A Short History of Nearly Everything-第3章

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protons　are　so　small　that　a　little　dib　of　ink　like　the　dot　on　this　i　can　hold　something　in　theregion　of　500；000；000；000　of　them；　rather　more　than　the　number　of　seconds　contained　in　halfa　million　years。　so　protons　are　exceedingly　microscopic；　to　say　the　very　least。

now　imagine　if　you　can　（and　of　course　you　can’t）　shrinking　one　of　those　protons　down　to　abillionth　of　its　normal　size　into　a　space　so　small　that　it　would　make　a　proton　look　enormous。

now　pack　into　that　tiny；　tiny　space　about　an　ounce　of　matter。　excellent。　you　are　ready　to　starta　universe。

i’m　assuming　of　course　that　you　wish　to　build　an　inflationary　universe。　if　you’d　preferinstead　to　build　a　more　old…fashioned；　standard　big　bang　universe；　you’ll　need　additionalmaterials。　in　fact；　you　will　need　to　gather　up　everything　there　is　every　last　mote　and　particle　ofmatter　between　here　and　the　edge　of　creation　and　squeeze　it　into　a　spot　so　infinitesimallypact　that　it　has　no　dimensions　at　all。　it　is　known　as　a　singularity。

in　either　case；　get　ready　for　a　really　big　bang。　naturally；　you　will　wish　to　retire　to　a　safeplace　to　observe　the　spectacle。　unfortunately；　there　is　nowhere　to　retire　to　because　outside　thesingularity　there　is　no　where。　when　the　universe　begins　to　expand；　it　won’t　be　spreading　outto　fill　a　larger　emptiness。　the　only　space　that　exists　is　the　space　it　creates　as　it　goes。

it　is　natural　but　wrong　to　visualize　the　singularity　as　a　kind　of　pregnant　dot　hanging　in　adark；　boundless　void。　but　there　is　no　space；　no　darkness。　the　singularity　has　no　“around”

around　it。　there　is　no　space　for　it　to　occupy；　no　place　for　it　to　be。　we　can’t　even　ask　how　longit　has　been　there—whether　it　has　just　lately　popped　into　being；　like　a　good　idea；　or　whether　ithas　been　there　forever；　quietly　awaiting　the　right　moment。　time　doesn’t　exist。　there　is　no　pastfor　it　to　emerge　from。

and　so；　from　nothing；　our　universe　begins。

in　a　single　blinding　pulse；　a　moment　of　glory　much　too　swift　and　expansive　for　any　form　ofwords；　the　singularity　assumes　heavenly　dimensions；　space　beyond　conception。　in　the　firstlively　second　（a　second　that　many　cosmologists　will　devote　careers　to　shaving　into　ever…finerwafers）　is　produced　gravity　and　the　other　forces　that　govern　physics。　in　less　than　a　minute　theuniverse　is　a　million　billion　miles　across　and　growing　fast。　there　is　a　lot　of　heat　now；　tenbillion　degrees　of　it；　enough　to　begin　the　nuclear　reactions　that　create　the　lighter　elements—principally　hydrogen　and　helium；　with　a　dash　（about　one　atom　in　a　hundred　million）　oflithium。　in　three　minutes；　98　percent　of　all　the　matter　there　is　or　will　ever　be　has　beenproduced。　we　have　a　universe。　it　is　a　place　of　the　most　wondrous　and　gratifying　possibility；and　beautiful；　too。　and　it　was　all　done　in　about　the　time　it　takes　to　make　a　sandwich。

when　this　moment　happened　is　a　matter　of　some　debate。　cosmologists　have　long　arguedover　whether　the　moment　of　creation　was　10　billion　years　ago　or　twice　that　or　something　inbetween。　the　consensus　seems　to　be　heading　for　a　figure　of　about　13。7　billion　years；　but　thesethings　are　notoriously　difficult　to　measure；　as　we　shall　see　further　on。　all　that　can　really　besaid　is　that　at　some　indeterminate　point　in　the　very　distant　past；　for　reasons　unknown；　therecame　the　moment　known　to　science　as　t　=　0。　we　were　on　our　way。

there　is　of　course　a　great　deal　we　don’t　know；　and　much　of　what　we　think　we　know　wehaven’t　known；　or　thought　we’ve　known；　for　long。　even　the　notion　of　the　big　bang　is　quite　arecent　one。　the　idea　had　been　kicking　around　since　the　1920s；　when　georges　lema？tre；　abelgian　priest…scholar；　first　tentatively　proposed　it；　but　it　didn’t　really　bee　an　activenotion　in　cosmology　until　the　mid…1960s　when　two　young　radio　astronomers　made　anextraordinary　and　inadvertent　discovery。

their　names　were　arno　penzias　and　robert　wilson。　in　1965；　they　were　trying　to　make　useof　a　large　munications　antenna　owned　by　bell　laboratories　at　holmdel；　new　jersey；　butthey　were　troubled　by　a　persistent　background　noise—a　steady；　steamy　hiss　that　made　anyexperimental　work　impossible。　the　noise　was　unrelenting　and　unfocused。　it　came　from　everypoint　in　the　sky；　day　and　night；　through　every　season。　for　a　year　the　young　astronomers　dideverything　they　could　think　of　to　track　down　and　eliminate　the　noise。　they　tested　everyelectrical　system。　they　rebuilt　instruments；　checked　circuits；　wiggled　wires；　dusted　plugs。

