CHAPTER 1 Inventing the Wheel - Cambridge University Pressassets.cambridge.org › 97811076 ›...
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CHAPTER 1 Wheels are all around us. You use them every day, but you probably don’t think about them very often. In fact, the wheel as we know it is quite a new invention. There are no real wheels in nature. There aren’t any animals that use wheels to get around. But why not? Why are there no animals with wheels instead of legs? Perhaps because wheels aren’t any good on some kinds of ground. It’s hard to cross the desert or the forest or to climb a mountain on wheels. However, for humans, the wheel has been an amazing invention. Inventing the Wheel IT’S A MAN-MADE INVENTION, IT HAS COMPLETELY CHANGED THE WAY WE LIVE, AND IT’S EVERYWHERE IN THE WORLD. WHAT IS IT? THE WHEEL! 6 www.cambridge.org © in this web service Cambridge University Press Cambridge University Press 978-1-107-66739-6 - Cambridge Discovery Education TM : Interactive Readers: The Wheel: A2 + Caroline Shackleton and Nathan Paul Turner Excerpt More information
Transcript of CHAPTER 1 Inventing the Wheel - Cambridge University Pressassets.cambridge.org › 97811076 ›...
CHAPTER 1
Wheelsareallaroundus.Youusethemeveryday,butyouprobablydon’tthinkaboutthemveryoften.Infact,thewheelasweknowitisquiteanewinvention.
Therearenorealwheelsinnature.Therearen’tanyanimalsthatusewheelstogetaround.Butwhynot?Whyaretherenoanimalswithwheelsinsteadoflegs?Perhapsbecausewheelsaren’tanygoodonsomekindsofground.It’shardtocrossthedesertortheforestortoclimbamountainonwheels.However,forhumans,thewheelhasbeenanamazinginvention.
Inventing the WheelIT’S A MAN-MADE INVENTION, IT HAS COMPLETELY CHANGED THE WAY WE LIVE, AND IT’S EVERYWHERE IN THE WORLD. WHAT IS IT? THE WHEEL!
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Iftherearenowheelsinnature,howdidpeoplefirstmakethem?Nobodyreallyknowstheanswer.Therearemanyroundshapesandcirclesinnature,buttheyaren’tlikewheels;theyaren’tusedtohelpmovethings.
Theearliestpeopleworkedwithstone.So,maybetheysawroundstonesrolling.Buttheyalsomadeboatsfromwood.Perhapstheysawthelogstheyusedforbuildingboatsrollingdownahill!
OneoftheearliestusesoflogstomovethingswasinEgyptabout3000BCE.Logswereusedtobuildthepyramids.Theheavystonesforthesebuildingswereputonflatsledsandpulledforwardoverlogs,calledrollers.Therollinglogshelpedmovethestonesmoreeasily.
Inventing the WheelIT’S A MAN-MADE INVENTION, IT HAS COMPLETELY CHANGED THE WAY WE LIVE, AND IT’S EVERYWHERE IN THE WORLD. WHAT IS IT? THE WHEEL!
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ThefirstrealwheelswereprobablymadeinMesopotamia,nowIraq.Butscientiststhinkthatthosefirstwheelswerenotusedformovingavehicle.Theywereusedinpotterywheels.Thesemachinesturnedquicklyinacircletohelppeoplemakethingslikecupsandbowls.Anotherearlywheel,amillstone,wasaheavy,roundstone.Itwasusedforbreakingdownplantsforcookingandformaking flour.1
TheearliestpicturesofwheelsonvehiclesareonMesopotamianpaintingsfrom3000–2700BCE.Thesewheelsweremadeofsolid2woodandturnedonasimpleaxle.Around2000BCEtheEgyptiansstartedusingspokesontheirchariotwheels.Thesewheelsneededlesswood,sotheywerecheapertomake.Theywerealsomuchlighterandcouldtravelfaster.
1� our:usedtomakebread,cakes,etc.2solid:withoutanyholesoropenings
The fi rst wheels were solid wood.
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ThewheelwassoonusedbydifferentgroupsofpeopleacrossEuropeandAsia.By500BCE,manytypesofwheeledvehicleswereinuse,fromfastchariotstolarge,slowcarts.3Thewheelstheyusedaremuchlikethewheelsweusetoday.
However,inotherplacesintheworld,wheelswereneverused.CentralandSouthAmericanpeoples,liketheMayansorIncas,builtamazingcitiesandtempleswithoutusingwheels.Nobodyknowswhy,butitmaybebecausetheylivedinmountainousareas,whereitwasimpossibletousewheeledvehicles.
Wheelsarenogoodinhighmountains,indeepsnow,orindesertsands.EventodayintheSaharadesert,animalslikethecamelaremoreusefulthanwheeledvehicles.3cart:avehiclewithtwoorfourwheelsthatispushedbyapersonorpulledbyananimal
4all-terrain vehicle:avehiclethatcantravelonmanydifferentkindsofground
Video QuestLegs or Wheels: part 1Watch this video about some men trying to make a new kind of all-terrain vehicle.4 What is the 4 What is the 4
idea behind the new invention?
