A Short History of Nearly Everything- 第32部分

as　always；　however；　nothing　was　quite　as　straightforward　as　such　a　breezy　descriptionmakes　it　sound。　meteorites　are　not　abundant　and　meteoritic　samples　not　especially　easy　to　gethold　of。　moreover；　brown’s　measurement　technique　proved　finicky　in　the　extreme　andneeded　much　refinement。　above　all；　there　was　the　problem　that　patterson’s　samples　werecontinuously　and　unaccountably　contaminated　with　large　doses　of　atmospheric　lead　wheneverthey　were　exposed　to　air。　it　was　this　that　eventually　led　him　to　create　a　sterile　laboratory—theworld’s　first；　according　to　at　least　one　account。

it　took　patterson　seven　years　of　patient　work　just　to　assemble　suitable　samples　for　finaltesting。　in　the　spring　of　1953　he　traveled　to　the　argonne　national　laboratory　in　illinois；where　he　was　granted　time　on　a　late…model　mass　spectrograph；　a　machine　capable　of　detectingand　measuring　the　minute　quantities　of　uranium　and　lead　locked　up　in　ancient　crystals。　whenat　last　he　had　his　results；　patterson　was　so　excited　that　he　drove　straight　to　his　boyhood　homein　iowa　and　had　his　mother　check　him　into　a　hospital　because　he　thought　he　was　having　aheart　attack。

soon　afterward；　at　a　meeting　in　wisconsin；　patterson　announced　a　definitive　age　for　theearth　of　4；550　million　years　（plus　or　minus　70　million　years）—“a　figure　that　standsunchanged　50　years　later；”　as　mcgrayne　admiringly　notes。　after　two　hundred　years　of　trying；the　earth　finally　had　an　age。

his　main　work　done；　patterson　now　turned　his　attention　to　the　nagging　question　of　all　thatlead　in　the　atmosphere。　he　was　astounded　to　find　that　what　little　was　known　about　the　effectsof　lead　on　humans　was　almost　invariably　wrong　or　misleading—and　not　surprisingly；　hediscovered；　since　for　forty　years　every　study　of　lead’s　effects　had　been　funded　exclusively　bymanufacturers　of　lead　additives。

in　one　such　study；　a　doctor　who　had　no　specialized　training　in　chemical　pathologyundertook　a　five…year　program　in　which　volunteers　were　asked　to　breathe　in　or　swallow　leadin　elevated　quantities。　then　their　urine　and　feces　were　tested。　unfortunately；　as　the　doctorappears　not　to　have　known；　lead　is　not　excreted　as　a　waste　product。　rather；　it　accumulates　inthe　bones　and　blood—that’s　what　makes　it　so　dangerous—and　neither　bone　nor　blood　wastested。　in　consequence；　lead　was　given　a　clean　bill　of　health。

patterson　quickly　established　that　we　had　a　lot　of　lead　in　the　atmosphere—still　do；　in　fact；since　lead　never　goes　away—and　that　about　90　percent　of　it　appeared　to　e　fromautomobile　exhaust　pipes；　but　he　couldn’t　prove　it。　what　he　needed　was　a　way　to　parelead　levels　in　the　atmosphere　now　with　the　levels　that　existed　before　1923；　when　tetraethyllead　was　introduced。　it　occurred　to　him　that　ice　cores　could　provide　the　answer。

it　was　known　that　snowfall　in　places　like　greenland　accumulates　into　discrete　annual　layers（because　seasonal　temperature　differences　produce　slight　changes　in　coloration　from　winter　tosummer）。　by　counting　back　through　these　layers　and　measuring　the　amount　of　lead　in　each；　hecould　work　out　global　lead　concentrations　at　any　time　for　hundreds；　or　even　thousands；　ofyears。　the　notion　became　the　foundation　of　ice　core　studies；　on　which　much　modernclimatological　work　is　based。

what　patterson　found　was　that　before　1923　there　was　almost　no　lead　in　the　atmosphere；　andthat　since　that　time　its　level　had　climbed　steadily　and　dangerously。　he　now　made　it　his　life’squest　to　get　lead　taken　out　of　gasoline。　to　that　end；　he　became　a　constant　and　often　vocalcritic　of　the　lead　industry　and　its　interests。

it　would　prove　to　be　a　hellish　campaign。　ethyl　was　a　powerful　global　corporation　withmany　friends　in　high　places。　（among　its　directors　have　been　supreme　court　justice　lewispowell　and　gilbert　grosvenor　of　the　national　geographic　society。）　patterson　suddenly　foundresearch　funding　withdrawn　or　difficult　to　acquire。　the　american　petroleum　institutecanceled　a　research　contract　with　him；　as　did　the　united　states　public　health　service；　asupposedly　neutral　government　institution。

as　patterson　increasingly　became　a　liability　to　his　institution；　the　school　trustees　wererepeatedly　pressed　by　lead　industry　officials　to　shut　him　up　or　let　him　go。　according　to　jamielincoln　kitman；　writing　in　the　nation　in　2000；　ethyl　executives　allegedly　offered　to　endow　achair　at　caltech　“if　patterson　was　sent　packing。”　absurdly；　he　was　excluded　from　a　1971national　research　council　panel　appointed　to　investigate　the　dangers　of　atmospheric　leadpoisoning　even　though　he　was　by　now　unquestionably　the　leading　expert　on　atmospheric　lead。

