The Problem of the Age of the Universe and the Earliest Galaxies
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Lecture 2 Our Place in the Universe (Cont'd)
Astronomy 110 –1 Lecture 2 Our Place in the Universe (Cont’d) 14/01/09 1 Copyright © 2009 Pearson Education, Inc. A few useful mathematical skills 14/01/09 2 Copyright © 2009 Pearson Education, Inc. Powers of ten 103 = 10 x 10 x 10 = 1000 102 = 10 x 10 = 100 101 = 10 100 = 1 10-1 = 1/10 = 0.1 10-2 = 1/10 x 1/10 = 0.01 10-3 = 1/10 x 1/10 x 1/10 = 0.001 Then: 300 = 3 x 100 = 3 x 102 2,500 = 2.5 x 1000 = 2.5 x 103 14/01/09 3 Copyright © 2009 Pearson Education, Inc. Multiplying & dividing 101 x 101 = 100 = 102 101 x 102 = 10 x 100 = 1000 = 103 102 x 102 = 100 x 100 = 10000 = 104 When multiplying two powers of ten, add the exponents 1000 ÷ 100 = 103 ÷ 102 = 10 = 101 10 ÷ 10 = 101 ÷ 101 = 1 = 100 10 ÷ 100 = 101 ÷ 102 = 1/10 = 10-1 When dividing, subtract exponent of divisor from exponent of numerator 14/01/09 4 Copyright © 2009 Pearson Education, Inc. Powers and roots (104)3 = 104 x 104 x 104 = 1012 Rule of thumb: when raising to a power, multiply exponents What about √(104)? √(104) = 102 taking roots is the same as raising to a fractional power, in this case 1/2 power: √(104) = (104)1/2 = 102 √ is the same as raising to 1/2 power 3√ is the same as raising to 1/3 power 4√ is the same as raising to 1/4 power 14/01/09 5 Copyright © 2009 Pearson Education, Inc. -
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. -
Critical Analysis of Article "21 Reasons to Believe the Earth Is Young" by Jeff Miller
1 Critical analysis of article "21 Reasons to Believe the Earth is Young" by Jeff Miller Lorence G. Collins [email protected] Ken Woglemuth [email protected] January 7, 2019 Introduction The article by Dr. Jeff Miller can be accessed at the following link: http://apologeticspress.org/APContent.aspx?category=9&article=5641 and is an article published by Apologetic Press, v. 39, n.1, 2018. The problems start with the Article In Brief in the boxed paragraph, and with the very first sentence. The Bible does not give an age of the Earth of 6,000 to 10,000 years, or even imply − this is added to Scripture by Dr. Miller and other young-Earth creationists. R. C. Sproul was one of evangelicalism's outstanding theologians, and he stated point blank at the Legionier Conference panel discussion that he does not know how old the Earth is, and the Bible does not inform us. When there has been some apparent conflict, either the theologians or the scientists are wrong, because God is the Author of the Bible and His handiwork is in general revelation. In the days of Copernicus and Galileo, the theologians were wrong. Today we do not know of anyone who believes that the Earth is the center of the universe. 2 The last sentence of this "Article In Brief" is boldly false. There is almost no credible evidence from paleontology, geology, astrophysics, or geophysics that refutes deep time. Dr. Miller states: "The age of the Earth, according to naturalists and old- Earth advocates, is 4.5 billion years. -
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. -
The Reionization of Cosmic Hydrogen by the First Galaxies Abstract 1
David Goodstein’s Cosmology Book The Reionization of Cosmic Hydrogen by the First Galaxies Abraham Loeb Department of Astronomy, Harvard University, 60 Garden St., Cambridge MA, 02138 Abstract Cosmology is by now a mature experimental science. We are privileged to live at a time when the story of genesis (how the Universe started and developed) can be critically explored by direct observations. Looking deep into the Universe through powerful telescopes, we can see images of the Universe when it was younger because of the finite time it takes light to travel to us from distant sources. Existing data sets include an image of the Universe when it was 0.4 million years old (in the form of the cosmic microwave background), as well as images of individual galaxies when the Universe was older than a billion years. But there is a serious challenge: in between these two epochs was a period when the Universe was dark, stars had not yet formed, and the cosmic microwave background no longer traced the distribution of matter. And this is precisely the most interesting period, when the primordial soup evolved into the rich zoo of objects we now see. The observers are moving ahead along several fronts. The first involves the construction of large infrared telescopes on the ground and in space, that will provide us with new photos of the first galaxies. Current plans include ground-based telescopes which are 24-42 meter in diameter, and NASA’s successor to the Hubble Space Telescope, called the James Webb Space Telescope. In addition, several observational groups around the globe are constructing radio arrays that will be capable of mapping the three-dimensional distribution of cosmic hydrogen in the infant Universe. -
Galaxies at High Redshift Mauro Giavalisco
