The Evolution of the Universe
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Dark Energy and Dark Matter As Inertial Effects Introduction
Dark Energy and Dark Matter as Inertial Effects Serkan Zorba Department of Physics and Astronomy, Whittier College 13406 Philadelphia Street, Whittier, CA 90608 [email protected] ABSTRACT A disk-shaped universe (encompassing the observable universe) rotating globally with an angular speed equal to the Hubble constant is postulated. It is shown that dark energy and dark matter are cosmic inertial effects resulting from such a cosmic rotation, corresponding to centrifugal (dark energy), and a combination of centrifugal and the Coriolis forces (dark matter), respectively. The physics and the cosmological and galactic parameters obtained from the model closely match those attributed to dark energy and dark matter in the standard Λ-CDM model. 20 Oct 2012 Oct 20 ph] - PACS: 95.36.+x, 95.35.+d, 98.80.-k, 04.20.Cv [physics.gen Introduction The two most outstanding unsolved problems of modern cosmology today are the problems of dark energy and dark matter. Together these two problems imply that about a whopping 96% of the energy content of the universe is simply unaccounted for within the reigning paradigm of modern cosmology. arXiv:1210.3021 The dark energy problem has been around only for about two decades, while the dark matter problem has gone unsolved for about 90 years. Various ideas have been put forward, including some fantastic ones such as the presence of ghostly fields and particles. Some ideas even suggest the breakdown of the standard Newton-Einstein gravity for the relevant scales. Although some progress has been made, particularly in the area of dark matter with the nonstandard gravity theories, the problems still stand unresolved. -
Dark Matter and the Early Universe: a Review Arxiv:2104.11488V1 [Hep-Ph
Dark matter and the early Universe: a review A. Arbey and F. Mahmoudi Univ Lyon, Univ Claude Bernard Lyon 1, CNRS/IN2P3, Institut de Physique des 2 Infinis de Lyon, UMR 5822, 69622 Villeurbanne, France Theoretical Physics Department, CERN, CH-1211 Geneva 23, Switzerland Institut Universitaire de France, 103 boulevard Saint-Michel, 75005 Paris, France Abstract Dark matter represents currently an outstanding problem in both cosmology and particle physics. In this review we discuss the possible explanations for dark matter and the experimental observables which can eventually lead to the discovery of dark matter and its nature, and demonstrate the close interplay between the cosmological properties of the early Universe and the observables used to constrain dark matter models in the context of new physics beyond the Standard Model. arXiv:2104.11488v1 [hep-ph] 23 Apr 2021 1 Contents 1 Introduction 3 2 Standard Cosmological Model 3 2.1 Friedmann-Lema^ıtre-Robertson-Walker model . 4 2.2 A quick story of the Universe . 5 2.3 Big-Bang nucleosynthesis . 8 3 Dark matter(s) 9 3.1 Observational evidences . 9 3.1.1 Galaxies . 9 3.1.2 Galaxy clusters . 10 3.1.3 Large and cosmological scales . 12 3.2 Generic types of dark matter . 14 4 Beyond the standard cosmological model 16 4.1 Dark energy . 17 4.2 Inflation and reheating . 19 4.3 Other models . 20 4.4 Phase transitions . 21 5 Dark matter in particle physics 21 5.1 Dark matter and new physics . 22 5.1.1 Thermal relics . 22 5.1.2 Non-thermal relics . -
A Brief Tour Into the History of Gravity: from Emocritus to Einstein
American Journal of Space Science 1 (1): 33-45, 2013 ISSN: 1948-9927 © 2013 Science Publications doi:10.3844/ajssp.2013.33.45 Published Online 1 (1) 2013 (http://www.thescipub.com/ajss.toc) A Brief Tour into the History of Gravity: From Emocritus to Einstein Panagiotis Papaspirou and Xenophon Moussas Department of Physics, Section of Astrophysics, Astronomy and Mechanics, University of Athens, Athens, Greece ABSTRACT The History of Gravity encompasses many different versions of the idea of the Gravitational interaction, which starts already from the Presocratic Atomists, continues to the doctrines of the Platonic and Neoplatonic School and of the Aristotelian School, passes through the works of John Philoponus and John Bouridan and reaches the visions of Johannes Kepler and Galileo Galilei. Then, the major breakthrough in the Theory of Motion and the Theory of Gravity takes place within the realm of Isaac Newton’s most famous Principia and of the work of Gottfried Leibniz, continues with the contributions of the Post- newtonians, such as Leonhard Euler, reaches the epoch of its modern formulation by Ernst Mach and other Giants of Physics and Philosophy of this epoch, enriches its structure within the work of Henry Poincare and finally culminates within the work of Albert Einstein, with the formulation of the Theory of Special Relativity and of General Relativity at the begin of the 20th century. The evolution of the Theory of General Relativity still continues up to our times, is rich in forms it takes and full of ideas of theoretical strength. Many fundamental concepts of the Epistemology and the History of Physics appear in the study of the Theory of Gravity, such as the notions of Space, of Time, of Motion, of Mass, in its Inertial, Active Gravitational and Passive Gravitational form, of the Inertial system of reference, of the Force, of the Field, of the Riemannian Geometry and of the Field Equations. -
