Astronomy 275 Lecture Notes, Spring 2015 Coedward L. Wright, 2015
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Fred Hoyle's Universe
GENERAL ARTICLE Fred Hoyle’s Universe Jayant V Narlikar This article recalls some of the seminal contri- butions to astronomy made by Fred Hoyle. His ideas were thought to be unrealistic at the time they were proposed, but have now been assim- ilated into mainstream science. A general com- ment that emerges from such examples is that highly creative individuals who are far ahead of their times do not get the recognition they de- Jayant V Narlikar is a serve once their ideas are rediscovered and ac- cosmologist and theoretical cepted as standard: for, by the time this hap- astrophysicist. He was a pens, they and their contributions are forgotten. research student and a long-time collaborator of 1. Introduction Fred Hoyle. He is the Founder Director of Fred Hoyle was arguably the most imaginative astro- IUCCA and is currently an emeritus professor there. physicist of the 20th century. He contributed very orig- He has made strong efforts inal ideas to astronomy and astrophysics in topics rang- to promote teaching and ing from the solar system to cosmology. He also made research in astronomy in contributions to fundamental physics, in particular to the universities. He has the concept of action at a distance. His studies on exo- written extensively in English and Marathi to biology evoked the most opposition from the Establish- popularize science. ment because their implications were so far reaching. This article presents glimpses of the work of this mul- tifaceted personality who is also known to the common man as an accomplished science populariser and writer of science ¯ction. -
20Th Century Cosmology
2200tthh century cosmology 1920s – 1990s (from Friedmann to Freedman) theoretical technology available, but no data 20 th century: birth of observational cosmology Hubble’s law ~1930 Development of astrophysics 1940s – 1950s Discovery of the CMB 1965 Inflation 1981 CMB anisotropies: COBE ~1990 PHY306 1 2200tthh century cosmology 1920s – 1990s (from Friedmann to Freedman) theoretical technology available, but no data 20 th century: birth of observational cosmology Hubble’s law ~1930 Development of astrophysics 1940s – 1950s – understanding of stellar structure and evolution – beginnings of quantitative predictions in cosmology ● birth of the Big Bang and Steady State models – beginnings of non-optical astronomy ● radio astronomy (1940s), satellites (1957 on) PHY306 2 1 State of Play, 1940 Hydrogen fusion finally understood pp chain, Bethe and Crichton, 1938 CNO cycle, Bethe, 1939 Hubble constant still ~500 km/s/Mpc Hubble time ~2 Gyr, recognised as problem Most cosmological papers basically playing with the maths not enough data to produce useful constraints different theories owe more to differences in philosophy than anything else PHY306 3 Cosmological models Theories of the 1930s Theories of the 1940s general relativistic Hot Big Bang cosmologies George Gamow, Ralph Friedmann, Lemaître, Alpher, Robert Herman Robertson – driven by nuclear physics “kinematic cosmology” – main prediction not Milne tested for ~20 years! not – special but Steady State general relativity – finite “bubble” of Fred Hoyle, Herman galaxies -
Observational Evidence Favors a Static Universe
1 Observational evidence favors a static universe David F. Crawford Sydney Institute for Astronomy, School of Physics, University of Sydney. Correspondence: 44 Market St, Naremburn, 2065, NSW, Australia email: [email protected] Abstract The common attribute of all Big Bang cosmologies is that they are based on the assumption that the universe is expanding. However exam- ination of the evidence for this expansion clearly favors a static universe. The major topics considered are: Tolman surface brightness, angular size, type 1a supernovae, gamma ray bursts, galaxy distributions, quasar dis- tributions, X-ray background radiation, cosmic microwave background ra- diation, radio source counts, quasar variability and the Butcher{Oemler effect. An analysis of the best raw data for these topics shows that they are consistent with expansion only if there is evolution that cancels the effects of expansion. An alternate cosmology, curvature cosmology, is a tired-light cosmology that predicts a well defined static and stable uni- verse and is fully described. It not only predicts accurate values for the Hubble constant and the temperature of cosmic microwave background radiation but shows good agreement with most of the topics considered. Curvature cosmology also predicts the deficiency in solar neutrino pro- duction rate and can explain the anomalous acceleration of Pioneer 10. Note: The editor of the Journal of Cosmology required this paper to be divided into three parts. Except for the abstracts, introductions and conclusions the text of the -
Quasi-Steady-State and Related Cosmological Models
