Chapter 18: Cosmology in This Chapter, We’Re Going to Cover Many of the Fundamental Questions in Astronomy
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Fine-Tuning, Complexity, and Life in the Multiverse*
Fine-Tuning, Complexity, and Life in the Multiverse* Mario Livio Dept. of Physics and Astronomy, University of Nevada, Las Vegas, NV 89154, USA E-mail: [email protected] and Martin J. Rees Institute of Astronomy, University of Cambridge, Cambridge CB3 0HA, UK E-mail: [email protected] Abstract The physical processes that determine the properties of our everyday world, and of the wider cosmos, are determined by some key numbers: the ‘constants’ of micro-physics and the parameters that describe the expanding universe in which we have emerged. We identify various steps in the emergence of stars, planets and life that are dependent on these fundamental numbers, and explore how these steps might have been changed — or completely prevented — if the numbers were different. We then outline some cosmological models where physical reality is vastly more extensive than the ‘universe’ that astronomers observe (perhaps even involving many ‘big bangs’) — which could perhaps encompass domains governed by different physics. Although the concept of a multiverse is still speculative, we argue that attempts to determine whether it exists constitute a genuinely scientific endeavor. If we indeed inhabit a multiverse, then we may have to accept that there can be no explanation other than anthropic reasoning for some features our world. _______________________ *Chapter for the book Consolidation of Fine Tuning 1 Introduction At their fundamental level, phenomena in our universe can be described by certain laws—the so-called “laws of nature” — and by the values of some three dozen parameters (e.g., [1]). Those parameters specify such physical quantities as the coupling constants of the weak and strong interactions in the Standard Model of particle physics, and the dark energy density, the baryon mass per photon, and the spatial curvature in cosmology. -
Cosmology Slides
Inhomogeneous cosmologies George Ellis, University of Cape Town 27th Texas Symposium on Relativistic Astrophyiscs Dallas, Texas Thursday 12th December 9h00-9h45 • The universe is inhomogeneous on all scales except the largest • This conclusion has often been resisted by theorists who have said it could not be so (e.g. walls and large scale motions) • Most of the universe is almost empty space, punctuated by very small very high density objects (e.g. solar system) • Very non-linear: / = 1030 in this room. Models in cosmology • Static: Einstein (1917), de Sitter (1917) • Spatially homogeneous and isotropic, evolving: - Friedmann (1922), Lemaitre (1927), Robertson-Walker, Tolman, Guth • Spatially homogeneous anisotropic (Bianchi/ Kantowski-Sachs) models: - Gödel, Schücking, Thorne, Misner, Collins and Hawking,Wainwright, … • Perturbed FLRW: Lifschitz, Hawking, Sachs and Wolfe, Peebles, Bardeen, Ellis and Bruni: structure formation (linear), CMB anisotropies, lensing Spherically symmetric inhomogeneous: • LTB: Lemaître, Tolman, Bondi, Silk, Krasinski, Celerier , Bolejko,…, • Szekeres (no symmetries): Sussman, Hellaby, Ishak, … • Swiss cheese: Einstein and Strauss, Schücking, Kantowski, Dyer,… • Lindquist and Wheeler: Perreira, Clifton, … • Black holes: Schwarzschild, Kerr The key observational point is that we can only observe on the past light cone (Hoyle, Schücking, Sachs) See the diagrams of our past light cone by Mark Whittle (Virginia) 5 Expand the spatial distances to see the causal structure: light cones at ±45o. Observable Geo Data Start of universe Particle Horizon (Rindler) Spacelike singularity (Penrose). 6 The cosmological principle The CP is the foundational assumption that the Universe obeys a cosmological law: It is necessarily spatially homogeneous and isotropic (Milne 1935, Bondi 1960) Thus a priori: geometry is Robertson-Walker Weaker form: the Copernican Principle: We do not live in a special place (Weinberg 1973). -
