mc.prey-第24部分

按键盘上方向键 ← 或 → 可快速上下翻页，按键盘上的 Enter 键可回到本书目录页，按键盘上方向键 ↑ 可回到本页顶部！
————未阅读完？加入书签已便下次继续阅读！


　You　could　think　of　a　molecule　as　a　series　of　atoms　snapped　together　like　Lego　blocks；　one　after　another。　But　the　image　was　misleading。　Because　unlike　a　Lego　set；　atoms　couldn't　be　snapped　together　in　any　arrangement　you　liked。　An　inserted　atom　was　subject　to　powerful　local　forces…magnetic　and　chemical…with　frequently　undesirable　results。　The　atom　might　be　kicked　out　of　its　position。　It　might　remain；　but　at　an　awkward　angle。　It　might　even　fold　the　entire　molecule　up　in　knots。
　As　a　result；　molecular　manufacturing　was　an　exercise　in　the　art　of　the　possible；　of　substituting　atoms　and　groups　of　atoms　to　make　equivalent　structures　that　would　work　in　the　desired　way。　In　the　face　of　all　this　difficulty；　it　was　impossible　to　ignore　the　fact　that　there　already　existed　proven　molecular　factories　capable　of　turning　out　large　numbers　of　molecules：　they　were　called　cells。
　〃Unfortunately；　cellular　manufacturing　can　take　us　only　so　far；〃　Ricky　said。　〃We　harvest　the　substrate　molecules…the　raw　materials…and　then　we　build　on　them　with　nanoengineering　procedures。　So　we　do　a　little　of　both。〃
　I　pointed　down　at　the　tanks。　〃What　cells　are　you　growing？〃
　〃Theta…d　5972；〃　he　said。
　〃Which　is？〃
　〃A　strain　of　E。　coli。〃
　E。　coli　was　a　mon　bacterium；　found　pretty　much　everywhere　in　the　natural　environment；　even　in　the　human　intestine。　I　said；　〃Did　anyone　think　it　might　not　be　a　good　idea　to　use　cells　that　can　live　inside　human　beings？〃
　〃Not　really；〃　he　said。　〃Frankly　that　wasn't　a　consideration。　We　just　wanted　a　well…studied　cell　that　was　fully　documented　in　the　literature。　We　chose　an　industry　standard。〃
　〃Uh…huh　。。。〃
　〃Anyway；〃　Ricky　continued；　〃I　don't　think　it's　a　problem；　Jack。　It　won't　thrive　in　the　human　gut。　Theta…d　is　optimized　for　a　variety　of　nutrient　sources…to　make　it　cheap　to　grow　in　the　laboratory。　In　fact；　I　think　it　can　even　grow　on　garbage。〃
　〃So　that's　how　you　get　your　molecules。　Bacteria　make　them　for　you。〃
　〃Yes；〃　he　said；　〃that's　how　we　get　the　primary　molecules。　We　harvest　twenty…seven　primary　molecules。　They　fit　together　in　relatively　high…temperature　settings　where　the　atoms　are　more　active　and　mix　quickly。〃
　〃That's　why　it's　hot　in　here？〃
　〃Yes。　Reaction　efficiency　has　a　maxima　at　one　hundred　forty…seven　degrees　Fahrenheit；　so　we　work　there。　That's　where　we　get　the　fastest　bination　rate。　But　these　molecules　will　bine　at　much　lower　temperatures。　Even　around　thirty…five；　forty　degrees　Fahrenheit；　you'll　get　a　certain　amount　of　molecular　bination。〃
　〃And　you　don't　need　other　conditions；〃　I　said。　〃Vacuum？　Pressure？　High　magnetic　fields？〃　Ricky　shook　his　head。　〃No；　Jack。　We　maintain　those　conditions　to　speed　up　assembly；　but　it's　not　strictly　necessary。　The　design　is　really　elegant。　The　ponent　molecules　go　together　quite　easily。〃
　〃And　these　ponent　molecules　bine　to　form　your　final　assembler？〃
　〃Which　then　assembles　the　molecules　we　want。　Yes。〃
　It　was　a　clever　solution；　creating　his　assemblers　with　bacteria。　But　Ricky　was　telling　me　the　ponents　assembled　themselves　almost　automatically；　with　nothing　required　but　high　temperature。　What；　then；　was　this　plex　glass　building　used　for？　〃Efficiency；　and　process　separation；〃　Ricky　said。　〃We　can　build　as　many　as　nine　assemblers　simultaneously；　in　the　different　arms。〃
　〃And　where　do　the　assemblers　make　the　final　molecules？〃
