深大研究生听力Lectures.docx

深大研究生听力Lectures.docx

《深大研究生听力Lectures.docx》由会员分享，可在线阅读，更多相关《深大研究生听力Lectures.docx（6页珍藏版）》请在冰豆网上搜索。

深大研究生听力Lectures

TonightI’mgoingtotalktoyouaboutthatremarkablecontinentAntarctica–remote,hostileandatpresentuninhabitedonapermanentbasis.Forearlyexplorers,itwastheultimatesurvivalcontest;forresearcherslikeme,itremainsaplaceofgreatintellectualchallenge;whileforthemoderntourist,it’ssimplyawildernessofgreatbeauty.

First,somefactsandfigures.Antarcticaisaplaceofextremes–thehighest,coldestandwindiestcontinentandoverfifty-eighttimesthesizeoftheUK.Theice-capcontainsalmost70％oftheworld’sfreshwaterand90％ofitsice,butwithverylowsnowfall,mostofthecontinenttechnicallyfallsunbelievablyintothecategoryof‘desert’!

hugeicebergsbreakoffthecontinenteachyear,whileinwinterhalfthesurroundingoceanfreezesover,whichmeansitssizealmostdoubles.

ResearchandexplorationhasbeengoingoninAntarcticaformorethantwohundredyears,andhasinvolvedscientistsfrommanydifferentcountries,whoworktogetheronresearchstations.Herescienceandtechnicalsupporthavebeenintegratedinaverycost-effectiveway–ourAntarcticresearchprogrammehasseveralsummers–onlystationsandtwoall-year-roundones;Iwasbasedononeoftheall-year-roundones.

Theresearchstationsarereallyself-containedcommunitiesofabouttwentypeople.There’slivingandworkingspace,akitchenwithahugefoodstore,asmallhospitalandawell-equippedgymtoensureeveryonekeepsfitintheirsparetime.Thestationgeneratesitsownelectricityandcommunicateswiththeoutsideworldusingasatellitelink.

Ourstation–ZeroOne–hadsomespecialfeatures.Itwasn’tbuiltonlandbutonanice-shelf,hundredsofmetersthick.Supplieswerebroughttousonlargesledgesfromashipfifteenkilometersawayattheiceedge.

LivingintheAntarctichasn’talwaysbeensocomfortable.Snowbuild-upscausedenormousproblemsforfourpreviousstationsonthesamesite,whichwereburiedandfinallycrushedbytheweight.Fortunatelyno-onewashurt,butthesebuildingsbecameahugechallengetoarchitectswhofinallycameupwitharemarkablesolution–thebuildingsareplacedonplatformswhichcanberaisedabovethechangingsnowlevelonlegswhichareextendable.

Foodisoneofthemostimportantaspectsofsurvivalinapolarclimate.Peoplelivingthereneedtoobtainalotmoreenergyfromtheirfood,bothtokeepwarmandtoundertakeheavyphysicalwork.MaybeyouknowthatanadultintheUKwillprobablyneedabout1,700kilocaloriesadayonaverage;someoneinAntarcticawillneedabout3,500–justoverdouble!

Thisenergyisprovidedbyfoodswhicharehighincarbohydrateandfat.

Rationsforfieldworkpresentandadditionalproblem.Theyneedtoprovidemaximumenergy,buttheymustalsobecompactandlightforeasytransport.Specialboxesareprepared,eachcontainingenoughfoodforonepersonfortwentydays.Youmaybefamiliarwithcoffeeprocessedbyfreeze-drying,whichpreservesthequalityofthefoodproductwhilemakingalargesavinginweight–well,thistypeofpresentationisidealinoursituation.Itwasn’tavailabletoearlierpolarexplorers,whosedietwascommonlyinsufficientfortheirhealth.

IthinkthatbeingatthecuttingedgeofsciencehasaspecialappealforeveryoneworkinginAntarctica,inwhatevercapacity.Asamarinebiologist,myownresearchwasfascinating;butit’sperhapsclimatechangeresearchthatisthemostcrucialfieldofstudy.

Withinthisgeneralfield,surveyingchangesinthevolumeandstabilityoftheice-capisvital,sincethesemayhaveprofoundeffectsonworldsealevelsandonoceancurrents.AsecondimportantareaismonitoringthesizeoftheholeintheozonelayeraboveAntarctica,sincethisisanindicatorofglobalultra–violetradiationlevels.Thirdly,bubblesintheice-sheetitselfprovideanindexofpollutionbecausefrozeninsidethemaresamplesofpreviousatmospheresoverthepast500,000years,andtheseprovideuswithevidencefortheeffectsofsuchhumanactivitiesasagricultureandindustry.

ThereareanincreasingnumberofopportunitiesforyoungpeopletoworkforaperiodinAntarctica–notonlyasresearchassistantsinprojectslikemine,butalsoinawiderangeofjunioradministrativeandtechnicalpositionsincludingvacanciesformap-makers.IhopethattheinsightsI’veprovidedwillencourageyoutotakeuptheseopportunitiesinthisfascinatingcontinent.

Thehistoryofmovingpictures

ManybelievethatthestoryfirstbeganinAmericain1877,whentwofriendswerearguingoverwhetherahorseeverhadall4feetorhoovesoffthegroundwhentheygalloped.Tosettlethebet,aphotographerwasaskedtophotographahorsegallopingandthebetwassettledbecauseyoucouldseethatallthehooveswereoffthegroundinsomeofthephotos.Whatwasevenmoreinterestingwasthatifthephotoswereshowninquicksuccessionthehorselookedlikeitwasrunning-inotherwords‘movingpictures’.