A Study of John Leslie's Infinite Minds, a Philosophical Cosmology
Document généré le 1 oct. 2021 09:18 Laval théologique et philosophique Infinite Minds, Determinism & Evil A Study of John Leslie’s Infinite Minds, A Philosophical Cosmology Leslie Armour La question de Dieu Volume 58, numéro 3, octobre 2002 URI : https://id.erudit.org/iderudit/000634ar DOI : https://doi.org/10.7202/000634ar Aller au sommaire du numéro Éditeur(s) Faculté de philosophie, Université Laval Faculté de théologie et de sciences religieuses, Université Laval ISSN 0023-9054 (imprimé) 1703-8804 (numérique) Découvrir la revue Citer cette note Armour, L. (2002). Infinite Minds, Determinism & Evil: A Study of John Leslie’s Infinite Minds, A Philosophical Cosmology. Laval théologique et philosophique, 58(3), 597–603. https://doi.org/10.7202/000634ar Tous droits réservés © Laval théologique et philosophique, Université Laval, Ce document est protégé par la loi sur le droit d’auteur. L’utilisation des 2002 services d’Érudit (y compris la reproduction) est assujettie à sa politique d’utilisation que vous pouvez consulter en ligne. https://apropos.erudit.org/fr/usagers/politique-dutilisation/ Cet article est diffusé et préservé par Érudit. Érudit est un consortium interuniversitaire sans but lucratif composé de l’Université de Montréal, l’Université Laval et l’Université du Québec à Montréal. Il a pour mission la promotion et la valorisation de la recherche. https://www.erudit.org/fr/ Laval théologique et philosophique, 58, 3 (octobre 2002) : 597-603 ◆ note critique INFINITE MINDS, DETERMINISM & EVIL A STUDY OF JOHN LESLIE’S INFINITE MINDS, A PHILOSOPHICAL COSMOLOGY * Leslie Armour The Dominican College of Philosophy and Theology Ottawa ohn Leslie’s Infinite Minds is a refreshingly daring book. -
Science and Religion in the Face of the Environmental Crisis
Roger S. Gottlieb, ed., The Oxford Handbook of Religion and Ecology. New York and Oxford: Oxford University Press, 2006. Pages 376-397. CHAPTER 17 .................................................................................................. SCIENCE AND RELIGION IN THE FACE OF THE ENVIRONMENTAL CRISIS ..................................................................................................... HOLMES ROLSTON III BOTH science and religion are challenged by the environmental crisis, both to reevaluate the natural world and to reevaluate their dialogue with each other. Both are thrown into researching fundamental theory and practice in the face of an upheaval unprecedented in human history, indeed in planetary history. Life on Earth is in jeopardy owing to the behavior of one species, the only species that is either scientific or religious, the only species claiming privilege as the "wise spe- cies," Homo sapiens. Nature and the human relation to nature must be evaluated within cultures, classically by their religions, currently also by the sciences so eminent in Western culture. Ample numbers of theologians and ethicists have become persuaded that religion needs to pay more attention to ecology, and many ecologists recognize religious dimensions to caring for nature and to addressing the ecological crisis. Somewhat ironically, just when humans, with their increasing industry and technology, seemed further and further from nature, having more knowledge about natural processes and more power to manage them, just when humans were more and more rebuilding their environments, thinking perhaps to escape nature, the natural world has emerged as a focus of concern. Nature remains the milieu of 376 SCIENCE AND RELIGION 377 culture—so both science and religion have discovered. In a currently popular vocabulary, humans need to get themselves "naturalized." Using another meta- phor, nature is the "womb" of culture, but a womb that humans never entirely leave. -
Arxiv:1707.01004V1 [Astro-Ph.CO] 4 Jul 2017
