text_combined: eugen leitl vnngxleitlorg httpdiscovermagazinecom2007novthismanwantstocontroltheinternet man wants control internet 10252007 man wants control internet let carl zimmer photographs trujillopaumier john doyle worried internet next years millions people gain access existing users place ever higher demands digital infrastructure driven applications like online movie services internet telephony doyle predicts skyrocketing traffic could cause internet slow disastrous crawl endless digital gridlock stifling economies doyle professor control dynamic systems electrical engineering bioengineering caltech also believes internet saved colleagues created theory revealed simple yet powerful ways accelerate flow information vastly accelerate flow doyle colleagues blast entire text books library congress across united states 15 minutes travel pasadena learn doyleâs work bit flummoxed suggestion meet lab gym doyle gets treadmill begins pound away turn machine try keep 53 doyle long lean hawkfaced championship athlete works furiously twice day least itâs hard catch enough air ask doyle questions problem holding forth response talks begin realize secret agenda meeting treadmill perfect place start understand ideas doyle world filled complex networksâand body middle workout good example networks system linked computers like internet obviously network jetliners human bodies even bacterial cells theyâre networks made lots lots parts work together robust networks parts continue work together smoothly even conditions fluctuate unpredictably case internet million people may try send email case doyleâs body treadmill physiology holds steady even pushes limit âinside everythingâs going crazyâ doyle says âbut itâs keeping body temperature steady body uprightâ doyle knows however networks look perfectly sound headed collapse little warning found order achieve robustness systems must follow certain rules robustness doesnât come cheap system tuned become robust one set conditions tuning makes system fragile sometimes unexpected conditions robustness fragility go hand hand doyle pounds away treadmill offers body exhibit number one optimized body meet grueling challenges winning triathlons made body vulnerable problems rarely plague nonathlete bad ankles groin injury injuries earned lifetime playing sports august almost died falling rock face hiking panama treadmill slows stop doyle checks pulse âone reasons iâm interested robustnessâ said âis iâm fragileâ doyle came mit 1975 fell love science known control theory control theorists roughly speaking try understand complicated things run efficiently quickly safely instead crashing exploding otherwise grinding halt analyze systems modeling variables dictate behave rather checking every possible combination variables see say plane fly straight stall wind picks control theorists look underlying laws control predict something behave using key variables âcontrol theory center modern technologyâ doyle explains technology become complex past century researchers find new ways control airplanes factories computers like much progress come bruteforce tinkering lot come growing understanding basic laws control doyle began developing innovative ideas control theory undergraduate 1976 consulting honeywell age 32 hired immediate tenure caltech doyle made mark figuring prove system robust early 1980s nasa asked look space shuttle several shuttles already flown agency wanted reassurance behavior reentry using wind tunnels computer simulations nasa come apparently stable designs many variables test everything âyou obscenely large space possibilitiesâ doyle says âsomewhere lurking could crash donât knowâ doyle looked forces might exerted space shuttle due atmospheric conditions velocity air forth nasaâs engineers plotted forces socalled multidimensional spaceâsay pitching torque along one axis longitudinal acceleration along another developing new mathematical tools doyle proved volume multidimensional space inside every combination forces certainly safe outside region lurked disaster space shuttle design lodged comfortably inside safe region part metabolic network ecolimicrobe image courtesy ouzounis karpgenome research ânot could show safe could prove itâ doyle says techniques doyle developed test space shuttle become standard tools testing new designs airplanes helicopters doyle fundamental question mind big could volume safety made certainly possible make things robustâin words expand safe region jetliner far robust worldâs first airplane 1903 wright flyer doyle took question concerned researchers since birth control theory 1930s â40s fundamental limits growth robustness focused one important ways engineers make things robust adding feedback loops jet keep track movement temperature long list readings continually correct every one adjusting bring variables back line doyle showed cranking robustness conditions creates new opportunities failure jet far stable high winds wright flyer hand vulnerable software bugs wright brothers never worry âyou replace mechanical failure lots software failureâ doyle says 1990s studying complex systems sorts became something fad following emergence âchaos theoryâ competing versions theory emerging left right chaos touted science future doyle unimpressed new ideas âit clear far markâ says doyle made name combined trendy buzzwords came across âemergilent chaoplexityâ one reason doyle loathes emergilent chaoplexity relies superficial patterns doyle contrast insists analyses draw gritty details things actually work example doyle points known scalefree networks many networksâinterlinked sets airports friends nerves body onâhave basic structure nodes highly connected hubs nodes connections given small city airport probably connects others passengers rely able transfer hub reach places live chicago take direct flight oâhare airport hundreds destinations researchers like albertlãszlã³ barabãsi university notre dame argued pdf internet shares similar structure accounts internet keeps humming even systems fail since hubs rare failures involving even rarer hub fail researchers warned would lead catastrophe warning made headlines cnn reporting 2000 âscientists spot achillesâ heel internetâ doyle impressed âeverybody knew internet worked puzzled thisâ says decided test achillesâ heel theory joining group collaborators mapping section internet unprecedented detail map found achillesâ heel internet large servers core servers actually well connected one links mainly large servers highbandwidth connections much activity occurs internet actually lies edges computers linked relatively lowbandwidth connections small servers think many emails office workers send people building compared many send overseas one big links core internet crashed doyle colleagues discovered would take internet traffic could simply rerouted big links vast amount traffic could make internet catastrophically fragile could wake one morning nothing works internet works spectacularly well