Cosmology: A Very Short Introduction
‘a fast track through the history of our endlessly fascinating Universe,
from then to now’
J. D. Barrow, Cambridge University
‘In a clear and elegant style, Coles succeeds in conveying the gist of some of the deepest concepts in Physics … that underlie our understanding of the cosmos. This concise, yet up-to-date, account of cosmic history makes for compelling reading for anyone who has ever wondered about how our universe works.’
Carlos Frenk, University of Durham
‘presents a wonderfully broad range of concepts in a clear and readable way [and] gives a vivid picture of the confusion and excitement of research in progress.’
P. J. E. Peebles, Princeton University
‘a pleasure to read’
New Scientist
* * *
VERY SHORT INTRODUCTIONS are for anyone wanting a stimulating and accessible way in to a new subject. They are written by experts, and have been published in more than 25 languages worldwide.
The series began in 1995, and now represents a wide variety of topics in history, philosophy, religion, science, and the humanities. Over the next few years it will grow to a library of around 200 volumes – a Very Short Introduction to everything from ancient Egypt and Indian philosophy to conceptual art and cosmology.
* * *
Very Short Introductions available now:
ANCIENT PHILOSOPHY
Julia Annas
THE ANGLO-SAXON AGE
John Blair
ANIMAL RIGHTS David DeGrazia
ARCHAEOLOGY Paul Bahn
ARCHITECTURE
Andrew Ballantyne
ARISTOTLE Jonathan Barnes
ART HISTORY Dana Arnold
ART THEORY Cynthia Freeland
THE HISTORY OF
ASTRONOMY Michael Hoskin
ATHEISM Julian Baggini
AUGUSTINE Henry Chadwick
BARTHES Jonathan Culler
THE BIBLE John Riches
BRITISH POLITICS
Anthony Wright
BUDDHA Michael Carrithers
BUDDHISM Damien Keown
CAPITALISM James Fulcher
THE CELTS Barry Cunliffe
CHOICE THEORY
Michael Allingham
CHRISTIAN ART Beth Williamson
CLASSICS Mary Beard and
John Henderson
CLAUSEWITZ Michael Howard
THE COLD WAR
Robert McMahon
CONTINENTAL PHILOSOPHY
Simon Critchley
COSMOLOGY Peter Coles
CRYPTOGRAPHY
Fred Piper and Sean Murphy
DADA AND SURREALISM
David Hopkins
DARWIN Jonathan Howard
DEMOCRACY Bernard Crick
DESCARTES Tom Sorell
DRUGS Leslie Iversen
THE EARTH Martin Redfern
EGYPTIAN MYTHOLOGY
Geraldine Pinch
EIGHTEENTH-CENTURY
BRITAIN Paul Langford
THE ELEMENTS Philip Ball
EMOTION Dylan Evans
EMPIRE Stephen Howe
ENGELS Terrell Carver
ETHICS Simon Blackburn
THE EUROPEAN UNION
John Pinder
EVOLUTION
Brian and Deborah Charlesworth
FASCISM Kevin Passmore
THE FRENCH REVOLUTION
William Doyle
FREUD Anthony Storr
GALILEO Stillman Drake
GANDHI Bhikhu Parekh
GLOBALIZATION
Manfred Steger
HEGEL Peter Singer
HEIDEGGER Michael Inwood
HINDUISM Kim Knott
HISTORY John H. Arnold
HOBBES Richard Tuck
HUME A. J. Ayer
IDEOLOGY Michael Freeden
INDIAN PHILOSOPHY
Sue Hamilton
INTELLIGENCE Ian J. Deary
ISLAM Malise Ruthven
JUDAISM Norman Solomon
JUNG Anthony Stevens
KANT Roger Scruton
KIERKEGAARD Patrick Gardiner
THE KORAN Michael Cook
LINGUISTICS Peter Matthews
LITERARY THEORY
Jonathan Culler
LOCKE John Dunn
LOGIC Graham Priest
MACHIAVELLI Quentin Skinner
MARX Peter Singer
MATHEMATICS Timothy Gowers
MEDIEVAL BRITAIN
John Gillingham and
Ralph A. Griffiths
MODERN IRELAND
Senia Pašeta
MOLECULES Philip Ball
MUSIC Nicholas Cook
NIETZSCHE Michael Tanner
NINETEENTH-CENTURY
BRITAIN Christopher Harvie and
H. C. G. Matthew
NORTHERN IRELAND
Marc Mulholland
PAUL E. P. Sanders
PHILOSOPHY Edward Craig
PHILOSOPHY OF SCIENCE
Samir Okasha
PLATO Julia Annas
POLITICS Kenneth Minogue
POLITICAL PHILOSOPHY
David Miller
POSTCOLONIALISM
Robert Young
POSTMODERNISM
Christopher Butler
POSTSTRUCTURALISM
Catherine Belsey
PREHISTORY Chris Gosden
PRESOCRATIC PHILOSOPHY
Catherine Osborne
