe looked like microseconds after the Big Bang. Dr. Schenke discusses theory that details the shape and structure of heavy ion collisions. He will also explain how this theory and data from experiments at RHIC and the LHC are being used to determine properties of the quark-gluon plasma.« less

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.

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

Singularities in loop quantum cosmology.

PubMed

Cailleteau, Thomas; Cardoso, Antonio; Vandersloot, Kevin; Wands, David

2008-12-19

We show that simple scalar field models can give rise to curvature singularities in the effective Friedmann dynamics of loop quantum cosmology (LQC). We find singular solutions for spatially flat Friedmann-Robertson-Walker cosmologies with a canonical scalar field and a negative exponential potential, or with a phantom scalar field and a positive potential. While LQC avoids big bang or big rip type singularities, we find sudden singularities where the Hubble rate is bounded, but the Ricci curvature scalar diverges. We conclude that the effective equations of LQC are not in themselves sufficient to avoid the occurrence of curvature singularities.

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.

New Area Law in General Relativity.

PubMed

Bousso, Raphael; Engelhardt, Netta

2015-08-21

We report a new area law in general relativity. A future holographic screen is a hypersurface foliated by marginally trapped surfaces. We show that their area increases monotonically along the foliation. Future holographic screens can easily be found in collapsing stars and near a big crunch. Past holographic screens exist in any expanding universe and obey a similar theorem, yielding the first rigorous area law in big bang cosmology. Unlike event horizons, these objects can be identified at finite time and without reference to an asymptotic boundary. The Bousso bound is not used, but it naturally suggests a thermodynamic interpretation of our result.

An Introduction to Galaxies and Cosmology

NASA Astrophysics Data System (ADS)

Jones, Mark H.; Lambourne, Robert J. A.; Serjeant, Stephen

2015-01-01

Introduction; 1. The Milky Way - our galaxy; 2. Normal galaxies; 3. Active galaxies; 4. The spatial distribution of galaxies; 5. Introducing cosmology - the science of the Universe; 6. Big bang cosmology - the evolving Universe; 7. Observational cosmology - measuring the Universe; 8. Questioning cosmology - outstanding problems about the Universe; Answers and comments; Appendix; Glossary; Further reading; Acknowledgements; Figure references; Index.

A Conversation with William A. Fowler Part II

NASA Astrophysics Data System (ADS)

Greenberg, John

2005-06-01

Physicist William A.Fowler initiated an experimental program in nuclear astrophysics after World War II. He recalls here the Steady State versus Big Bang controversy and his celebrated collaboration with Fred Hoyle and Geoffrey and Margaret Burbidge on nucleosynthesis in stars. He also comments on the shift away from nuclear physics in universities to large accelerators and national laboratories.

The Big Bang Theory--Coping with Multi-Religious Beliefs in the Super-Diverse Science Classroom

ERIC Educational Resources Information Center

De Carvalho, Roussel

2013-01-01

Large urban schools have to cope with a "super-diverse" population with a multireligious background in their classrooms. The job of the science teacher within this environment requires an ultra-sensitive pedagogical approach, and a deeper understanding of students' backgrounds and of scientific epistemology. Teachers must create a safe…

Education in the U.S. and the Netherlands: An Equity Comparison and a Few Big Questions

ERIC Educational Resources Information Center

Owings, William A.; Kaplan, Leslie S.; Volman, Monique

2015-01-01

Using an equity perspective, this article compares the education systems of the United States and the Netherlands. Existing data examining student demographics, the organizational structures, curricula, funding, and student outcomes are examined. The Netherlands appears to be getting a "bigger bang for their buck." We make the case that…

Cosmochemistry

NASA Astrophysics Data System (ADS)

Esteban, C.; García López, R. J.; Herrero, A.; Sánchez, F.

2004-03-01

1. Primordial alchemy: from the Big Bang to the present Universe G. Steigman; 2. Stellar nucleosynthesis N. Langer; 3. Obervational aspects of stellar nucleosynthesis D. L. Lambert; 4. Abundance determinations in HII regions and planetary nebulae G. Stasinska; 5. Element abundances in nearby galaxies D. R. Garnett; 6. Chemical evolution of galaxies and intracluster medium F.Matteucci; 7. Element abundances through the cosmic ages M. Pettini.

Cosmochemistry

NASA Astrophysics Data System (ADS)

Esteban, C.; García López, R. J.; Herrero, A.; Sánchez, F.

2011-01-01

1. Primordial alchemy: from the Big Bang to the present Universe G. Steigman; 2. Stellar nucleosynthesis N. Langer; 3. Obervational aspects of stellar nucleosynthesis D. L. Lambert; 4. Abundance determinations in HII regions and planetary nebulae G. Stasinska; 5. Element abundances in nearby galaxies D. R. Garnett; 6. Chemical evolution of galaxies and intracluster medium F.Matteucci; 7. Element abundances through the cosmic ages M. Pettini.

John C. Mather, the Big Bang, and the COBE

Science.gov Websites

Additional Information * Videos John C. Mather Courtesy of NASA "Dr. John C. Mather of NASA's Goddard excerpt from NASA Scientist Shares Nobel Prize for Physics 2Edited excerpt from John Mather: The Path to a Spacecraft Courtesy of Lawrence Berkeley National Laboratory Additional Web Pages: Dr. John C Mather, NASA

Investigating Student Ideas about Cosmology III: Big Bang Theory, Expansion, Age, and History of the Universe

ERIC Educational Resources Information Center

Trouille, Laura E.; Coble, Kim; Cochran, Geraldine L.; Bailey, Janelle M.; Camarillo, Carmen T.; Nickerson, Melissa D.; Cominsky, Lynn R.

2013-01-01

We have undertaken a multi-semester study of student ideas in an undergraduate general education astronomy integrated lecture and lab course with a focus on active learning at an urban, minority serving institution. We collected individual interviews ("N" = 15) and course artifacts ("N" approximately 60), such as pre-course…

Molecular selection in a unified evolutionary sequence

NASA Technical Reports Server (NTRS)

Fox, S. W.

1986-01-01

With guidance from experiments and observations that indicate internally limited phenomena, an outline of unified evolutionary sequence is inferred. Such unification is not visible for a context of random matrix and random mutation. The sequence proceeds from Big Bang through prebiotic matter, protocells, through the evolving cell via molecular and natural selection, to mind, behavior, and society.

Ex-Nihilo: Obstacles Surrounding Teaching the Standard Model

ERIC Educational Resources Information Center

Pimbblet, Kevin A.

2002-01-01

The model of the Big Bang is an integral part of the national curricula in England and Wales. Previous work (e.g. Baxter 1989) has shown that pupils often come into education with many and varied prior misconceptions emanating from both internal and external sources. Whilst virtually all of these misconceptions can be remedied, there will remain…

Magnetic Bianchi type II string cosmological model in loop quantum cosmology

NASA Astrophysics Data System (ADS)

Rikhvitsky, Victor; Saha, Bijan; Visinescu, Mihai

2014-07-01

The loop quantum cosmology of the Bianchi type II string cosmological model in the presence of a homogeneous magnetic field is studied. We present the effective equations which provide modifications to the classical equations of motion due to quantum effects. The numerical simulations confirm that the big bang singularity is resolved by quantum gravity effects.

Pictures in the Sky

ERIC Educational Resources Information Center

Brako, Elisa; Fout, James; Peltz, William H.

2005-01-01

The authors teach an astronomy unit in their seventh-grade course that they find never fails to motivate and stretch the imagination. The questions students ask are wonder-full: "What was here before the universe?" "If there was nothing before the Big Bang, where did energy and matter come from?" "Does the universe have a boundary, and if it does,…

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.

The New Possibilities from "Big Data" to Overlooked Associations Between Diabetes, Biochemical Parameters, Glucose Control, and Osteoporosis.

PubMed

Kruse, Christian

2018-06-01

To review current practices and technologies within the scope of "Big Data" that can further our understanding of diabetes mellitus and osteoporosis from large volumes of data. "Big Data" techniques involving supervised machine learning, unsupervised machine learning, and deep learning image analysis are presented with examples of current literature. Supervised machine learning can allow us to better predict diabetes-induced osteoporosis and understand relative predictor importance of diabetes-affected bone tissue. Unsupervised machine learning can allow us to understand patterns in data between diabetic pathophysiology and altered bone metabolism. Image analysis using deep learning can allow us to be less dependent on surrogate predictors and use large volumes of images to classify diabetes-induced osteoporosis and predict future outcomes directly from images. "Big Data" techniques herald new possibilities to understand diabetes-induced osteoporosis and ascertain our current ability to classify, understand, and predict this condition.

[Impact of reflux on the kidney].

PubMed

Mollard, P; Louis, D; Basset, T

1984-03-01

Description of the reflux nephropathy. Pyelonephritis lesions are undoubtedly linked to the vesico-ureteric reflux. The role of the intra-renal reflux ( Hodson ) and the Big Bang Theory ( Ransley ) are discussed as the data from animal experiments. The role of the sterile reflux and of the segmental hypoplasia is relatively less important. The actual management of vesico-ureteric reflux treatment is questioned.

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…

Swedish Upper Secondary Students' Views of the Origin and Development of the Universe

ERIC Educational Resources Information Center

Hansson, Lena; Redfors, Andreas

2006-01-01

The article is addressing how students reason about the origin and development of the universe. Students' own views as well as their descriptions of physical models are analysed. Data consists of written surveys, and interviews of a subset of the students. Most of the students relate to the Big Bang model when describing the origin of the…

Gamma-Ray background spectrum and annihilation rate in the baryon-symmetric big-bang cosmology

NASA Technical Reports Server (NTRS)

Puget, J. L.

1973-01-01

An attempt was made to extract experimental data on baryon symmetry by observing annihilation products. Specifically, gamma rays and neutrons with long mean free paths were analyzed. Data cover absorption cross sections and radiation background of the 0.511 MeV gamma rays from positron annihilations and the 70 MeV gamma rays from neutral pion decay.

The "Big Bang" in Public and Private Faculty Salaries

ERIC Educational Resources Information Center

Rippner, Jennifer A.; Toutkoushian, Robert K.

2015-01-01

The gap between average faculty salaries at public and private institutions has been growing wider over the past 40 years, yet little is known about the nature and causes of the gap. This study uses data on more than 1,000 institutions to examine institutional average faculty salaries and how they have changed for public and private institutions.…

Engendering a Culture of Thinking in a Culture of Performativity: The Challenge of Mediating Tensions in the Singaporean Educational System

ERIC Educational Resources Information Center

Ab Kadir, Mohammad Akshir

2017-01-01

Among the major policies that have been implemented to ensure its continued success, "Thinking Schools, Learning Nation" (TSLN) has been described as the "big bang of educational reforms" in Singapore. However, while the policy aims to develop critical thinkers in school leavers, the corporatisation of education in the shape of…

Arizona State's Origins Project Starts with a Big Bang

ERIC Educational Resources Information Center

Mangan, Katherine

2009-01-01

For 12 hours at Arizona State University, a sold-out crowd of 3,000 people gave a group of famous scientists a pop-star welcome, cheering their remarks and lining up for autographs after a day full of discussion about black holes, string theory, and evolutionary biology. At a time when program cuts and faculty layoffs dominate the headlines of…

Gravity in twisted space

NASA Technical Reports Server (NTRS)

Farrar, Kelly A.; Melott, Adrian L.

1990-01-01

Numerical simulations with periodic boundary conditions are widely used in cosmology. These have a multiply connected topology known as a three-torus. Such nontrivial topologies for the actual universe may have arisen in the Big Bang. A two-dimensional numerical model with a twisted topology, sometimes a Klein bottle, is shown as well as the fact that local properties of the model are not dependent on topology.

