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1、TheFutureofQuantumCosmologyS.W.HawkingDepartmentofAppliedMathematicsandTheoreticalPhysics,UniversityofCambridge,SilverStreet,CambridgeCB39EW,UnitedKingdom.August1999AbstractThisisatranscriptofalecturegivenbyProfessorS.W.HawkingfortheNATOASIconference.ProfessorHawkingistheLucasianPro
2、fessorattheUniversityofCambridge,England.Inthislecture,IwilldescribewhatIseeastheframeworkforquantumcosmology,onthebasisofMtheory.IshalladoptthenoboundaryproposalandshallarguethattheAnthropicPrincipleisessential,ifoneistopickoutasolutiontorepresentouruniversefromthewholezooofsolution
3、sallowedbyMtheory.Cosmologyusedtoberegardedasapseudoscience,anareawherewildspeculationwasuncon-strainedbyanyreliableobservations.Wenowhavelotsandlotsofobservationaldata,andagenerallyagreedpictureofhowtheuniverseisevolving.Butcosmologyisstillnotaproperscience,inthesensethat,asusuallyp
4、racticed,ithasnopredictivepower.Ourobservationstellusthepresentstateoftheuniverse,andwecanruntheequationsbackwardtocalculatewhattheuniversewaslikeatearliertimes.Butallthattellsusisthattheuniverseisasitisnowbecauseitwasasitwasthen.Togofurther,andbearealscience,cosmologywouldhavetopred
5、icthowtheuniverseshouldbe.Wecouldthentestitspredictionsagainstobservation,likeinanyotherscience.Thetaskofmakingpredictionsincosmology,ismademoredicultbythesingularitytheoremsthatRogerPenroseandIproved.TheUniversemusthavehadabeginningif1.Einstein'sGeneralTheoryofRelativityiscorrect2.
6、Theenergydensityispositive(1)3.TheuniversecontainstheammountofmatterweobserveTheseshowedthatifGeneralRelativitywerecorrect,theuniversewouldhavebegunwithasin-gularity.Ofcourse,wewouldexpectclassicalGeneralRelativitytobreakdownnearasingularity,whenquantumgravitationale ectshavetobetake
7、nintoaccount.Sowhatthesingularitytheoremsemail:S.W.Hawking@damtp.cam.ac.uk1arereallytellingusisthattheuniversehadaquantumorigin,andthatweneedatheoryofquantumcosmology,ifwearetopredictthepresentstateoftheuniverse.Atheoryofquantumcosmology,hasthreeaspects.QuantumCosmology1.Localtheory
8、-MTheory2.Bo
