万物简史英文版_比尔·布莱森-第26章

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ical　figureyou　care　to　name。　（the　personages　have　to　be　historical；　apparently；　as　it　takes　the　atomssome　decades　to　bee　thoroughly　redistributed；　however　much　you　may　wish　it；　you　arenot　yet　one　with　elvis　presley。）so　we　are　all　reincarnations鈥攖hough　short…lived　ones。　when　we　die　our　atoms　willdisassemble　and　move　off　to　find　new　uses　elsewhere鈥攁s　part　of　a　leaf　or　other　human　beingor　drop　of　dew。　atoms；　however；　go　on　practically　forever。　nobody　actually　knows　how　longan　atom　can　survive；　but　according　to　martin　rees　it　is　probably　about　1035years鈥攁　numberso　big　that　even　i　am　happy　to　express　it　in　notation。

above　all；　atoms　are　tiny鈥攙ery　tiny　indeed。　half　a　million　of　them　lined　up　shoulder　toshoulder　could　hide　behind　a　human　hair。　on　such　a　scale　an　individual　atom　is　essentiallyimpossible　to　imagine；　but　we　can　of　course　try。

start　with　a　millimeter；　which　is　a　line　this　long：　…。　now　imagine　that　line　divided　into　athousand　equal　widths。　each　of　those　widths　is　a　micron。　this　is　the　scale　of　microorganisms。

a　typical　paramecium；　for　instance；　is　about　two　microns　wide；　0。002　millimeters；　which　isreally　very　small。　if　you　wanted　to　see　with　your　naked　eye　a　paramecium　swimming　in　adrop　of　water；　you　would　have　to　enlarge　the　drop　until　it　was　some　forty　feet　across。

however；　if　you　wanted　to　see　the　atoms　in　the　same　drop；　you　would　have　to　make　the　dropfifteen　miles　across。

atoms；　in　other　words；　exist　on　a　scale　of　minuteness　of　another　order　altogether。　to　getdown　to　the　scale　of　atoms；　you　would　need　to　take　each　one　of　those　micron　slices　and　shaveit　into　ten　thousand　finer　widths。　that鈥檚　the　scale　of　an　atom：　one　ten…millionth　of　amillimeter。　it　is　a　degree　of　slenderness　way　beyond　the　capacity　of　our　imaginations；　but　youcan　get　some　idea　of　the　proportions　if　you　bear　in　mind　that　one　atom　is　to　the　width　of　amillimeter　line　as　the　thickness　of　a　sheet　of　paper　is　to　the　height　of　the　empire　statebuilding。

it　is　of　course　the　abundance　and　extreme　durability　of　atoms　that　makes　them　so　useful；and　the　tininess　that　makes　them　so　hard　to　detect　and　understand。　the　realization　that　atomsare　these　three　things鈥攕mall；　numerous；　practically　indestructible鈥攁nd　that　all　things　aremade　from　them　first　occurred　not　to　antoine…laurent　lavoisier；　as　you　might　expect；　or　evento　henry　cavendish　or　humphry　davy；　but　rather　to　a　spare　and　lightly　educated　englishquaker　named　john　dalton；　whom　we　first　encountered　in　the　chapter　on　chemistry。

dalton　was　born　in　1766　on　the　edge　of　the　lake　district　near　cockermouth　to　a　family　ofpoor　but　devout　quaker　weavers。　（four　years　later　the　poet　william　wordsworth　would　alsojoin　the　world　at　cockermouth。）　he　was　an　exceptionally　bright　student鈥攕o　very　brightindeed　that　at　the　improbably　youthful　age　of　twelve　he　was　put　in　charge　of　the　local　quakerschool。　this　perhaps　says　as　much　about　the　school　as　about　dalton鈥檚　precocity；　but　perhapsnot：　we　know　from　his　diaries　that　at　about　this　time　he　was　reading　newton鈥檚　principia　in　theoriginal　latin　and　other　works　of　a　similarly　challenging　nature。　at　fifteen；　stillschoolmastering；　he　took　a　job　in　the　nearby　town　of　kendal；　and　a　decade　after　that　hemoved　to　manchester；　scarcely　stirring　from　there　for　the　remaining　fifty　years　of　his　life。　inmanchester　he　became　something　of　an　intellectual　whirlwind；　producing　books　and　paperson　subjects　ranging　from　meteorology　to　grammar。　color　blindness；　a　condition　from　whichhe　suffered；　was　for　a　long　time　called　daltonism　because　of　his　studies。　but　it　was　a　plumpbook　called　a　new　system　of　chemical　philosophy；　published　in　1808；　that　established　hisreputation。

