The bigger bang

146 Pages·2002·1.031 MB·English

by  James E. Lidsey

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The Bigger Bang
Societies through the ages have always been fascinated with our origins.
In the last few years, scientists have begun to answer some of the most
fundamentalquestionsabouttheoriginandearlyevolutionoftheuniverse.
This book presents a fresh, engaging and highly readable introduction to
theseideas.
Usingnovel,down-to-earthanalogies,authorJamesLidseysteersusdeftly
onajourneytothecuttingedgeofcosmology.Step-by-step,wetravelbackin
timethroughLidsey’sbookuntilwearriveattheveryoriginoftheuniverse.
There we look at the fascinating ideas scientists are currently developing
to explain what happened in the first billion, billion, billion, billionth of
a second of the universe’s existence – the ‘inflationary’ epoch. Along the
way, we are given lucid accounts of many fascinating topics in theoretical
cosmology,includingthelatestideasonsuperstrings,paralleluniverses,and
theultimatefateofouruniverse.Wealsodiscoverhowtheworldofthevery
small(describedbythephysicsofelementaryparticles)andtheworldofthe
verylarge(describedbycosmology)areinextricablylinkedbyeventswhich
wovethemtogetherinthefirstfewmomentsoftheuniverse’shistory.
Lucid analogies, clear and concise prose and straightforward language
makethisbookadelighttoread.Itmakesaccessibletothegeneralreader
someofthemostprofoundandcomplexideasabouttheoriginofouruni-
versecurrentlyvexingthemindsoftheworld’sbestscientists.
JamesE.LidseyisaRoyalSocietyUniversityResearchFellowatQueenMary
andWestfieldCollege,UniversityofLondon.Hisresearchinterestsfocuson
theveryearlyuniverse,especiallyinflationandthecosmologicalaspectsof
superstringtheory.In1998,heappearedintheSundayTimes“Hot100”list
ofpromisingacademics.Forrecreation,heislearningtoplaythemandolin,
butwithlimitedsuccesstodate.

The Bigger Bang
James E. Lidsey
QueenMaryandWestfieldCollege
UniversityofLondon
  
Cambridge, New York, Melbourne, Madrid, Cape Town, Singapore, São Paulo
Cambridge University Press
The Edinburgh Building, Cambridge  , United Kingdom
Published in the United States by Cambridge University Press, New York
www.cambridge.org
Information on this title: www.cambridge.org/9780521012737
© Cambridge University Press 2000
This book is in copyright. Subject to statutory exception and to the provision of
relevant collective licensing agreements, no reproduction of any part may take place
without the written permission of Cambridge University Press.
First published in print format 2002
ISBN-13 978-0-511-06738-9 eBook (EBL)
ISBN-10 0-511-06738-0 eBook (EBL)
ISBN-13 978-0-521-01273-7 paperback
ISBN-10 0-521-01273-2 paperback
Cambridge University Press has no responsibility for the persistence or accuracy of
s for external or third-party internet websites referred to in this book, and does not
guarantee that any content on such websites is, or will remain, accurate or appropriate.
Canto edition 2002
Contents
Preface pagevii
Acknowledgements ix
1 TheStructureoftheUniverse 1
2 WhyDoestheSunShine? 8
3 TheExpansionoftheUniverse 18
4 Space,TimeandGravity 23
5 ParticlesandForces 32
6 GrandUnification,HigherDimensionsandSuperstrings 43
7 TheBigBang 55
8 BeyondtheBigBang 66
9 TheInflatingUniverse 77
10 TheEternalUniverse 87
11 BlackHoles 96
12 TheBirthoftheUniverse 112
Index 131
v

Preface
We live in a big universe. Even if we were able to travel across the
universe at the speed of light, the journey would take us at least ten
billion years. Why is the universe so large? Has the universe always
been this big, or was it smaller in the past? If smaller, how small was
it?Wasthereatimewhenthevolumeoftheuniversevanished?
Wecanaskrelatedquestionsregardingmatterintheuniverse.Why
istheuniversenotempty?Fromwheredotheatomsthatmakeupour
bodiesoriginate?Whenweretheseatomscreated?
Questions such as these lead us inevitably to the origin of the uni-
verse.Didtheuniversehaveadefinitebeginning,orhasitalwaysex-
isted?Ifithadabeginning,canwetalkmeaningfullyaboutwhatmight
havehappenedbeforehand?Andwhatcausedtheuniversetocomeinto
existenceinthefirstplace?
Thepurposeofthisbookistoaddressquestionssuchasthese.More-
over, because our own origin is linked with that of the universe as a
whole, we are indirectly studying our own past when we investigate
thebeginningoftheuniverse.
We will see that the structure of the universe is intimately related
tothestructureofthesmallestelementaryparticles.Thisrelationship
between the world of the very large and that of the very small was
manifestevenduringthefirstsecondoftheuniverse’shistory.Remark-
ably,theconditionsthatprevailedwhentheuniversewasnomorethan
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Preface
a fraction of a second old may have led to the formation of galaxies,
starsandplanets.Ourexistencebillionsofyearslaterdependsdirectly
onwhathappenedatthatveryearlytime.
Throughout this book we will encounter very large and very small
numbers.Thestandardnotationistoexpresssuchnumbersaspowers
of ten. Thus one million (1,000,000) is ten to the power six because
there are six zeros that follow the 1. It is written as 106. One billion
(one thousand million), then, is written as 109. We will refer to one
millionmillionasonetrillionandwriteitas1012.Verysmallnumbers
arewritteninasimilarway.Forexample,onemillionthisonedivided
byamillionandiswrittenas10−6.Onebillionthisdenotedby10−9,
andsoon.
We will also encounter in this book references to a wide range of
temperatures.Unlessotherwisestated,wewillmeasuretemperaturein
degreesCelsius.Thelowesttemperaturepossibleis−273.16oC,which
isknownasabsolutezero.Thetemperatureofouterspace,forexample,
isaboutthreedegreesaboveabsolutezero.
viii