A Short History of Nearly Everything-第8章

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“or　where　he’s　put　things；”　called　elaine　from　the　kitchen。

he　nodded　frankly　again　and　grinned；　then　asked　me　if　i’d　like　to　see　his　telescope。　i　hadimagined　that　evans　would　have　a　proper　observatory　in　his　backyard—a　scaled…downversion　of　a　mount　wilson　or　palomar；　with　a　sliding　domed　roof　and　a　mechanized　chair　thatwould　be　a　pleasure　to　maneuver。　in　fact；　he　led　me　not　outside　but　to　a　crowded　storeroomoff　the　kitchen　where　he　keeps　his　books　and　papers　and　where　his　telescope—a　whitecylinder　that　is　about　the　size　and　shape　of　a　household　hot…water　tank—rests　in　a　homemade；swiveling　plywood　mount。　when　he　wishes　to　observe；　he　carries　them　in　two　trips　to　a　smalldeck　off　the　kitchen。　between　the　overhang　of　the　roof　and　the　feathery　tops　of　eucalyptustrees　growing　up　from　the　slope　below；　he　has　only　a　letter…box　view　of　the　sky；　but　he　says　itis　more　than　good　enough　for　his　purposes。　and　there；　when　the　skies　are　clear　and　the　moonnot　too　bright；　he　finds　his　supernovae。

the　term　supernova　was　coined　in　the　1930s　by　a　memorably　odd　astrophysicist　namedfritz　zwicky。　born　in　bulgaria　and　raised　in　switzerland；　zwicky　came　to　the　californiainstitute　of　technology　in　the　1920s　and　there　at　once　distinguished　himself　by　his　abrasivepersonality　and　erratic　talents。　he　didn’t　seem　to　be　outstandingly　bright；　and　many　of　hiscolleagues　considered　him　little　more　than　“an　irritating　buffoon。”　a　fitness　buff；　he　wouldoften　drop　to　the　floor　of　the　caltech　dining　hall　or　other　public　areas　and　do　one…armedpushups　to　demonstrate　his　virility　to　anyone　who　seemed　inclined　to　doubt　it。　he　wasnotoriously　aggressive；　his　manner　eventually　being　so　intimidating　that　his　closestcollaborator；　a　gentle　man　named　walter　baade；　refused　to　be　left　alone　with　him。　amongother　things；　zwicky　accused　baade；　who　was　german；　of　being　a　nazi；　which　he　was　not。　onat　least　one　occasion　zwicky　threatened　to　kill　baade；　who　worked　up　the　hill　at　the　mountwilson　observatory；　if　he　saw　him　on　the　caltech　campus。

but　zwicky　was　also　capable　of　insights　of　the　most　startling　brilliance。　in　the　early　1930s；he　turned　his　attention　to　a　question　that　had　long　troubled　astronomers：　the　appearance　in　thesky　of　occasional　unexplained　points　of　light；　new　stars。　improbably　he　wondered　if　theneutron—the　subatomic　particle　that　had　just　been　discovered　in　england　by　jameschadwick；　and　was　thus　both　novel　and　rather　fashionable—might　be　at　the　heart　of　things。　itoccurred　to　him　that　if　a　star　collapsed　to　the　sort　of　densities　found　in　the　core　of　atoms；　theresult　would　be　an　unimaginably　pacted　core。　atoms　would　literally　be　crushed　together；their　electrons　forced　into　the　nucleus；　forming　neutrons。　you　would　have　a　neutron　star。

imagine　a　million　really　weighty　cannonballs　squeezed　down　to　the　size　of　a　marble　and—well；　you’re　still　not　even　close。　the　core　of　a　neutron　star　is　so　dense　that　a　single　spoonfulof　matter　from　it　would　weigh　200　billion　pounds。　a　spoonful！　but　there　was　more。　zwickyrealized　that　after　the　collapse　of　such　a　star　there　would　be　a　huge　amount　of　energy　leftover—enough　to　make　the　biggest　bang　in　the　universe。　he　called　these　resultant　explosionssupernovae。　they　would　be—they　are—the　biggest　events　in　creation。

on　january　15；　1934；　the　journal　physical　review　published　a　very　concise　abstract　of　apresentation　that　had　been　conducted　by　zwicky　and　baade　the　previous　month　at　stanforduniversity。　despite　its　extreme　brevity—one　paragraph　of　twenty…four　lines—the　abstractcontained　an　enormous　amount　of　new　science：　it　provided　the　first　reference　to　supernovaeand　to　neutron　stars；　convincingly　explained　their　method　of　formation；　correctly　calculatedthe　scale　of　their　explosiveness；　and；　as　a　kind　of　concluding　bonus；　connected　supernovaexplosions　to　the　production　of　a　mysterious　new　phenomenon　called　cosmic　rays；　which　hadrecently　been　found　swarming　through　the　universe。　these　ideas　were　revolutionary　to　say　theleast。　neutron　stars　wouldn’t　be　confirmed　for　thirty…four　years。　the　cosmic　rays　notion；though　considered　plausible；　hasn’t　been　verified　yet。　altogether；　the　abstract　was；　in　thewords　of　caltech　astrophysicist　kip　s。　thorne；　“one　of　the　most　prescient　documents　in　thehistory　of　physics　and　astronomy。”

interestingly；　zwicky　had　almost　no　understanding　of　why　any　of　this　would　happen。

according　to　thorne；　“he　did　not　understand　the　laws　of　physics　well　enough　to　be　able　tosubstantiate　his　ideas。”　zwicky’s　talent　was　for　big　ideas。　others—baade　mostly—were　leftto　do　the　mathematical　sweeping　up。

