Expanding Or Static Universe: Emergence of a New Paradigm
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Is the Universe Expanding?: an Historical and Philosophical Perspective for Cosmologists Starting Anew
Western Michigan University ScholarWorks at WMU Master's Theses Graduate College 6-1996 Is the Universe Expanding?: An Historical and Philosophical Perspective for Cosmologists Starting Anew David A. Vlosak Follow this and additional works at: https://scholarworks.wmich.edu/masters_theses Part of the Cosmology, Relativity, and Gravity Commons Recommended Citation Vlosak, David A., "Is the Universe Expanding?: An Historical and Philosophical Perspective for Cosmologists Starting Anew" (1996). Master's Theses. 3474. https://scholarworks.wmich.edu/masters_theses/3474 This Masters Thesis-Open Access is brought to you for free and open access by the Graduate College at ScholarWorks at WMU. It has been accepted for inclusion in Master's Theses by an authorized administrator of ScholarWorks at WMU. For more information, please contact [email protected]. IS THEUN IVERSE EXPANDING?: AN HISTORICAL AND PHILOSOPHICAL PERSPECTIVE FOR COSMOLOGISTS STAR TING ANEW by David A Vlasak A Thesis Submitted to the Faculty of The Graduate College in partial fulfillment of the requirements forthe Degree of Master of Arts Department of Philosophy Western Michigan University Kalamazoo, Michigan June 1996 IS THE UNIVERSE EXPANDING?: AN HISTORICAL AND PHILOSOPHICAL PERSPECTIVE FOR COSMOLOGISTS STARTING ANEW David A Vlasak, M.A. Western Michigan University, 1996 This study addresses the problem of how scientists ought to go about resolving the current crisis in big bang cosmology. Although this problem can be addressed by scientists themselves at the level of their own practice, this study addresses it at the meta level by using the resources offered by philosophy of science. There are two ways to resolve the current crisis. -
Olbers' Paradox
Astro 101 Fall 2013 Lecture 12 Cosmology T. Howard Cosmology = study of the Universe as a whole • ? What is it like overall? • ? What is its history? How old is it? • ? What is its future? • ? How do we find these things out from what we can observe? • In 1996, researchers at the Space Telescope Science Institute used the Hubble to make a very long exposure of a patch of seemingly empty sky. Q: What did they find? A: Galaxies “as far as The eye can see …” (nearly everything in this photo is a galaxy!) 40 hour exposure What do we know already (about the Universe) ? • Galaxies in groups; clusters; superclusters • Nearby universe has “filament” and void type of structure • More distant objects are receding from us (light is redshifted) • Hubble’s Law: V = H0 x D (Hubble's Law) Structure in the Universe What is the largest kind of structure in the universe? The ~100-Mpc filaments, shells and voids? On larger scales, things look more uniform. 600 Mpc Olbers’ Paradox • Assume the universe is homogeneous, isotropic, infinte, and static • Then: Why don’t we see light everywhere? Why is the night sky (mostly) dark? Olbers’ Paradox (cont’d.) • We believe the universe is homogeneous and isotropic • So, either it isn’t infinite OR it isn’t static • “Big Bang” theory – universe started expanding a finite time ago Given what we know of structure in the universe, assume: The Cosmological Principle On the largest scales, the universe is roughly homogeneous (same at all places) and isotropic (same in all directions). Laws of physics are everywhere the same. -
Friedmann Equation (1.39) for a Radiation Dominated Universe Will Thus Be (From Ada ∝ Dt)