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.

Building baby universes

NASA Astrophysics Data System (ADS)

Coles, Peter

2017-08-01

The thought of a scientist trying to design a laboratory experiment in which to create a whole new universe probably sounds like it belongs in the plot of a science-fiction B-movie. But as author Zeeya Merali explains in her new book A Big Bang in a Little Room, there are more than a few eminent physicists who think that this is theoretically possible.

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.

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.

A luminous quasar at a redshift of z = 7.085.

PubMed

Mortlock, Daniel J; Warren, Stephen J; Venemans, Bram P; Patel, Mitesh; Hewett, Paul C; McMahon, Richard G; Simpson, Chris; Theuns, Tom; Gonzáles-Solares, Eduardo A; Adamson, Andy; Dye, Simon; Hambly, Nigel C; Hirst, Paul; Irwin, Mike J; Kuiper, Ernst; Lawrence, Andy; Röttgering, Huub J A

2011-06-29

The intergalactic medium was not completely reionized until approximately a billion years after the Big Bang, as revealed by observations of quasars with redshifts of less than 6.5. It has been difficult to probe to higher redshifts, however, because quasars have historically been identified in optical surveys, which are insensitive to sources at redshifts exceeding 6.5. Here we report observations of a quasar (ULAS J112001.48+064124.3) at a redshift of 7.085, which is 0.77 billion years after the Big Bang. ULAS J1120+0641 has a luminosity of 6.3 × 10(13)L(⊙) and hosts a black hole with a mass of 2 × 10(9)M(⊙) (where L(⊙) and M(⊙) are the luminosity and mass of the Sun). The measured radius of the ionized near zone around ULAS J1120+0641 is 1.9 megaparsecs, a factor of three smaller than is typical for quasars at redshifts between 6.0 and 6.4. The near-zone transmission profile is consistent with a Lyα damping wing, suggesting that the neutral fraction of the intergalactic medium in front of ULAS J1120+0641 exceeded 0.1.

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.

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

PubMed

Koonin, Eugene V

2007-08-20

Major transitions in biological evolution show the same pattern of sudden emergence of diverse forms at a new level of complexity. The relationships between major groups within an emergent new class of biological entities are hard to decipher and do not seem to fit the tree pattern that, following Darwin's original proposal, remains the dominant description of biological evolution. The cases in point include the origin of complex RNA molecules and protein folds; major groups of viruses; archaea and bacteria, and the principal lineages within each of these prokaryotic domains; eukaryotic supergroups; and animal phyla. In each of these pivotal nexuses in life's history, the principal "types" seem to appear rapidly and fully equipped with the signature features of the respective new level of biological organization. No intermediate "grades" or intermediate forms between different types are detectable. Usually, this pattern is attributed to cladogenesis compressed in time, combined with the inevitable erosion of the phylogenetic signal. I propose that most or all major evolutionary transitions that show the "explosive" pattern of emergence of new types of biological entities correspond to a boundary between two qualitatively distinct evolutionary phases. The first, inflationary phase is characterized by extremely rapid evolution driven by various processes of genetic information exchange, such as horizontal gene transfer, recombination, fusion, fission, and spread of mobile elements. These processes give rise to a vast diversity of forms from which the main classes of entities at the new level of complexity emerge independently, through a sampling process. In the second phase, evolution dramatically slows down, the respective process of genetic information exchange tapers off, and multiple lineages of the new type of entities emerge, each of them evolving in a tree-like fashion from that point on. This biphasic model of evolution incorporates the 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). 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.

The Biological Big Bang model for the major transitions in evolution

PubMed Central

Koonin, Eugene V

2007-01-01

Background Major transitions in biological evolution show the same pattern of sudden emergence of diverse forms at a new level of complexity. The relationships between major groups within an emergent new class of biological entities are hard to decipher and do not seem to fit the tree pattern that, following Darwin's original proposal, remains the dominant description of biological evolution. The cases in point include the origin of complex RNA molecules and protein folds; major groups of viruses; archaea and bacteria, and the principal lineages within each of these prokaryotic domains; eukaryotic supergroups; and animal phyla. In each of these pivotal nexuses in life's history, the principal "types" seem to appear rapidly and fully equipped with the signature features of the respective new level of biological organization. No intermediate "grades" or intermediate forms between different types are detectable. Usually, this pattern is attributed to cladogenesis compressed in time, combined with the inevitable erosion of the phylogenetic signal. Hypothesis I propose that most or all major evolutionary transitions that show the "explosive" pattern of emergence of new types of biological entities correspond to a boundary between two qualitatively distinct evolutionary phases. The first, inflationary phase is characterized by extremely rapid evolution driven by various processes of genetic information exchange, such as horizontal gene transfer, recombination, fusion, fission, and spread of mobile elements. These processes give rise to a vast diversity of forms from which the main classes of entities at the new level of complexity emerge independently, through a sampling process. In the second phase, evolution dramatically slows down, the respective process of genetic information exchange tapers off, and multiple lineages of the new type of entities emerge, each of them evolving in a tree-like fashion from that point on. This biphasic model of evolution incorporates the 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 was reviewed by William Martin, Sergei Maslov, and Leonid Mirny. PMID:17708768

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.

How do I resolve problems reading the binary data?

Atmospheric Science Data Center

2014-12-08

... affecting compilation would be differing versions of the operating system and compilers the read software are being run on. Big ... Unix machines are Big Endian architecture while Linux systems are Little Endian architecture. Data generated on a Unix machine are ...

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.

Secular Evolution of Spiral Galaxies

DTIC Science & Technology

2003-01-01

recombination (z=1000). Furthermore, the BigBang nucleosynthesis model also requires a signi cantamount of non- baryonic dark matter (Primack 1999) ifthe universe...momentum (as well as energy) outward. Associ-ated with this outward angular momentum transport isan expected secular redistribution of disk matter , co...mode, a secular transfer of energy andangular momentum between the disk matter and thedensity wave. The existence of the phase shift betweenthe

Webb Telescope Tested for Space, Ready for Science

NASA Image and Video Library

2018-01-10

NASA’s James Webb Space Telescope is a civilization scale mission, set to look back to the first galaxies formed after the Big Bang and help answer the question “are we alone in the universe?” After passing a key test at Johnson Space Center designed to simulate the cold vacuum of space, Webb is ready for the next step ahead of a launch in 2019

Creating New Child Care Slots in Mini Child Care Centers: Big Bang for the Buck in New Jersey.

ERIC Educational Resources Information Center

Frankel, Arthur J.; And Others

1992-01-01

Small grants of $7,500 with technical assistance were offered to the child care community of New Jersey to either start or increase licensed capacity in mini-child care centers. Results of a subsequent analysis showed that 26 grantees created 481 new child care slots at an average cost of $561 per slot. (Author/SM)

'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.

An Investigation into Introductory Astronomy Students' Difficulties with Cosmology, and the Development, Validation, and Efficacy of a New Suite of Cosmology Lecture-Tutorials

ERIC Educational Resources Information Center

Wallace, Colin S.

2011-01-01

This study reports the results of the first systematic investigation into Astro 101 students' conceptual and reasoning difficulties with cosmology. We developed four surveys with which we measured students' conceptual knowledge of the Big Bang, the expansion and evolution of the universe, and the evidence for dark matter. Our classical test theory…

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 that are required to treat 100 people at the scene of a big bang mass casualties event. The findings can be used, both in the UK and internationally, to support decision makers in the planning of equipment for such incidents.

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 practicalities, training implications, performance characteristics and reliance on computer technology during a mass casualty incident require further evaluation. 2010 Elsevier Ltd. All rights reserved.

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 forward using clues from observations and from new ideas connecting the worlds of the very small and the very large, from the atom out through the deepest reaches of the cosmos.

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.

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.

Life and consciousness – The Vedāntic view

PubMed Central

Shanta, Bhakti Niskama

2015-01-01

In the past, philosophers, scientists, and even the general opinion, had no problem in accepting the existence of consciousness in the same way as the existence of the physical world. After the advent of Newtonian mechanics, science embraced a complete materialistic conception about reality. Scientists started proposing hypotheses like abiogenesis (origin of first life from accumulation of atoms and molecules) and the Big Bang theory (the explosion theory for explaining the origin of universe). How the universe came to be what it is now is a key philosophical question. The hypothesis that it came from Nothing (as proposed by Stephen Hawking, among others), proves to be dissembling, since the quantum vacuum can hardly be considered a void. In modern science, it is generally assumed that matter existed before the universe came to be. Modern science hypothesizes that the manifestation of life on Earth is nothing but a mere increment in the complexity of matter — and hence is an outcome of evolution of matter (chemical evolution) following the Big Bang. After the manifestation of life, modern science believed that chemical evolution transformed itself into biological evolution, which then had caused the entire biodiversity on our planet. The ontological view of the organism as a complex machine presumes life as just a chance occurrence, without any inner purpose. This approach in science leaves no room for the subjective aspect of consciousness in its attempt to know the world as the relationships among forces, atoms, and molecules. On the other hand, the Vedāntic view states that the origin of everything material and nonmaterial is sentient and absolute (unconditioned). Thus, sentient life is primitive and reproductive of itself – omne vivum ex vivo – life comes from life. This is the scientifically verified law of experience. Life is essentially cognitive and conscious. And, consciousness, which is fundamental, manifests itself in the gradational forms of all sentient and insentient nature. In contrast to the idea of objective evolution of bodies, as envisioned by Darwin and followers, Vedānta advocates the idea of subjective evolution of consciousness as the developing principle of the world. In this paper, an attempt has been made to highlight a few relevant developments supporting a sentient view of life in scientific research, which has caused a paradigm shift in our understanding of life and its origin. PMID:27066168

Life and consciousness - The Vedāntic view.

PubMed

Shanta, Bhakti Niskama

2015-01-01

In the past, philosophers, scientists, and even the general opinion, had no problem in accepting the existence of consciousness in the same way as the existence of the physical world. After the advent of Newtonian mechanics, science embraced a complete materialistic conception about reality. Scientists started proposing hypotheses like abiogenesis (origin of first life from accumulation of atoms and molecules) and the Big Bang theory (the explosion theory for explaining the origin of universe). How the universe came to be what it is now is a key philosophical question. The hypothesis that it came from Nothing (as proposed by Stephen Hawking, among others), proves to be dissembling, since the quantum vacuum can hardly be considered a void. In modern science, it is generally assumed that matter existed before the universe came to be. Modern science hypothesizes that the manifestation of life on Earth is nothing but a mere increment in the complexity of matter - and hence is an outcome of evolution of matter (chemical evolution) following the Big Bang. After the manifestation of life, modern science believed that chemical evolution transformed itself into biological evolution, which then had caused the entire biodiversity on our planet. The ontological view of the organism as a complex machine presumes life as just a chance occurrence, without any inner purpose. This approach in science leaves no room for the subjective aspect of consciousness in its attempt to know the world as the relationships among forces, atoms, and molecules. On the other hand, the Vedāntic view states that the origin of everything material and nonmaterial is sentient and absolute (unconditioned). Thus, sentient life is primitive and reproductive of itself - omne vivum ex vivo - life comes from life. This is the scientifically verified law of experience. Life is essentially cognitive and conscious. And, consciousness, which is fundamental, manifests itself in the gradational forms of all sentient and insentient nature. In contrast to the idea of objective evolution of bodies, as envisioned by Darwin and followers, Vedānta advocates the idea of subjective evolution of consciousness as the developing principle of the world. In this paper, an attempt has been made to highlight a few relevant developments supporting a sentient view of life in scientific research, which has caused a paradigm shift in our understanding of life and its origin.

Paradigms for Realizing Machine Learning Algorithms.

