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1、LifeintheUniverseInthistalk,Iwouldliketospeculatealittle,onthedevelopmentoflifeintheuniverse,andinparticular,thedevelopmentofintelligentlife.Ishalltakethistoincludethehumanrace,eventhoughmuchofitsbehaviourthroughouthistory,hasbeenprettystupid,andnotcalculatedtoaidthesurvivalofthespecies.Twoq
2、uestionsIshalldiscussare,'Whatistheprobabilityoflifeexistingelsewhereintheuniverse?'and,'Howmaylifedevelopinthefuture?'Itisamatterofcommonexperience,thatthingsgetmoredisorderedandchaoticwithtime.Thisobservationcanbeelevatedtothestatusofalaw,theso-calledSecondLawofThermodynamics.Thissaysthatt
3、hetotalamountofdisorder,orentropy,intheuniverse,alwaysincreaseswithtime.However,theLawrefersonlytothetotalamountofdisorder.Theorderinonebodycanincrease,providedthattheamountofdisorderinitssurroundingsincreasesbyagreateramount.Thisiswhathappensinalivingbeing.OnecandefineLifetobeanorderedsyste
4、mthatcansustainitselfagainstthetendencytodisorder,andcanreproduceitself.Thatis,itcanmakesimilar,butindependent,orderedsystems.Todothesethings,thesystemmustconvertenergyinsomeorderedform,likefood,sunlight,orelectricpower,intodisorderedenergy,intheformofheat.Inthisway,thesystemcansatisfythereq
5、uirementthatthetotalamountofdisorderincreases,while,atthesametime,increasingtheorderinitselfanditsoffspring.Alivingbeingusuallyhastwoelements:asetofinstructionsthattellthesystemhowtosustainandreproduceitself,andamechanismtocarryouttheinstructions.Inbiology,thesetwopartsarecalledgenesandmetab
6、olism.Butitisworthemphasisingthatthereneedbenothingbiologicalaboutthem.Forexample,acomputervirusisaprogramthatwillmakecopiesofitselfinthememoryofacomputer,andwilltransferitselftoothercomputers.Thusitfitsthedefinitionofalivingsystem,thatIhavegiven.Likeabiologicalvirus,itisaratherdegeneratefor
7、m,becauseitcontainsonlyinstructionsorgenes,anddoesn'thaveanymetabolismofitsown.Instead,itreprogramsthemetabolismofthehostcomputer,orcell.Somepeoplehavequestionedwhethervirusesshouldcountaslife,becausetheyareparasites,andcannotexistindependentlyofth