1 Quasi-Steady-State and Related Cosmological Models: A Historical Review* Helge Kragh Centre for Science Studies, Aarhus University, Denmark Abstract. Since the emergence in the late 1960s of the standard hot big-bang theory, cosmology has been dominated by finite-age models. However, the rival view that the universe has existed for an indefinite time has continued to be defended by a minority of researchers. This view has roots far back in history and in the 1950s and 1960s several models were proposed in opposition to the big-bang paradigm. The most important of the alternative models, the steady-state cosmology proposed in 1948, was uniformly expanding rather than exhibiting a cyclical behaviour. In a much revised version it was developed into the quasi- steady-state cosmological model (QSSC) of the 1990s. From a historical point of view, this model, and a few other related models, can be seen as the latest examples of a tradition in cosmological thought that goes back to ancient Greece. The paper describes the background and development of the QSSC model. 1. Early conceptions of a cyclical-eternal world The notion of an eternal universe, either in the steady-state version or some cyclical version, is as old as the idea of a created universe. Many of the ancient cosmo- mythologies imagined a future cosmic catastrophe represented by a huge battle between the good and evil forces of nature. The catastrophe did not necessarily imply * Slightly revised version of contribution to Rüdiger Vaas, ed., Beyond the Big Bang: Prospects for an Eternal Universe, a book to be published by Springer, but which has now been delayed for several years. -
Re-Interpreting the Significance of the Cosmic Microwave Background
Re-interpreting the Significance of the Cosmic Microwave Background Jacob Pearce PhD Candidate History and Philosophy of Science Program University of Melbourne Introduction: the Cosmic Microwave Background Radiation The discovery of the Cosmic Microwave Background (CMB) radiation by Penzias and Wilson in 1965 was heralded as proof of Big Bang theory. It was also termed the final ‘nail in the coffin’ for the rival Steady State research program. This paper will examine the role of the CMB in re-shaping the conceptual space of modern cosmology—the landscape of possible styles of reasoning (as used by Ian Hacking) and scenes of inquiry (as used by Nicholas Jardine). The CMB added unprecedented support to a style of reasoning characterized by factual-extrapolation, inherited by the cosmological community from Gamow. Steady State theory was based on a fundamentally opposed style of idealized-postulation, arising from Bondi. The value of the CMB was far more than as mere evidence for a theory. Rather, it made the case for observationally driven cosmology. This moment in 20th century cosmology signified a turning point, whereby observational evidence became the decisive factor for both consolidating and generating lines of inquiry. What the CMB symbolically represented for the style of reasoning—notwithstanding the lasting effect this epistemic object had on shifting the trajectory of the conceptual space of cosmology—is far more significant than its relation to theory choice. The CMB buried Steady State, so to speak, because of the style it legitimated, rather than due to its epistemic content. Tracing the history of the notion of the CMB further highlights the contingent 1965 interpretation, and calls into question the role of this entity in epistemic practices and strategies in cosmology today. -
Antigravity and Antigravitational Forces
A n t i g r a One hundred years ago, Albert Einstein came up with a new theory of v i t gravitation. Later he added to his field equations the cosmological y constant which is accountable for the accelerated expansion of the universe. Thus a natural question arises concerning what is the energy source for this expansion. This monograph is about the novel concept of antigravity and antigravitational forces. We present various observational arguments showing the expansion on small cosmological scales. In particular, the Solar system and single galaxies expand at a rate comparable to the Hubble constant. The novelty of our ideas is that traditionally the expansion of the universe according to Edwin Hubble has been assumed to take place only between galaxies. The boldness of our approach is that it points to a weak violation of the law of conservation of energy. We claim that any system of free bodies that interact gravitationally with delays expands on average. We suggest that this is due to gravitational aberration effects resulting from a finite speed of gravity. Our book should be especially useful for scientists who look for the origin of dark matter and dark energy. Michal Křížek Filip Křížek Lawrence Somer Michal Křížek is a senior researcher at the Institute of Mathematics of the Czech Academy of Sciences and Professor at Charles University. Filip Křížek is a junior researcher at the Nuclear Physics Institute of the Czech Antigravity - Its Origin and Academy of Sciences. Lawrence Somer is Professor of Mathematics at the Catholic University of America in Washington, D.C. -