to　his　great　credit；　patterson　never　wavered　or　buckled。　eventually　his　efforts　led　to　theintroduction　of　the　clean　air　act　of　1970　and　finally　to　the　removal　from　sale　of　all　leadedgasoline　in　the　united　states　in　1986。　almost　immediately　lead　levels　in　the　blood　ofamericans　fell　by　80　percent。　but　because　lead　is　forever；　those　of　us　alive　today　have　about625　times　more　lead　in　our　blood　than　people　did　a　century　ago。　the　amount　of　lead　in　theatmosphere　also　continues　to　grow；　quite　legally；　by　about　a　hundred　thousand　metric　tons　ayear；　mostly　from　mining；　smelting；　and　industrial　activities。　the　united　states　also　bannedlead　in　indoor　paint；　“forty…four　years　after　most　of　europe；”　as　mcgrayne　notes。

remarkably；　considering　its　startling　toxicity；　lead　solder　was　not　removed　from　americanfood　containers　until　1993。

as　for　the　ethyl　corporation；　it’s　still　going　strong；　though　gm；　standard　oil；　and　du　pontno　longer　have　stakes　in　the　pany。　（they　sold　out　to　a　pany　called　albemarle　paper　in1962。）　according　to　mcgrayne；　as　late　as　february　2001　ethyl　continued　to　contend　“thatresearch　has　failed　to　show　that　leaded　gasoline　poses　a　threat　to　human　health　or　theenvironment。”　on　its　website；　a　history　of　the　pany　makes　no　mention　of　lead—or　indeedof　thomas　midgley—but　simply　refers　to　the　original　product　as　containing　“a　certainbination　of　chemicals。”

ethyl　no　longer　makes　leaded　gasoline；　although；　according　to　its　2001　pany　accounts；tetraethyl　lead　（or　tel　as　it　calls　it）　still　accounted　for　25。1　million　in　sales　in　2000　（out　ofoverall　sales　of　795　million）；　up　from　24。1　million　in　1999；　but　down　from　117　million　in1998。　in　its　report　the　pany　stated　its　determination　to　“maximize　the　cash　generated　bytel　as　its　usage　continues　to　phase　down　around　the　world。”　ethyl　markets　tel　through　anagreement　with　associated　octel　of　england。

as　for　the　other　scourge　left　to　us　by　thomas　midgley；　chlorofluorocarbons；　they　werebanned　in　1974　in　the　united　states；　but　they　are　tenacious　little　devils　and　any　that　youloosed　into　the　atmosphere　before　then　（in　your　deodorants　or　hair　sprays；　for　instance）　willalmost　certainly　be　around　and　devouring　ozone　long　after　you　have　shuffled　off。　worse；　weare　still　introducing　huge　amounts　of　cfcs　into　the　atmosphere　every　year。　according　towayne　biddle；　60　million　pounds　of　the　stuff；　worth　1。5　billion；　still　finds　its　way　onto　themarket　every　year。　so　who　is　making　it？　we　are—that　is　to　say；　many　of　our　largecorporations　are　still　making　it　at　their　plants　overseas。　it　will　not　be　banned　in　third　worldcountries　until　2010。

clair　patterson　died　in　1995。　he　didn’t　win　a　nobel　prize　for　his　work。　geologists　neverdo。　nor；　more　puzzlingly；　did　he　gain　any　fame　or　even　much　attention　from　half　a　century　ofconsistent　and　increasingly　selfless　achievement。　a　good　case　could　be　made　that　he　was　themost　influential　geologist　of　the　twentieth　century。　yet　who　has　ever　heard　of　clair　patterson？

most　geology　textbooks　don’t　mention　him。　two　recent　popular　books　on　the　history　of　thedating　of　earth　actually　manage　to　misspell　his　name。　in　early　2001；　a　reviewer　of　one　ofthese　books　in　the　journal　nature　made　the　additional；　rather　astounding　error　of　thinkingpatterson　was　a　woman。

at　all　events；　thanks　to　the　work　of　clair　patterson　by　1953　the　earth　at　last　had　an　ageeveryone　could　agree　on。　the　only　problem　now　was　it　was　older　than　the　universe　thatcontained　it。

．co



11MUSTER　MARK’S　QUARKS

：
in　1911；　a　british　scientist　named　c。　t。　r。　wilson　was　studying　cloud　formations　bytramping　regularly　to　the　summit　of　ben　nevis；　a　famously　damp　scottish　mountain；　when　itoccurred　to　him　that　there　must　be　an　easier　way　to　study　clouds。　back　in　the　cavendish　labin　cambridge　he　built　an　artificial　cloud　chamber—a　simple　device　in　which　he　could　cooland　moisten　the　air；　creating　a　reasonable　model　of　a　cloud　in　laboratory　conditions。

the　　device　　worked　　very　　well；　　but　　had　　an　additional；　unexpected　benefit。　when　heaccelerated　an　alpha　particle　through　the　chamber　to　seed　his　make…believe　clouds；　it　left　avisible　trail—like　the　contrails　of　a　passing　airliner。　he　had　just　invented　the　particle　detector。

it　provided　convincing　evidence　that　subatomic　particles　did　indeed　exist。

eventually　two　other　cavendish　scientists　invented　a　more　powerful　proton…beam　device；while　in　california　ernest　lawrence　at　berkeley　produced　his　famous　and　impressivecyclotron；　or　atom　smasher；　as　such　devices　were　long　excitingly　known。　all　of　thesecontraptions　worked—and　indeed　still　work—on　more　or　less　the　same　principle；　the　ideabeing　to　accelerate　a　proton