Lecture 2 The quest for the origin of the elements The quest for the origins of the elements, C. Bertulani, RISP, 2016 1 Reading2.1 - material Geometry of the Universe 2-dimensional analogy: Surface of a sphere. The surface is finite, but has no edge. For a creature living on the sphere, having no sense of the third dimension, there is no center (on the sphere). All points are equal. Any point on the surface can be defined as the center of a coordinate system. But, how can a 2-D creature investigate the geometry of the sphere? Answer: Measure curvature of its space. Flat surface (zero curvature, k = 0) Closed surface Open surface (posiDve curvature, k = 1) (negave curvature, k = -1) The quest for the origins of the elements, C. Bertulani, RISP, 2016 2 ReadingGeometry material of the Universe These are the three possible geometries of the Universe: closed, open and flat, corresponding to a density parameter Ωm = ρ/ρcrit which is greater than, less than or equal to 1. The relation to the curvature parameter is given by Eq. (1.58). The closed universe is of finite size. Traveling far enough in one direction will lead back to one's starting point. The open and flat universes are infinite and traveling in a constant direction will never lead to the same point. The quest for the origins of the elements, C. Bertulani, RISP, 2016 3 2.2 - Static Universe 2 2 The static Universe requires a = a0 = constant and thus d a/dt = da/dt = 0. From Eq. -
Possible Matter and Background Connection
Do Cosmic Backgrounds Cyclical Renew by Matter and Quanta Emissions? The Origin of Backgrounds, Space Distributions and Cyclical Earth Phenomena by Two Phase Dynamics Eduardo del Pozo Garcia Institute of Geophysics and Astronomy, Havana, Cuba, [email protected], [email protected], [email protected] August 2018 Abstract: A numerical coincidence p=-0.000489 was found between the ratios of proton emission at 459-keV and cosmic background at 0.25-keV respect to proton and to electron proper energy respectively. Multiplying 459-keV and 0.25-keV by p, two more numerical coincidences were found with 0.1-keV background and 0.06-eV of relic neutrino energy, respectively. Global criticality phenomena plus “c” and “G” discontinued decreasing provoke small cyclical reorganization of particles and quanta originating background emissions every 30-Myr are propose. At the beginning of each cycle, gradually emissions from electrons lasting 0.1 Myr originate the 0.25-keV background and, a possible 459-keV background from proton emissions. At following cycle, the 459-keV quanta makes two emissions of 0.1-keV originating a diffuse background, and 0.25-keV quanta makes two of 0.06-eV originating the relic neutrinos. The p is a possible physical constant that characterize the threshold, which trigger cyclical phenomena at space and Earth every 30-Myr. This hypothesis explains: The about 30 Myr cyclic phenomena observed in tectonic, Mass Extinction, crater impact rate, and some features of space global distribution: quantized redshift, change of galaxy fractal distribution at 10 Mpc scale, galaxy average luminosity and the luminosity fluctuation of galaxy pairs are enhanced out to separations near 10 Mpc. -
The High Redshift Universe: Galaxies and the Intergalactic Medium
The High Redshift Universe: Galaxies and the Intergalactic Medium Koki Kakiichi M¨unchen2016 The High Redshift Universe: Galaxies and the Intergalactic Medium Koki Kakiichi Dissertation an der Fakult¨atf¨urPhysik der Ludwig{Maximilians{Universit¨at M¨unchen vorgelegt von Koki Kakiichi aus Komono, Mie, Japan M¨unchen, den 15 Juni 2016 Erstgutachter: Prof. Dr. Simon White Zweitgutachter: Prof. Dr. Jochen Weller Tag der m¨undlichen Pr¨ufung:Juli 2016 Contents Summary xiii 1 Extragalactic Astrophysics and Cosmology 1 1.1 Prologue . 1 1.2 Briefly Story about Reionization . 3 1.3 Foundation of Observational Cosmology . 3 1.4 Hierarchical Structure Formation . 5 1.5 Cosmological probes . 8 1.5.1 H0 measurement and the extragalactic distance scale . 8 1.5.2 Cosmic Microwave Background (CMB) . 10 1.5.3 Large-Scale Structure: galaxy surveys and Lyα forests . 11 1.6 Astrophysics of Galaxies and the IGM . 13 1.6.1 Physical processes in galaxies . 14 1.6.2 Physical processes in the IGM . 17 1.6.3 Radiation Hydrodynamics of Galaxies and the IGM . 20 1.7 Bridging theory and observations . 23 1.8 Observations of the High-Redshift Universe . 23 1.8.1 General demographics of galaxies . 23 1.8.2 Lyman-break galaxies, Lyα emitters, Lyα emitting galaxies . 26 1.8.3 Luminosity functions of LBGs and LAEs . 26 1.8.4 Lyα emission and absorption in LBGs: the physical state of high-z star forming galaxies . 27 1.8.5 Clustering properties of LBGs and LAEs: host dark matter haloes and galaxy environment . 30 1.8.6 Circum-/intergalactic gas environment of LBGs and LAEs . -
Is the Universe Really Expanding?
