AlbertEinsteinwasbornatUlm,inW眉rttemberg,Germany,onMarch14,1879.SixweekslaterthefamilymovedtoMunichandhebeganhisschoolingthereattheLuitpoldGymnasium.Later,theymovedtoItalyandAlbertcontinuedhiseducationatAarau,Switzerlandandin1896heenteredtheSwissFederalPolytechnicSchoolinZurichtobetrainedasateacherinphysicsandmathematics.In1901,theyearhegainedhisdiploma,heacquiredSwisscitizenshipand,ashewasunabletofindateachingpost,heacceptedapositionastechnicalassistantintheSwissPatentOffice.In1905heobtainedhisdoctor'sdegree. 　　DuringhisstayatthePatentOffice,andinhissparetime,heproducedmuchofhisremarkableworkandin1908hewasappointedPrivatdozentinBerne.In1909hebecameProfessorExtraordinaryatZurich,in1911ProfessorofTheoreticalPhysicsatPrague,returningtoZurichinthefollowingyeartofillasimilarpost.In1914hewasappointedDirectoroftheKaiserWilhelmPhysicalInstituteandProfessorintheUniversityofBerlin.HebecameaGermancitizenin1914andremainedinBerlinuntil1933whenherenouncedhiscitizenshipforpoliticalreasonsandemigratedtoAmericatotakethepositionofProfessorofTheoreticalPhysicsatPrinceton*.HebecameaUnitedStatescitizenin1940andretiredfromhispostin1945. 　　AfterWorldWarII,EinsteinwasaleadingfigureintheWorldGovernmentMovement,hewasofferedthePresidencyoftheStateofIsrael,whichhedeclined,andhecollaboratedwithDr.ChaimWeizmanninestablishingtheHebrewUniversityofJerusalem. 　　Einsteinalwaysappearedtohaveaclearviewoftheproblemsofphysicsandthedeterminationtosolvethem.Hehadastrategyofhisownandwasabletovisualizethemainstagesonthewaytohisgoal.Heregardedhismajorachievementsasmerestepping-stonesforthenextadvance. 　　Atthestartofhisscientificwork,EinsteinrealizedtheinadequaciesofNewtonianmechanicsandhisspecialtheoryofrelativitystemmedfromanattempttoreconcilethelawsofmechanicswiththelawsoftheelectromagneticfield.Hedealtwithclassicalproblemsofstatisticalmechanicsandproblemsinwhichtheyweremergedwithquantumtheory:thisledtoanexplanationoftheBrownianmovementofmolecules.Heinvestigatedthethermalpropertiesoflightwithalowradiationdensityandhisobservationslaidthefoundationofthephotontheoryoflight. 　　InhisearlydaysinBerlin,Einsteinpostulatedthatthecorrectinterpretationofthespecialtheoryofrelativitymustalsofurnishatheoryofgravitationandin1916hepublishedhispaperonthegeneraltheoryofrelativity.Duringthistimehealsocontributedtotheproblemsofthetheoryofradiationandstatisticalmechanics. 　　Inthe1920's,Einsteinembarkedontheconstructionofunifiedfieldtheories,althoughhecontinuedtoworkontheprobabilisticinterpretationofquantumtheory,andheperseveredwiththisworkinAmerica.Hecontributedtostatisticalmechanicsbyhisdevelopmentofthequantumtheoryofamonatomicgasandhehasalsoaccomplishedvaluableworkinconnectionwithatomictransitionprobabilitiesandrelativisticcosmology. 　　Afterhisretirementhecontinuedtoworktowardstheunificationofthebasicconceptsofphysics,takingtheoppositeapproach,geometrisation,tothemajorityofphysicists. 　　Einstein'sresearchesare,ofcourse,wellchronicledandhismoreim