PSYCHOLOGY Gillian Butler and
Freda McManus
QUANTUM THEORY
John Polkinghorne
ROMAN BRITAIN Peter Salway
ROUSSEAU Robert Wokler
RUSSELL A. C. Grayling
RUSSIAN LITERATURE
Catriona Kelly
THE RUSSIAN REVOLUTION
S. A. Smith
SCHIZOPHRENIA
Chris Frith and Eve Johnstone
SCHOPENHAUER
Christopher Janaway
SHAKESPEARE Germaine Greer
SOCIAL AND CULTURAL
ANTHROPOLOGY
John Monaghan and Peter Just
SOCIOLOGY Steve Bruce
SOCRATES C. C. W. Taylor
SPINOZA Roger Scruton
STUART BRITAIN John Morrill
TERRORISM Charles Townshend
THEOLOGY David F. Ford
THE TUDORS John Guy
TWENTIETH-CENTURY
BRITAIN Kenneth O. Morgan
WITTGENSTEIN A. C. Grayling
WORLD MUSIC Philip Bohlman
Available soon:
AFRICAN HISTORY
John Parker and Richard Rathbone
ANCIENT EGYPT Ian Shaw
THE BRAIN Michael O’Shea
BUDDHIST ETHICS
Damien Keown
CHAOS Leonard Smith
CHRISTIANITY Linda Woodhead
CITIZENSHIP Richard Bellamy
CLASSICAL ARCHITECTURE
Robert Tavernor
CLONING Arlene Judith Klotzko
CONTEMPORARY ART
Julian Stallabrass
THE CRUSADES
Christopher Tyerman
DERRIDA Simon Glendinning
DESIGN John Heskett
DINOSAURS David Norman
DREAMING J. Allan Hobson
ECONOMICS Partha Dasgupta
THE END OF THE WORLD
Bill McGuire
EXISTENTIALISM Thomas Flynn
THE FIRST WORLD WAR
Michael Howard
FREE WILL Thomas Pink
FUNDAMENTALISM
Malise Ruthven
HABERMAS Gordon Finlayson
HIEROGLYPHS
Penelope Wilson
HIROSHIMA B. R. Tomlinson
HUMAN EVOLUTION
Bernard Wood
INTERNATIONAL RELATIONS
Paul Wilkinson
JAZZ Brian Morton
MANDELA Tom Lodge
MEDICAL ETHICS
Tony Hope
THE MIND Martin Davies
MYTH Robert Segal
NATIONALISM Steven Grosby
PERCEPTION Richard Gregory
PHILOSOPHY OF RELIGION
Jack Copeland and Diane Proudfoot
PHOTOGRAPHY
Steve Edwards
THE RAJ Denis Judd
THE RENAISSANCE
Jerry Brotton
RENAISSANCE ART
Geraldine Johnson
SARTRE Christina Howells
THE SPANISH CIVIL WAR
Helen Graham
TRAGEDY Adrian Poole
THE TWENTIETH CENTURY
Martin Conway
For more information visit our web site
www.oup.co.uk/vsi
Peter Coles
COSMOLOGY
A Very Short Introduction
Great Clarendon Street, Oxford OX2 6DP
Oxford University Press is a department of the University of Oxford.
It furthers the University’s objective of excellence in research, scholarship,
and education by publishing worldwide in
Oxford New York
Auckland Bangkok Buenos Aires Cape Town Chennai
Dar es Salaam Delhi Hong Kong Istanbul Karachi Kolkata
Kuala Lumpur Madrid Melbourne Mexico City Mumbai Nairobi
São Paulo Shanghai Taipei Tokyo Toronto
Oxford is a registered trade mark of Oxford University Press
in the UK and in certain other countries
Published in the United States
by Oxford University Press Inc., New York
© Peter Coles 2001
The moral rights of the author have been asserted
Database right Oxford University Press (maker)
First published as an Oxford University Press paperback 2001
All rights reserved. No part of this publication may be reproduced,
stored in a retrieval system, or transmitted, in any form or by any means,
without the prior permission in writing of Oxford University Press,
or as expressly permitted by law, or under terms agreed with the appropriate
reprographics rights organizations. Enquiries concerning reproduction
outside the scope of the above should be sent to the Rights Department,
Oxford University Press, at the address above
You must not circulate this book in any other binding or cover
British Library Cataloguing in Publication Data
Data available
Library of Congress Cataloging in Publication Data
Data available
ISBN 13: 978–0–19–285416–2
ISBN 10: 0–19–285416–X
5 7 9 10 8 6 4
Typeset by RefineCatch Ltd, Bungay, Suffolk
Printed in Great Britain by
TJ International Ltd., Padstow, Cornwall
Preface
This book is an introduction to the ideas, methods, and results of scientific cosmology.
