IsaccNewton 　　Towardtheendofthe1600sNewtonpickeduponDescartes'theoriesofmotionandcompletedthemechanisticvisionoftheuniversethathehadlaidout.InhisPrincipia(1687)hesothoroughlypulledthemechanisticvisiontogetherthatitbecamethesinglemostimportantfoundationpieceforthemodernworld-view. 　　He"demonstrated"thatallthingswithintheuniversearemadeupofminutebitsofmatterwhichareheldtogetherintheirshapeandmovementthroughtheforceofnaturalattractionorgravity(thegravitationalattractionoftwobodiesisequaltotheproductoftheirmassdividedbythesquareofthedistancebetweenthem).Thistheoryexplainedquitefullyeverythingfromthemovementoftheplanetsthroughtheskies,tothemovementsofthetides,tothevelocityoffallingobjects--andmore. 　　Justasimportantly--thecompletenessofthetheoryleftnopossibilityofseeingcreationasa"living"thing.Creationwaswithoutlifeofitsown;itwasinsteadmere"matter"respondingmechanicallytoasetoffixedmathematicallaws. 　　Nonetheless,Newtonthoughtofhimselfasbeingreligiouslyquitedevout.Histheoryoftheuniverse--sohethought--wasintendedasapowerfultributetotheGrandArchitectwhodesignedsuchawonderfullycomplexyetbeautifulcreation. 　　However,NewtondepictedGodinsuchawaythatGodactuallylost"personality"andtherealmofsovereignaction.Godwasleftaroleinnaturelargelyas"FirstMover"withnofurthersignificantinterventioninlife.Godnearlybecameidentifiedwiththeeternityorinfinityoftheuniverse. 　　ThomasEdison'sLife 　　ThomasAlvaEdisonwasbornin1847inMilan,Ohio.Atthattime,JamesPolkwasPresidentandAbrahamLincolnwasjustcontemplatingrunningforthelegislature.WhenEdisondiedin1931,attheageof84,HerbertHooverwasPresidentandwewereinthemiddleoftheGreatDepression.DuringhislifetimeEdisonsawtheUnitedStatesengagedintwomajorwars:theCivilWarwhenhewasateenager,andWorldWarIwhenhewasanadultandappointedtoassisttheSecretaryoftheNavy.Hisinventionshadasignificanteffectuponhistimesandpermanentlyalteredthewayinwhichwelivetoday.Canyouimaginelifewithouttheelectriclight?Thephonographandallofitsimprovements?Themotionpicture? 　　Attheageof12,Edisonbeganworkasa"candybutcher"aboardtheGrandTrunkRailroad'scommuterlinebetweenPortHuron,Michigan,wherewelivedwithhisparents,andDetroit.Hesoldnewspapers,fruitandcandytothepassengers.ThetrainleftPortHuronabout7:00inthemorningandreturnedat9:00or9:30atnight.ThetripincludedasixhourlayoverinDetroit,duringwhichtimeheclaimstohaveread"theentirepubliclibrary."Hewasanomnivorousreaderandlovedtoexperimentwithchemicalsandmachinery.Heconstantlywantedtoinvestigatehowthingsworkedandlikedtoseeifhecouldmakethingsbetter.Onthetrainhewasallowedatableinanemptybaggagecaronwhichtowork.Heevenbroughtabrokenprintingpress,repaireditandtaughthimselftoprint.Hemayhaveproducedthefirstnewspaperprintedonamovingtrain.Edisonbegannoticingalossofhearingaroundthistime,whichincreasedthroughouthislife. 　　Atthattime,telegraphlinesoftenranparalleltotherailroadtracks,andmanyofthestationmastersweretelegraphoperators.Edisonwasstruckbytheimportanceoftelegraphyincommunicatio