eaa.iop.org DOI: 10.1888/0333750888/1669 Galaxies at High Redshift Mauro Giavalisco From Encyclopedia of Astronomy & Astrophysics P. Murdin © IOP Publishing Ltd 2006 ISBN: 0333750888 Institute of Physics Publishing Bristol and Philadelphia Downloaded on Thu Mar 02 23:08:45 GMT 2006 [131.215.103.76] Terms and Conditions Galaxies at High Redshift E NCYCLOPEDIA OF A STRONOMY AND A STROPHYSICS Galaxies at High Redshift that is progressively higher for objects that are separated in space by larger distances. If the recession velocity between Galaxies at high REDSHIFT are very distant galaxies and, two objects is small compared with the speed of light, since light propagates through space at a finite speed of its value is directly proportional to the distance between approximately 300 000 km s−1, they appear to an observer them, namely v = H d on the Earth as they were in a very remote past, when r 0 the light departed them, carrying information on their H properties at that time. Observations of objects with very where the constant of proportionality 0 is called the high redshifts play a central role in cosmology because ‘HUBBLE CONSTANT’. For larger recession velocities this they provide insight into the epochs and the mechanisms relation is replaced by a more general one calculated from the theory of general relativity. In each cases, the value of GALAXY FORMATION, if one can reach redshifts that are high H enough to correspond to the cosmic epochs when galaxies of 0 provides the recession velocity of a pair of galaxies were forming their first populations of stars and began to separated by unitary distance, and hence sets the rate of shine light throughout space. -
The Anthropic Principle and Multiple Universe Hypotheses Oren Kreps
The Anthropic Principle and Multiple Universe Hypotheses Oren Kreps Contents Abstract ........................................................................................................................................... 1 Introduction ..................................................................................................................................... 1 Section 1: The Fine-Tuning Argument and the Anthropic Principle .............................................. 3 The Improbability of a Life-Sustaining Universe ....................................................................... 3 Does God Explain Fine-Tuning? ................................................................................................ 4 The Anthropic Principle .............................................................................................................. 7 The Multiverse Premise ............................................................................................................ 10 Three Classes of Coincidence ................................................................................................... 13 Can The Existence of Sapient Life Justify the Multiverse? ...................................................... 16 How unlikely is fine-tuning? .................................................................................................... 17 Section 2: Multiverse Theories ..................................................................................................... 18 Many universes or all possible -
Year 1 Cosmology Results from the Dark Energy Survey
Year 1 Cosmology Results from the Dark Energy Survey Elisabeth Krause on behalf of the Dark Energy Survey collaboration TeVPA 2017, Columbus OH Our Simple Universe On large scales, the Universe can be modeled with remarkably few parameters age of the Universe geometry of space density of atoms density of matter amplitude of fluctuations scale dependence of fluctuations [of course, details often not quite as simple] Our Puzzling Universe Ordinary Matter “Dark Energy” accelerates the expansion 5% dominates the total energy density smoothly distributed 25% acceleration first measured by SN 1998 “Dark Matter” 70% Our Puzzling Universe Ordinary Matter “Dark Energy” accelerates the expansion 5% dominates the total energy density smoothly distributed 25% acceleration first measured by SN 1998 “Dark Matter” next frontier: understand cosmological constant Λ: w ≡P/ϱ=-1? 70% magnitude of Λ very surprising dynamic dark energy varying in time and space, w(a)? breakdown of GR? Theoretical Alternatives to Dark Energy Many new DE/modified gravity theories developed over last decades Most can be categorized based on how they break GR: The only local, second-order gravitational field equations that can be derived from a four-dimensional action that is constructed solely from the metric tensor, and admitting Bianchi identities, are GR + Λ. Lovelock’s theorem (1969) [subject to viability conditions] Theoretical Alternatives to Dark Energy Many new DE/modified gravity theories developed over last decades Most can be categorized based on how they break GR: The only local, second-order gravitational field equations that can be derived from a four-dimensional action that is constructed solely from the metric tensor, and admitting Bianchi identities, are GR + Λ. -
Earth: Atmospheric Evolution of a Habitable Planet