they　climbed　into　the　dish　and　placed　duct　tape　over　every　seam　and　rivet。　they　climbedback　into　the　dish　with　brooms　and　scrubbing　brushes　and　carefully　swept　it　clean　of　whatthey　referred　to　in　a　later　paper　as　“white　dielectric　material；”　or　what　is　known　moremonly　as　bird　shit。　nothing　they　tried　worked。

unknown　to　them；　just　thirty　miles　away　at　princeton　university；　a　team　of　scientists　led　byrobert　dicke　was　working　on　how　to　find　the　very　thing　they　were　trying　so　diligently　to　getrid　of。　the　princeton　researchers　were　pursuing　an　idea　that　had　been　suggested　in　the　1940sby　the　russian…born　astrophysicist　george　gamow　that　if　you　looked　deep　enough　into　spaceyou　should　find　some　cosmic　background　radiation　left　over　from　the　big　bang。　gamowcalculated　that　by　the　time　it　crossed　the　vastness　of　the　cosmos；　the　radiation　would　reachearth　in　the　form　of　microwaves。　in　a　more　recent　paper　he　had　even　suggested　an　instrumentthat　might　do　the　job：　the　bell　antenna　at　holmdel。　unfortunately；　neither　penzias　andwilson；　nor　any　of　the　princeton　team；　had　read　gamow’s　paper。

the　noise　that　penzias　and　wilson　were　hearing　was；　of　course；　the　noise　that　gamow　hadpostulated。　they　had　found　the　edge　of　the　universe；　or　at　least　the　visible　part　of　it；　90　billiontrillion　miles　away。　they　were　“seeing”　the　first　photons—the　most　ancient　light　in　theuniverse—though　time　and　distance　had　converted　them　to　microwaves；　just　as　gamow　hadpredicted。　in　his　book　the　inflationary　universe　；　alan　guth　provides　an　analogy　that　helps　toput　this　finding　in　perspective。　if　you　think　of　peering　into　the　depths　of　the　universe　as　likelooking　down　from　the　hundredth　floor　of　the　empire　state　building　（with　the　hundredth　floorrepresenting　now　and　street　level　representing　the　moment　of　the　big　bang）；　at　the　time　ofwilson　and　penzias’s　discovery　the　most　distant　galaxies　anyone　had　ever　detected　were　onabout　the　sixtieth　floor；　and　the　most　distant　things—quasars—were　on　about　the　twentieth。

penzias　and　wilson’s　finding　pushed　our　acquaintance　with　the　visible　universe　to　within　halfan　inch　of　the　sidewalk。

still　unaware　of　what　caused　the　noise；　wilson　and　penzias　phoned　dicke　at　princeton　anddescribed　their　problem　to　him　in　the　hope　that　he　might　suggest　a　solution。　dicke　realized　atonce　what　the　two　young　men　had　found。　“well；　boys；　we’ve　just　been　scooped；”　he　told　hiscolleagues　as　he　hung　up　the　phone。

soon　afterward　the　astrophysical　journal　published　two　articles：　one　by　penzias　andwilson　describing　their　experience　with　the　hiss；　the　other　by　dicke’s　team　explaining　itsnature。　although　penzias　and　wilson　had　not　been　looking　for　cosmic　background　radiation；didn’t　know　what　it　was　when　they　had　found　it；　and　hadn’t　described　or　interpreted　itscharacter　in　any　paper；　they　received　the　1978　nobel　prize　in　physics。　the　princetonresearchers　got　only　sympathy。　according　to　dennis　overbye　in　lonely　hearts　of　the　cosmos；　neither　penzias　nor　wilson　altogether　understood　the　significance　of　what　they　had　founduntil　they　read　about　it　in　the　new　york　times　。

incidentally；　disturbance　from　cosmic　background　radiation　is　something　we　have　allexperienced。　tune　your　television　to　any　channel　it　doesn’t　receive；　and　about　1　percent　of　thedancing　static　you　see　is　accounted　for　by　this　ancient　remnant　of　the　big　bang。　the　next　timeyou　plain　that　there　is　nothing　on；　remember　that　you　can　always　watch　the　birth　of　theuniverse。

although　everyone　calls　it　the　big　bang；　many　books　caution　us　not　to　think　of　it　as　anexplosion　in　the　conventional　sense。　it　was；　rather；　a　vast；　sudden　expansion　on　a　whoppingscale。　so　what　caused　it？

one　notion　is　that　perhaps　the　singularity　was　the　relic　of　an　earlier；　collapsed　universe—that　we’re　just　one　of　an　eternal　cycle　of　expanding　and　collapsing　universes；　like　the　bladderon　an　oxygen　machine。　others　attribute　the　big　bang　to　what　they　call　“a　false　vacuum”　or　“ascalar　field”　or　“vacuum　energy”—some　quality　or　thing；　at　any　rate；　that　introduced　ameasure　of　instability　into　the　nothingness　that　was。　it　seems　impossible　that　you　could　getsomething　from　nothing；　but　the　fact　that　once　there　was　nothing　and　now　there　is　a　universeis　evident　proof　that　you　can。　it　may　be　that　our　universe　is　merely　part　of　many　largeruniverses；　some　in　different　dimensions；　and　that　big　bangs　are　going　on　all　the　time　all　overthe　place。　or　it　may　be　that　space　and　time　had　some　other　forms　altogether　before　the　bigbang—forms　too　alien　for　us　to　imagine—and　that　the　big　bang　represents　some　sort　oftransition　phase；　where　the　universe　went　from　a　form　we　can’t　understand　to　one　we　almostcan。　“these　are　very　close　to　religious　questions；”　dr。　andrei　linde；　a　cosmologist　atstanford；　told　the　new　york　times　in　2001。

the　big　bang　the