PubMed

Agneeswaran, Vijay Srinivas; Tonpay, Pranay; Tiwary, Jayati

2013-12-01

The article explains the three generations of machine learning algorithms-with all three trying to operate on big data. The first generation tools are SAS, SPSS, etc., while second generation realizations include Mahout and RapidMiner (that work over Hadoop), and the third generation paradigms include Spark and GraphLab, among others. The essence of the article is that for a number of machine learning algorithms, it is important to look beyond the Hadoop's Map-Reduce paradigm in order to make them work on big data. A number of promising contenders have emerged in the third generation that can be exploited to realize deep analytics on big data.

Clinical chemistry in higher dimensions: Machine-learning and enhanced prediction from routine clinical chemistry data.

PubMed

Richardson, Alice; Signor, Ben M; Lidbury, Brett A; Badrick, Tony

2016-11-01

Big Data is having an impact on many areas of research, not the least of which is biomedical science. In this review paper, big data and machine learning are defined in terms accessible to the clinical chemistry community. Seven myths associated with machine learning and big data are then presented, with the aim of managing expectation of machine learning amongst clinical chemists. The myths are illustrated with four examples investigating the relationship between biomarkers in liver function tests, enhanced laboratory prediction of hepatitis virus infection, the relationship between bilirubin and white cell count, and the relationship between red cell distribution width and laboratory prediction of anaemia. Copyright © 2016 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Lean Green Machines

ERIC Educational Resources Information Center

Villano, Matt

2011-01-01

Colleges and universities have been among the leaders nationwide in adopting green initiatives, partly due to their demographics, but also because they are facing their own budget pressures. Virtualization has become the poster child of many schools' efforts, because it provides significant bang for the buck. However, more and more higher…

PARTICLE PHYSICS: CERN Gives Higgs Hunters Extra Month to Collect Data.

PubMed

Morton, O

2000-09-22

After 11 years of banging electrons and positrons together at higher energies than any other machine in the world, CERN, the European laboratory for particle physics, had decided to shut down the Large Electron-Positron collider (LEP) and install a new machine, the Large Hadron Collider (LHC), in its 27-kilometer tunnel. In 2005, the LHC will start bashing protons together at even higher energies. But tantalizing hints of a long-sought fundamental particle have forced CERN managers to grant LEP a month's reprieve.

A spatially homogeneous and isotropic Einstein-Dirac cosmology

NASA Astrophysics Data System (ADS)

Finster, Felix; Hainzl, Christian

2011-04-01

We consider a spatially homogeneous and isotropic cosmological model where Dirac spinors are coupled to classical gravity. For the Dirac spinors we choose a Hartree-Fock ansatz where all one-particle wave functions are coherent and have the same momentum. If the scale function is large, the universe behaves like the classical Friedmann dust solution. If however the scale function is small, quantum effects lead to oscillations of the energy-momentum tensor. It is shown numerically and proven analytically that these quantum oscillations can prevent the formation of a big bang or big crunch singularity. The energy conditions are analyzed. We prove the existence of time-periodic solutions which go through an infinite number of expansion and contraction cycles.

The NASA Beyond Einstein Program

NASA Technical Reports Server (NTRS)

White, Nicholas E.

2004-01-01

The Laser Interferometer Space Antenna (LISA) mission is part of NASA s Beyond Einstein program. This program seeks to answer the questions What Powered the Big Bang?, What happens at the edge of a Black Hole?, and What is Dark Energy?. LISA IS the first mission to be launched in this new program. This paper will give an overview of the Beyond Einstein program, its current status and where LISA fits in.

Addressing the Barriers to Agile Development in the Department of Defense: Program Structure, Requirements, and Contracting

DTIC Science & Technology

2015-04-30

approach directly contrast with the traditional DoD acquisition model designed for a single big-bang waterfall approach (Broadus, 2013). Currently...progress, reduce technical and programmatic risk, and respond to feedback and changes more quickly than traditional waterfall methods (Modigliani...requirements, and contracting. The DoD can address these barriers by utilizing a proactively tailored Agile acquisition model , implementing an IT Box

Smoot Cosmology Group

Science.gov Websites

. ___________________________________________________________________________________ What do the different colors on the map of the CMB represent? Although the temperature of the CMB is The most conclusive and carefully examined evidence for The Big Bang is the existence of an isotropic radiation bath that permeates the entirety of the universe known as the cosmic microwave

Introduction to CERN

ScienceCinema

Heuer, R.-D.

2018-02-19

Summer Student Lecture Programme Introduction. The mission of CERN; push back the frontiers of knowledge, e.g. the secrets of the Big Bang...what was the matter like within the first moments of the Universe's existence? You have to develop new technologies for accelerators and detectors (also information technology--the Web and the GRID and medicine--diagnosis and therapy). There are three key technology areas at CERN; accelerating, particle detection, large-scale computing.

Neutrinos in astrophysics and cosmology

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

Balantekin, A. B.

Neutrinos play a crucial role in many aspects of astrophysics and cosmology. Since they control the electron fraction, or equivalently neutron-to-proton ratio, neutrino properties impact yields of r-process nucleosynthesis. Similarly the weak decoupling temperature in the Big Bang Nucleosynthesis epoch is exponentially dependent on the neutron-to-proton ratio. In these conference proceedings, I briefly summarize some of the recent work exploring the role of neutrinos in astrophysics and cosmology.

Hilltop supernatural inflation and gravitino problem

NASA Astrophysics Data System (ADS)

Kohri, Kazunori; Lin, Chia-Min

2010-11-01

In this paper, we explore the parameter space of hilltop supernatural inflation model and show the regime within which there is no gravitino problem even if we consider both thermal and nonthermal production mechanisms. We make plots for the allowed reheating temperature as a function of gravitino mass by constraints from big-bang nucleosynthesis. We also plot the constraint when gravitino is assumed to be stable and plays the role of dark matter.

Explained in 60 Seconds: A collaboration with Symmetry Magazine, a Fermilab/SLAC publication

NASA Astrophysics Data System (ADS)

Trodden, M.

2011-07-01

The Big Bang refers to the start of the rapid expansion of our Universe. Edwin Hubble discovered this expansion in the 1920s through observations of faraway galaxies, showing that the distances between them are growing as time passes. This stunning discovery is beautifully explained by general relativity — Einstein's theory of gravity — augmented by two new concepts, dark matter and dark energy.

OneSAF as an In-Stride Mission Command Asset

DTIC Science & Technology

2014-06-01

implementation approach. While DARPA began with a funded project to complete the capability as a “ big bang ” approach the approach here is based on reuse and...Command (MC), Modeling and Simulation (M&S), Distributed Interactive Simulation (DIS) ABSTRACT: To provide greater interoperability and integration...within Mission Command (MC) Systems the One Semi-Automated Forces (OneSAF) entity level simulation is evolving from a tightly coupled client server

Report on the Workshop ''Metal Production and Distribution in a Hierarchical Universe''

NASA Astrophysics Data System (ADS)

Saviane, I.; Bonifacio, P.; Spite, M.; Monaco, L.

2014-06-01

The workshop aimed at taking a global view of the evolution of metal abundances from the Big Bang to the present day, considering both observations and simulations. Abundance studies in stars and galaxies, and the variety of interstellar and intergalactic media, were covered. A summary of the workshop topics in order of decreasing redshift is presented, with considerable attention given to abundance studies of the Milky Way.

An upper limit on the neutrino rest mass.

NASA Technical Reports Server (NTRS)

Cowsik, R.; Mcclelland, J.

1972-01-01

It is pointed out that the measurement of the deceleration parameter by Sandage (1972) implies an upper limit of a few tens of electron volts on the sum of the masses of all the possible light, stable particles that interact only weakly. In the discussion of the problem, it is assumed that the universe is expanding from an initially hot and condensed state as envisaged in the 'big-bang' theories.

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.

Bouncing cosmology from warped extra dimensional scenario

NASA Astrophysics Data System (ADS)

Das, Ashmita; Maity, Debaprasad; Paul, Tanmoy; SenGupta, Soumitra

2017-12-01

From the perspective of four dimensional effective theory on a two brane warped geometry model, we examine the possibility of "bouncing phenomena"on our visible brane. Our results reveal that the presence of a warped extra dimension lead to a non-singular bounce on the brane scale factor and hence can remove the "big-bang singularity". We also examine the possible parametric regions for which this bouncing is possible.

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

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.

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.

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.

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.

Value Added: History of Physics in a ``Science, Technology, and Society'' General Education Undergraduate Course

NASA Astrophysics Data System (ADS)

Neuenschwander, Dwight

2016-03-01

In thirty years of teaching a capstone ``Science, Technology, and Society'' course to undergraduate students of all majors, I have found that, upon entering STS, to most of them the Manhattan Project seems about as remote as the Civil War; few can describe the difference between nuclear and large non-nuclear weapons. With similar lack of awareness, many students seem to think the Big Bang was dreamed up by science sorcerers. One might suppose that a basic mental picture of weapons that held entire populations hostage should be part of informed citizenship. One might also suppose that questions about origins, as they are put to nature through evidence-based reasoning, should be integral to a culture's identity. Over the years I have found the history of physics to be an effective tool for bringing such subjects to life for STS students. Upon hearing some of the history behind (for example) nuclear weapons and big bang cosmology, these students can better imagine themselves called upon to help in a Manhattan Project, or see themselves sleuthing about in a forensic science like cosmology. In this talk I share sample student responses to our class discussions on nuclear weapons, and on cosmology. The history of physics is too engaging to be appreciated only by physicists.

What can the CMB tell about the microphysics of cosmic reheating?

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

Drewes, Marco, E-mail: marcodrewes@googlemail.com

In inflationary cosmology, cosmic reheating after inflation sets the initial conditions for the hot big bang. We investigate how CMB data can be used to study the effective potential and couplings of the inflaton during reheating to constrain the underlying microphysics. If there is a phase of preheating that is driven by a parametric resonance or other instability, then the thermal history and expansion history during the reheating era depend on a large number of microphysical parameters in a complicated way. In this case the connection between CMB observables and microphysical parameters can only established with intense numerical studies. Suchmore » studies can help to improve CMB constraints on the effective inflaton potential in specific models, but parameter degeneracies usually make it impossible to extract meaningful best-fit values for individual microphysical parameters. If, on the other hand, reheating is driven by perturbative processes, then it can be possible to constrain the inflaton couplings and the reheating temperature from CMB data. This provides an indirect probe of fundamental microphysical parameters that most likely can never be measured directly in the laboratory, but have an immense impact on the evolution of the cosmos by setting the stage for the hot big bang.« less

How Did the Universe Make People? A Brief History of the Universe from the Beginning to the End

NASA Technical Reports Server (NTRS)

Mather, John C.

2009-01-01

Astronomers are beginning to know the easy part: How did the Big Bang make stars and galaxies and the chemical elements? How did solar systems form and evolve? How did the Earth and the Moon form, and how did water and carbon come to the Earth? Geologists are piecing together the history of the Earth, and biologists are coming to know the history and process of life from the earliest times. But is our planet the only life-supporting place in the universe, or are there many? Astronomers are working on that too. I will tell the story of the discovery of the Big Bang by Edwin Hubble, and how the primordial heat radiation tells the details of that universal explosion. I will tell how the James Webb Space Telescope will extend the discoveries of the Hubble Space Telescope to ever greater distances, will look inside dust clouds to see stars being born today, will measure planets around other stars, and examine the dwarf planets in the outer Solar System. I will show concepts for great new space telescopes to follow the JWST and how they could use future moon rockets to hunt for signs of life on planets around other stars.

Analyzing big data with the hybrid interval regression methods.