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. -
Rcosmo: R Package for Analysis of Spherical, Healpix and Cosmological Data Arxiv:1907.05648V1 [Stat.CO] 12 Jul 2019
CONTRIBUTED RESEARCH ARTICLE 1 rcosmo: R Package for Analysis of Spherical, HEALPix and Cosmological Data Daniel Fryer, Ming Li, Andriy Olenko Abstract The analysis of spatial observations on a sphere is important in areas such as geosciences, physics and embryo research, just to name a few. The purpose of the package rcosmo is to conduct efficient information processing, visualisation, manipulation and spatial statistical analysis of Cosmic Microwave Background (CMB) radiation and other spherical data. The package was developed for spherical data stored in the Hierarchical Equal Area isoLatitude Pixelation (Healpix) representation. rcosmo has more than 100 different functions. Most of them initially were developed for CMB, but also can be used for other spherical data as rcosmo contains tools for transforming spherical data in cartesian and geographic coordinates into the HEALPix representation. We give a general description of the package and illustrate some important functionalities and benchmarks. Introduction Directional statistics deals with data observed at a set of spatial directions, which are usually positioned on the surface of the unit sphere or star-shaped random particles. Spherical methods are important research tools in geospatial, biological, palaeomagnetic and astrostatistical analysis, just to name a few. The books (Fisher et al., 1987; Mardia and Jupp, 2009) provide comprehensive overviews of classical practical spherical statistical methods. Various stochastic and statistical inference modelling issues are covered in (Yadrenko, 1983; Marinucci and Peccati, 2011). The CRAN Task View Spatial shows several packages for Earth-referenced data mapping and analysis. All currently available R packages for spherical data can be classified in three broad groups. The first group provides various functions for working with geographic and spherical coordinate systems and their visualizations. -
The Age of the Universe Transcript
The Age of the Universe Transcript Date: Wednesday, 6 February 2013 - 1:00PM Location: Museum of London 6 February 2013 The Age of The Universe Professor Carolin Crawford Introduction The idea that the Universe might have an age is a relatively new concept, one that became recognised only during the past century. Even as it became understood that individual objects, such as stars, have finite lives surrounded by a birth and an end, the encompassing cosmos was always regarded as a static and eternal framework. The change in our thinking has underpinned cosmology, the science concerned with the structure and the evolution of the Universe as a whole. Before we turn to the whole cosmos then, let us start our story nearer to home, with the difficulty of solving what might appear a simpler problem, determining the age of the Earth. Age of the Earth The fact that our planet has evolved at all arose predominantly from the work of 19th century geologists, and in particular, the understanding of how sedimentary rocks had been set down as an accumulation of layers over extraordinarily long periods of time. The remains of creatures trapped in these layers as fossils clearly did not resemble any currently living, but there was disagreement about how long a time had passed since they had died. The cooling earth The first attempt to age the Earth based on physics rather than geology came from Lord Kelvin at the end of the 19th Century. Assuming that the whole planet would have started from a completely molten state, he then calculated how long it would take for the surface layers of Earth to cool to their present temperature. -
Galaxy Redshifts: from Dozens to Millions
GALAXY REDSHIFTS: FROM DOZENS TO MILLIONS Chris Impey University of Arizona The Expanding Universe • Evolution of the scale factor from GR; metric assumes homogeneity and isotropy (~FLRW). • Cosmological redshift fundamentally differs from a Doppler shift. • Galaxies (and other objects) are used as space-time markers. Expansion History and Contents Science is Seeing The expansion history since the big bang and the formation of large scale structure are driven by dark matter and dark energy. Observing Galaxies Galaxy Observables: • Redshift (z) • Magnitude (color, SED) • Angular size (morphology) All other quantities (size, luminosity, mass) derive from knowing a distance, which relates to redshift via a cosmological model. The observables are poor distance indicators. Other astrophysical luminosity predictors are required. (Cowie) ~90% of the volume or look-back time is probed by deep field • Number of galaxies in observable universe: ~90% of the about 100 billion galaxies in the volume • Number of stars in the are counted observable universe: about 1022 Heading for 100 Million (Baldry/Eisenstein) Multiplex Advantage Cannon (1910) Gemini/GMOS (2010) Sluggish, Spacious, Reliable. Photography CCD Imaging Speedy, Cramped, Finicky. 