ThepersonwhobecameinterestedintakingthemovingpicturestoitsnextstepwasthefamousAmericaninventorThomasEdison.Actually,hedidn’tdotheworkhimselfbutratheraskedayoungScotsmaninhisemploytodesignasystem,whichhedid.Nowthisyoungfellowwascleverbecausethefirstthinghedidwasstudyothersystems-primitiveastheywere–ofmovingpicturesandthenputalltheexistingtechnologiestogethertomakethefirstentiremotionpicturesystem.Hedesignedacamera,aprojectiondeviceandthefilm.ThesystemwasfirstshowninNewYorkin1894andwasreallyverypopular.Apparentlypeoplelineduparoundtheblocktoseethewonderfulnewinvention.Therewere,however,acoupleofproblemswiththesystem.Thecameraweighedover200kilogramsandonlyonepersonatatimecouldseethefilm.

Well,nownewsofthenewsysteminAmericatravelledfastandanumberofrivalEuropeansystemsstartedtoappearoncepeoplehadheardaboutit.Thesingleproblemwithallthesystemswastheycouldn’treallyprojectthefilmontoascreen--youknow,somorethanonepersoncouldseeit.Thenin1895,threesystemswerealldeveloped,moreorlessatthesametimeandindependentlyofeachother.IguessthemostfamousofthesewasbytheLumiereBrothersfromFrance,andtheycalledtheirsystemthecinematographewhichofcourseiswherethewordcinemacomesfrom.Therewerealso2brothersinGermanywhodevelopedasuccessfulsystemandtheycalleditbioskop.

Wellnow,oncetheproblemofprojectionhadbeensolved,thenextchallengefortheinventorswastomakethefilmslongerandmoreinteresting.Acontinuingproblematthattimewasthatthefilmshadatendencytobreakwhentheywerebeingplayed--aproblemwhichwascausedbythetensionbetweenthe2wheels,or‘reels’astheyarecalled,whichholdthefilm.Nowthisproblemwassolvedby2Americanbrothers.Theydevelopedthe“LanthamLoop”,whichwasthesimpleadditionofathirdreelbetweenthe2mainreelsandthistookallthetensionawaywiththeresultthatthefilmstoppedsnapping.

Sonowtherewasarealpossibilityofhavingfilmsofmorethan2or3minutes,andthisledtothemakingofTheGreatTrainRobbery--theveryfirstmoviemade.Itonlylaststhe11minutesbutwasanabsolutesensation,andtherewerecasesofpeoplewatchingthemovieandactuallyfaintingwhenthecharacterfiredagunatthecamera!

Almostovernightmoviesbecameacraze,andby1905peopleinAmericawerelininguptoseemoviesin‘storetheatres’,astheywerecalledthen.

Iguessthenextbigstepintermsofdevelopmentoftechnologywastohavepeopleactuallytalkingonthefilm,andfirststeptowardsthiswasin1926whensoundeffectswerefirstusedonthefilm.Itwasn’tuntilthefollowingyearhoweverthefirst‘talkie’,astheywerecalledthen,wasmade.ThisfilmfeaturedactorsspeakingonlyduringpartsofthefilmandwascalledTheJazzSinger,anditwasn’tuntilthe1928thatthefirstall-talkingfilmwasproduced,andthiswasTheLightsofNewYork.Unfortunately,thesoundonthisearlyfilmwasnotverygoodandIbelievetheyputsubtitlesonthefilm.--thatis,theyprintedthedialoguealongthebottomofthefilmtocompensateforthispoorsoundquality.Now,withtheadditionofsound,movingpicturesbecamefarmoredifficulttomake…

Today,I’mgoingtotalkaboutrisk,orhowpeoplethinkaboutrisk.First,I’lldiscusstwoconcepts.Perceivedriskversusactualrisk.ThenI’lltalkaboutwhyweworryaboutsomerisksmorethanothers.

Therearetwoimportantturnsyouneedunderstandbeforewebegin,perceivedriskandactualrisk.Perceivedriskisthewayapersonthinksaboutrisk.Perceivedriskisnowriskyapersonthinkstheactivityis.Ah,thisissupposedtoactualriskwhichisthetruerisk.Therisksomethingifyouactuallookathowmanypeoplearehurtorinjuredbyactivity.Solet’sbeginwithexample.Andexampleloveperceivedriskversusactualrisk.Let’scomparetwowaystotravel.Flyingversusdrivingacar.Manypeopledriveacareachday,buttheydon’tworryaboutverymuch.Theyknowthatthereisriskofaccident,butmostpeoplewillnotsaytheyareafraidofdriving.Theyfellthattheriskislow,sotheperceivedriskofislow.Ontheotherhand,manypeopleworryaboutflying.Theyareafraidthatairplanewillhaveanaccidentandcrash.Theyfeelthatriskofflyingishigherthanriskifdriving.Theperceivedriskofflyingishigh.

Infact,theflyingisfortytimessaferthandrivingacar,butourperceptionisthatflyingismoredangerous.Why?

Whydoweworryaboutsomerisksmorethanothers?

Well,itturnsoutthatweperceivedriskdifferentlyinspecialcertainstandards.Somefacto