TheconferenceChanceinPhysics:FoundationsandPerspectiveswasheldfrom 29thNovemberto3rdDecember1999inIschia,Italy. Itwassponsoredbythe IstitutoItalianoPerGliStudiFiloso?ciinNaples,bytheDeutscheForschun- gemeinschaft(DFG),andbytheSociet`aItalianaDiFondamentiDellaFisica. SponsoringbytheInternationalSchoolforAdvancedStudies(ISAS)ofTrieste, Italy,madethecompilationofthisvolumepossible;thefundingbytheIs- tutoItalianoPerGliStudiFiloso?ciwascrucialfortheconferenceandisvery gratefullyacknowledged. TheIstitutomanagedtoprovideauniqueatmosphere foraninterdisciplinarymeeting,andtheseproceedingsre?ectindeedthevery friendlybutneverthelessintenseandneverendingdiscussionsononeofthemost debatedissuesofscience:probability,andinparticularprobabilityinphysics. Wegratefullyacknowlegdetheorganisationalworkaswellastheeditorialwork donebyoursecretaryofthemeetingPhDstudentRoderichTumulka. Themeetingwasintendedtostimulaterenewedre?ectiononthefundam- talandpracticalaspectsofprobabilityinphysics,inparticularthefoundations ofstatisticalsechanics,theprobabilityinthefoundationsofquantummech- ics,thealgebraicviewofprobabilityandthephilosophyofprobabilityinits interrelationwithphysics. Questionslikewhatprobabilityis,orwhatitisabout,orhowprobability entersphysicsareofasubtlekind. Theyaredi?cultinvariousways,often mixedupwiththeenormouscomplexityandtheinescapablelackofmat- maticalrigorinthephysicalapplication,orwiththefoundationalproblemsof quantummechanics,wheretheprobabilisticignoranceconcerningthevaluesof certainphysicalquantitieshasevenbeenelevatedtoamatterofprinciple. At present,theunderstandingofprobabilityinphysicsisalmostaspersonalasthe understandingofquantumtheory. Theaimoftheconferencewasthustofocusonideasaboutprobabilityin physics,itsmeaninganditsphilosophicalimplications,byreviewingthedi?erent facetsofprobabilityinphysicsinitsmodernsettingsandbytakingintoaccount modernquantumtheorieswithoutobservers,wheretheoriginofprobabilityis notmysti?edbydogmatism. Thereviewsweregiveninone-hourtalks,andthediscussionswereheldin theformofroundtables,whereshortercontributionswerealsogiven. Thespeakerswereaskednottodilutethemainthemesoftheconference withtechnicalitiesandtofocussharplyontheissueofprobability. Thiswas VI Preface takentoheartbyallspeakersandthemeetingthusprovedverysuccessful. The contributionsinthisvolumeconsequentlyfocusonconceptualissues,andthey makeworthwhilereadingforspecialistsinthe?eldoffoundationsaswellasfor nonspecialists,becauseextensivetechnicalpriorknowledgeisnotrequired. The contributionshavebeenleftintheordertheywerediscussedinthemeeting, whichprovedtobeaverynaturalone: 1. ClassicalStatisticalMechanics,whereBoltzmann sunderstandingofstat- ticalmechnanicsasarisingfromkineticgastheoryisreviewedandputinto modernperspectives,withanoutlookonrelativisticstatisticalmechanics. Therelativelackofemphasisonthee?ectofchaoticbehaviouronthefo- dationsofprobabilityisnoteworthy. 2. QuantumMechanics,wherewereviewthoseontologicalquantumtheories, thathavebeenmostseriouslydiscussedintherecentyears. Amongthese areadeterministictheory(Bohmianmechanics)andboththeintrinsically randomtheoriesofwavepacketreductionandtheoperator-basedconsistent (decoherent)histories. Itstartswiththe orthodox view,againwith- phasisontheprobabilisticaspectsofthesetheories. 3. Chaoticsystems,wherethedynamicalaspectsforthefoundationsofpro- bilityinphysicsareadressed. 4. PhilosophyofProbability,wheretheissuesoftheearliersectionsarefurther scrutinizedonphilosophicalgrounds. Thesecontributionshavenoabstracts. Thebookstartswithanintroductorypaper,inwhichalmostallthetopics whicharediscussedbythelatercontributionsarecriticallypresented. M unchen, J. Bricmont,D. Durr, M. C. Galavotti, January2001 G. C. Ghirardi,F. Petruccione,N. Zangh`? TableofContents PartI Introduction Bayes,BoltzmannandBohm:ProbabilitiesinPhysics JeanBricmont. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 PartII ClassicalStatisticalMechanics TheRiseofStatisticalMe
Bayes, Boltzmann and Bohm: Probabilities in Physics.- Classical Statistical Mechanics.- The Rise of Statistical Mechanics.- Boltzmann's Approach to Statistical Mechanics.- Microscopic Time Reversibility and the Boltzmann Equation.- The Direction of Time.- How to Implement Boltzmann's Probabilistic Ideas in a Relativistic World?.- Quantum Mechanics.- Probability in Orthodox Quantum Mechanics: Probability as a Postulate Versus Probability as an Emergent Phenomenon.- Bohmian Mechanics.- Chance of Reduction as Chance of Spontaneous Localisation.- Probabilities, Decohering Histories, and the Interpretation of Quantum Mechanics.- Space Time and Probability.- Hidden Variables, Statistical Mechanics and the Early Universe.- Perspectives of the Dynamical Reduction Program.- Relativistic Theory of Continuous Measurements.- Probabilistic Results for Six Detectors in a Three-Particle GHZ Experiment.- Classical Versus Quantum Probabilities.- Chaotic Systems.- Does Quantum Chaos Exist?.- Time-Scales for the Approach to Thermal Equilibrium.- Einstein's Nonconventional Conception of the Photon and the Modern Theory of Dynamical Systems.- Philosophy of Probability.- What Interpretation for Probability in Physics?.- Statistical Mechanics and the Propensity Interpretation of Probability.- Interpreting Probabilities: What's Interference Got to Do with It?.