PubMed

Huang, Chia-Hui; Yang, Keng-Chieh; Kao, Han-Ying

2014-01-01

Big data is a new trend at present, forcing the significant impacts on information technologies. In big data applications, one of the most concerned issues is dealing with large-scale data sets that often require computation resources provided by public cloud services. How to analyze big data efficiently becomes a big challenge. In this paper, we collaborate interval regression with the smooth support vector machine (SSVM) to analyze big data. Recently, the smooth support vector machine (SSVM) was proposed as an alternative of the standard SVM that has been proved more efficient than the traditional SVM in processing large-scale data. In addition the soft margin method is proposed to modify the excursion of separation margin and to be effective in the gray zone that the distribution of data becomes hard to be described and the separation margin between classes.

Analyzing Big Data with the Hybrid Interval Regression Methods

PubMed Central

Kao, Han-Ying

2014-01-01

Big data is a new trend at present, forcing the significant impacts on information technologies. In big data applications, one of the most concerned issues is dealing with large-scale data sets that often require computation resources provided by public cloud services. How to analyze big data efficiently becomes a big challenge. In this paper, we collaborate interval regression with the smooth support vector machine (SSVM) to analyze big data. Recently, the smooth support vector machine (SSVM) was proposed as an alternative of the standard SVM that has been proved more efficient than the traditional SVM in processing large-scale data. In addition the soft margin method is proposed to modify the excursion of separation margin and to be effective in the gray zone that the distribution of data becomes hard to be described and the separation margin between classes. PMID:25143968

Big Data in Public Health: Terminology, Machine Learning, and Privacy.

PubMed

Mooney, Stephen J; Pejaver, Vikas

2018-04-01

The digital world is generating data at a staggering and still increasing rate. While these "big data" have unlocked novel opportunities to understand public health, they hold still greater potential for research and practice. This review explores several key issues that have arisen around big data. First, we propose a taxonomy of sources of big data to clarify terminology and identify threads common across some subtypes of big data. Next, we consider common public health research and practice uses for big data, including surveillance, hypothesis-generating research, and causal inference, while exploring the role that machine learning may play in each use. We then consider the ethical implications of the big data revolution with particular emphasis on maintaining appropriate care for privacy in a world in which technology is rapidly changing social norms regarding the need for (and even the meaning of) privacy. Finally, we make suggestions regarding structuring teams and training to succeed in working with big data in research and practice.

Experimental Realization of a Quantum Support Vector Machine

NASA Astrophysics Data System (ADS)

Li, Zhaokai; Liu, Xiaomei; Xu, Nanyang; Du, Jiangfeng

2015-04-01

The fundamental principle of artificial intelligence is the ability of machines to learn from previous experience and do future work accordingly. In the age of big data, classical learning machines often require huge computational resources in many practical cases. Quantum machine learning algorithms, on the other hand, could be exponentially faster than their classical counterparts by utilizing quantum parallelism. Here, we demonstrate a quantum machine learning algorithm to implement handwriting recognition on a four-qubit NMR test bench. The quantum machine learns standard character fonts and then recognizes handwritten characters from a set with two candidates. Because of the wide spread importance of artificial intelligence and its tremendous consumption of computational resources, quantum speedup would be extremely attractive against the challenges of big data.

Dark matter

PubMed Central

Peebles, P. James E.

2015-01-01

The evidence for the dark matter (DM) of the hot big bang cosmology is about as good as it gets in natural science. The exploration of its nature is now led by direct and indirect detection experiments, to be complemented by advances in the full range of cosmological tests, including judicious consideration of the rich phenomenology of galaxies. The results may confirm ideas about DM already under discussion. If we are lucky, we also will be surprised once again. PMID:24794526

Nearby galaxies as pointers to a better theory of cosmic evolution.

PubMed

Peebles, P J E; Nusser, Adi

2010-06-03

The great advances in the network of cosmological tests show that the relativistic Big Bang theory is a good description of our expanding Universe. However, the properties of nearby galaxies that can be observed in greatest detail suggest that a better theory would describe a mechanism by which matter is more rapidly gathered into galaxies and groups of galaxies. This more rapid growth occurs in some theoretical ideas now under discussion.

Fully covariant cosmology and its astrophysical implications

NASA Technical Reports Server (NTRS)

Wesson, Paul S.; Liu, Hongya

1995-01-01

We present a cosmological model with good physical properties which is invariant not only under changes of the space and time coordinates but also under changes of an extra (Kaluza-Klein) coordinate related to rest mass. In frames where the latter is chosen to be constant we recover standard cosmology. In frames where it is chosen to be variable we obtain new astrophysical effects and gain insight into the nature of the big bang.

Solving Operational Models of Interdependent Infrastructure Systems

DTIC Science & Technology

2014-12-01

resilience, getting the biggest “reduction in bang ” for their buck. The most important part of those modeling efforts is the formulation of a mathematical...about the requirements of each system to the model of the other system through shared data. This type of algorithm simulates the dynamic...than just another big project. I found a true interest and excitement working with you both and consider you both the highest caliber faculty I have

Program Manager Assessments: Professionalism Personified

DTIC Science & Technology

2015-08-01

dozens of legacy systems. A few years ago, the idea of modernizing this collection in a “ big bang ” approach was rejected in favor of a lower-risk and...chain of com- mand. The assessments are simul - taneously sent to me, the Service or Component acquisition executive, and the program executive officer...use of actual test results at sub-scale, com- ponent testing, modeling, simulation , and field testing were all described in fair detail. Key near

Recent Progresses in Ab-Initio Studies of Low-Energy Few-Nucleon Reactions of Astrophysical Interest

NASA Astrophysics Data System (ADS)

Marcucci, Laura E.

2017-03-01

We review the most recent theoretical studies of nuclear reactions of astrophysical interest involving few-nucleon systems. In particular, we focus on the radiative capture of protons by deuterons in the energy range of interest for Big Bang Nucleosynthesis. Related to this, we will discuss also the most recent calculation of tritium β -decay. Two frameworks will be considered, the conventional and the chiral effective field theory approach.

Recent progress in ab-initio studies of nuclear reactions of astrophysical interest with A ≤ 3

NASA Astrophysics Data System (ADS)

Marcucci, Laura E.

2018-03-01

We review the most recent theoretical studies of nuclear reactions of astrophysical interest involving few-nucleon systems. In particular, we focus on the consequences for the solar neutrino fluxes of the recent determination for the astrophysical S-factor of the proton weak capture by proton, and on the radiative capture of protons by deuterons in the energy range of interest for Big Bang Nucleosynthesis.

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.

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 structures like plants, animals and fungi. 3. Matter starts to think A comet or an asteroid crashed into Earth about 66 million years ago, ending the dominance of dinosaurs. Small animals giving birth to living offspring were now able to evolve into a multitude of species, among them the primates. A group of primates migrated from Africa to other continents less than 100000 years ago. Their brain developed a special quality, self-conscience. This ability to reflect about oneself boosted their survival considerably. Man (Homo sapiens) had entered the scene, becoming one of the dominant species of this planet. Due to his immense ability today to handle matter and energy he has become something of a caretaker of planet Earth. Man is responsible for sustainable development for the good of his society and of the whole biosphere. If there is a fourth step in the history of the universe, discoveries in astrobiology may provide us with some clues in the next decades.

Palatini actions and quantum gravity phenomenology

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

Olmo, Gonzalo J., E-mail: gonzalo.olmo@csic.es

2011-10-01

We show that an invariant an universal length scale can be consistently introduced in a generally covariant theory through the gravitational sector using the Palatini approach. The resulting theory is able to capture different aspects of quantum gravity phenomenology in a single framework. In particular, it is found that in this theory field excitations propagating with different energy-densities perceive different background metrics, which is a fundamental characteristic of the DSR and Rainbow Gravity approaches. We illustrate these properties with a particular gravitational model and explicitly show how the soccer ball problem is avoided in this framework. The isotropic and anisotropicmore » cosmologies of this model also avoid the big bang singularity by means of a big bounce.« less

Analysis of the Fisher solution

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

Abdolrahimi, Shohreh; Shoom, Andrey A.

2010-01-15

We study the d-dimensional Fisher solution which represents a static, spherically symmetric, asymptotically flat spacetime with a massless scalar field. The solution has two parameters, the mass M and the 'scalar charge' {Sigma}. The Fisher solution has a naked curvature singularity which divides the spacetime manifold into two disconnected parts. The part which is asymptotically flat we call the Fisher spacetime, and another part we call the Fisher universe. The d-dimensional Schwarzschild-Tangherlini solution and the Fisher solution belong to the same theory and are dual to each other. The duality transformation acting in the parameter space (M,{Sigma}) maps the exteriormore » region of the Schwarzschild-Tangherlini black hole into the Fisher spacetime which has a naked timelike singularity, and interior region of the black hole into the Fisher universe, which is an anisotropic expanding-contracting universe and which has two spacelike singularities representing its 'big bang' and 'big crunch'. The big bang singularity and the singularity of the Fisher spacetime are radially weak in the sense that a 1-dimensional object moving along a timelike radial geodesic can arrive to the singularities intact. At the vicinity of the singularity the Fisher spacetime of nonzero mass has a region where its Misner-Sharp energy is negative. The Fisher universe has a marginally trapped surface corresponding to the state of its maximal expansion in the angular directions. These results and derived relations between geometric quantities of the Fisher spacetime, the Fisher universe, and the Schwarzschild-Tangherlini black hole may suggest that the massless scalar field transforms the black hole event horizon into the naked radially weak disjoint singularities of the Fisher spacetime and the Fisher universe which are 'dual to the horizon'.« less

Big Data Bioinformatics

PubMed Central

GREENE, CASEY S.; TAN, JIE; UNG, MATTHEW; MOORE, JASON H.; CHENG, CHAO

2017-01-01

Recent technological advances allow for high throughput profiling of biological systems in a cost-efficient manner. The low cost of data generation is leading us to the “big data” era. The availability of big data provides unprecedented opportunities but also raises new challenges for data mining and analysis. In this review, we introduce key concepts in the analysis of big data, including both “machine learning” algorithms as well as “unsupervised” and “supervised” examples of each. We note packages for the R programming language that are available to perform machine learning analyses. In addition to programming based solutions, we review webservers that allow users with limited or no programming background to perform these analyses on large data compendia. PMID:27908398

Big Data Bioinformatics

PubMed Central

GREENE, CASEY S.; TAN, JIE; UNG, MATTHEW; MOORE, JASON H.; CHENG, CHAO

2017-01-01

Recent technological advances allow for high throughput profiling of biological systems in a cost-efficient manner. The low cost of data generation is leading us to the “big data” era. The availability of big data provides unprecedented opportunities but also raises new challenges for data mining and analysis. In this review, we introduce key concepts in the analysis of big data, including both “machine learning” algorithms as well as “unsupervised” and “supervised” examples of each. We note packages for the R programming language that are available to perform machine learning analyses. In addition to programming based solutions, we review webservers that allow users with limited or no programming background to perform these analyses on large data compendia. PMID:24799088

Big data bioinformatics.

PubMed

Greene, Casey S; Tan, Jie; Ung, Matthew; Moore, Jason H; Cheng, Chao

2014-12-01

Recent technological advances allow for high throughput profiling of biological systems in a cost-efficient manner. The low cost of data generation is leading us to the "big data" era. The availability of big data provides unprecedented opportunities but also raises new challenges for data mining and analysis. In this review, we introduce key concepts in the analysis of big data, including both "machine learning" algorithms as well as "unsupervised" and "supervised" examples of each. We note packages for the R programming language that are available to perform machine learning analyses. In addition to programming based solutions, we review webservers that allow users with limited or no programming background to perform these analyses on large data compendia. © 2014 Wiley Periodicals, Inc.