100 Years of Measuring Galaxy Redshifts Who When # Galaxies Size Time Mag Scheiner 1899 1 (M31) 0.3m 7.5h V = 3.4 Slipher 1914 15 0.6m ~5h V ~ 8 Slipher 1917 25 0.6m ~5h V ~ 8 Hubble/Slipher 1929 46 1.5m ~6h V ~ 10 Hum/May/San 1956 800 5m ~2h V = 11.6 Photographic 1960s 1 ~4m ~2.5h V ~ 15 Image Intensifier 1970s -
From Stargazing to Space Travel Our Brief History Into Space
From Stargazing to Space Travel Our brief history into space Science in the News Elaine Garcia Angela She November 4th, 2015 Why do we care? Gives us perspective • What did our forefathers think of the Heavens? • Why did they think that? • How did theories change throughout time? Gives us purpose • Mystery drives inquiry and discovery. Important Lessons were Learned and will Continue to be Discovered! Keywords Astrologyl – The study and interpretation of the movements and positions of celestial bodies in relation to Earth and Earthly affairs. Astronomy – The study of physical objects in space: gas, dust, stars, planets, moons, comets, and other non-Earthly mass and phenomena. • Astrophysics – The study of the physical nature and energy of cosmic mass. • Cosmology – A branch of study that theorizes about the origin and nature of the universe. Outline 1. Star Gazing • Theories about why, where, and how 2. Star Studying • Technology to study the unknown 3. Star Reaching • Demo on space exploration Outline 1. Star Gazing • Theories about why, where, and how 2. Star Studying • Technology to study the unknown 3. Star Reaching • Demo on space exploration What are stars’ purpose? Are they the actions, moods, or warnings of celestial beings? Star Worship Is their existence independent and separated from Earth’s existence and purpose? Star Navigation and Measurement Millennia of Lessons 570 BC 384 BC 276 BC 1600 O 1750+ BC 427 BC 310 BC 90 1700 Millennia of Lessons The earliest records of astronomical observations and mathematics. 1750+ BC Greek Rule Zeus King of Gods Hera Queen of Gods Poseidon God of the Sea Hades God of the Underworld Helios The Sun God Ares God of War Aphrodite Goddess of Love Eros God of Love Athena Goddess of Wisdom Hephaestus God of Fire/Forge Wikicommons.com What season is it? Zodiac surrounds the Earth, noting the Seasons Wikicommons.com Millennia of Lessons The earliest records of astronomical observations and mathematics. -
Cosmic Background Explorer (COBE) and Beyond
From the Big Bang to the Nobel Prize: Cosmic Background Explorer (COBE) and Beyond Goddard Space Flight Center Lecture John Mather Nov. 21, 2006 Astronomical Search For Origins First Galaxies Big Bang Life Galaxies Evolve Planets Stars Looking Back in Time Measuring Distance This technique enables measurement of enormous distances Astronomer's Toolbox #2: Doppler Shift - Light Atoms emit light at discrete wavelengths that can be seen with a spectroscope This “line spectrum” identifies the atom and its velocity Galaxies attract each other, so the expansion should be slowing down -- Right?? To tell, we need to compare the velocity we measure on nearby galaxies to ones at very high redshift. In other words, we need to extend Hubble’s velocity vs distance plot to much greater distances. Nobel Prize Press Release The Royal Swedish Academy of Sciences has decided to award the Nobel Prize in Physics for 2006 jointly to John C. Mather, NASA Goddard Space Flight Center, Greenbelt, MD, USA, and George F. Smoot, University of California, Berkeley, CA, USA "for their discovery of the blackbody form and anisotropy of the cosmic microwave background radiation". The Power of Thought Georges Lemaitre & Albert Einstein George Gamow Robert Herman & Ralph Alpher Rashid Sunyaev Jim Peebles Power of Hardware - CMB Spectrum Paul Richards Mike Werner David Woody Frank Low Herb Gush Rai Weiss Brief COBE History • 1965, CMB announced - Penzias & Wilson; Dicke, Peebles, Roll, & Wilkinson • 1974, NASA AO for Explorers: ~ 150 proposals, including: – JPL anisotropy proposal (Gulkis, Janssen…) – Berkeley anisotropy proposal (Alvarez, Smoot…) – Goddard/MIT/Princeton COBE proposal (Hauser, Mather, Muehlner, Silverberg, Thaddeus, Weiss, Wilkinson) COBE History (2) • 1976, Mission Definition Science Team selected by HQ (Nancy Boggess, Program Scientist); PI’s chosen • ~ 1979, decision to build COBE in-house at GSFC • 1982, approval to construct for flight • 1986, Challenger explosion, start COBE redesign for Delta launch • 1989, Nov. -
Hubble's Law and the Expanding Universe