there；　in　a　short　chapter　of　just　five　pages　（out　of　the　book鈥檚　more　than　nine　hundred）；people　of　learning　first　encountered　atoms　in　something　approaching　their　modernconception。　dalton鈥檚　simple　insight　was　that　at　the　root　of　all　matter　are　exceedingly　tiny；irreducible　particles。　鈥渨e　might　as　well　attempt　to　introduce　a　new　planet　into　the　solarsystem　or　annihilate　one　already　in　existence；　as　to　create　or　destroy　a　particle　of　hydrogen；鈥�

he　wrote。

neither　the　idea　of　atoms　nor　the　term　itself　was　exactly　new。　both　had　been　developed　bythe　ancient　greeks。　dalton鈥檚　contribution　was　to　consider　the　relative　sizes　and　characters　ofthese　atoms　and　how　they　fit　together。　he　knew；　for　instance；　that　hydrogen　was　the　lightestelement；　so　he　gave　it　an　atomic　weight　of　one。　he　believed　also　that　water　consisted　of　sevenparts　of　oxygen　to　one　of　hydrogen；　and　so　he　gave　oxygen　an　atomic　weight　of　seven。　bysuch　means　was　he　able　to　arrive　at　the　relative　weights　of　the　known　elements。　he　wasn鈥檛always　terribly　accurate鈥攐xygen鈥檚　atomic　weight　is　actually　sixteen；　not　seven鈥攂ut　theprinciple　was　sound　and　formed　the　basis　for　all　of　modern　chemistry　and　much　of　the　rest　ofmodern　science。

the　work　made　dalton　famous鈥攁lbeit　in　a　low…key；　english　quaker　sort　of　way。　in　1826；the　french　chemist　p　。j。　pelletier　traveled　to　manchester　to　meet　the　atomic　hero。　pelletierexpected　to　find　him　attached　to　some　grand　institution；　so　he　was　astounded　to　discover　himteaching　elementary　arithmetic　to　boys　in　a　small　school　on　a　back　street。　according　to　thescientific　historian　e。　j。　holmyard；　a　confused　pelletier；　upon　beholding　the　great　man；stammered：

鈥渆st…ce　que　j鈥檃i　l鈥檋onneur　de　m鈥檃ddresser　脿　monsieur　dalton？鈥潯�for　he　couldhardly　believe　his　eyes　that　this　was　the　chemist　of　european　fame；　teaching　a　boyhis　first　four　rules。　鈥測es；鈥潯�said　the　matter…of…fact　quaker。　鈥渨ilt　thou　sit　downwhilst　i　put　this　lad　right　about　his　arithmetic？鈥�

although　dalton　tried　to　avoid　all　honors；　he　was　elected　to　the　royal　society　against　hiswishes；　showered　with　medals；　and　given　a　handsome　government　pension。　when　he　died　in1844；　forty　thousand　people　viewed　the　coffin；　and　the　funeral　cortege　stretched　for　twomiles。　his　entry　in　the　dictionary　of　national　biography　is　one　of　the　longest；　rivaled　inlength　only　by　those　of　darwin　and　lyell　among　nineteenth…century　men　of　science。

for　a　century　after　dalton　made　his　proposal；　it　remained　entirely　hypothetical；　and　a　feweminent　scientists鈥攏otably　the　viennese　physicist　ernst　mach；　for　whom　is　named　the　speedof　sound鈥攄oubted　the　existence　of　atoms　at　all。　鈥渁toms　cannot　be　perceived　by　the　senses　。　。

。　they　are　things　of　thought；鈥潯�he　wrote。　the　existence　of　atoms　was　so　doubtfully　held　in　thegerman…speaking　world　in　particular　that　it　was　said　to　have　played　a　part　in　the　suicide　of　thegreat　theoretical　physicist；　and　atomic　enthusiast；　ludwig　boltzmann　in　1906。

it　was　einstein　who　provided　the　first　incontrovertible　evidence　of　atoms鈥櫋�existence　withhis　paper　on　brownian　motion　in　1905；　but　this　attracted　little　attention　and　in　any　caseeinstein　was　soon　to　bee　consumed　with　his　work　on　general　relativity。　so　the　first　realhero　of　the　atomic　age；　if　not　the　first　personage　on　the　scene；　was　ernest　rutherford。

rutherford　was　born　in　1871　in　the　鈥渂ack　blocks鈥潯�of　new　zealand　to　parents　who　hademigrated　from　scotland　to　raise　a　little　flax　and　a　lot　of　children　（to　paraphrase　stevenweinberg）。　growing　up　in　a　remote　part　of　a　remote　country；　he　was　about　as　far　from　themainstream　of　science　as　it　was　possible　to　be；　but　in　1895　he　won　a　scholarship　that　took　himto　the　cavendish　laboratory　at　cambridge　university；　which　was　about　to　bee　the　hottestplace　in　the　world　to　do　physics。