Machine learning of big data in gaining insight into successful treatment of hypertension.

PubMed

Koren, Gideon; Nordon, Galia; Radinsky, Kira; Shalev, Varda

2018-06-01

Despite effective medications, rates of uncontrolled hypertension remain high. Treatment protocols are largely based on randomized trials and meta-analyses of these studies. The objective of this study was to test the utility of machine learning of big data in gaining insight into the treatment of hypertension. We applied machine learning techniques such as decision trees and neural networks, to identify determinants that contribute to the success of hypertension drug treatment on a large set of patients. We also identified concomitant drugs not considered to have antihypertensive activity, which may contribute to lowering blood pressure (BP) control. Higher initial BP predicts lower success rates. Among the medication options and their combinations, treatment with beta blockers appears to be more commonly effective, which is not reflected in contemporary guidelines. Among numerous concomitant drugs taken by hypertensive patients, proton pump inhibitors (PPIs), and HMG CO-A reductase inhibitors (statins) significantly improved the success rate of hypertension. In conclusions, machine learning of big data is a novel method to identify effective antihypertensive therapy and for repurposing medications already on the market for new indications. Our results related to beta blockers, stemming from machine learning of a large and diverse set of big data, in contrast to the much narrower criteria for randomized clinic trials (RCTs), should be corroborated and affirmed by other methods, as they hold potential promise for an old class of drugs which may be presently underutilized. These previously unrecognized effects of PPIs and statins have been very recently identified as effective in lowering BP in preliminary clinical observations, lending credibility to our big data results.

Exploring for Galaxies in the First Billion Years with Hubble and Spitzer - Pathfinding for JWST

NASA Astrophysics Data System (ADS)

Illingworth, Garth D.

2017-01-01

Hubble has revolutionized the field of distant galaxies through its deep imaging surveys, starting with the Hubble Deep Field (HDF) in 1995. That first deep survey revealed galaxies at redshift z~1-3 that provided insights into the development of the Hubble sequence. Each new HST instrument has explored new regimes, through the peak of star formation at z~2-3, just 2-3 billion years after the Big Bang, to our first datasets at a billion years at z~6, and then earlier to z~11. HST's survey capabilities were enhanced by 40X with ACS, and then similarly with the WFC3/IR, which opened up the first billion years to an unforeseen degree. I will discuss what we have learned from the remarkable HST and Spitzer imaging surveys (HUDF, GOODS, HUDF09/12 and CANDELS), as well as surveys of clusters like the Hubble Frontier Fields (HFF). Lensing clusters provide extraordinary opportunities for characterizing the faintest earliest galaxies, but also present extraordinary challenges. Together these surveys have resulted in the measurement of the volume density of galaxies in the first billion years down to astonishingly faint levels. The role of faint galaxies in reionizing the universe is still much-discussed, but there is no doubt that such galaxies contribute greatly to the UV ionizing flux, as shown by deep luminosity function studies. Together Hubble and Spitzer have also established the stellar-mass buildup over 97% of cosmic history. Yet some of the greatest surprises have come from the discovery of very luminous galaxies at z~8-11, around 400-650 million years after the Big Bang. Spectroscopic followup by Keck of some of these very rare, bright galaxies has confirmed redshifts from z~7 to z~9, and revealed, surprisingly, strong Lyα emission near the peak of reionization when the HI fraction in the IGM is high. The recent confirmation of a z=11.1 galaxy, just 400 million years after the Big Bang, by a combination of Hubble and Spitzer data, moved Hubble into JWST territory, far beyond what we ever expected Hubble could do. Twenty years of astonishing progress with Hubble and Spitzer leave me looking to JWST to provide even more remarkable exploration of the realm of the first galaxies.

L'Abondance du Deutérium, de l'Ultraviolet au Visible

NASA Astrophysics Data System (ADS)

Hébrard, Guillaume

2000-12-01

Dans le cadre du modèle standard du Big Bang, le deutérium est l'élément dont l'abondance primordiale est la plus sensible à la densité baryonique de l'Univers. Cet élément est uniquement créé lors de la nucléosynthèse primordiale, quelques minutes après le Big Bang ; aucune théorie standard n'en prédit actuellement d'autres sources significatives. Au contraire, étant brûlé dans les étoiles, son abondance D/H décroît au cours de l'évolution cosmique. Les mesures de D/H apportent ainsi des contraintes sur les modèles de Big Bang et d'évolution chimique des galaxies. On peut distinguer trois types de mesures de D/H: les abondances primordiale, proto-solaire et interstellaire, respectivement représentatives de l'Univers il y a environ 15 milliards d'années, 4.5 milliards d'années et à l'époque actuelle. Si l'évolution du deutérium semble qualitativement claire, les résultats concernant ces trois types d'abondance ne convergent pas pour l'instant vers trois valeurs bien définies. Les travaux entrepris durant cette thèse sont reliés à la mesure de l'abondance interstellaire du deutérium. Celle-ci s'obtient habituellement par l'observation spectroscopique en absorption des séries de Lyman de l'hydrogène et du deutérium. Ces observations se font dans le domaine ultraviolet, au moyen d'observatoires spatiaux. Les résultats présentés ici ont été obtenus avec le Télescope spatial Hubble puis le satellite FUSE, récemment mis en orbite. D'autre part, une nouvelle méthode d'observation du deutérium a été proposée, dans le domaine visible à partir de télescopes au sol. Ce travail a mené aux premières détections et à l'identification de la série de Balmer du deutérium, observée en émission dans des régions HII avec le Télescope Canada-France-Hawaii et le Very Large Telescope. On-line Thesis, Guillaume Hébrard

Machine Learning in the Big Data Era: Are We There Yet?

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

Sukumar, Sreenivas Rangan

In this paper, we discuss the machine learning challenges of the Big Data era. We observe that recent innovations in being able to collect, access, organize, integrate, and query massive amounts of data from a wide variety of data sources have brought statistical machine learning under more scrutiny and evaluation for gleaning insights from the data than ever before. In that context, we pose and debate the question - Are machine learning algorithms scaling with the ability to store and compute? If yes, how? If not, why not? We survey recent developments in the state-of-the-art to discuss emerging and outstandingmore » challenges in the design and implementation of machine learning algorithms at scale. We leverage experience from real-world Big Data knowledge discovery projects across domains of national security and healthcare to suggest our efforts be focused along the following axes: (i) the data science challenge - designing scalable and flexible computational architectures for machine learning (beyond just data-retrieval); (ii) the science of data challenge the ability to understand characteristics of data before applying machine learning algorithms and tools; and (iii) the scalable predictive functions challenge the ability to construct, learn and infer with increasing sample size, dimensionality, and categories of labels. We conclude with a discussion of opportunities and directions for future research.« less

Using Multiple Big Datasets and Machine Learning to Produce a New Global Particulate Dataset: A Technology Challenge Case Study

NASA Astrophysics Data System (ADS)

Lary, D. J.

2013-12-01

A BigData case study is described where multiple datasets from several satellites, high-resolution global meteorological data, social media and in-situ observations are combined using machine learning on a distributed cluster using an automated workflow. The global particulate dataset is relevant to global public health studies and would not be possible to produce without the use of the multiple big datasets, in-situ data and machine learning.To greatly reduce the development time and enhance the functionality a high level language capable of parallel processing has been used (Matlab). A key consideration for the system is high speed access due to the large data volume, persistence of the large data volumes and a precise process time scheduling capability.

Guidelines for Developing and Reporting Machine Learning Predictive Models in Biomedical Research: A Multidisciplinary View

PubMed Central

2016-01-01

Background As more and more researchers are turning to big data for new opportunities of biomedical discoveries, machine learning models, as the backbone of big data analysis, are mentioned more often in biomedical journals. However, owing to the inherent complexity of machine learning methods, they are prone to misuse. Because of the flexibility in specifying machine learning models, the results are often insufficiently reported in research articles, hindering reliable assessment of model validity and consistent interpretation of model outputs. Objective To attain a set of guidelines on the use of machine learning predictive models within clinical settings to make sure the models are correctly applied and sufficiently reported so that true discoveries can be distinguished from random coincidence. Methods A multidisciplinary panel of machine learning experts, clinicians, and traditional statisticians were interviewed, using an iterative process in accordance with the Delphi method. Results The process produced a set of guidelines that consists of (1) a list of reporting items to be included in a research article and (2) a set of practical sequential steps for developing predictive models. Conclusions A set of guidelines was generated to enable correct application of machine learning models and consistent reporting of model specifications and results in biomedical research. We believe that such guidelines will accelerate the adoption of big data analysis, particularly with machine learning methods, in the biomedical research community. PMID:27986644

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.

Discovery of the hot Big Bang: What happened in 1948

NASA Astrophysics Data System (ADS)

Peebles, Phillip James Edwin

2014-04-01

The idea that the universe is filled with the thermal radiation now termed the Cosmic Microwave Background was discussed in eleven publications in the year 1948. These papers offer a detailed example of the process of development of a new and now very productive line of research, and of the confusion that can attend new ideas. The confusion in this case left a common misunderstanding of the considerations that motivated the idea of the sea of radiation.

Brane decay and an initial spacelike singularity.

PubMed

Kawai, Shinsuke; Keski-Vakkuri, Esko; Leigh, Robert G; Nowling, Sean

2006-01-27

We present a novel string theory scenario where matter in a spacetime originates from a decaying brane at the origin of time. The decay could be considered as a big-bang-like event at X0=0. The closed string interpretation is a time-dependent spacetime with a semi-infinite time direction, with the initial energy of the brane converted into energy flux from the origin. The open string interpretation can be viewed as a string theoretic nonsingular initial condition.

Constraints on cosmic superstrings from Kaluza-Klein emission.

PubMed

Dufaux, Jean-François

2012-07-06

Cosmic superstrings interact generically with a tower of light and/or strongly coupled Kaluza-Klein (KK) modes associated with the geometry of the internal space. We study the production of KK particles by cosmic superstring loops, and show that it is constrained by big bang nucleosynthesis. We study the resulting constraints in the parameter space of the underlying string theory model and highlight their complementarity with the regions that can be probed by current and upcoming gravitational wave experiments.

Ancient prototypes of the big bang and the Hot Universe (to the prehistory of some fundamental ideas in cosmology)

NASA Astrophysics Data System (ADS)

Eremeeva, A. I.

Gamov's cosmological (as a matter of fact, cosmophysical!) Hot Universe theory, which shocked the astrophysics by its unusual universality at first, had "predecessors" in the antiquity. In spite of the ancient natural philosophers' poor scientific knowledge, their apprehension of the world as a whole helped them to catch some profound analogies and to express some surprising guesses concerning the process of the birth of the Universe.

Application of particle accelerators in research.

PubMed

Mazzitelli, Giovanni

2011-07-01

Since the beginning of the past century, accelerators have started to play a fundamental role as powerful tools to discover the world around us, how the universe has evolved since the big bang and to develop fundamental instruments for everyday life. Although more than 15 000 accelerators are operating around the world only a very few of them are dedicated to fundamental research. An overview of the present high energy physics (HEP) accelerator status and prospectives is presented.

A new view of Baryon symmetric cosmology based on grand unified theories

NASA Technical Reports Server (NTRS)

Stecker, F. W.

1981-01-01

Within the framework of grand unified theories, it is shown how spontaneous CP violation leads to a domain structure in the universe with the domains evolving into separate regions of matter and antimatter excesses. Subsequent to exponential horizon growth, this can result in a universe of matter galaxies and antimatter galaxies. Various astrophysical data appear to favor this form of big bang cosmology. Future direct tests for cosmologically significant antimatter are discussed.

