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时间:2018-12-18
《高一英语 unit16《scientists at work》备课资料 旧人教版第一册》由会员上传分享,免费在线阅读,更多相关内容在教育资源-天天文库。
1、ReferenceforTeaching一、异域风情1.AlexanderBell'sGreatInventionMostpeopleknowthatAlexanderGrahamBellinventedthetelephone.Butnotmanyknowaboutaccothertalkingdeviceheinventedjustfouryearslater,in1880.Hecalledthedevicethephotophone.‘Photophone’comesfromtheGreekwordsfor‘light’and‘sound’.Thephotophonedidno
2、tuseelectricitytocarrysoundoverwiresbetweentwopeople.That'swhatatelephonedoes.Instead,thephotophoneusedabeamofsunlighttravellingthroughtheair.Withhisinvention,Bellcouldactuallytransmithumanspeechonabeamoflight.Todoso,hespokeclosetoathinmirrorthatwasreflectingsunlight.Thevibrationsofhisvoicecaus
3、edthemirrortovibrate,andthevibratingmirrorcausedthelighttovibrate.Thevibratinglighthitalight-sensitivecellinareceiverplacedsomedistanceaway.Thecellchangedthelightpatternsintoelectricalsignals.Earphoneschangedthesignalsbackintosounds.Bellbelievedthathisideaoftalkingonabeamoflightwouldprovetobeim
4、portant.Heoftencalledthephotophonehisgreatestinvention.Eventhoughthephotophonedependedonasourceofenergythatwasnotconstant—thesun—Bellwasn'tabitdiscouraged.Hefeltsurethatpeoplewouldonedaytalkusingbeamsoflight.TwomuchmorerecentdevelopmentsmadeBell'sdreamcometrue.In1960,ascientistbuiltthelaser.Ala
5、serproducesahighlyconcentratedbeamoflight.Shortlyafterward,otherscientistsdevelopedanewkindofopticalfibre.Theopticalfibreisaglassthread.Thenewfibrecouldcarrylightbeamslongdistances—asfarasseveralmiles.2.WhoInventedMotionPictures?Thepleasureswhichamoviefilmoffterstooureyeshavebeenpaidforwiththel
6、ossofsightofamanwhosenameishardlyknownoutsidetheannalsofscience—JosephPlateau,aBelgianprofessorborninBrusselsin1801.Hestudiedthemechanismofsight,beginningaseriesofmostdangerousexperimentsattheageof28bystaringintothesunfor25secondstoseewhattheeffectonhiseyeswouldbe.Hewasblindfornearlyamonth.Buth
7、ewentonexperimenting,increasingthelengthoftimeduringwhichhelookedintothesun,knowingthatintheendthiswouldcosthimhissight.Attheageof42hewascompletelyandincurablyblind;thesunhaddestroyedtheretinaofhiseyes.Buthecontinuedtoworkaswellas
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