范文Unit 4 Astronomy the science of stars教案.docx
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范文Unit4Astronomythescienceofstars教案
Unit4Astronomy:
thescienceofstars教案
Unit
4
Astronomy:
the
science
of
stars教案Teachingaims:
.Talkaboutthescienceofstars
2.PractisegivinginstructionsTeachingdifficulties:
1.Learntousenounclausesasthesubject
2.Learntowriteanessaytoshowyourproblemsandthewaytoovercomethem.
3.Vocabulary:
astronomy,atmosphere,violent,explode,surface,disappointed,gradually,cheer,mass,harmful,presence,intime,prevent…from…dependon,nowthat,getthehangof,breakout
Teachingprocedures:
ThefirstperiodIntensivereading
StepⅠPresentation
T:
Hello,everyone!
TodaywewillcometoUnit4,Astronomy.BeforethatIhaveaquestion:
wheredowecomefrom?
orwecansay:
whoareourancestors?
S1:
monkeys!
S2:
BeijingRenwholivedmanyyearsago.
S3:
dinosaurs
…
T:
Verygood!
Doyouknowwhatitwaslikebeforelifeappearedonearth?
S4:
Fullofwater…
Bs:
Idon’tknow.
T:
Doyouwanttogetmoreinformation?
Ss:
yes,wedo.
T:
Todaywewilllearnsomethingabouthowlifebeganonearth.Turntopage25.Let’scometowarmingupfirst.
StepⅡwarmingup
.Readthethreequestions,whilethestudentslistenandfollow.
2.Givethestudentsseveralminutestodiscussthequestions.
3.collectanswersfromtheclass.
4.checkanswerswhilediscussing.
StepⅢPre-reading
Getthestudentstodiscussthequestionsonpage25withtheirpartners.Thenaskthestudentstotelltheirstories.Encouragethemtotelldifferentstories,Iftheydon’tknowany,tellthemsome.
T:
Nowdiscussthesequestionswithyourpartners.ThenIwillasksomeofyoutotellusyourstories.Areyouclear?
Ss:
yes.
a.Doyouknoweachreligionorculturehasitsownideasaboutthebeginningoftheuniverse?
Giveanexampleifyouknow.
b.Doyouknowwhatascientificideais?
Readsomestoriestothestudents.
Panguseparatestheskyfromtheearth;
TheBiblicalAccount;
India;
japan;
Europe;
…
StepⅣReading
.Scanning
Getthestudentstoreadthepassagequicklyandaccuratelyandmeanwhilehelpthestudentstoformagoodhabitofreading.Givethestudentsacoupleofminutestolookthrouththewholepassage.Tellthemtoreadsilentlyandthenasksomedetailedquestionsaboutthetext.Encouragethemtoexpresstheirideas.
T:
wearegoingtolearnapassageabouthowlifebeganontheearth.Nowreadthetextquicklyandthenanswermyquestions.
a.whatwasthereontheearthbeforelifebegan?
b.whydoscientistthinktherehasneverbeenlifeonthemoon?
c.whydoanimalsfirstappearinthesea?
d.whydogreenplantshelplifetodevelop?
e.whyweremammalsdifferentfromotheranimals?
Discusstheanswerswiththewholeclass.
2.Skimming
Inthispart,studentswillreadthetextagainandfinishpart1,2,3
T:
Nowskimthepassagefasttofinishpart1,2,3,4Thenwewillchecktheanswerstogether.
keytopart1:
DBIGEHAcFj
Discusstherestwiththestudents.
StepⅤListening
Listentothetapeforthestudentstofollowandhavefurtherunderstandingofthepassage.
T:
Readafterthetape,thenanswermesomequestionswithyourbookclosed.
a.Howdidwatercomeintobeingontheearth?
b.whyiswaterimportantonearth?
StepⅥLanguagepoints
T:
Turntopage25.Let’slookatthesentences:
a.Itexplodedloudlywithfireandrock,whichwereintimetoproducethewatervapour.
whichleadsnon-restrictiveattributiveclause.
intime:
soonerorlater;eventually
Iwillseehimintime.
Intime:
notlate
Shewillbebackintimetopreparedinner.
In/outoftime:
in/notinthecorrecttime
Theaudienceclappedintimetothemusic.
b.Nobodyknewthatitwasgoingtobedifferentfromotherplanetsgoingaroundthesun.
Bedifferentfrom:
notlikesomeoneorsomethingelseinoneormoreways
citylifeisquitedifferentfromcountrylife.
c.whetherlifewillcontinueontheearthformillionsofyearstocomewilldependonwhetherthisproblemcanbesolved.