Comment on "Deep mixing of 3He: reconciling Big Bang and stellar nucleosynthesis".

PubMed

Balser, Dana S; Rood, Robert T; Bania, T M

2007-08-31

Eggleton et al. (Reports, 8 December 2006, p. 1580) reported on a deep-mixing mechanism in low-mass stars caused by a Rayleigh-Taylor instability that destroys all of the helium isotope 3He produced during the star's lifetime. Observations of 3He in planetary nebulae, however, indicate that some stars produce prodigious amounts of 3He. This is inconsistent with the claim that all low-mass stars should destroy 3He.

DoD Lead System Integrator (LSI) Transformation - Creating a Model Based Acquisition Framework (MBAF)

DTIC Science & Technology

2014-04-30

cost to acquire systems as design maturity could be verified incrementally as the system was developed vice waiting for specific large “ big bang ...Framework (MBAF) be applied to simulate or optimize process variations on programs? LSI Roles and Responsibilities A review of the roles and...the model/process optimization process. It is the current intent that NAVAIR will use the model to run simulations on process changes in an attempt to

Some nuclear physics aspects of BBN

NASA Astrophysics Data System (ADS)

Coc, Alain

2017-09-01

Primordial or big bang nucleosynthesis (BBN) is now a parameter free theory whose predictions are in good overall agreement with observations. However, the 7 Li calculated abundance is significantly higher than the one deduced from spectroscopic observations. Nuclear physics solutions to this lithium problem have been investigated by experimental means. Other solutions which were considered involve exotic sources of extra neutrons which inevitably leads to an increase of the deuterium abundance, but this seems now excluded by recent deuterium observations.

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.

Cosmic Background Explorer (COBE) press kit

NASA Technical Reports Server (NTRS)

1989-01-01

COBE, the Cosmic Background Explorer spacecraft, and its mission are described. COBE was designed to study the origin and dynamics of the universe including the theory that the universe began with a cataclysmic explosion referred to as the Big Bang. To this end, earth's cosmic background - the infrared radiation that bombards earth from every direction - will be measured by three sophisticated instruments: the Differential Microwave Radiometer (DMR), the Far Infrared Absolute Spectrophotometer (FIRAS), and the Diffuse Infrared Background Experiment (DIRBE).

Study on the opinion of university students about the themes of the origin of Universe and evolution of life

NASA Astrophysics Data System (ADS)

de Souza, Rogério F.; de Carvalho, Marcelo; Matsuo, Tiemi; Zaia, Dimas A. M.

2010-04-01

This paper reports the results of a questionnaire administered to university students, about several questions involving the origin of the Universe and life and biological evolution, as well as questions related to more common scientific themes. As few as between 2.4% (philosophy students) and 14% (geography students) did not accept the theory of evolution, because they believed in creation as described in the Bible. However, between 41.5% (philosophy students) and 71.3% (biology students) did not see any conflict between religion and evolution. About 80% of the students believed that the relationship between lung cancer and smoking is well established by science, but this number falls to 65% for biological evolution and 28.9% for the big bang theory. It should be pointed out that for 24.5% and 7.4% of the students the big bang theory and biological evolution, respectively, are poorly established by science. The students who self-reported being Christian but not Roman Catholic are more conservative in the acceptance of biological evolution and the old age of Earth and the Universe than are other groups of students. Other factors, such as family income and the level of education of parents, appear to influence the students' acceptance of themes related to the origin of the Universe and biological evolution.

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.

Inflation in the standard cosmological model

NASA Astrophysics Data System (ADS)

Uzan, Jean-Philippe

2015-12-01

The inflationary paradigm is now part of the standard cosmological model as a description of its primordial phase. While its original motivation was to solve the standard problems of the hot big bang model, it was soon understood that it offers a natural theory for the origin of the large-scale structure of the universe. Most models rely on a slow-rolling scalar field and enjoy very generic predictions. Besides, all the matter of the universe is produced by the decay of the inflaton field at the end of inflation during a phase of reheating. These predictions can be (and are) tested from their imprint of the large-scale structure and in particular the cosmic microwave background. Inflation stands as a window in physics where both general relativity and quantum field theory are at work and which can be observationally studied. It connects cosmology with high-energy physics. Today most models are constructed within extensions of the standard model, such as supersymmetry or string theory. Inflation also disrupts our vision of the universe, in particular with the ideas of chaotic inflation and eternal inflation that tend to promote the image of a very inhomogeneous universe with fractal structure on a large scale. This idea is also at the heart of further speculations, such as the multiverse. This introduction summarizes the connections between inflation and the hot big bang model and details the basics of its dynamics and predictions. xml:lang="fr"

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.

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

Cancer and metaphysics.

PubMed

Zajicek, G

2001-08-01

Metaphysics, is generally a pleasant, and harmless intellectual endeavor. Even if leading to wrong conclusions, nobody is hurt. Suppose that contrary to general belief, the Big Bang (1) never happened and the world is eternal. No harm is done. Some philosophers, like Kant, enjoyed life despite the fact that, nature, or the thing in itself, eluded their understanding (2). But suppose that the thing in itself is your patient, and you apply metaphysical reasoning for his treatment, metaphysics may occasionally be damaging. This is particularly pertinent to cancer, a disease that is haunted by false metaphysical statements. Since cancer is part of medicine, the present discourse deals with medical metaphysics. Medicine provides a simple way, or rule of thumb, for distinguishing between correct and wrong medical metaphysical statements. If they harm the patient, they are wrong, and if they aid him, they are correct. Statements that do not affect a patient's well being, e.g., 'Big Bang may be hazardous to your health', are of no apparent value and doubtful. Since treatment outcome is generally uncertain, the physician continually searches for new ideas that may aid his patient, even if they are metaphysical. In diseases, like cancer, that elude his understanding, his adherence to metaphysics intensifies, and he is ready to consider even doubtful suggestions for treatment. Yet by relaxing the rules of thumb for evaluating metaphysical concepts, he gradually slips into the irrational domain. Copyright 2001 Harcourt Publishers Ltd.

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.

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.

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.

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.

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.

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.

Spectroscopic confirmation of a galaxy at redshift z = 8.6.

PubMed

Lehnert, M D; Nesvadba, N P H; Cuby, J-G; Swinbank, A M; Morris, S; Clément, B; Evans, C J; Bremer, M N; Basa, S

2010-10-21

Galaxies had their most significant impact on the Universe when they assembled their first generations of stars. Energetic photons emitted by young, massive stars in primeval galaxies ionized the intergalactic medium surrounding their host galaxies, cleared sightlines along which the light of the young galaxies could escape, and fundamentally altered the physical state of the intergalactic gas in the Universe continuously until the present day. Observations of the cosmic microwave background, and of galaxies and quasars at the highest redshifts, suggest that the Universe was reionized through a complex process that was completed about a billion years after the Big Bang, by redshift z ≈ 6. Detecting ionizing Lyman-α photons from increasingly distant galaxies places important constraints on the timing, location and nature of the sources responsible for reionization. Here we report the detection of Lyα photons emitted less than 600 million years after the Big Bang. UDFy-38135539 (ref. 5) is at a redshift of z = 8.5549 ± 0.0002, which is greater than those of the previously known most distant objects, at z = 8.2 (refs 6 and 7) and z = 6.96 (ref. 8). We find that this single source is unlikely to provide enough photons to ionize the volume necessary for the emission line to escape, requiring a significant contribution from other, probably fainter galaxies nearby.

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.

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.

Emergent universe with wormholes in massive gravity

NASA Astrophysics Data System (ADS)

Paul, B. C.; Majumdar, A. S.

2018-03-01

An emergent universe (EU) scenario is proposed to obtain a universe free from big-bang singularity. In this framework the present universe emerged from a static Einstein universe phase in the infinite past. A flat EU scenario is found to exist in Einstein’s gravity with a non-linear equation of state (EoS). It has been shown subsequently that a physically realistic EU model can be obtained considering cosmic fluid composed of interacting fluids with a non-linear equation of state. It results a viable cosmological model accommodating both early inflation and present accelerating phases. In the present paper, the origin of an initial static Einstein universe needed in the EU model is explored in a massive gravity theory which subsequently emerged to be a dynamically evolving universe. A new gravitational instanton solution in a flat universe is obtained in the massive gravity theory which is a dynamical wormhole that might play an important role in realizing the origin of the initial state of the emergent universe. The emergence of a Lorentzian universe from a Euclidean gravity is understood by a Wick rotation τ = i t . A universe with radiation at the beginning finally transits into the present observed universe with a non-linear EoS as the interactions among the fluids set in. Thus a viable flat EU scenario where the universe stretches back into time infinitely, with no big bang is permitted in a massive gravity.

Quantum Support Vector Machine for Big Data Classification

NASA Astrophysics Data System (ADS)

Rebentrost, Patrick; Mohseni, Masoud; Lloyd, Seth

2014-09-01

Supervised machine learning is the classification of new data based on already classified training examples. In this work, we show that the support vector machine, an optimized binary classifier, can be implemented on a quantum computer, with complexity logarithmic in the size of the vectors and the number of training examples. In cases where classical sampling algorithms require polynomial time, an exponential speedup is obtained. At the core of this quantum big data algorithm is a nonsparse matrix exponentiation technique for efficiently performing a matrix inversion of the training data inner-product (kernel) matrix.

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 study (8) led by Palevsky and colleagues in the USA, also testing the importance of dose in the treatment for ARF. Nevertheless, 'early goal-directed hemofiltration therapy' like early goal directed therapy (9) has to be studied in our critical ill patients. Regarding this issue, fewer studies, mainly retrospective exist, but again the IVOIRE study (6) will address this issue by studying septic patients with acute renal injury according to the Rifle classification (10). So, this review focuses on the early application and on the adequate dose of continuous high volume hemofiltration in septic shock in order to improve not only hemodynamics, but survival in this very severely ill cohort of patients. This could well be called the 'big bang of hemofiltration' as one could never have anticipated that an adequate dose of hemofiltration could markedly influence the survival rate of ICU-septic acute renal failure patients. On top of the use of early and adequate dose of hemofiltration in sepsis, a higher dose could also provide better renal recovery rate and reduce the risk of associate chronic dialysis in these patients. Furthermore, this paper also reviews 'brand' new theories regarding the rationale for hemofiltration in sepsis. Finally, this paper also addresses the so-called negative studies as well anticipated side effects.

Cosmology in the laboratory: An analogy between hyperbolic metamaterials and the Milne universe

NASA Astrophysics Data System (ADS)

Figueiredo, David; Moraes, Fernando; Fumeron, Sébastien; Berche, Bertrand

2017-11-01

This article shows that the compactified Milne universe geometry, a toy model for the big crunch/big bang transition, can be realized in hyperbolic metamaterials, a new class of nanoengineered systems which have recently found its way as an experimental playground for cosmological ideas. On one side, Klein-Gordon particles, as well as tachyons, are used as probes of the Milne geometry. On the other side, the propagation of light in two versions of a liquid crystal-based metamaterial provides the analogy. It is shown that ray and wave optics in the metamaterial mimic, respectively, the classical trajectories and wave function propagation, of the Milne probes, leading to the exciting perspective of realizing experimental tests of particle tunneling through the cosmic singularity, for instance.

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.

Testing the Big Bang: Light elements, neutrinos, dark matter and large-scale structure

NASA Technical Reports Server (NTRS)

Schramm, David N.

1991-01-01

Several experimental and observational tests of the standard cosmological model are examined. In particular, a detailed discussion is presented regarding: (1) nucleosynthesis, the light element abundances, and neutrino counting; (2) the dark matter problems; and (3) the formation of galaxies and large-scale structure. Comments are made on the possible implications of the recent solar neutrino experimental results for cosmology. An appendix briefly discusses the 17 keV thing and the cosmological and astrophysical constraints on it.