COMMENTARY COMMENTARY Hubble’s Law and the expanding universe Neta A. Bahcall1 the expansion rate is constant in all direc- Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 tions at any given time, this rate changes with time throughout the life of the uni- verse. When expressed as a function of cos- In one of the most famous classic papers presented the observational evidence for one H t in the annals of science, Edwin Hubble’s of science’s greatest discoveries—the expand- mic time, ( ), it is known as the Hubble 1929 PNAS article on the observed relation inguniverse.Hubbleshowedthatgalaxiesare Parameter. The expansion rate at the pres- between distance and recession velocity of receding away from us with a velocity that is ent time, Ho, is about 70 km/s/Mpc (where 1 Mpc = 106 parsec = 3.26 × 106 light-y). galaxies—the Hubble Law—unveiled the proportional to their distance from us: more The inverse of the Hubble Constant is the expanding universe and forever changed our distant galaxies recede faster than nearby gal- Hubble Time, tH = d/v = 1/H ; it reflects understanding of the cosmos. It inaugurated axies. Hubble’s classic graph of the observed o the time since a linear cosmic expansion has the field of observational cosmology that has velocity vs. distance for nearby galaxies is begun (extrapolating a linear Hubble Law uncovered an amazingly vast universe that presented in Fig. 1; this graph has become back to time t = 0); it is thus related to has been expanding and evolving for 14 bil- a scientific landmark that is regularly repro- the age of the Universe from the Big-Bang lion years and contains dark matter, dark duced in astronomy textbooks. -
Newton.Indd | Sander Pinkse Boekproductie | 16-11-12 / 14:45 | Pag
omslag Newton.indd | Sander Pinkse Boekproductie | 16-11-12 / 14:45 | Pag. 1 e Dutch Republic proved ‘A new light on several to be extremely receptive to major gures involved in the groundbreaking ideas of Newton Isaac Newton (–). the reception of Newton’s Dutch scholars such as Willem work.’ and the Netherlands Jacob ’s Gravesande and Petrus Prof. Bert Theunissen, Newton the Netherlands and van Musschenbroek played a Utrecht University crucial role in the adaption and How Isaac Newton was Fashioned dissemination of Newton’s work, ‘is book provides an in the Dutch Republic not only in the Netherlands important contribution to but also in the rest of Europe. EDITED BY ERIC JORINK In the course of the eighteenth the study of the European AND AD MAAS century, Newton’s ideas (in Enlightenment with new dierent guises and interpre- insights in the circulation tations) became a veritable hype in Dutch society. In Newton of knowledge.’ and the Netherlands Newton’s Prof. Frans van Lunteren, sudden success is analyzed in Leiden University great depth and put into a new perspective. Ad Maas is curator at the Museum Boerhaave, Leiden, the Netherlands. Eric Jorink is researcher at the Huygens Institute for Netherlands History (Royal Dutch Academy of Arts and Sciences). / www.lup.nl LUP Newton and the Netherlands.indd | Sander Pinkse Boekproductie | 16-11-12 / 16:47 | Pag. 1 Newton and the Netherlands Newton and the Netherlands.indd | Sander Pinkse Boekproductie | 16-11-12 / 16:47 | Pag. 2 Newton and the Netherlands.indd | Sander Pinkse Boekproductie | 16-11-12 / 16:47 | Pag. -
Introduction
Introduction Queen's College, the predecessor of Rutgers University, was the eighth college to be founded in the American colonies. The early colonial colleges were founded to meet the emerging needs for an educated clergy, and to provide education to other leaders of the community. The religious leaders of the colonies were foremost in the movements to establish these colleges. Although denominational sponsorship was critical to the founding and early support of the colleges, there were generally no religious tests for students, and the colleges were chartered by the colonies. Leaders of the Puritan Congregational Church founded Harvard College in 1636 with a bequest of £400 from the Massachusetts Bay Colony. The College was organized and named Harvard College in 1639, and chartered in 1650. The traditional list of colonial colleges that followed Harvard College begins with William and Mary College, which was founded in 1693 by leaders of the Anglican Episcopal Church, followed by Yale College, which was founded in 1701 by leaders of the Puritan Congregational Church. The College of Philadelphia (later University of Pennsylvania) was founded in 1740 by Benjamin Franklin and other leading citizens of Philadelphia, and had the weakest religious connections of the colonial colleges. The College of New Jersey (later Princeton College) was founded in 1746 by leaders of the Presbyterian Church, King's College (later Columbia College) was founded in 1754 by leaders of the Anglican Episcopal Church, and the College of Rhode Island (later Brown College) was founded in 1764 by leaders of the Baptist Church. 1 History of Physics and Astronomy Some elements of physics and astronomy were taught in the colonial colleges from the time they opened.