Time and Chance

188 Pages·2003·0.81 MB·English

by  David Z Albert

TIME AND CHANCE

▲▲▲
DAVID Z ALBERT
TIME AND CHANCE
HARVARD UNIVERSITY PRESS
Cambridge,Massachusetts
London,England
Copyright©2000bythePresidentandFellowsofHarvardCollege
Allrightsreserved
PrintedintheUnitedStatesofAmerica
Second printing, 2003
LibraryofCongressCataloging-in-PublicationData
Albert,DavidZ.
Timeandchance/DavidZAlbert.
p. cm.
Includesindex.
ISBN0-674-00317-9(cloth)
ISBN 0-674-01132-5 (paper)
1.Timereversal. 2.Physics—Philosophy. I.Title.
QC173.59.T53A432000
530.11—dc21 00-056732
FOR BEN

CONTENTS
Preface ix
1. Time-ReversalInvariance 1
2. Thermodynamics 22
3. StatisticalMechanics 35
4. TheReversibilityObjectionsandthePast-Hypothesis 71
5. TheScopeofThermodynamics 97
6. TheAsymmetriesofKnowledgeandIntervention 113
7. QuantumMechanics 131
Appendix:GedankenexperimentswithHeatEngines 165
Index 171

PREFACE
Thisbookisintendedbothasanelementaryintroductionandasanoriginal
contributiontothedevelopmentofascientificaccountofthedistinctionbe-
tweenthepastandthefuture.
▲▲▲ Chapter1isarelativelystraightforwardrehearsalofwhatisperenni-
allyreferredtointhephysicalliteratureas“theproblemofthedirectionof
time”—butinwhatIhopeisanunprecedentedlypreciselanguageofphys-
ical states, and with what I hope is an unprecedentedly careful discussion
ofexactlywhatitmeansforasetofdynamicallawstodistinguish,ortofail
to distinguish, between the past and the future. Chapter 2, together with
themoredetailedappendixonGedankenexperimentswithheatengines,is
a report on the second law of thermodynamics—which is the point at
which distinctions between past and future have made their most explicit
and most widely heralded and most intensively studied appearance in the
laws of physics—very much along the lines of the beautiful treatment of
that subject in the famous book by Enrico Fermi. Chapter 3 is an outline,
more or less in the spirit of Ludwig Boltzmann, of the project of statistical
mechanics—including what I hope will prove relatively novel discussions
of the mathematical structure and the metaphysical status of the probabil-
ity-distributions over initial conditions, and of the connection between en-
tropyandinformation,andofthequestionofHaecceisstism,andofanum-
ber of other matters as well. Chapter 4 is about the famous objections to
that project due to J. Loschmidt and Ernst Zermello and Henri Poincaré,
and also about what seems to me to be the proper remedy for those objec-
tions—which is a new and fundamental and non-dynamical law of nature
calledthe“past-hypothesis.”Chapter5isacritiqueofthelonghistoryofat-