　〃In　this　same　structure。　But　first；　we　reapply　them。〃
　I　shook　my　head。　I　wasn't　familiar　with　the　term。　〃Reapply？〃
　〃It's　a　little　refinement　we　developed　here。　We're　patenting　it。　You　see；　our　system　worked　perfectly　right　from　the　start…but　our　yields　were　extremely　low。　We　were　harvesting　half　a　gram　of　finished　molecules　an　hour。　At　that　rate；　it　would　take　several　days　to　make　a　single　camera。　We　couldn't　figure　out　what　the　problem　was。　The　late　assembly　in　the　arms　is　done　in　gas　phase。　It　turned　out　that　the　molecular　assemblers　were　heavy；　and　tended　to　sink　to　the　bottom。　The　bacteria　settled　on　a　layer　above　them；　releasing　ponent　molecules　that　were　lighter　still；　and　floated　higher。　So　the　assemblers　were　making　very　little　contact　with　the　molecules　they　were　meant　to　assemble。　We　tried　mixing　technologies　but　they　didn't　help。〃
　〃So　you　did　what？〃
　〃We　modified　the　assembler　design　to　provide　a　lipotrophic　base　that　would　attach　to　the　surface　of　the　bacteria。　That　brought　the　assemblers　into　better　contact　with　the　ponent　molecules；　and　immediately　our　yields　jumped　five　orders　of　magnitude。〃
　〃And　now　your　assemblers　sit　on　the　bacteria？〃
　〃Correct。　They　attach　to　the　outer　cell　membrane。〃
　At　a　nearby　workstation；　Ricky　punched　up　the　assembler　design　on　the　flat　panel　display。　The　assembler　looked　like　a　sort　of　pinwheel；　a　series　of　spiral　arms　going　off　in　different　directions；　and　a　dense　knot　of　atoms　in　the　center。　〃It's　fractal；　as　I　said；〃　he　said。　〃So　it　looks　sort　of　the　same　at　smaller　orders　of　magnitude。〃　He　laughed。　〃Like　the　old　joke；　turtles　all　the　way　down。〃　He　pressed　more　keys。　〃Anyway；　here's　the　attached　configuration。〃　The　screen　now　showed　the　assembler　adhering　to　a　much　larger　pill…shaped　object；　like　a　pinwheel　attached　to　a　submarine。　〃That's　the　Theta…d　bacterium；〃　Ricky　said。　〃With　the　assembler　on　it。〃
　As　I　watched；　several　more　pinwheels　attached　themselves。　〃And　these　assemblers　make　the　actual　camera　units？〃
　〃Correct。〃　He　typed　again。　I　saw　a　new　image。　〃This　is　our　target　micromachine；　the　final　camera。　You've　seen　the　bloodstream　version。　This　is　the　Pentagon　version；　quite　a　bit　larger　and　designed　to　be　airborne。　What　you're　looking　at　is　a　molecular　helicopter。〃
　〃Where's　the　propeller？〃　I　said。
　〃Hasn't　got　one。　The　machine　uses　those　little　round　protrusions　you　see　there；　stuck　in　at　angles。　Those're　motors。　The　machines　actually　maneuver　by　climbing　the　viscosity　of　the　air。〃
　〃Climbing　the　what？〃
　〃Viscosity。　Of　the　air。〃　He　smiled。　〃Micromachine　level；　remember？　It's　a　whole　new　world；　Jack。〃
　However　innovative　the　design；　Ricky　was　still　bound　by　the　Pentagon's　engineering　specs　for　the　product；　and　the　product　wasn't　performing。　Yes；　they　had　built　a　camera　that　couldn't　be　shot　down；　and　it　transmitted　images　very　well。　Ricky　explained　it　worked　perfectly　during　tests　indoors。　But　outside；　even　a　modest　breeze　tended　to　blow　it　away　like　the　cloud　of　dust　it　was。　The　engineering　team　at　Xymos　was　attempting　to　modify　the　units　to　increase　mobility；　but　so　far　without　success。　Meanwhile　the　Department　of　Defense　decided　the　design　constraints　were　unbeatable；　and　had　backed　away　from　the　whole　nano　concept；　the　Xymos　contract　had　been　canceled；　DOD　was　going　to　pull　funding　in　another　six　weeks。　I　said；　〃That's　why　Julia　was　so　desperate　for　venture　capital；　these　last　few　weeks？〃
　〃Right；〃　Ricky　said。　〃Frankly；　this　whole　pany　could　go　belly　up　before　Christmas。〃