The subject matter of cosmology is everything that exists. The entire system of things that is the Universe encompasses the very large and the very small, the astronomical scale of stars and galaxies and the microscopic world of elementary particles. Between these limits lies a complex hierarchy of structure and pattern that results from the interplay of forces and matter. And in the midst of all this we find ourselves.
The aim of cosmology is to place all known physical phenomena within a single coherent framework. This is an ambitious goal, and significant gaps in our knowledge still remain. Nevertheless, there has been such rapid progress that many cosmologists regard this as something of a ‘Golden Age’. I have taken a roughly historical path through the subject to show how it has evolved, how it has drawn together many different conceptual strands along the way, and how new avenues for exploration have opened up with improvements in technology.
It is a good time to write this kind of book. An emerging consensus about the form and distribution of matter and energy in the Universe suggests that a complete understanding of it all may be within reach. But interesting puzzles remain, and if history tells us anything it is that we should expect surprises!
Contents
List of illustrations
1 A brief history
2 Einstein and all that
3 First principles
4 The expanding Universe
5 The Big Bang
6 What’s the matter with the Universe?
7 Cosmic structures
8 A theory of everything?
Epilogue
Further reading
Index
List of illustrations
1 The Babylonian God Marduk
From The Mythology of All Races, ed. J. A. MacCulloch (Cooper Square, 1964); see Echoes of the Ancient Skies, E. C. Krupp, p. 68.
2 Thought-experiment illustrating the equivalence principle
From P. Coles, Einstein and the Birth of Big Science (Icon Books, 2000)
3 The bending of light
From P. Coles, Einstein and the Birth of Big Science (Icon Books, 2000)
4 The curvature of space
From P. Coles, Einstein and the Birth of Big Science (Icon Books, 2000)
5 Open, flat, and closed spaces in two dimensions
6 Hubble’s Law
7 The Hubble diagram
From Hubble (1929), Proceedings of Nat. Acad. Sci., 15, 168–173; see The Expanding Universe, R. C. Smith, p. 92
8 Redshift
9 The Hubble diagram updated
10 The Hubble Space Telescope
Space Telescope Science Institute
11 Cepheids in M100
Space Telescope Science Institute
12 The age of the Universe
13 The spectrum of the cosmic microwave background
NASA and George Smoot
14 Looking back in time
15 Building blocks of matter
Fermi National Accelerator Laboratory
16 The Friedmann models
17 The Coma cluster
National Optical Astronomy Observatories
18 Coma in X-rays
High Energy Astrophysics Archive Research Center
19 Gravitational lensing
Space Telescope Science Institute
20 The Andromeda Nebula
Jason Ware
21 The Lick Map
Steve Maddox
22 The 2dF galaxy redshift survey
Steve Maddox and the 2dF Consortium
23 The COBE ripples
NASA and George Smoot
24 The Hubble deep field
The Virgo Consortium
25 Simulation of structure formation
Space Telescope Science Institute
26 BOOMERANG
The Boomerang Collaboration
27 The flatness of space
The Boomerang Collaboration
28 A theory of everything
29 Space–time foam
From 300 Years of Gravity, ed. S. W. Hawking and W. Israel (Cambridge University Press, 1987), p. 625
Chapter 1
A brief history
Cosmology is a relatively new branch of physical science. This is quite a paradoxical state of affairs, because among the questions cosmology asks are some of the most ancient that humanity has ever posed. Is the Universe infinite? Has it been around for ever? If not, how did it come into being? Will it ever come to an end? Since prehistoric times, humans have sought to build some kind of conceptual framewor
k for answering questions about the world and their relationship to it. The first such theories or models were myths that we nowadays regard as naive or meaningless. But these primitive speculations demonstrate the importance we as a species have always attached to thinking about the Universe. Today’s cosmologists use very different language and symbolism, but their motivation is largely the same as our distant ancestors. What I want to do in this chapter is briefly chart the historical development of cosmology ‘the subject’ and explain how some of the key ideas have evolved. I hope this will also provide a useful springboard into the other chapters in which I explore these key ideas in more detail.