Is the Universe really expanding? J.G. Hartnett School of Physics, the University of Western Australia 35 Stirling Hwy, Crawley 6009 WA Australia; [email protected] (Dated: November 22, 2011) The Hubble law, determined from the distance modulii and redshifts of galaxies, for the past 80 years, has been used as strong evidence for an expanding universe. This claim is reviewed in light of the claimed lack of necessary evidence for time dilation in quasar and gamma-ray burst luminosity variations and other lines of evidence. It is concluded that the observations could be used to describe either a static universe (where the Hubble law results from some as-yet-unknown mechanism) or an expanding universe described by the standard Λ cold dark matter model. In the latter case, size evolution of galaxies is necessary for agreement with observations. Yet the simple non-expanding Euclidean universe fits most data with the least number of assumptions. From this review it is apparent that there are still many unanswered questions in cosmology and the title question of this paper is still far from being answered. Keywords: expanding universe, static universe, time dilation I. INTRODUCTION eral relativity, which has been successfully empirically tested in the solar system by numerous tests [74], and with pulsar/neutron star and pulsar/pulsar binary pairs Ever since the late 1920’s, when Edwin Hubble discov- [16, 45, 62] in the Galaxy, is a very strong point in its fa- ered a simple proportionality [40] between the redshifts vor, and strong evidence for an expanding universe [69]. -
Einstein's Role in the Creation of Relativistic Cosmology
EINSTEIN'S ROLE IN THE CREATION OF RELATIVISTIC COSMOLOGY CHRISTOPHER SMEENK 1. Introduction Einstein's paper, \Cosmological Considerations in the General Theory of Relativ- ity" (Einstein 1917b), is rightly regarded as the first step in modern theoretical cosmology. Perhaps the most striking novelty introduced by Einstein was the very idea of a cosmological model, an exact solution to his new gravitational field equations that gives a global description of the universe in its entirety. Einstein's paper inspired a small group of theorists to study cosmological models using his new gravitational theory, and the ideas developed during these early days have been a crucial part of cosmology ever since. We will see below that understanding the physical properties of these models and their possible connections to astro- nomical observations was the central problem facing relativistic cosmology in the 20s. By the early 30s, there was widespread consensus that a class of models de- scribing the expanding universe was in at least rough agreement with astronomical observations. But this achievement was certainly not what Einstein had in mind in introducing the first cosmological model. Einstein's seminal paper was not simply a straightforward application of his new theory to an area where one would ex- pect the greatest differences from Newtonian theory. Instead, Einstein's foray into cosmology was a final attempt to guarantee that a version of \Mach's principle" holds. The Machian idea that inertia is due only to matter shaped Einstein's work on a new theory of gravity, but he soon realized that this might not hold in his “final” theory of November 1915. -
Appendix a the Return of a Static Universe and the End of Cosmology
Appendix A The Return of a Static Universe and the End of Cosmology Lawrence M. Krauss and Robert J. Scherrer Abstract We demonstrate that as we extrapolate the current CDM universe forward in time, all evidence of the Hubble expansion will disappear, so that observers in our “island universe” will be fundamentally incapable of determining the true nature of the universe, including the existence of the highly dominant vacuum energy, the existence of the CMB, and the primordial origin of light elements. With these pillars of the modern Big Bang gone, this epoch will mark the end of cosmology and the return of a static universe. In this