despite fact past 30 years expanded millionfold absorbing new technology blackberries itunes music store hardly major changes basic rules uses move data doyle knows itâs physical arrangement cables servers makes net robust doyle colleagues showed software runs internet uses feedback much way jetlinerâs computer internet sense changing conditions adjust internet two kinds feedback maintains constantly updated picture entire network messages directed along fastest routes also breaks messages encapsulates inside standardized packets data little like using standardized waybills boxes provided fedex packet take path internet packets arrive recipientâs computer message fragments packet extracted reassembled critically packet arrives sends back receipt senderâs computer heavy traffic packets get lost response lost packets computers slow rate send data reducing congestion together two types feedback give internet robustness powerful anyone anticipated âthese internet engineers werenât control theorists built incredibly robust networkâ doyle says âman thatâs awesomeâ engineers something evolution figured long ago back doyleâs messy caltech office props robust yet fragile body recliner desk shifts conversation technology back biology around time doyle began use control theory understand internet also began using explore mechanism life ideas control really universal realized cell ought share basic organizational principles airplane internetâalthough finding similarities might require digging âif want understand airplanes fly looking birds helps may end thinking itâs flappingâ says âif look bats insects youâll see itâs lift drag things like use understand deep stuffâ control theorists pondered living things decades recently lacked mathematical tools analyze would technological system doyle colleagues created tools keeping doyleâs gritty realworld philosophy set see applied common bacterium escherichia coli soon discovered remarkably precise parallels living networks technological ones going moon trivial compared dealing e coli heated dangerous temperatures example rapidly churn thousands heatshock proteins molecules help protect microbeâs workings temperature falls heatshock proteins quickly get dismantled doyle demonstrated behavior takes place series feedback loops inside bacterium akin feedback loops keep airplane autopilot steady even plane buffeted gusts doyle tackling far bigger network genes e coli master network responsible governing metabolism team probing control systems allow microbe eat many different kinds sugar transform thousands molecules make bacterium e coliâs metabolism nothing robust able easily withstand significant environmental fluctuations reason bacterium works well doyle finds organized much way internet internet e coli conceptually organized like bow tie broad fan incoming material flowing central knot flowing another broad fan outgoing material internet incoming fan made data huge range sourcesâ email youtube videos skype phone calls like e coli incoming fan made many sorts food eats information food move respective bow ties get homogenized e coli breaks food building blocks internet breaks motley incoming data streams streams standardized packets knot bow ties fan e coli turns building blocks dna proteins membrane molecules special ingredient needs internet data packets reach computer reassembled original email youtube videos skype telephone calls like bowtie organization allows internet e coli run quickly efficiently e coli like bacteria indeed like living things bow tie would use different set enzymes make thousands different molecules needs type food rather use huge slow system e coli points metabolic pathways bowtie knot making everything raw materials likewise internetâs bowtie architecture means doesnât different ways handle say email traffic instantmessage traffic everything passes types data packets bowtie architecture also makes internet e coli robust type incoming material changes rapidlyâsay surge video traffic internetâs case new food source e coliâthe system process material without retool entire metabolism cope another advantage bow tie makes feedback control easy information travels back receiving computer sender speed slow packets response e coliâs metabolism loaded analogous feedback loops normally e coli synthesize amino acids needs making proteins get certain kind amino acid environment information shuts production line doyle points improving robustness comes price bowtie structure opens door vulnerability could prove hard fix homogenization occurs heart bow tie itâs difficult identify block harmful agents case internet takes short piece code produce digital virus spread quickly millions computers cause billions dollars damage living organisms real viruses hijack cells much way doyle thinks similarity e coli internet accident networks get big complicatedâeither tinkering internet engineers millions years evolutionâthey must follow certain rules stay robust âthere inevitable architectureâ doyle says dinner doyle muses deal fundamental vulnerabilities hasnât found way improve biological reliability yet think help address internetâs limits current packetreceipt feedback system known tcp worked wonderfully years control flow internet traffic wonât able cope coming jam fridges scan rfid chip milk carton send alert expiration date arrives âwhether like internet equipment giant cisco network everything soon glasses tell kitchen theyâre emptyâ doyle says vast amount traffic make internet catastrophically fragile âwe could wake one morning nothing worksâ many internet experts also worried theyâve launched several projects save network including steven low another caltech professor doyle working low project unusual simplicity plan speed internet simply better job paying attention measurements internet traffic today computers sense internet congestion noticing many packets lose thatâs like trying drive highway looking whatâs 20 feet ahead constantly accelerating slamming brakes soon see something doyle coworkers enable computers use information traffic flow noting long takes packets get destination less traffic shorter time traffic reports hand computers make much smarter decisions result string victories highspeed internet communication competitions last faceoff 2006 managed send 17 gigabitsâabout fulllength movieâs worthâeach second across internet doyle smiles describes success flash athleteâs spirit face âyouâre proving theoremsâ says âit beats anything anyone else doâ last year caltech team started operating company fastsoft market protocol march started selling box size dvd player plug server one test fortune 500 company able speed transmissions 30fold doyle stresses real solution internet crisis require rethinking control process bottom âif someone said âdo radical redesignâ iâd say weâre ready yetâ doyle confesses âgoing moon trivial compared dealing weâve got research path thereâs hard math doneâ thu 07 aug 2008 102919 0100 fork man wants control internet