Axino dark matter and baryon number asymmetry production by the Q-ball decay in gauge mediation

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

Kasuya, Shinta; Kawakami, Etsuko; Kawasaki, Masahiro, E-mail: kasuya@kanagawa-u.ac.jp, E-mail: kwkm@icrr.u-tokyo.ac.jp, E-mail: kawasaki@icrr.u-tokyo.ac.jp

2016-03-01

We investigate the Q-ball decay into the axino dark matter in the gauge-mediated supersymmetry breaking. In our scenario, the Q ball decays mainly into nucleons and partially into axinos to account respectively for the baryon asymmetry and the dark matter of the universe. The Q ball decays well before the big bang nucleosynthesis so that it is not affected by the decay. We show the region of the parameters which realizes this scenario.

Astronomers gossip about the (cosmic) neighborhood.

PubMed

Jayawardhana, R

1994-09-09

The Hague, Netherlands, last month welcomed 2000 astronomers from around the world for the 22nd General Assembly of the International Astronomical Union (IAU). From 15 to 27 August, they participated in symposia and discussions on topics ranging from the down-to-Earth issue of light and radio-frequency pollution to the creation of elements at the farthest reaches of time and space, in the big bang. Some of the most striking news, however, came in new findings from our galaxy and its immediate surroundings.

The Big Bang, Superstring Theory and the origin of life on the Earth.

PubMed

Trevors, J T

2006-03-01

This article examines the origin of life on Earth and its connection to the Superstring Theory, that attempts to explain all phenomena in the universe (Theory of Everything) and unify the four known forces and relativity and quantum theory. The four forces of gravity, electro-magnetism, strong and weak nuclear were all present and necessary for the origin of life on the Earth. It was the separation of the unified force into four singular forces that allowed the origin of life.

Dark matter and the baryon asymmetry of the universe.

PubMed

Farrar, Glennys R; Zaharijas, Gabrijela

2006-02-03

We present a mechanism to generate the baryon asymmetry of the Universe which preserves the net baryon number created in the big bang. If dark matter particles carry baryon number Bx, and sigmaxannih

Observable tensor-to-scalar ratio and secondary gravitational wave background

NASA Astrophysics Data System (ADS)

Chatterjee, Arindam; Mazumdar, Anupam

2018-03-01

In this paper we will highlight how a simple vacuum energy dominated inflection-point inflation can match the current data from cosmic microwave background radiation, and predict large primordial tensor to scalar ratio, r ˜O (10-3-10-2), with observable second order gravitational wave background, which can be potentially detectable from future experiments, such as DECi-hertz Interferometer Gravitational wave Observatory (DECIGO), Laser Interferometer Space Antenna (eLISA), cosmic explorer (CE), and big bang observatory (BBO).

The ring of life hypothesis for eukaryote origins is supported by multiple kinds of data

PubMed Central

McInerney, James; Pisani, Davide; O'Connell, Mary J.

2015-01-01

The literature is replete with manuscripts describing the origin of eukaryotic cells. Most of the models for eukaryogenesis are either autogenous (sometimes called slow-drip), or symbiogenic (sometimes called big-bang). In this article, we use large and diverse suites of ‘Omics' and other data to make the inference that autogeneous hypotheses are a very poor fit to the data and the origin of eukaryotic cells occurred in a single symbiosis. PMID:26323755

White House Science Fair

NASA Image and Video Library

2013-04-22

Director of Strategic Communications and Senior Science and Technology Policy Analyst, Office of Science and Technology Policy, Executive Office of the President, Rick Weiss, left, “Big Bang Theory” co-creator Bill Prady, center, and NASA Mars Curiosity Landing mission controller, Bobak "Mohawk Guy" Ferdowsi talk during the White House Science Fair held at the White House, April 22, 2013. The science fair celebrated student winners of a broad range of science, technology, engineering and math (STEM) competitions from across the country. Photo Credit: (NASA/Bill Ingalls)

Gamma-ray Background Spectrum and Annihilation Rate in the Baryon-symmetric Big-bang Cosmology

NASA Technical Reports Server (NTRS)

Puget, J. L.

1973-01-01

An attempt was made to acquire experimental information on the problem of baryon symmetry on a large cosmological scale by observing the annihilation products. Data cover absorption cross sections and background radiation due to other sources for the two main products of annihilation, gamma rays and neutrinos. Test results show that the best direct experimental test for the presence of large scale antimatter lies in the gamma ray background spectrum between 1 and 70 MeV.

Fire, Aim… Ready? Alberta's Big Bang Approach to Healthcare Disintegration.

PubMed

Donaldson, Cam

2010-08-01

Alberta's abolition in 2008 of its health regions and the creation of Alberta Health Services (AHS) was a bold move, but the reasons for the change remain hazy. The stated goals were to "help make Alberta's … system more effective and efficient" and to "provide equitable access to health services and long-term sustainability." Data show, however, that Alberta's health regions were already performing well on these goals relative to other provinces, and where changes have since occurred, they cannot necessarily be attributed to AHS.

USA Science and Engineering Festival 2014

NASA Image and Video Library

2014-04-25

An attendee of the USA Science and Engineering Festival examines how glass blocks some heat, altering the infrared image of himself. The James Webb Space Telescope will be a large infrared telescope with a 6.5 meter primary mirror and will study every phase in the history of our Universe ranging from the Big Bang to the formation of our Solar System. The USA Science and Engineering Festival took place at the Washington Convention Center in Washington, DC on April 26 and 27, 2014. Photo Credit: (NASA/Aubrey Gemignani)

USA Science and Engineering Festival 2014

NASA Image and Video Library

2014-04-25

Attendees of the USA Science and Engineering Festival observe their infrared images as a NASA Staff member describes the James Webb Space Telescope. It will be a large infrared telescope with a 6.5 meter primary mirror and will study every phase in the history of our Universe ranging from the Big Bang to the formation of our Solar System. The USA Science and Engineering Festival took place at the Washington Convention Center in Washington, DC on April 26 and 27, 2014. Photo Credit: (NASA/Aubrey Gemignani)

Expanding protein universe and its origin from the biological Big Bang.

PubMed

Dokholyan, Nikolay V; Shakhnovich, Boris; Shakhnovich, Eugene I

2002-10-29

The bottom-up approach to understanding the evolution of organisms is by studying molecular evolution. With the large number of protein structures identified in the past decades, we have discovered peculiar patterns that nature imprints on protein structural space in the course of evolution. In particular, we have discovered that the universe of protein structures is organized hierarchically into a scale-free network. By understanding the cause of these patterns, we attempt to glance at the very origin of life.

Large-scale anisotropy in the extragalactic gamma-ray background as a probe for cosmological antimatter

NASA Technical Reports Server (NTRS)

Gao, Yi-Tian; Stecker, Floyd W.; Gleiser, Marcelo; Cline, David B.

1990-01-01

Intrinsic anisotropies in the extragalactic gamma-ray background (EGB), which should be detectable with the forthcoming Gamma Ray Observatory, can be used to examine some of the mechanisms proposed to explain its origin, one of which, the baryon-symmetric big bang (BSBB) model, is investigated here. In this simulation, large domains containing matter and antimatter galaxies produce gamma rays by annihilation at the domain boundaries. This mechanism can produce mountain-chain-shaped angular fluctuations in the EGB flux.

Searching for Baryon Acoustic Oscillations in Intergalactic Absorption: The Expanding Universe

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

None

This simulation follows the growth of density perturbations in both gas and dark matter components in a volume 1 billion light years on a side beginning shortly after the Big Bang and evolved to half the present age of the universe. Credits: Science: Michael L. Norman, Robert Harkness, Pascal Paschos, Rick Wagner, San Diego Supercomputer Center/University of California, San Diego Visualization: Mark Hereld, Joseph A. Insley, Michael E. Papka, Argonne National Laboratory; Eric C. Olson, University of Chicago

Beyond Einstein: Exploring the Extreme Universe

NASA Technical Reports Server (NTRS)

Barbier, Louis M.

2005-01-01

This paper will give an overview of the NASA Universe Division Beyond Einstein program. The Beyond Einstein program consists of a series of exploratory missions to investigate some of the most important and pressing problems in modern-day astrophysics - including searches for Dark Energy and studies of the earliest times in the universe, during the inflationary period after the Big Bang. A variety of new technologies are being developed both in the science instrumentation these missions will carry and in the spacecraft that will carry those instruments.

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.

Long Fuse, Big Bang: Thomas Edison, Electricity, and the Locus of Innovation

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

Hargadon, Andrew

2012-10-22

Calls for breakthroughs in science and technology have never been louder, and yet the demand for innovation is made more challenging by public and political misconceptions surrounding where, when, and how it happens. Professor Andrew Hargadon uses historical research to advance our current understanding of the innovation process. He discussed the social and technical context in which electric light, and the modern electric power infrastructure, were born and considers its implications for managing innovation in science and technology today.

Does Cosmological Scale Expansion Explain the Universe?

NASA Astrophysics Data System (ADS)

Masreliez, C. J.

2009-12-01

The idea of the creation of the world has been central in Western civilization since the earliest recorded history some 6000 years ago and it still prevails, supported by religious dogma. If the creation idea is wrong and the universe is eternal we might wonder why science has not yet revealed this fundamental truth. To understand why, we have to review how the Big Bang theory came to be the dominant cosmological paradigm in spite of many clear indications that the theory might be fundamentally flawed.

PredicT-ML: a tool for automating machine learning model building with big clinical data.

PubMed

Luo, Gang

2016-01-01

Predictive modeling is fundamental to transforming large clinical data sets, or "big clinical data," into actionable knowledge for various healthcare applications. Machine learning is a major predictive modeling approach, but two barriers make its use in healthcare challenging. First, a machine learning tool user must choose an algorithm and assign one or more model parameters called hyper-parameters before model training. The algorithm and hyper-parameter values used typically impact model accuracy by over 40 %, but their selection requires many labor-intensive manual iterations that can be difficult even for computer scientists. Second, many clinical attributes are repeatedly recorded over time, requiring temporal aggregation before predictive modeling can be performed. Many labor-intensive manual iterations are required to identify a good pair of aggregation period and operator for each clinical attribute. Both barriers result in time and human resource bottlenecks, and preclude healthcare administrators and researchers from asking a series of what-if questions when probing opportunities to use predictive models to improve outcomes and reduce costs. This paper describes our design of and vision for PredicT-ML (prediction tool using machine learning), a software system that aims to overcome these barriers and automate machine learning model building with big clinical data. The paper presents the detailed design of PredicT-ML. PredicT-ML will open the use of big clinical data to thousands of healthcare administrators and researchers and increase the ability to advance clinical research and improve healthcare.

