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1、TheFutureofQuantumCosmologyS.W.HawkingDepartmentofAppliedMathematicsandTheoreticalPhysics,UniversityofCambridge,SilverStreet,CambridgeCB39EW,UnitedKingdom.August1999AbstractThisisatranscriptofalecturegivenbyProfessorS.W.HawkingfortheNATOASIconference.ProfessorHawkingistheLucasianProfesso
2、rattheUniversityofCambridge,England.Inthislecture,IwilldescribewhatIseeastheframeworkforquantumcosmology,onthebasisofMtheory.IshalladoptthenoboundaryproposalandshallarguethattheAnthropicPrincipleisessential,ifoneistopickoutasolutiontorepresentouruniversefromthewholezooofsolutionsallowedby
3、Mtheory.Cosmologyusedtoberegardedasapseudoscience,anareawherewildspeculationwasuncon-strainedbyanyreliableobservations.Wenowhavelotsandlotsofobservationaldata,andagenerallyagreedpictureofhowtheuniverseisevolving.Butcosmologyisstillnotaproperscience,inthesensethat,asusuallypracticed,ithasn
4、opredictivepower.Ourobservationstellusthepresentstateoftheuniverse,andwecanruntheequationsbackwardtocalculatewhattheuniversewaslikeatearliertimes.Butallthattellsusisthattheuniverseisasitisnowbecauseitwasasitwasthen.Togofurther,andbearealscience,cosmologywouldhavetopredicthowtheuniversesho
5、uldbe.Wecouldthentestitspredictionsagainstobservation,likeinanyotherscience.Thetaskofmakingpredictionsincosmology,ismademoredicultbythesingularitytheoremsthatRogerPenroseandIproved.TheUniversemusthavehadabeginningif1.Einstein'sGeneralTheoryofRelativityiscorrect2.Theenergydensityispositiv
6、e(1)3.TheuniversecontainstheammountofmatterweobserveTheseshowedthatifGeneralRelativitywerecorrect,theuniversewouldhavebegunwithasin-gularity.Ofcourse,wewouldexpectclassicalGeneralRelativitytobreakdownnearasingularity,whenquantumgravitationale ectshavetobetakenintoaccount.Sowhatthesingular
7、itytheoremsemail:S.W.Hawking@damtp.cam.ac.uk1arereallytellingusisthattheuniversehadaquantumorigin,andthatweneedatheoryofquantumcosmology,ifwearetopredictthepresentstateoftheuniverse.Atheoryofquantumcosmology,hasthreeaspects.QuantumCosmology1.Localtheory-MTheory2.Bo