July 5, 2017 0:15 WSPC/INSTRUCTION FILE coc2ijmpe International Journal of Modern Physics E c World Scientific Publishing Company Primordial Nucleosynthesis Alain Coc Centre de Sciences Nucl´eaires et de Sciences de la Mati`ere (CSNSM), CNRS/IN2P3, Univ. Paris-Sud, Universit´eParis–Saclay, Bˆatiment 104, F–91405 Orsay Campus, France [email protected] Elisabeth Vangioni Institut d’Astrophysique de Paris, UMR-7095 du CNRS, Universit´ePierre et Marie Curie, 98 bis bd Arago, 75014 Paris (France), Sorbonne Universit´es, Institut Lagrange de Paris, 98 bis bd Arago, 75014 Paris (France) [email protected] Received July 5, 2017 Revised Day Month Year Primordial nucleosynthesis, or big bang nucleosynthesis (BBN), is one of the three evi- dences for the big bang model, together with the expansion of the universe and the Cos- mic Microwave Background. There is a good global agreement over a range of nine orders of magnitude between abundances of 4He, D, 3He and 7Li deduced from observations, and calculated in primordial nucleosynthesis. However, there remains a yet–unexplained discrepancy of a factor ≈3, between the calculated and observed lithium primordial abundances, that has not been reduced, neither by recent nuclear physics experiments, nor by new observations. The precision in deuterium observations in cosmological clouds has recently improved dramatically, so that nuclear cross sections involved in deuterium BBN need to be known with similar precision. We will shortly discuss nuclear aspects re- lated to BBN of Li and D, BBN with non-standard neutron sources, and finally, improved sensitivity studies using Monte Carlo that can be used in other sites of nucleosynthesis. -
Physical Cosmology Physics 6010, Fall 2017 Lam Hui
Physical Cosmology Physics 6010, Fall 2017 Lam Hui My coordinates. Pupin 902. Phone: 854-7241. Email: [email protected]. URL: http://www.astro.columbia.edu/∼lhui. Teaching assistant. Xinyu Li. Email: [email protected] Office hours. Wednesday 2:30 { 3:30 pm, or by appointment. Class Meeting Time/Place. Wednesday, Friday 1 - 2:30 pm (Rabi Room), Mon- day 1 - 2 pm for the first 4 weeks (TBC). Prerequisites. No permission is required if you are an Astronomy or Physics graduate student { however, it will be assumed you have a background in sta- tistical mechanics, quantum mechanics and electromagnetism at the undergrad- uate level. Knowledge of general relativity is not required. If you are an undergraduate student, you must obtain explicit permission from me. Requirements. Problem sets. The last problem set will serve as a take-home final. Topics covered. Basics of hot big bang standard model. Newtonian cosmology. Geometry and general relativity. Thermal history of the universe. Primordial nucleosynthesis. Recombination. Microwave background. Dark matter and dark energy. Spatial statistics. Inflation and structure formation. Perturba- tion theory. Large scale structure. Non-linear clustering. Galaxy formation. Intergalactic medium. Gravitational lensing. Texts. The main text is Modern Cosmology, by Scott Dodelson, Academic Press, available at Book Culture on W. 112th Street. The website is http://www.bookculture.com. Other recommended references include: • Cosmology, S. Weinberg, Oxford University Press. • http://pancake.uchicago.edu/∼carroll/notes/grtiny.ps or http://pancake.uchicago.edu/∼carroll/notes/grtinypdf.pdf is a nice quick introduction to general relativity by Sean Carroll. • A First Course in General Relativity, B. -
Structure Formation in a CDM Universe
Structure formation in a CDM Universe Thomas Quinn, University of Washington Greg Stinson, Charlotte Christensen, Alyson Brooks Ferah Munshi Fabio Governato, Andrew Pontzen, Chris Brook, James Wadsley Microwave Background Fluctuations Image courtesy NASA/WMAP Large Scale Clustering A well constrained cosmology ` Contents of the Universe Can it make one of these? Structure formation issues ● The substructure problem ● The angular momentum problem ● The cusp problem Light vs CDM structure Stars Gas Dark Matter The CDM Substructure Problem Moore et al 1998 Substructure down to 100 pc Stadel et al, 2009 