Further Definition of the Mass-Metallicity Relation
GLOBULAR CLUSTER SYSTEMS IN BRIGHTEST CLUSTER GALAXIES: FURTHER DEFINITION OF THE MASS-METALLICITY RELATION By ROBERT COCKCROFT, M.SCI. GLOBULAR CLUSTER SYSTEMS IN BRIGHTEST CLUSTER GALAXIES: FURTHER DEFINITION OF THE MASS-METALLICITY RELATION By ROBERT COCKCROFT, M.SCI. A Thesis Submitted to the School of Graduate Studies in Partial Fulfilment of the Requirements for the Degree Master of Science McMaster University @Copyright by Robert Cockcroft, May 2008 MASTER OF SCIENCE (2008) McMaster University (Department of Physics and Astronomy) Hamilton, Ontario TITLE: Globular Cluster Systems in Brightest Cluster Galaxies: Further Definition of the Mass-Metallicity Relation AUTHOR: Robert Cockcroft, M.Sci. SUPERVISOR: Prof. William E. Harris NUMBER OF PAGES: xii, 111 ii Abstract Globular clusters (GCs) can be divided into two subpopulations when plot ted on a colour-magnitude diagram: one red and metal-rich (MR), and the other blue and metal-poor (MP). For each subpopulation, any correlation between colour and luminosity can then be converted into mass-metallicity relations (MM Rs). Tracing the MMRs for fifteen GC systems ( GCSs) - all around Brightest Cluster Galaxies - we see a nonzero trend for the MP subpopulation but not the MR. This trend is characterised by p in the relation Z=M'. We find p V"I 0.35 for the MP GCs, and a relation for the MR GCs that is consistent with zero. When we look at how this trend varies with the host galaxy luminosity, we extend previous studies (e.g., Mieske et al, 2006b) into the bright end of the host galaxy sample. In addition to previously presented (B-1) photometry for eight GCSs ob tained with ACS/WFC on the HST, we present seven more GCSs. -
Historical Aspects of Post-1850 Cosmology
Historical Aspects of Post-1850 Cosmology Helge Kragh*§ * Department of Physics and Astronomy, Aarhus University, Ny Munkegade, 8000 Aarhus, Denmark. § Lectures at XVIII Special Courses at Observatorio Nacional, Rio de Janeiro, Brazil, October 2013. AIP Proceedings (in press). Abstract. Cosmology as an exact physical science is of new date, but it has long roots in the past. This essay is concerned with four important themes in the history of cosmological thought which, if taken together, offer a fairly comprehensive account of the some of the key developments that have led to the modern understanding of the universe. Apart from the first section, dealing with early views of curved space, it focuses on mainstream cosmology from the expanding universe about 1930 to the emergence of the standard big bang model in the 1960s. This development includes theories we would not today consider “mainstream,” such as the steady state model of the universe. The last section outlines what might be called the prehistory of the concept of dark energy, that is, ideas that were discussed before dark energy was actually inferred from supernovae observations in the late 1990s. Keywords: Curved Space, Expanding Universe, Steady State Theory, Cosmological Models, Cosmological Constant, Dark Energy PACS: 04; 95. 1. INTRODUCTION eventually coalesced into the modern idea of dark energy. Attempts to understand the universe in terms of mathematics and natural philosophy go back the 2. CURVED SPACE BEFORE AND ancients Greeks and are covered in a rich historical AFTER EINSTEIN literature. On the other hand, the developments in the twentieth century that transformed cosmology into a proper physical science have attracted relatively little 2.1. -
Astronomy November
Telescopes for KIDS p. 60 OCEAN WORLDS of the solar system p. 24 NOVEMBER 2017 The world’s best-selling astronomy magazine NEW RESEARCH Gravitational waves From novelty to science p. 18 Discover autumn’s A pair of black holes spiral together, unleashing a brightest torrent of gravitational waves that eventually will galaxies p. 46 sweep across the universe. www.Astronomy.com BONUS Vol. 45 OBSERVE WITH MEET THE Why ONLINE • BOTH EYES FILTER GUY CONTENT Issue 11 DARK MATTER WIDE OPEN p. 52 PLUS CODE p. 4 matters p. 30 p. 58 Introducing Meade’s new and improved Coronado SolarMax III Hydrogen – alpha solar telescopes! :4000TT-YLMYHJ[VYLX\PWWLK^P[O! TTL_[LYUHSO`KYVNLU¶HSWOH/ʸMPS[LYZ 10mm or 15mm ISVJRPUNMPS[LYZ (]HPSHISLPUZPUNSLZ[HJRLK#ࠫ HUKKV\ISLZ[HJRLK#ࠫIHUKWHZZLZ +6<)3,:;(*2,+44 INCLUDES EXTERNAL “TRUE” H-a ETALON FILTERS Give higher contrast views and sharper features compared with models using ZTHSSLYPU[LYUHS/ʸL[HSVUKLZPNUZ,_WLYPLUJLKHYRLYIHJRNYV\UKZZOHYWLY MLH[\YLZHUKOPNOLYJVU[YHZ[ 2” TWO-SPEED RACK RichView TUNING & PINION FOCUSER Coronado’s patented RichView tuning allows *YLH[LZHTVYL\ZLYMYPLUKS`PU[LYHJ[PVU KPYLJ[[\UPUNVM[OLWYPTHY`L[HSVUMPS[LY;OL SHOT USING allowing the user to get a more precise patented RichView tuning technology provides SOLARMAX III MVJ\Z"JYP[PJHSMVYIV[OZVSHYPTHNPUNHUK HKKP[PVUHS[\UPUNYHUNLHUKHUV]LYHSSIL[[LY TAKEN BY SIMON T. ]PZ\HSVIZLY]PUN ^H`VMHKQ\Z[PUN[OLMPS[LYZIHUKWHZZ SEE THE UNIVERSE LIVE AND IN COLOUR WITH MALLINCAM SKYRAIDER DS2.3PLUS—2.3 Megapixel The SkyRaider DS2.3PLUS video/imager/autoguider is the newest in the SkyRaider family of astronomical video/imaging cameras. -