physicists　are　notoriously　scornful　of　scientists　from　other　fields。　when　the　wife　of　thegreat　austrian　physicist　wolfgang　pauli　left　him　for　a　chemist；　he　was　staggered　withdisbelief。　鈥渉ad　she　taken　a　bullfighter　i　would　have　understood；鈥潯�he　remarked　in　wonder　to　afriend。　鈥渂ut　a　chemist　。　。　。鈥�

it　was　a　feeling　rutherford　would　have　understood。　鈥渁ll　science　is　either　physics　or　stampcollecting；鈥潯�he　once　said；　in　a　line　that　has　been　used　many　times　since。　there　is　a　certainengaging　irony　therefore　that　when　he　won　the　nobel　prize　in　1908；　it　was　in　chemistry；　notphysics。

rutherford　was　a　lucky　man鈥攍ucky　to　be　a　genius；　but　even　luckier　to　live　at　a　time　whenphysics　and　chemistry　were　so　exciting　and　so　patible　（his　own　sentimentsnotwithstanding）。　never　again　would　they　quite　so　fortably　overlap。

for　all　his　success；　rutherford　was　not　an　especially　brilliant　man　and　was　actually　prettyterrible　at　mathematics。　often　during　lectures　he　would　get　so　lost　in　his　own　equations　thathe　would　give　up　halfway　through　and　tell　the　students　to　work　it　out　for　themselves。

according　to　his　longtime　colleague　james　chadwick；　discoverer　of　the　neutron；　he　wasn鈥檛even　particularly　clever　at　experimentation。　he　was　simply　tenacious　and　open…minded。　forbrilliance　he　substituted　shrewdness　and　a　kind　of　daring。　his　mind；　in　the　words　of　onebiographer；　was　鈥渁lways　operating　out　towards　the　frontiers；　as　far　as　he　could　see；　and　thatwas　a　great　deal　further　than　most　other　men。鈥潯�confronted　with　an　intractable　problem；　hewas　prepared　to　work　at　it　harder　and　longer　than　most　people　and　to　be　more　receptive　tounorthodox　explanations。　his　greatest　breakthrough　came　because　he　was　prepared　to　spendimmensely　tedious　hours　sitting　at　a　screen　counting　alpha　particle　scintillations；　as　they　wereknown鈥攖he　sort　of　work　that　would　normally　have　been　farmed　out。　he　was　one　of　the　firstto　see鈥攑ossibly　the　very　first鈥攖hat　the　power　inherent　in　the　atom　could；　if　harnessed；　makebombs　powerful　enough　to　鈥渕ake　this　old　world　vanish　in　smoke。鈥�

physically　he　was　big　and　booming；　with　a　voice　that　made　the　timid　shrink。　once　whentold　that　rutherford　was　about　to　make　a　radio　broadcast　across　the　atlantic；　a　colleague　drilyasked：　鈥渨hy　use　radio？鈥潯�he　also　had　a　huge　amount　of　good…natured　confidence。　whensomeone　remarked　to　him　that　he　seemed　always　to　be　at　the　crest　of　a　wave；　he　responded；鈥渨ell；　after　all；　i　made　the　wave；　didn鈥檛　i？鈥潯�c。　p。　snow　recalled　how　once　in　a　cambridgetailor鈥檚　he　overheard　rutherford　remark：　鈥渆very　day　i　grow　in　girth。　and　in　mentality。鈥�

but　both　girth　and　fame　were　far　ahead　of　him　in　1895　when　he　fetched　up　at　thecavendish。

1it　was　a　singularly　eventful　period　in　science。　in　the　year　of　his　arrival　incambridge；　wilhelm　roentgen　discovered　x　rays　at　the　university　of　w眉rzburg　in　germany；and　the　next　year　henri　becquerel　discovered　radioactivity。　and　the　cavendish　itself　wasabout　to　embark　on　a　long　period　of　greatness。　in　1897；　j。　j。　thomson　and　colleagues　woulddiscover　the　electron　there；　in　1911　c。　t。　r。　wilson　would　produce　the　first　particle　detectorthere　（as　we　shall　see）；　and　in　1932　james　chadwick　would　discover　the　neutron　there。

further　still　in　the　future；　james　watson　and　francis　crick　would　discover　the　structure　ofdna　at　the　cavendish　in　1953。

in　the　beginning　rutherford　worked　on　radio　waves；　and　with　some　distinction鈥攈emanaged　to　transmit　a　crisp　signal　more　than　a　mile；　a　very　reasonable　achievement　for　thetime鈥攂ut　gave　it　up　when　he　was　persuaded　by　a　senior　colleague　that　radio　had　little　future。

on　the　whole；　however；　rutherford　didn鈥檛　thrive　at　the　cavendish。　after　three　years　there；feeling　he　was　going　nowhere；　he　took　a　post　at　mcgill　university　in　montreal；　and　there　hebegan