Consequences for direct detection Afshordi etal 2010 Warm Dark Matter cold warm hot Constant Core Mass Strigari et al 2008 Light vs Mass Number density log(halo or galaxy mass) Simulations of Galaxy formation Guo e tal, 2010 Origin of Galaxy Spins ● Torques on the collapsing galaxy (Peebles, 1969; Ryden, 1988) λ ≡ L E1/2/GM5/2 ≈ 0.09 for galaxies Distribution of Halo Spins f(λ) Λ = LE1/2/GM5/2 Gardner, 2001 Angular momentum Problem Too few low-J baryons Van den Bosch 01 Bullock 01 Core/Cusps in Dwarfs Moore 1994 Warm DM doesn't help Moore et al 1999 Dwarf simulated to z=0 Stellar mass = 5e8 M sun` M = -16.8 i g - r = 0.53 V = 55 km/s rot R = 1 kpc d M /M = 2.5 HI * f = .3 f cosmic b b i band image Dwarf Light Profile Rotation Curve Resolution effects Low resolution: bad Low resolution star formation: worse Inner Profile Slopes vs Mass Governato, Zolotov etal 2012 Constant Core Masses Angular Momentum Outflows preferential remove low J baryons Simulation Results: Resolution and H2 Munshi, in prep. -
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 . -
Week 5: More on Structure Formation
Week 5: More on Structure Formation Cosmology, Ay127, Spring 2008 April 23, 2008 1 Mass function (Press-Schechter theory) In CDM models, the power spectrum determines everything about structure in the Universe. In particular, it leads to what people refer to as “bottom-up” and/or “hierarchical clustering.” To begin, note that the power spectrum P (k), which decreases at large k (small wavelength) is psy- chologically inferior to the scaled power spectrum ∆2(k) = (1/2π2)k3P (k). This latter quantity is monotonically increasing with k, or with smaller wavelength, and thus represents what is going on physically a bit more intuitively. Equivalently, the variance σ2(M) of the mass distribution on scales of mean mass M is a monotonically decreasing function of M; the variance in the mass distribution is largest at the smallest scales and smallest at the largest scales. Either way, the density-perturbation amplitude is larger at smaller scales. It is therefore smaller structures that go nonlinear and undergo gravitational collapse earliest in the Universe. With time, larger and larger structures undergo gravitational collapse. Thus, the first objects to undergo gravitational collapse after recombination are probably globular-cluster–sized halos (although the halos won’t produce stars. As we will see in Week 8, the first dark-matter halos to undergo gravitational collapse and produce stars are probably 106 M halos at redshifts z 20. A typical L galaxy probably forms ∼ ⊙ ∼ ∗ at redshifts z 1, and at the current epoch, it is galaxy groups or poor clusters that are the largest ∼ mass scales currently undergoing gravitational collapse. -
Cosmic Microwave Background
1 29. Cosmic Microwave Background 29. Cosmic Microwave Background Revised August 2019 by D. Scott (U. of British Columbia) and G.F. Smoot (HKUST; Paris U.; UC Berkeley; LBNL). 29.1 Introduction The energy content in electromagnetic radiation from beyond our Galaxy is dominated by the cosmic microwave background (CMB), discovered in 1965 [1]. The spectrum of the CMB is well described by a blackbody function with T = 2.7255 K. This spectral form is a main supporting pillar of the hot Big Bang model for the Universe. The lack of any observed deviations from a 7 blackbody spectrum constrains physical processes over cosmic history at redshifts z ∼< 10 (see earlier versions of this review). Currently the key CMB observable is the angular variation in temperature (or intensity) corre- lations, and to a growing extent polarization [2–4]. Since the first detection of these anisotropies by the Cosmic Background Explorer (COBE) satellite [5], there has been intense activity to map the sky at increasing levels of sensitivity and angular resolution by ground-based and balloon-borne measurements. These were joined in 2003 by the first results from NASA’s Wilkinson Microwave Anisotropy Probe (WMAP)[6], which were improved upon by analyses of data added every 2 years, culminating in the 9-year results [7]. In 2013 we had the first results [8] from the third generation CMB satellite, ESA’s Planck mission [9,10], which were enhanced by results from the 2015 Planck data release [11, 12], and then the final 2018 Planck data release [13, 14]. Additionally, CMB an- isotropies have been extended to smaller angular scales by ground-based experiments, particularly the Atacama Cosmology Telescope (ACT) [15] and the South Pole Telescope (SPT) [16]. -