Masses of Galaxies: Singles and Members of Multiple Systems
MASSES OF GALAXIES: SINGLES AND MEMBERS OF MULTIPLE SYSTEMS THORNTON PAGE WESLEYAN UNIVERSITY 1. Introduction The masses of galaxies are important in several areas of astronomy and physics. In cosmology the mean mass is used to derive the average density of matter in the universe, a quantity which is related to the curvature of space in the cosmological models of general relativity. In any theory of the origin and evolution of galaxies, the masses are important in the dynamical aspects. Also, the wide range in mass estimates must be explained by a statistical theory of the origin of galaxies. In principle, mass can be detected and measured by the Einstein redshift and the gravitational deflection of light, as well as by its dynamical effect on other masses. In practice, the Einstein redshift can be separated from Doppler red- shift in only a few cases of no cosmological significance; gravitational deflection is unlikely to be useful [54]; and all determinations of the masses of galaxies have so far been based on simpler Newtonian mechanics. It is true that lower limits to the mass can be established in terms of emission lines of hot gases (in optical spectra) and cold hydrogen (in radio spectra). Moreover, many authors assume a relationship between luminosity L and mass M in the form of stars. This amounts to assuming a "normal" value of the ratio M/L, even though this ratio is known to vary from less than 0.01 to over 1000. Statistics have been involved in practically all phases of these studies, and one of the basic problems concerns observational selection [50]. -
BRAS Newsletter October 2013
www.brastro.org October 2013 Next meeting Oct 14th 7:00PM at the HRPO Dark Site Observing Dates: Primary on Oct. 5th (New Moon) Secondary on Oct. 12th (1st Quarter Moon) Model of the Mars Curiosity Rover 1 What's in this issue: PRESIDENT'S MESSAGE.....................................................................................................................3 NOTES FROM THE VICE PRESIDENT .............................................................................................4 MESSAGE FROM THE HRPO ….....................................................................................................5 MONTHLY OBSERVING NOTES .....................................................................................................6 OUTREACH CHAIRPERSON’S NOTES .........................................................................................13 MINUTES FROM SEPTEMBER MEETING….................................................................................14 MEMBERSHIP APPLICATION..........................................................................................................15 2 PRESIDENT'S MESSAGE Hi Everyone, Ah, the smell of caramel apples and pumpkin pie are in the air! I'm sure you've also noticed the days starting to get shorter. Hopefully we'll get some clear sky as well. My main point in this month's message is to remind everyone that we are going to be electing all new officers this December. We'll be fielding nominations at our November meeting. The positions are as follow: President - This person will head -
Revised Shapley Ames.Pdf
A REVISED SHAPLEY-AMES CATALOG OF BRIGHT GALAXIES The Las Canspanas ridge iii Chile during the last stages of construction of the dome for the du Pont 2.5-meter reflector. The du Pout instrument is at the north end of'thr long escarpment. The Swope 1-meter reflector is in the left foreground. Photu courtesy oi'R, J. Bruuito ; 1*<7*J-. A Revised Shapley-Ames Catalog of Bright Galaxies Containing Data on Magnitudes, Types, and Redshifts for Galaxies in the Original Harvard Survey, Updated to Summer 1980. Also Contains a Selection of Photographs Illustrating the Luminosity Classification and a List of Additional Galaxies that Satisfy the Magnitude Limit of the Original Catalog. Allan Sandage and G. A. Tammann CARNEGIE INSTITUTION OF WASHINGTON PUBLICATION 635 WASHINGTON, D.C. • 198 1 ISBN:0-87U79-<i52-:i Libran oi'CongrrssCatalog Card No. 80-6H146 (JompoMtion. Printing, and Binding by Mmden-Stinehour. Inr. ('<»p\ritiht C ]'M\, (Jariit'^it* Institution nf Washington ACKNOWLEDGMENTS We are indebted to Miss B. Flach and Mrs. R. C. Kraan- Korteweg for their help in compiling part of the data. We also owe special thanks to Basil Katem for his large effort in de- termining revised coordinates by measurement of National Geo- graphic-Palomar Sky Survey prints and Uppsala Schmidt plates for most of the listed galaxies, and to John Bedke for his skill in reproducing the photographs. We are especially grateful to R. J. Brucato for his important help in obtaining the most recent plates at Las Campanas. We greatly appreciate the help of several observers for provid- ing prepublication redshift data.