Earth: Atmospheric Evolution of a Habitable Planet Stephanie L. Olson1,2*, Edward W. Schwieterman1,2, Christopher T. Reinhard1,3, Timothy W. Lyons1,2 1NASA Astrobiology Institute Alternative Earth’s Team 2Department of Earth Sciences, University of California, Riverside 3School of Earth and Atmospheric Science, Georgia Institute of Technology *Correspondence: [email protected] Table of Contents 1. Introduction ............................................................................................................................ 2 2. Oxygen and biological innovation .................................................................................... 3 2.1. Oxygenic photosynthesis on the early Earth .......................................................... 4 2.2. The Great Oxidation Event ......................................................................................... 6 2.3. Oxygen during Earth’s middle chapter ..................................................................... 7 2.4. Neoproterozoic oxygen dynamics and the rise of animals .................................. 9 2.5. Continued oxygen evolution in the Phanerozoic.................................................. 11 3. Carbon dioxide, climate regulation, and enduring habitability ................................. 12 3.1. The faint young Sun paradox ................................................................................... 12 3.2. The silicate weathering thermostat ......................................................................... 12 3.3. Geological -
The Solar System
The Solar System Our automated spacecraft have traveled to the Moon and to all the planets beyond our world The Sun appears to have been active for 4.6 billion years and has enough fuel for another 5 except Pluto; they have observed moons as large as small planets, flown by comets, and billion years or so. At the end of its life, the Sun will start to fuse helium into heavier elements sampled the solar environment. The knowledge gained from our journeys through the solar and begin to swell up, ultimately growing so large that it will swallow Earth. After a billion years system has redefined traditional Earth sciences like geology and meteorology and spawned an as a "red giant," it will suddenly collapse into a "white dwarf" -- the final end product of a star like entirely new discipline called comparative planetology. By studying the geology of planets, ours. It may take a trillion years to cool off completely. moons, asteroids, and comets, and comparing differences and similarities, we are learning more about the origin and history of these bodies and the solar system as a whole. We are also Mercury gaining insight into Earth's complex weather systems. By seeing how weather is shaped on other worlds and by investigating the Sun's activity and its influence through the solar system, Obtaining the first close-up views of Mercury was the primary objective of the Mariner 10 we can better understand climatic conditions and processes on Earth. spacecraft, launched Nov 3, 1973. After a journey of nearly 5 months, including a flyby of Venus, the spacecraft passed within 703 km (437 mi) of the solar system's innermost planet on Mar 29, The Sun 1974. -
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]. -
Does the Rapid Appearance of Life on Earth Suggest That Life Is Common in the Universe?
ASTROBIOLOGY Volume 2, Number 3, 2002 © Mary Ann Liebert, Inc. Does the Rapid Appearance of Life on Earth Suggest that Life Is Common in the Universe? CHARLES H. LINEWEAVER 1,2 and TAMARA M. DAVIS 1 ABSTRACT It is sometimes assumed that the rapidity of biogenesis on Earth suggests that life is common in the Universe. Here we critically examine the assumptions inherent in this if-life-evolved- rapidly-life-must-be-common argument. We use the observational constraints on the rapid- ity of biogenesis on Earth to infer the probability of biogenesis on terrestrial planets with the same unknown probability of biogenesis as the Earth. We find that on such planets, older than ,1 Gyr, the probability of biogenesis is .13% at the 95% confidence level. This quan- tifies an important term in the Drake Equation but does not necessarily mean that life is com- mon in the Universe. Key Words: Biogenesis—Drake Equation. Astrobiology 2, 293–304. THE BIOGENESIS LOTTERY duction–oxidation pairs are common (Nealson and Conrad, 1999). UCHOFCURRENTASTROBIOLOGICALRESEARCH Mis focused on learning more about the early It is difficult to translate this circumstantial ev- evolution of the Earth and about the origin of life. idence into an estimate of how common life is in We may be able to extrapolate and generalize our the Universe. Without definitive detections of ex- knowledge of how life formed here to how it traterrestrial life we can say very little about how might have formed elsewhere. Indirect evidence common it is or even whether it exists. Our exis- suggesting that life may be common in the Uni- tence on Earth can tell us little about how com- verse includes: mon life is in the Universe or about the proba- bility of biogenesis on a terrestrial planet because, Sun-like stars are common.