9. the Cosmic Microwave Background
A5682: Introduction to Cosmology Course Notes 9. The Cosmic Microwave Background Reading: Chapter 8, sections 8.0-8.3. (We will cover 8.4 and 8.5 later.) “Re”combination After Big Bang Nucleosynthesis, the universe was still much too hot for the formation of neutral atoms. As expansion continued, the background radiation photons redshifted and the temperature dropped. Naively, one would expect p + e− → H when kT ∼ 13.6eV. Just as with deuterium synthesis, however, the high value of nγ/nb implies that the exponential tail of the photon distribution can dissociate hydrogen atoms. Less naively, we expect p + e− → H when kT ∼ 13.6eV/(− ln η) ∼ 0.65eV, corresponding to (1 + z) ≈ 2700. A more accurate version of this argument given in the textbook (section 9.3) yields a predicted redshift of (1 + z) ≈ 1370 for hydrogen formation. In practice, there are several complicating factors, e.g., any recombination direct to the ground state produces a photon that can immediately ionize another neutral atom unless the photon survives long enough to be redshifted below 13.6 eV. A proper, somewhat tricky calculation of cosmic recombination shows that there is a fairly rapid transition from a free electron fraction xe ≈ 1 to xe ≈ 0 at z ≈ 1100, with most of the transition occuring over a redshift range ∆z ≈ 80. In the laboratory, or in regions ionized by hot stars or quasars or shocks, the process p + e− → H is usually referred to as “recombination.” In the early universe, the protons and electrons were never in the form of hydrogen to begin with, so this process should arguably be called “combination” rather than “recombination.” But “combination” sounds rather silly, so “recombination” is still the standard term for this tran- sition. -
Music and Environment: Registering Contemporary Convergences
JOURNAL OF OF RESEARCH ONLINE MusicA JOURNALA JOURNALOF THE MUSIC OF MUSICAUSTRALIA COUNCIL OF AUSTRALIA ■ Music and Environment: Registering Contemporary Convergences Introduction H O L L I S T A Y L O R & From the ancient Greek’s harmony of the spheres (Pont 2004) to a first millennium ANDREW HURLEY Babylonian treatise on birdsong (Lambert 1970), from the thirteenth-century round ‘Sumer Is Icumen In’ to Handel’s Water Music (Suites HWV 348–50, 1717), and ■ Faculty of Arts Macquarie University from Beethoven’s Pastoral Symphony (No. 6 in F major, Op. 68, 1808) to Randy North Ryde 2109 Newman’s ‘Burn On’ (Newman 1972), musicians of all stripes have long linked ‘music’ New South Wales Australia and ‘environment’. However, this gloss fails to capture the scope of recent activity by musicians and musicologists who are engaging with topics, concepts, and issues [email protected] ■ relating to the environment. Faculty of Arts and Social Sciences University of Technology Sydney Despite musicology’s historical preoccupation with autonomy, our register of musico- PO Box 123 Broadway 2007 environmental convergences indicates that the discipline is undergoing a sea change — New South Wales one underpinned in particular by the1980s and early 1990s work of New Musicologists Australia like Joseph Kerman, Susan McClary, Lawrence Kramer, and Philip Bohlman. Their [email protected] challenges to the belief that music is essentially self-referential provoked a shift in the discipline, prompting interdisciplinary partnerships to be struck and methodologies to be rethought. Much initial activity focused on the role that politics, gender, and identity play in music.