Automating Construction of Machine Learning Models With Clinical Big Data: Proposal Rationale and Methods

PubMed Central

Stone, Bryan L; Johnson, Michael D; Tarczy-Hornoch, Peter; Wilcox, Adam B; Mooney, Sean D; Sheng, Xiaoming; Haug, Peter J; Nkoy, Flory L

2017-01-01

Background To improve health outcomes and cut health care costs, we often need to conduct prediction/classification using large clinical datasets (aka, clinical big data), for example, to identify high-risk patients for preventive interventions. Machine learning has been proposed as a key technology for doing this. Machine learning has won most data science competitions and could support many clinical activities, yet only 15% of hospitals use it for even limited purposes. Despite familiarity with data, health care researchers often lack machine learning expertise to directly use clinical big data, creating a hurdle in realizing value from their data. Health care researchers can work with data scientists with deep machine learning knowledge, but it takes time and effort for both parties to communicate effectively. Facing a shortage in the United States of data scientists and hiring competition from companies with deep pockets, health care systems have difficulty recruiting data scientists. Building and generalizing a machine learning model often requires hundreds to thousands of manual iterations by data scientists to select the following: (1) hyper-parameter values and complex algorithms that greatly affect model accuracy and (2) operators and periods for temporally aggregating clinical attributes (eg, whether a patient’s weight kept rising in the past year). This process becomes infeasible with limited budgets. Objective This study’s goal is to enable health care researchers to directly use clinical big data, make machine learning feasible with limited budgets and data scientist resources, and realize value from data. Methods This study will allow us to achieve the following: (1) finish developing the new software, Automated Machine Learning (Auto-ML), to automate model selection for machine learning with clinical big data and validate Auto-ML on seven benchmark modeling problems of clinical importance; (2) apply Auto-ML and novel methodology to two new modeling problems crucial for care management allocation and pilot one model with care managers; and (3) perform simulations to estimate the impact of adopting Auto-ML on US patient outcomes. Results We are currently writing Auto-ML’s design document. We intend to finish our study by around the year 2022. Conclusions Auto-ML will generalize to various clinical prediction/classification problems. With minimal help from data scientists, health care researchers can use Auto-ML to quickly build high-quality models. This will boost wider use of machine learning in health care and improve patient outcomes. PMID:28851678

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

The QuEST for multi-sensor big data ISR situation understanding

NASA Astrophysics Data System (ADS)

Rogers, Steven; Culbertson, Jared; Oxley, Mark; Clouse, H. Scott; Abayowa, Bernard; Patrick, James; Blasch, Erik; Trumpfheller, John

2016-05-01

The challenges for providing war fighters with the best possible actionable information from diverse sensing modalities using advances in big-data and machine learning are addressed in this paper. We start by presenting intelligence, surveillance, and reconnaissance (ISR) related big-data challenges associated with the Third Offset Strategy. Current approaches to big-data are shown to be limited with respect to reasoning/understanding. We present a discussion of what meaning making and understanding require. We posit that for human-machine collaborative solutions to address the requirements for the strategy a new approach, Qualia Exploitation of Sensor Technology (QuEST), will be required. The requirements for developing a QuEST theory of knowledge are discussed and finally, an engineering approach for achieving situation understanding is presented.

Book Review:

NASA Astrophysics Data System (ADS)

Barbour, J. B.

2007-02-01

These colloquium proceedings will be valuable, the blurb says, for graduate students and researchers in cosmology and theoretical astrophysics. Specifically, the book 'looks at both the strengths and weaknesses of the current big bang model in explaining certain puzzling data' and gives a 'comprehensive coverage of the expanding field of cosmology'. The reality is rather different. Conference proceedings rarely compare in value with a solid monograph or good review articles, and Current Issues in Cosmology is no exception. The colloquium was convened by the two editors, who have both long harboured doubts about the big bang, and was held in Paris in June 2004. The proceedings contain 19 presented papers and relatively brief summary comments by four panel speakers. The questions and answers at the end of each talk and a general discussion at the end were recorded and transcribed but contain little of interest. The nature of the colloquium is indicated by panellist Francesco Bertola's comment: 'While in the 1950s it was possible to speak of rival theories in cosmology, now the big-bang picture has no strong rivals. This is confirmed by the fact that out of 1500 members of the IAU Division VIII (Galaxies and the Universe) only a dozen, although bright people, devote their time to the heterodox views.' This was largely a platform for them to give their views. At least half of the dozen, all the 'usual suspects', were present: Geoffery and Margaret Burbidge, Jayant Narlikar, Halton Arp, Chandra Wickramasinghe and, in spirit only but playing a role somewhat like the ghost of Hamlet's father, the late Fred Hoyle. Doubters presented 12 of the 19 papers. Orthodoxy should certainly be challenged and the sociology of science questioned, but I found two main problems with this book. The papers putting the orthodox view are too short, even perfunctory. The most that a serious graduate student would get out of them is a reference to a far better review article or book on modern cosmology. The doubters' case is threadbare at best, as Alain Blanchard put it rather more politely in his panel contribution. The Burbidges and Halton Arp reiterate the difficulties that these eminent scientists have long had in reconciling certain observations with the standard model. Most workers in the field are aware of their views and find they lack substance, especially Arp's worries about some close coincidences between the observed positions of low-redshift galaxies and high-redshift quasars. Virtually everyone believes that they have no statistical significance. Arp's belief that some quasars have non-cosmological redshifts and are being spewed out of nearby exploding galactic centres raises eyebrows. For me the most worthwhile of the 'rebel' papers is Narlikar's. Its first half is a thought-provoking survey of the many modifications through which the big-bang model has passed. He calls them additions of epicycles and in some cases I think he has a point. But his rival theory seems very far fetched and makes my point about Hamlet's ghost. The steady-state theory just will not die: in 1994, Hoyle, G. Burbidge, and Narlikar published the quasi-steady-state theory (The Astrophysical Journal 410 437) in which the universe expands, not perfectly steadily but 'in mini-creation events at regular intervals and in response the universe oscillates on a short-term period of about 50 Gyr while it also has a steady (exponential) long-term expansion at a characteristic time scale of about 1000 Gyr.' I won't go into details, but this looks like a whopping epicycle on the steady-state model! Wickramasinghe's paper is on iron whiskers, which have now taken over from standard dust as the agents that must transform starlight into the microwave background. In my view the two best papers in the volume are those of the panellists Alain Blanchard (in favour of the standard model though he has difficulties with X-ray clusters) and the observer Michael Disney, who expresses radical doubts about the concordance model and cites a paper of his (astro-ph/0009020) that is entertaining and hard hitting. But is it worth buying 278 pages for the sake of at most 20? I welcomed the opportunity to review this book since I have stuck my neck out even further than Narlikar and Disney, and this journal has even published an article by me in which I question whether the universe is actually expanding (Classical and Quantum Gravity 20 1571). I wanted to see if there were any chinks in the armour of the standard model. I have to say that having read this book, three modern books on cosmology and attended the recent Cosmic Frontiers conference in Durham (UK), I have to agree with Blanchard when he says: 'When I try to find what the weaknesses of the standard big bang are, I get rather more convinced of its robustness!' However, I was glad to see that he does not regard inflation as part of the model, and I do think Disney is right to be sceptical about exaggerated claims for the specific concordance model (rather than the basic big-bang idea). However, what I find immensely impressive is how the one simple idea of the expanding universe has proved so fruitful and successful.

[Algorithms, machine intelligence, big data : general considerations].

PubMed

Radermacher, F J

2015-08-01

We are experiencing astonishing developments in the areas of big data and artificial intelligence. They follow a pattern that we have now been observing for decades: according to Moore's Law,the performance and efficiency in the area of elementary arithmetic operations increases a thousand-fold every 20 years. Although we have not achieved the status where in the singular sense machines have become as "intelligent" as people, machines are becoming increasingly better. The Internet of Things has again helped to massively increase the efficiency of machines. Big data and suitable analytics do the same. If we let these processes simply continue, our civilization may be endangerd in many instances. If the "containment" of these processes succeeds in the context of a reasonable political global governance, a worldwide eco-social market economy, andan economy of green and inclusive markets, many desirable developments that are advantageous for our future may result. Then, at some point in time, the constant need for more and faster innovation may even stop. However, this is anything but certain. We are facing huge challenges.

Direct measurement of nuclear cross-section of astrophysical interest: Results and perspectives

NASA Astrophysics Data System (ADS)

Cavanna, Francesca; Prati, Paolo

2018-03-01

Stellar evolution and nucleosynthesis are interconnected by a wide network of nuclear reactions: the study of such connection is usually known as nuclear astrophysics. The main task of this discipline is the determination of nuclear cross-section and hence of the reaction rate in different scenarios, i.e. from the synthesis of a few very light isotopes just after the Big Bang to the heavy element production in the violent explosive end of massive stars. The experimental determination of reaction cross-section at the astrophysical relevant energies is extremely difficult, sometime impossible, due to the Coulomb repulsion between the interacting nuclei which turns out in cross-section values down to the fbar level. To overcome these obstacles, several experimental approaches have been developed and the adopted techniques can be roughly divided into two categories, i.e. direct and indirect methods. In this review paper, the general problem of nuclear astrophysics is introduced and discussed from the point of view of experimental approach. We focus on direct methods and in particular on the features of low-background experiments performed at underground laboratory facilities. The present knowledge of reactions involved in the Big Bang and stellar hydrogen-burning scenarios is discussed as well as the ongoing projects aiming to investigate mainly the helium- and carbon-burning phases. Worldwide, a new generation of experiment in the MeV range is in the design phase or at the very first steps and decisive progresses are expected to come in the next years.

New reaction rates for improved primordial D /H calculation and the cosmic evolution of deuterium

NASA Astrophysics Data System (ADS)

Coc, Alain; Petitjean, Patrick; Uzan, Jean-Philippe; Vangioni, Elisabeth; Descouvemont, Pierre; Iliadis, Christian; Longland, Richard

2015-12-01

Primordial or big bang nucleosynthesis (BBN) is one of the three historically strong evidences for the big bang model. Standard BBN is now a parameter-free theory, since the baryonic density of the Universe has been deduced with an unprecedented precision from observations of the anisotropies of the cosmic microwave background radiation. There is a good agreement between the primordial abundances of 4He, D, 3He, and 7Li deduced from observations and from primordial nucleosynthesis calculations. However, the 7Li calculated abundance is significantly higher than the one deduced from spectroscopic observations and remains an open problem. In addition, recent deuterium observations have drastically reduced the uncertainty on D /H , to reach a value of 1.6%. It needs to be matched by BBN predictions whose precision is now limited by thermonuclear reaction rate uncertainties. This is especially important as many attempts to reconcile Li observations with models lead to an increased D prediction. Here, we reevaluate the d (p ,γ )3He, d (d ,n ) 3H3, and d (d ,p ) 3H reaction rates that govern deuterium destruction, incorporating new experimental data and carefully accounting for systematic uncertainties. Contrary to previous evaluations, we use theoretical ab initio models for the energy dependence of the S factors. As a result, these rates increase at BBN temperatures, leading to a reduced value of D /H =(2.45 ±0.10 )×10-5 (2 σ ), in agreement with observations.

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

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

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

The Hottest, and Most Liquid, Liquid in the Universe

NASA Astrophysics Data System (ADS)

Rajagopal, Krishna

2012-03-01

What was the universe like microseconds after the big bang? At very high temperatures, protons and neutrons fall apart --- the quarks that are ordinarily confined within them are freed. Before experiments at the Relativistic Heavy Ion Collider started recreating little droplets of big bang matter, it was thought to be a tenuous gas-like plasma. Now we know from experiments at RHIC and at the Large Hadron Collider that at these extreme temperatures nature serves up hot quark soup --- the hottest liquid in the universe and the liquid that flows with the least dissipation. The only other comparably liquid liquid is the coldest liquid in the universe, namely the fluid made of trapped fermionic atoms at microKelvin rather than TeraKelvin temperatures. These are two examples of strongly coupled fluids without any apparent quasiparticle description, a feature that they share with other phases of matter like the strange metal phase of the cuprate superconductors that aren't conventionally thought of as liquids but that are equally challenging to understand. I will describe how physicists are using RHIC and LHC experiments --- as well as calculations done using dualities between liquids and black holes discovered in string theory --- to discern the properties of hot quark soup. In this domain, string theory is answering questions posed by laboratory experiments. I will describe the opportunities and challenges for coming experiments at RHIC and the LHC, chief among them being understanding how a liquid with no apparent particulate description emerges from quarks and gluons.

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.

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.