Tocome:
servesasattributive
Sheisthelastpersontodosuchathing.
Dependon:
somethingmightonlyhappenorbetrueifthecircumstancesarerightforit
oursuccessdependsonwhethereveryoneworkshardornot.
d.walkingdoesneedabitofpracticenowthatgravityhaschanged.
Nowthat:
becauseofthefactthat
NowthatIamfree,Icanenjoymusicforawhile.
Nowthatyouhavegrownup,youcandecideitbyyourself.
StepⅦHomework
.Retellthepassage
2.Rememberimportantlanguagepoints
ThesecondperiodLanguagestudy
StepⅠRevision
.checkretellingofthepassage
2.Translatethefollowingsentences.
a.你迟早会成功的.
b.我的车与你的不一样.
c.站在门旁边的那个人是谁?
d.他总是第一个来,最后一个走.
e.既然你已经长大了,你自己决定吧.
Suggestedanswers:
a.youwillsucceedintime.
b.mycarisdifferentfromyours.
c.whoisthepersonstandingbythedoor?
d.Heisalwaysthefirsttocomeandthelasttogo.
e.Nowthatyouhavegrownupyoucandecideityourself.
StepⅡwordstudy
Thispartisaconsolidationofthewordslearntinthisunit.Askthestudentstodotheexercisesindividually.
a.Page27.Firstletstudentsfinishpart1,2
b.checktheanswerswiththewholeclass.
c.Givestudents3minutestofinishpart3.
d.Letthestudentsreadpart4forawhileandfinishit.
e.Turntopage63.Firstletthestudentsfinish1and2andchecktheanswers.
StepⅢPreparation
Showsomesentencesontheblackboard.
a.Atreehasfallenacrosstheroad.
b.youareastudent.
c.Tofindyourwaycanbeaproblem.
d.Smokingisbadforyou.
e.“Howdoyoudo?
”isagreeting.
f.whatshesaidisnotyetknown.
g.Thatweshallbelateiscertain.
h.It’scertainthatweshallbelate.
T:
whatpartdoestheunderlinedpartserveasineachsentence?
orfinditssubjectineachsentence.
StepⅣGrammar
.Givethestudentssometimetofindthesentencesinthepassage.Thecollectanswersfromtheclass.
2.Showtypicalexamplesofhowtomakeasubjectclause.GuidetheSstofindoutwhatchangeswehavetomakewhenwemakeasentenceorcombinetwosentencesusingsubjectclause.TeachershowstheexampleandSswritedownthesentences.
3.Turntopage64.Readthefollowingpassagequicklyandfinishtheeightsentences.
4.Haveadiscussioninpairs.Thetopicismydream.onetalksabouttheproblemsinhisstudyorlife,anothergivessomeadvice.Remindthestudentstousethefollowingstructures
a.myproblemis…
b.mytroubleis…
c.Thequestionis…
d.myadviceis…
e.whatIthinkaboutitis…
f.Thefactis…
g.mysuggestionis…
StepⅤHomework
.Finishpart3
2.Finishpart3
Addedmaterial:
什么是黑洞？
就是在宇宙中有那么一些点，这些点的体积趋向于零而密度变得无穷大，由于具有强大的吸引力，物体只要进入离这个点一定距离的范围内，就会被这个强大的引力吸收掉，连光线也不例外。
因此任何进入这个范围的物体都无法再逃出来，就是说，没有任何信号能够从这个范围内传出，因此这个范围的界限被称作视界，里面的情形人类无法看到。
所以科学家给它起了个名字叫黑洞，英文就是blackhole。
一颗燃烧尽了的恒星由于自身的重力而不断坍缩，最后就会形成黑洞。
历时30年霍金改观点称黑洞能“吸”能“吐”
从事宇宙黑洞研究近三十年的世界天体物理学泰斗斯蒂芬•霍金在前不久承认“黑洞悖论”有误之后，21号，他在爱尔兰都柏林举行的一个学术研讨会上终于就自己的新发现向外界进行了详细阐述。
黑洞是宇宙中引力极强的区域。
19世纪70年代，霍金首次提出黑洞能够辐射能量的理论，但是在引入这一理论的同时，霍金也制造了物理学上的一个巨大难题，因为他认为
黑洞辐射不包含以前吸入物质的相关信息，而且随着黑洞的消失，曾经存在的黑洞的相关信息也会消失于无形。
这与量子力学中认为物质信息不会完全消失的理论相矛盾。
对此，过去近30年来，霍金的解释是：
黑洞中的量子运动是一种特殊情况，这种说法受到了许多科学家的质疑。
如今，霍金终于改变了观点，在当天召开的学术研讨会上，霍金说，根据他的最新发现，黑洞并非只是吞噬物质。
除了会在星系形成的过程中扮演重要角色外，在经过一段相当漫长的时间后，黑洞也会把一些曾被它吸入的物质信息向外界释放出来。
霍金的最新阐述被不少人称为黑洞理论的一个重要逆转。
美国加州理工学院的理论物理学家约翰•普雷斯基就是其中之一。
20多年前，霍金提出黑洞辐射理论时，普雷斯基就一直坚持物质信息不会完全消失，当时两人还因此打赌。
所以，在当天结束演讲后，霍金将一本百科全书赠予普雷斯基，作为打赌输了的代价，而普雷斯基则获得了全场的热烈掌声。
Blackholes
whatisablackhole?