sense, the coordinate system appropriate for future observers will perhaps fittingly resemble the static coordinate system in which the de Sitter universe was first presented. Shortly after Einstein’s development of general relativity, the Dutch astronomer Willem de Sitter proposed a static model of the universe containing no matter, which he thought might be a reasonable approximation to our low-density uni- verse. One can define a coordinate system in which the de Sitter metric takes a static form by defining de Sitter spacetime with a cosmological constant ƒ S W A B D 2 2 D 1 as a four-dimensional hyperboloid ƒ AB R ;R 3ƒ em- 2 D A B D bedded in a 5d Minkowski spacetime with ds AB d d ; and .AB / diag.1; 1; 1; 1; 1/;A;B D 0;:::;4: The static form of the de Sitter metric is then dr2 ds2 D .1 r2=R2/dt 2 s r2d2; s s s 2 2 s 1 rs =R L.M. -
The Nature of the Redshift
The Nature of the Redshift William G. Tifft Professor Emeritus, Retired Steward Observatory, University of Arizona Abstract This paper presents an illustrated introduction to an alternate cosmology, Quantum Tem- poral Cosmology (QTC), an updated review based upon extensive observational data con- cerning the nature of the redshift and the structure of time. 1 Introduction This is a modified version of a paper (Tifft 2013) presented at the "Origins of the Expanding Universe: 1912-1932" Conference in September 2012 held in honor of V. M. Slipher, the first person to measure redshifts of external galaxies in 1912 at Lowell Observatory. The redshift itself was not (and probably could not have been), carefully tested to see if it was consistent with the concept of a dynamical expansion of space much before I began a study in 1970. In the meantime, the concept of expanding dynamical spatial cosmologies was widely accepted. Subsequent study was dedicated to defining the character of spatial expansion and rarely to questioning the nature of the redshift itself. Many problems have emerged including dark matter and dark energy, which can be addressed in an alternate cosmology. My dissertation at Caltech and continued studies at Lowell Observatory in 1963-1964 in- volving photometry as a function of radius indicated that some galaxies had abnormally blue or red nuclei (Tifft 1963, 1969). This was early evidence of active nuclear studies to come. A 1970 paper reported unexpected possible correlations of nuclear photometry with redshifts of Virgo Cluster galaxies (Tifft 1972a). The concept that there could be any re- lationship between an intrinsic property of galaxies (nuclear photometry) and an extrinsic property (redshift) was clearly inconsistent with classical views, but ultimately led to a new approach to cosmology. -
Common Misconceptions of Cosmological Horizons and the Superluminal Expansion of the Universe
CSIRO PUBLISHING www.publish.csiro.au/journals/pasa Publications of the Astronomical Society of Australia, 2004, 21, 97–109 Expanding Confusion: Common Misconceptions of Cosmological Horizons and the Superluminal Expansion of the Universe Tamara M. Davis and Charles H. Lineweaver University of New South Wales, Sydney NSW 2052, Australia (e-mail: [email protected]; [email protected]) Received 2003 June 3, accepted 2003 October 10 Abstract: We use standard general relativity to illustrate and clarify several common misconceptions about the expansion of the universe. To show the abundance of these misconceptions we cite numerous misleading, or easily misinterpreted, statements in the literature. In the context of the new standard CDM cosmology we point out confusions regarding the particle horizon, the event horizon, the ‘observable universe’ and the Hubble sphere (distance at which recession velocity = c). We show that we can observe galaxies that have, and always have had, recession velocities greater than the speed of light. We explain why this does not violate special relativity and we link these concepts to observational tests. Attempts to restrict recession velocities to less than the speed of light require a special relativistic interpretation of cosmological redshifts. We analyze apparent magnitudes of supernovae and observationally rule out the special relativistic Doppler interpretation of cosmological redshifts at a confidence level of 23σ. Keywords: cosmology: observations — cosmology: theory 1 Introduction description of the expanding universe using spacetime The general relativistic (GR) interpretation of the redshifts diagrams and we provide a mathematical summary in of distant galaxies, as the expansion of the universe, is Appendix A. -
