大学英语精读第6册课文全文翻译-中英对照

大学英语精读第6册全文课文翻译THEQUESTFOREXTRATERRESTRIALINTELLIGENCEThroughallofourhistorywehaveponderedthestarsandmusedwhetherhumanityisuniqueorif,somewhereelseinthedarkofthenightsky,thereareotherbeingswhocontemplateandwonderaswedo,fellowthinkersinthecosmos.Suchbeingsmightviewthemselvesandtheuniversedifferently.Somewhereelsetheremightbeveryexoticbiologiesandtechnologiesandsocieties.Inacosmicsettingvastandoldbeyondordinaryhumanunderstanding,wearealittlelonely;andwepondertheultimatesignificance,ifany,ofourtinybutexquisiteblueplanet.Thesearchforextraterrestrialintelligenceisthesearchforagenerallyacceptablecosmiccontextforthehumanspecies.Inthedeepestsense,thesearchforextraterrestrialintelligenceisasearchforourselves.Inthelastfewyears--inone-millionththelifetimeofourspeciesonthisplanet--wehaveachievedanextraordinarytechnologicalcapabilitywhichenablesustoseekoutunimaginablydistantcivilizationseveniftheyarenomoreadvancedthanwe.Thatcapabilityiscalledradioastronomyandinvolvessingleradiotelescopes,collectionsorarraysofradiotelescopes,sensitiveradiodetectors,advancedcomputersforprocessingreceiveddate,andtheimaginationandskillofdedicatedscientists.Radioastronomyhasinthelastdecadeopenedanewwindowonthephysicaluniverse.Itmayalso,ifwearewiseenoughtomaketheeffort,castaprofoundlightonthebiologicaluniverse.Somescientistsworkingonthequestionofextraterrestrialintelligence,myselfamongthem,haveattemptedtoestimatethenumberofadvancedtechnicalcivilizations--definedoperationallyassocietiescapableofradioastronomy--intheMilkyWayGalaxy.Suchestimatesarelittlebetterthanguesses.Theyrequireassigningnumericalvaluestoquantitiessuchasthenumbersandagesofstars;theabundanceofplanetarysystemsandthelikelihoodoftheoriginoflife,whichweknowlesswell;andtheprobabilityoftheevolutionofintelligentlifeandthelifetimeoftechnicalcivilizations,aboutwhichweknowverylittleindeed.Whenwedothearithmetic,thesortsofnumberswecomeupwithare,characteristically,aroundamilliontechnical探寻外星人自从人类有历史记载以来，我们一直在思索着星星，反复考虑是否只有人类存在，或者说在太空深处的某个地方是否存在其他同我们一样在不停地思索着的生命，也就是宇宙中跟我们一起思考的人。这样的人可能对自己和宇宙算法不同。在别的什么地方可能存在着非常奇异的生物、技术和社会。我们在一种空间和时间都超出人类理解的宇宙环境里感到有点孤独。我们深思着根本的意义，我们这个渺小的但精巧的蓝色星。探寻外星人就是为人类寻找一个普遍能接受的宇宙环境。从最深层次的意义来说，探寻外星人就是寻找我们自己。在过去的几年中——在我们人类生活在这个星球上的百万分之一的时间里，——我们已经具有了一种非凡的能力。这种技术能力能使我们搜寻到无比遥远的文明世界，即使他们和我们一样不先进。这种技术能力叫做射电天文学。它涉及到单架射望远镜、阵列射电望远镜、高灵敏度的无线电探测器，用于处理接收的信息的先进计算机以及全身心投入的科学家们的想象力和技能。射电天文学在过去的十年中已经打开了一个研究宇宙的新窗口。如果我们充分发挥自己的聪明才智去努力，它可能会帮助我们弄清楚宇宙生物世界。一些研究外星人问题的科学家，包括我自己，都已努力设法对银河系的先进技术文明社会的数目进行了估计——先进技术文明社会定义为具有射民天文学能力的社会。这样的估计比猜想强不了多少。它们要求将这些情况数字化，诸如星球的数量和年龄，有多少个行星系、生命起源的可能性有多大，这些我们较少知道：还有智慧生物进化的可能性和技术文明世界的寿命，这些我们近乎一无所知。当我们进行计算时我们得出的这类数字是很有特点的大约有一百万个文明世界。想象一下这百万civilizations.Amillioncivilizationsisabreathtakinglylargenumber,anditisexhilaratingtoimaginethediversity,lifestylesandcommerceofthosemillionworlds.ButtheMilkyWayGalaxycontainssome250billionstars,andevenwithamillioncivilizations,lessthanonestarin200,000wouldhaveaplanetinhabitedbyanadvancedcivilization.Sincewehavelittleideawhichstarsarelikelycandidates,wewillhavetoexamineaverylargenumberofthem.Suchconsiderationssuggestthatthequestforextraterrestrialintelligencemayrequireasignificanteffort.Despiteclaimsaboutancientastronautsandunidentifiedflyingobjects,thereisnofirmevidenceforpastvisitationoftheEarthbyothercivilizations.Wearerestrictedtoremotesignalingand,ofthelong-distancetechniquesavailabletoourtechnology,radioisbyfarthebest.Radiotelescopesarerelativelyinexpensive;radiosignalstravelatthespeedoflight,fasterthanwhichnothingcango;andtheuseofradioforcommunicationisnotashort-sightedoranthropocentricactivity.RadiorepresentsalargepartoftheelectromagneticspectrumandanytechnicalcivilizationanywhereintheGalaxywillhavediscoveredradioearly--justasinthelastfewcenturieswehaveexploredtheentireelectromagneticspectrumfromshortgammaraystoverylongradiowaves.Advancedcivilizationsmightverywellusesomeothermeansofcommunicationwiththeirpeers.Butiftheywishtocommunicatewithbackwardoremergingcivilizations,thereareonlyafewobviousmethods,thechiefofwhichisradio.ThefirstseriousattempttolistenforpossibleradiosignalsfromothercivilizationswascarriedoutattheNationalRadioAstronomyObservatoryinGreenbank,WestVirginia,in1959and1960.ItwasorganizedbyFrankDrake,nowatCornelUniversity,andwascalledProjectOzma,aftertheprincessoftheLandofOz,aplaceveryexotic,verydistantandverydifficulttoreach.Drakeexaminedtwonearbystarsforafewweekswithnegativeresults.Positiveresultswouldhavebeenastonishingbecauseaswehaveseen,evenratheroptimisticestimatesofthenumberoftechnicalcivilizationsintheGalaxyimplythatseveralhundredthousandstarsmustbeexaminedinordertoachievesuccessbyrandomstellarselection.SinceProjectOzma,therehavebeensixoreightothersuchprograms,allatarathermodestlevel,intheUnitedStates,CanadaandtheSovietUnion.Allresultshavebeen个文明世界的五花八门、这真令人兴奋，各种生活方式以及商业，可是银河系有大约二千五百亿个恒星，即使有一百万个文明世界，可每二十万个恒星中不到一个有文明世界的人居住的行星。既然我们几乎不知道哪些恒星可能存在文明世界，我们将不得不搜寻大量的恒星。这样就意味着探寻外星人可能需要作出极大的努力。尽管有人声称古代在太空人，见过不明飞行物，然而却缺乏确凿的证据证明过去有其他文明世界的人来过地球。我们只限于运用远距离的通信，在目前我们的技术所能运用的长距离的技术手段中，无线电肯定是最好的。无线电望远镜相对来说价格便宜；无线电象光速那样快速发送信号