Unit9THEEDUCATIONOFAPHYSICISTMICHIOKAKUIdlywatchingfishswimminginapondandallowingthemindtowandercanleadtosomesurprisingresults.Twoincidentsfrommychildhoodgreatlyenrichedmyunderstandingoftheworldandsentmeonacoursetobecomeatheoreticalphysicist.IrememberthatmyparentswouldsometimestakemetovisitthefamousJapaneseTeaGardeninSanFrancisco.Oneofmyhappiestchildhoodmemoriesisofcrouchingnexttothepond,fascinatedbythebrilliantlycoloredcarpswimmingslowlybeneaththewaterlilies.Inthesequietmoments,Ifeltfreetoletmyimaginationwander;Iwouldaskmyselfsillyquestionsthatonlyachildmightask,suchashowthecarpinthatpondwouldviewtheworldaroundthem.Ithought,Whatastrangeworldtheirsmustbe!Livingtheirentirelivesintheshallowpond,thecarpwouldbelievethattheir“universe”consistedofthedarkwaterandthelilies.Spendingmostoftheirtimemovingaroundforfoodonthebottomofthepond,theywouldbeonlydimlyawarethatanalienworldcouldexistabovethesurface.Thenatureofmyworldwasbeyondtheircomprehension.IwasintriguedthatIcouldsitonlyafewinchesfromthecarp,yetbeseparatedfromthembyaveryhugegap.ThecarpandIspentourlivesintwodistinctuniverses,neverenteringeachother’sworld,yetwereseparatedbyonlythethinnestbarrier,thewater’ssurface.Ionceimaginedthattheremaybecarp“scientists”livingamongthefish.Theywould,Ithought,laughatanyfishwhoproposedthataparallelworldcouldexistjustabovethelilies.Toacarp“scientist,”theonlythingsthatwererealwerewhatthefishcouldseeortouch.Thepondwaseverything.Anunseenworldbeyondthepondmadenoscientificsense.OnceIwascaughtinarainstorm.Inoticedthatthepond’ssurfacewasbombardedbythousandsoftinyraindrops.Thepond’ssurfacebecameturbulent,andthewaterlilieswerebeingpushedinalldirectionsbywaterwaves.Takingshelterfromthewindandtherain,Iwonderedhowallthisappearedtothecarp.Tothem,thewaterlilieswouldappeartobemovingaroundbythemselves,withoutanythingpushingthem.Sincethewatertheylivedinwouldappearinvisible,muchliketheairandspacearoundus,theywouldbebaffledthatthewaterliliescouldmovearoundbythemselves.Their“scientists,”Iimagined,wouldmakeupacleverinventioncalleda“force”inordertohidetheirignorance.Unabletocomprehendthattherecouldbewavesontheunseensurface,theywouldconcludethatliliescouldmovewithoutbeingtouchedbecauseamysteriousinvisibleentitycalledaforceactedbetweenthem.Theymightgivethisillusionimpressive,loftynames(suchasaction-at-a-distance,ortheabilityoftheliliestomovewithoutanythingtouchingthem).OnceIimaginedwhatwouldhappenifIreacheddownandliftedoneofthecarp“scientists”outofthepond.BeforeIthrewhimbackintothewater,hemightstrugglefuriouslyasIexaminedhim.Iwonderedhowthiswouldappeartotherestofthecarp.Tothem,itwouldbeatrulyunsettlingevent.Theywouldfirstnoticethatoneoftheir“scientists”haddisappearedfromtheiruniverse.Simplyvanished,withoutleavingatrace.Wherevertheywouldlook,therewouldbenoevidenceofthemissingcarpintheiruniverse.Then,secondslater,whenIthrewhimbackintothepond,the“scientist”wouldabruptlyreappearoutofnowhere.Totheothercarp,itwouldappearthatamiraclehadhappened.Aftercollectinghiswits,the“scientist”wouldtellatrulyamazingstory.“Withoutwarning,”hewouldsay,“Iwassomehowliftedoutoftheuniverse(thepond)andhurledintoamysteriousworld,withblindinglightsandstrangelyshapedobjectsthatIhadneverseenbefore.Thestrangestofallwasthecreaturewhoheldmeprisoner,whodidnotresembleafishintheslightest.Iwasshockedtoseethatithadnofinswhatsoever,butneverthelesscouldmovewithoutthem.Itstruckmethatthefamiliarlawsofnaturenolongerappliedinthisotherworld.Then,justassuddenly,Ifoundmyselfthrownbackintoouruniverse.”(Thisstory,ofcourse,ofajourneybeyondtheuniversewouldbesofantasticthatmostofthecarpwoulddismissitasutternonsense.)Ioftenthinkthatwearelikethecarpswimmingcontentedlyinthatpond.Weliveoutourlivesinourown“pond,”confidentthatouruniverseconsistsofonlythosethingswecanseeortouch.Likethecarp,ouruniverseconsistsofonlythefamiliarandthevisible.Wesmuglyrefusetoadmitthatparalleluniversesordimensionscanexistnexttoours,justbeyondourgrasp.Ifourscientistsinventconceptslikeforces,itisonlybecausetheycannotvisualizetheinvisiblevibrationsthatfilltheemptyspacearoundus.Asecondincidentfrommychildhoodalsomadeadeep,lastingimpressiononme.WhenIwas8yearsold,Iheardastorythatwouldstaywithmefortherestofmylife.Iremembermyschoolteacherstellingtheclassaboutagreatscientistwhohadjustdied.Theytalkedabouthimwithgreatreverence,callinghimoneofthegreatestscientistsinallhistory.Theysaidthatveryfewpeoplecouldunderstandhisideas,butthathisdiscoverieschangedtheentireworldandeverythingaroundus.Ididn'tunderstandmuchofwhattheyweretryingtotellus,butwhatmostintriguedmeaboutthismanwasthathediedbeforehecouldcompletehisgreatestdiscovery.Theysaidhespentyearsonthistheory,buthediedwithhisunfinishedpapersstillsittingonhisdesk.Iwasfascinatedbythestory.Toachild,thiswasagreatmystery.Whatwashisunfinishedwork?Whatwasinthosepapersonhisdesk?Whatproblemcouldpossiblybesodifficultandsoimportantthatsuchagreatscientistwoulddedicateyearsofhislifetoitspursuit?Curious,IdecidedtolearnallIcouldaboutAlbertEinsteinandhisunfinishedtheory.Istillhavewarmmemoriesofspendingmanyquiethoursre