The First Galaxies
The First Galaxies Abraham Loeb and Steven R. Furlanetto PRINCETON UNIVERSITY PRESS PRINCETON AND OXFORD To our families Contents Preface vii Chapter 1. Introduction 1 1.1 Preliminary Remarks 1 1.2 Standard Cosmological Model 3 1.3 Milestones in Cosmic Evolution 12 1.4 Most Matter is Dark 16 Chapter 2. From Recombination to the First Galaxies 21 2.1 Growth of Linear Perturbations 21 2.2 Thermal History During the Dark Ages: Compton Cooling on the CMB 24 Chapter 3. Nonlinear Structure 27 3.1 Cosmological Jeans Mass 27 3.2 Halo Properties 33 3.3 Abundance of Dark Matter Halos 36 3.4 Nonlinear Clustering: the Halo Model 41 3.5 Numerical Simulations of Structure Formation 41 Chapter 4. The Intergalactic Medium 43 4.1 The Lyman-α Forest 43 4.2 Metal-Line Systems 43 4.3 Theoretical Models 43 Chapter 5. The First Stars 45 5.1 Chemistry and Cooling of Primordial Gas 45 5.2 Formation of the First Metal-Free Stars 49 5.3 Later Generations of Stars 59 5.4 Global Parameters of High-Redshift Galaxies 59 5.5 Gamma-Ray Bursts: The Brightest Explosions 62 Chapter 6. Supermassive Black holes 65 6.1 Basic Principles of Astrophysical Black Holes 65 6.2 Accretion of Gas onto Black Holes 68 6.3 The First Black Holes and Quasars 75 6.4 Black Hole Binaries 81 Chapter 7. The Reionization of Cosmic Hydrogen by the First Galaxies 85 iv CONTENTS 7.1 Ionization Scars by the First Stars 85 7.2 Propagation of Ionization Fronts 86 7.3 Swiss Cheese Topology 92 7.4 Reionization History 95 7.5 Global Ionization History 95 7.6 Statistical Description of Size Distribution and Topology of Ionized Regions 95 7.7 Radiative Transfer 95 7.8 Recombination of Ionized Regions 95 7.9 The Sources of Reionization 95 7.10 Helium Reionization 95 Chapter 8. -
Hubble's Diagram and Cosmic Expansion
Hubble’s diagram and cosmic expansion Robert P. Kirshner* Harvard–Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 Contributed by Robert P. Kirshner, October 21, 2003 Edwin Hubble’s classic article on the expanding universe appeared in PNAS in 1929 [Hubble, E. P. (1929) Proc. Natl. Acad. Sci. USA 15, 168–173]. The chief result, that a galaxy’s distance is proportional to its redshift, is so well known and so deeply embedded into the language of astronomy through the Hubble diagram, the Hubble constant, Hubble’s Law, and the Hubble time, that the article itself is rarely referenced. Even though Hubble’s distances have a large systematic error, Hubble’s velocities come chiefly from Vesto Melvin Slipher, and the interpretation in terms of the de Sitter effect is out of the mainstream of modern cosmology, this article opened the way to investigation of the expanding, evolving, and accelerating universe that engages today’s burgeoning field of cosmology. he publication of Edwin Hub- ble’s 1929 article ‘‘A relation between distance and radial T velocity among extra-galactic nebulae’’ marked a turning point in un- derstanding the universe. In this brief report, Hubble laid out the evidence for one of the great discoveries in 20th cen- tury science: the expanding universe. Hubble showed that galaxies recede from us in all directions and more dis- tant ones recede more rapidly in pro- portion to their distance. His graph of velocity against distance (Fig. 1) is the original Hubble diagram; the equation that describes the linear fit, velocity ϭ ϫ Ho distance, is Hubble’s Law; the slope of that line is the Hubble con- ͞ stant, Ho; and 1 Ho is the Hubble time.