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1、TheFutureofQuantumCosmologyS.W.HawkingDepartmentofAppliedMathematicsandTheoreticalPhysics,UniversityofCambridge,SilverStreet,CambridgeCB39EW,UnitedKingdom.August1999AbstractThisisatranscriptofalecturegivenbyProfessorS.W.HawkingfortheNATOASIconference.Profe
2、ssorHawkingistheLucasianProfessorattheUniversityofCambridge,England.Inthislecture,IwilldescribewhatIseeastheframeworkforquantumcosmology,onthebasisofMtheory.IshalladoptthenoboundaryproposalandshallarguethattheAnthropicPrincipleisessential,ifoneistopickoutas
3、olutiontorepresentouruniversefromthewholezooofsolutionsallowedbyMtheory.Cosmologyusedtoberegardedasapseudoscience,anareawherewildspeculationwasuncon-strainedbyanyreliableobservations.Wenowhavelotsandlotsofobservationaldata,andagenerallyagreedpictureofhowthe
4、universeisevolving.Butcosmologyisstillnotaproperscience,inthesensethat,asusuallypracticed,ithasnopredictivepower.Ourobservationstellusthepresentstateoftheuniverse,andwecanruntheequationsbackwardtocalculatewhattheuniversewaslikeatearliertimes.Butallthattells
5、usisthattheuniverseisasitisnowbecauseitwasasitwasthen.Togofurther,andbearealscience,cosmologywouldhavetopredicthowtheuniverseshouldbe.Wecouldthentestitspredictionsagainstobservation,likeinanyotherscience.Thetaskofmakingpredictionsincosmology,ismademoredicu
6、ltbythesingularitytheoremsthatRogerPenroseandIproved.TheUniversemusthavehadabeginningif1.Einstein'sGeneralTheoryofRelativityiscorrect2.Theenergydensityispositive(1)3.TheuniversecontainstheammountofmatterweobserveTheseshowedthatifGeneralRelativitywerecorrect
7、,theuniversewouldhavebegunwithasin-gularity.Ofcourse,wewouldexpectclassicalGeneralRelativitytobreakdownnearasingularity,whenquantumgravitationale ectshavetobetakenintoaccount.Sowhatthesingularitytheoremsemail:S.W.Hawking@damtp.cam.ac.uk1arereallytellingusi
8、sthattheuniversehadaquantumorigin,andthatweneedatheoryofquantumcosmology,ifwearetopredictthepresentstateoftheuniverse.Atheoryofquantumcosmology,hasthreeaspects.QuantumCosmology1.Localtheory-MTheory2.Bo