zwicky　also　was　the　first　to　recognize　that　there　wasn’t　nearly　enough　visible　mass　in　theuniverse　to　hold　galaxies　together　and　that　there　must　be　some　other　gravitational　influence—what　we　now　call　dark　matter。　one　thing　he　failed　to　see　was　that　if　a　neutron　star　shrankenough　it　would　bee　so　dense　that　even　light　couldn’t　escape　its　immense　gravitationalpull。　you　would　have　a　black　hole。　unfortunately；　zwicky　was　held　in　such　disdain　by　mostof　his　colleagues　that　his　ideas　attracted　almost　no　notice。　when；　five　years　later；　the　greatrobert　oppenheimer　turned　his　attention　to　neutron　stars　in　a　landmark　paper；　he　made　not　asingle　reference　to　any　of　zwicky’s　work　even　though　zwicky　had　been　working　for　years　onthe　same　problem　in　an　office　just　down　the　hall。　zwicky’s　deductions　concerning　dark　matterwouldn’t　attract　serious　attention　for　nearly　four　decades。　we　can　only　assume　that　he　did　alot　of　pushups　in　this　period。

surprisingly　little　of　the　universe　is　visible　to　us　when　we　incline　our　heads　to　the　sky。　onlyabout　6；000　stars　are　visible　to　the　naked　eye　from　earth；　and　only　about　2；000　can　be　seenfrom　any　one　spot。　with　binoculars　the　number　of　stars　you　can　see　from　a　single　locationrises　to　about　50；000；　and　with　a　small　two…inch　telescope　it　leaps　to　300；000。　with　a　sixteen…inch　telescope；　such　as　evans　uses；　you　begin　to　count　not　in　stars　but　in　galaxies。　from　hisdeck；　evans　supposes　he　can　see　between　50；000　and　100；000　galaxies；　each　containing　tensof　billions　of　stars。　these　are　of　course　respectable　numbers；　but　even　with　so　much　to　take　in；supernovae　are　extremely　rare。　a　star　can　burn　for　billions　of　years；　but　it　dies　just　once　andquickly；　and　only　a　few　dying　stars　explode。　most　expire　quietly；　like　a　campfire　at　dawn。　in　atypical　galaxy；　consisting　of　a　hundred　billion　stars；　a　supernova　will　occur　on　average　onceevery　two　or　three　hundred　years。　finding　a　supernova　therefore　was　a　little　bit　like　standingon　the　observation　platform　of　the　empire　state　building　with　a　telescope　and　searchingwindows　around　manhattan　in　the　hope　of　finding；　let　us　say；　someone　lighting　a　twenty…first…birthday　cake。

so　when　a　hopeful　and　softspoken　minister　got　in　touch　to　ask　if　they　had　any　usable　fieldcharts　for　hunting　supernovae；　the　astronomical　munity　thought　he　was　out　of　his　mind。

at　the　time　evans　had　a　ten…inch　telescope—a　very　respectable　size　for　amateur　stargazingbut　hardly　the　sort　of　thing　with　which　to　do　serious　cosmology—and　he　was　proposing　tofind　one　of　the　universe’s　rarer　phenomena。　in　the　whole　of　astronomical　history　before　evansstarted　looking　in　1980；　fewer　than　sixty　supernovae　had　been　found。　（at　the　time　i　visitedhim；　in　august　of　2001；　he　had　just　recorded　his　thirty…fourth　visual　discovery；　a　thirty…fifthfollowed　three　months　later　and　a　thirty…sixth　in　early　2003。）evans；　however；　had　certain　advantages。　most　observers；　like　most　people　generally；　are　inthe　northern　hemisphere；　so　he　had　a　lot　of　sky　largely　to　himself；　especially　at　first。　he　alsohad　speed　and　his　uncanny　memory。　large　telescopes　are　cumbersome　things；　and　much　oftheir　operational　time　is　consumed　with　being　maneuvered　into　position。　evans　could　swinghis　little　sixteen…inch　telescope　around　like　a　tail　gunner　in　a　dogfight；　spending　no　more　thana　couple　of　seconds　on　any　particular　point　in　the　sky。　in　consequence；　he　could　observeperhaps　four　hundred　galaxies　in　an　evening　while　a　large　professional　telescope　would　belucky　to　do　fifty　or　sixty。

looking　for　supernovae　is　mostly　a　matter　of　not　finding　them。　from　1980　to　1996　heaveraged　two　discoveries　a　year—not　a　huge　payoff　for　hundreds　of　nights　of　peering　andpeering。　once　he　found　three　in　fifteen　days；　but　another　time　he　went　three　years　withoutfinding　any　at　all。

“there　is　actually　a　certain　value　in　not　finding　anything；”　he　said。　“it　helps　cosmologists　towork　out　the　rate　at　which　galaxies　are　evolving。　it’s　one　of　those　rare　areas　where　theabsence　of　evidenceis　evidence。”

on　a　table　beside　the　telescope　were　stacks　of　photos　and　papers　relevant　to　his　pursuits；and　he　showed　me　some　of　them　now。　if　you　have　ever　looked　through　popular　astronomicalpublications；　and　at　some　time　you　must　have；　you　will　know　that　they　are　generally　full　ofrichly　luminous　color　photos　of　distant　nebulae　and　the　like—fairy…lit　clouds　of　celestial　lightof　the　most　delicate　and　moving　splendor。　evans’s　working　images　are　nothing　like　that。　theyare　just　blurry　black…and…white　photos　with　little　points　of　haloed　brightness。　one　he　showedme　depicted　a　swarm　of　stars　with　a　trifling　flare　that　i　had　to　put　close　to　my　face　to　see。