well,it'sdifficulttoanswerthisquestion,sincethetermswewouldnormallyusetodescribeascientificphenomenonareinadequatehere.Astronomersandscientiststhinkthatablackholeisaregionofspaceintowhichmatterhasfallenandfromwhichnothingcanescape----notevenlight.Sowecan'tseeablackhole.Ablackholeexpertsastronggravitationalpullandyetithasnomatter.Itisonlyspace----orsowethink.howcanthishappen?
Thetheoryisthatsomestarsexplodewhentheirdensityincreasestoaparticularpoint;theycollapseandsometimesasupernovaoccurs.Formearth,asupernovalookslikeaverybrightlightintheskywhichshineseveninthedaytime.Supernovaewerereportedbyastronomersintheseventeenthandeighteenthcenturies.SomepeoplethinkthattheStarofBethlehemcouldhavebeenasupernova.ThecollapseofastarmayproduceawhiteDwarforaneutronstar---astar,whosematterissodensethatitcontinuallyshrinksbytheforceofitsowngravity.Butifthestarisverylargethisprocessofshrinkingmaybesointensethatablackholeresults.Imaginetheearthreducedtothesizeofamarble,butstillhavingthesamemassandastrongergravitationalpull,andyouhavesomeideaoftheforceofablackhole.Anymatterneartheblackholeissuckedin.Itisimpossibletosaywhathappensinsideablackhole.Scientistshavecalledtheboundaryareaaroundtheholethe"eventhorizon."weknownothingabouteventswhichhappenonceobjectspassthisboundary.Butintheory,mattermustbehaveverydifferentlyinsidethehole.
Forexample,ifamanfellintoablackhole,hewouldthinkthathereachedthecenterofitveryquickly.Howeveranobserverattheeventhorizonwouldthinkthatthemanneverreachedthecenteratall.ourspaceandtimelawsdon'tseemtoapplytoobjectsintheareaofablackhole.Einstein'srelativitytheoryistheonlyonewhichcanexplainsuchphenomena,sothatthereisno"absolute"timeandspacedependonthepositionoftheobserver.Theyarerelative.wedonotyetfullyunderstandtheimplicationsoftherelativitytheory;butitisinterestingthatEinstein'stheoryprovidedabasisfortheideaofblackholesbeforeastronomersstartedtofindsomeevidencefortheirexistence.Itisonlyrecentlythatastronomershavebegunspecificresearchintoblackholes.InAugust1977,asatellitewaslaunchedtogatherdataaboutthe10millionblackholeswhicharethoughttbeinthemilkyway.Andastronomersareplanninganewobservatorytostudytheindividualexplodingstarsbelievedtobeblackholes.
Themostconvincingevidenceofblackholescomesfromresearchintobinarystarsystems.Binarystars,astheirnamesuggests,aretwinstarswhosepositioninspaceaffectseachother.Insomebinarysystems,astronomershaveshownthatthereisaninvisiblecompanionstar,a"partner"totheonewhichwecanseeinthesky.matterfromtheonewecanseeisbeingpulledtowardsthecompanionstar.couldthisinvisiblestar,whichexertssuchagreatforce,beablackhole?
Astronomershaveevidenceofafewotherstarstoo,whichmighthaveblackholesascompanions.
Thestoryofblackholesisjustbeginning.Speculationsaboutthemareendless.Theremightbeamassiveblackholeatthecenteronourgalaxyswallowingupstarsataveryrapidrate.mankindmayonedaymeetthisfate.ontheotherhand,scientistshavesuggestedthatveryadvancedtechnologycouldonedaymakeuseoftheenergyofblackholesformankind.Thesespeculationssoundlikesciencefiction.Butthetheoryofblackholesinspaceisacceptedbymanyseriousscientistsandastronomers.theyshowusaworldwhichoperatesinatotallydifferentwayfromourownandtheyquest
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