　〃Unless　you　fix　the　units；　so　they　can　work　in　wind。〃
　〃Right；　right。〃
　I　said；　〃Ricky；　I'm　a　programmer。　I　can't　help　you　with　your　agent　mobility　problems。　That's　an　issue　of　molecular　design。　It's　engineering。　It's　not　my　area。〃
　〃Um；　I　know　that。〃　He　paused；　frowned。　〃But　actually；　we　think　the　program　code　may　be　involved　in　the　solution。〃
　〃The　code？　Involved　in　the　solution　to　what？〃
　〃Jack；　I　have　to　be　frank　with　you。　We've　made　a　mistake；〃　he　said。　〃But　it's　not　our　fault。　I　swear　to　you。　It　wasn't　us。　It　was　the　contractors。〃　He　started　down　the　stairs。　〃e　on；　I'll　show　you。〃
　Walking　briskly；　he　led　me　to　the　far　side　of　the　facility；　where　I　saw　an　open　yellow　elevator　cage　mounted　on　the　wall。　It　was　a　small　elevator；　and　I　was　unfortable　because　it　was　open；　I　averted　my　eyes。　Ricky　said；　〃Don't　like　heights？〃
　〃Can't　stand　them。〃
　〃Well；　it's　better　than　walking。〃　He　pointed　off　to　one　side；　where　an　iron　ladder　ran　up　the　wall　to　the　ceiling。　〃When　the　elevator　goes　out；　we　have　to　climb　up　that。〃　I　shuddered。　〃Not　me。〃
　We　rode　the　elevator　all　the　way　up　to　the　ceiling；　three　stories　above　the　ground。　Hanging　beneath　the　ceiling　was　a　tangle　of　ducts　and　conduits；　and　a　network　of　mesh　walkways　to　enable　workers　to　service　them。　I　hated　the　mesh；　because　I　could　see　through　it　to　the　floor　far　below。　I　tried　not　to　look　down。　We　had　to　duck　repeatedly　beneath　the　low…hanging　pipes。　Ricky　shouted　over　the　roar　of　the　equipment。
　〃Everything's　up　here！〃　he　yelled；　pointing　in　various　directions。　〃Air　handlers　over　there！　Water　tank　for　the　fire　sprinkler　system　there！　Electrical　junction　boxes　there！　This　is　really　the　center　of　everything！〃　Ricky　continued　down　the　walkway；　finally　stopping　beside　a　big　air　vent；　about　three　feet　in　diameter；　that　went　into　the　outer　wall。
　〃This　is　vent　three；〃　he　said；　leaning　close　to　my　ear。　〃It's　one　of　four　main　vents　that　exhausts　air　to　the　outside。　Now；　you　see　those　slots　along　the　vent；　and　the　square　boxes　that　sit　in　the　slots？　Those　are　filter　packs。　We　have　microfilters　arranged　in　successive　layers；　to　prevent　any　external　contamination　from　the　facility。〃
　〃I　see　them　。。。〃
　〃You　see　them　now；〃　Ricky　said。　〃Unfortunately；　the　contractor　forgot　to　install　the　filters　in　this　particular　vent。　In　fact；　they　didn't　even　cut　the　slots；　so　the　building　inspectors　never　realized　anything　was　missing。　They　signed　off　on　the　building；　we　started　working　here。　And　we　vented　unfiltered　air　to　the　outside　environment。〃
　〃For　how　long？〃
　Ricky　bit　his　lip。　〃Three　weeks。〃
　〃And　you　were　at　full　production？〃
　He　nodded。　〃We　figure　we　vented　approximately　twenty…five　kilos　of　contaminants。〃
　〃And　what　were　the　contaminants？〃
　〃A　little　of　everything。　We're　not　sure　of　exactly　what。〃
　〃So　you　vented　E。　coli；　assemblers；　finished　molecules；　everything？〃
　〃Correct。　But　we　don't　know　what　proportions。〃
　〃Do　the　proportions　matter？〃
　〃They　might。　Yes。〃
　Ricky　was　increasingly　edgy　as　he　told　me　all　this；　biting　his　lip；　scratching　his　head；　avoiding　my　eyes。　I　didn't　get　it。　In　the　annals　of　industrial　pollution；　fifty　pounds　of　contamination　was　trivial。　Fifty　pounds　of　material　would　fit　fortably　in　a　gym　bag。　Unless　it　was　highly　toxic　or　radioactive…and　it　wasn't…such　a　small　quantity　simply　didn't　matter。　I　said；　〃Ricky；　so　what？　Those　particles　were　scattered　by　the　wind　across　hundred