Module4GreatScientistsPartTwoTeachingResourcesSection1Backgroundreadings1.cashcropInagriculture,acashcropisacropwhichissoldformoney.Thetermisusedtodifferentiatefromsubsistencecrops,whicharethosefedtotheproducer'sownlivestockorgrownasfoodfortheproducer'sfamily.2.hybridhybrid,termappliedbyplantandanimalbreederstotheoffspringofacrossbetweentwodifferentsubspeciesorspecies,andbygeneticiststotheoffspringofparentsdifferinginanygeneticcharacteristic.3.cosmologyCosmologyisthestudyoftheuniverseinitstotalityandbyextensionman'splaceinit.Thoughthewordcosmologyisitselfoffairlyrecentorigin,firstusedinChristianWolff'sCosmologiaGeneralis(1730),thestudyoftheuniversehasalonghistoryinvolvingscience,philosophy,esotericism,andreligion.4.CambridgeThecityofCambridgeisanoldEnglishUniversitytownandtheadministrativecenterofthecountyofCambridgeshire.Itliesapproximately50miles(80km)north-northeastofLondonandissurroundedbyanumberofsmallertownsandvillages.ItisalsoattheheartofSiliconFen,whichhasareputationastheleadinghigh-technologycenterofBritainandisoneofthemajorconstituentpartsoftheOxford-CambridgeArc.5.OxfordOxfordisacityandlocalgovernmentdistrictinOxfordshire,England,withapopulationof134,248(2001census).ItishometotheUniversityofOxford,theoldestuniversityintheEnglish-speakingworld.6.relativityrelativity,physicaltheory,introducedbyAlbertEinstein,thatdiscardstheconceptofabsolutemotionandinsteadtreatsonlyrelativemotionbetweentwosystemsorframesofreference.Oneconsequenceofthetheoryisthatspaceandtimearenolongerviewedasseparate,independententitiesbutratherareseentoformafour-dimensionalcontinuumcalledspace-time.7.ResearchfieldsofHawkingHawking’sprincipalfieldsofresearcharetheoreticalcosmologyandquantumgravity.In1971,incollaborationwithRogerPenrose,heprovidedmathematicalsupportfortheBigBangtheoryoftheoriginoftheuniverse;ifthegeneraltheoryofrelativitywascorrect,theuniversemusthaveasingularity,orstartingpoint,inspace-time.Hawkingalsosuggestedthat,aftertheBigBang,primordialorminiblackholeswereformed.Heshowedthat,neglectingquantummechanicaleffects,thesurfaceareaofablackholecanincreasebutneverdecreasederivedalimittotheradiationemittedwhenblackholescollide,andthatasingleblackholecannotbreakapartintotwoseparateblackholes.In1974,hecalculatedthatblackholesthermallycreateandemitsubatomicparticlesuntiltheyexhausttheirenergyandexplode.KnownasHawkingradiation,thistheorywas用心爱心专心firsttodescribeamathematicallinkamonggravity,quantummechanics,andthermodynamics.In1981,Hawkingproposedthat,althoughtheuniversehadnoboundary,itwasfiniteinspace-time;1983sawhismathematicalproofofthistheory.用心爱心专心