A Mayan temple
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Throughouthistorymachineshaveusedwheels.Andforalongtimewheelsalsomademachineswork.Thefirstwheelusedforpowerwasthewaterwheel.Thiswasagreatimprovementintechnologybecauseitletpeopleuserunningwatertopowermachinesinsteadofusinganimalsorotherpeople.
ThefirstwaterwheelweknowaboutwasinaflourmillinByzantium,nowTurkey.Thefirstwaterwheelslayontheirsides.Butby240CE,inAlexandriainEgypt,peoplewereusingwheelsthatstoodupinriversandweremuchmorepowerful.
Making Wheels WorkTHE WHEEL IS BEST KNOWN FOR ITS USE IN VEHICLES, BUT IT WAS FIRST USED IN INDUSTRY.
CHAPTER 2
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Tousewaterwheelstodrivemachines,peopleneededawaytosendthepowerfromtheturningwheeltothethingstheywantedtoworkon.Theyusedmorewheels!Theyfoundthatifyoucutteethintotwowheelsandputthemtogether,thefirstwheelturnsthesecondone.
Asearlyas330BCE,theGreekinventorArchimedestalkedabouttoothedwheels,calledgears.Herealizedthatwhentheteethfromthefirstwheelpushthesecond,thesecondwheelturnsintheoppositedirection.Butathirdwheelmovesoppositetothesecond,inthesamedirectionasthefirstone.Byputtinggearstogether,youcansendthepowerfromawaterwheeltoamachine.TheGreeksusedgearstomakecomplicatedmechanisms5likeclocks.
5mechanism:onepartofamachinethatdoesaspecialjob
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PerhapsthemostcomplicatedearlyuseofgearsthatweknowaboutistheAntikytheraMechanism.Itwasfoundundertheseainashipwreck6neartheGreekIslandofAntikytherain1901.TherewasacasewithinstructionsinGreek,30gears,and82piecesmadeofthemetalbronze.
Scientiststhoughtthatthesepieceswerepartofaverycomplicatedkindofclock,butittookthemalmost100yearstoputthepiecestogether!Infact,theAntikytherawasaplanetarium,amachinethatshowsthemovementsoftheplanets7andthemoonaroundthesun.Itwasactuallyakindofcalendar.Itshowedscientiststhattheancientworldhadcomplicatedtechnologyandknewalotabout space.
6shipwreck:ashipthatsankinanaccident7planets:verybig,roundthings,likeEarth,thatmovearoundastar
Drawing of the Antikythera Mechanism
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UNDERSTANDDescribe two ways wheels were used in the past.Describe two ways wheels were used
Anotherimportantwheelforindustrywasthewindmill.Windmillsusesailstocatchthewindandmakepower.Unfortunately,windmillsonlyworkifit’swindy!Buttheyhaveonegreatadvantage.Waterwheelsneedrivers,butyoucanbuildawindmillanywherethat’swindy.Modernwindmills,calledwindturbines,areusedasacleanwaytomakeelectricity.
Finally,steampower,thekeytotheIndustrialRevolution,8alsousedthewheel.Steamfromboilingwatermovedwheelsandpoweredmachines.Fromthe17thcentury,steampowerwasseenmoreandmoreinmillsandfactories.Bythe19thcentury,steamwaspoweringthenewtrainsandshipsanddrivingforwardtrade9andindustry.Theageofindustrialpowerhadbegun!
8Industrial Revolution:thetimeinhistorywhenmachinesinbigfactoriesstarteddoingalotofwork
9trade:buyingandsellingthings
A windmill with sails
A steam engine
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Wheelsmakemoderntransportationpossible.Therearebigwheels,smallwheels,fastwheels,slowwheels.Let’stakealookatsomefactsaboutwheels,andsomeoftheinventionsthathavemadethembetter.
Small wheelsThesmallestmotorvehicleyoucandriveonaroad
isthePeelP50.Itwasfirstbuiltinthe1960sontheIsleofManbetweenEnglandandIreland,butonly50weremade.TheP50hadonlythreewheels,wasverylight,andhadjustonefrontlightandonedoor.Itcouldonlydriveforward.Ifyouwantedtogobackward,youhadtopullitbyhand.Butitwassmallenoughtokeepinyourhouse!
A World Full of Wheels!WE SEE WHEELS EVERYWHERE WE LOOK.
CHAPTER 3
A bucket wheel excavator moving earth
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Big wheelsThebiggestvehicleintheworldisthebucket-wheel
excavator.Thesemachinesuseverybigwheelstomovelargepiecesofearth.Thebiggest,theBagger293,is96meterstalland225meterslong,anditweighs142,000kilograms!Itswheelis21metersacross!Butitcanonlymoveveryslowly,travelingjusthalfakilometeranhour!
Lots of wheelsTheroadvehiclewiththemostwheelsisthe
articulatedtruck.Thesebig,heavyvehiclescarryfood,animals,gas,andmanyotherthings.Theyoftenhavefiveaxlesandeighteenwheelsandaresometimesknownas18-wheelers.Onlythefronttwowheelsarelikethewheelsonanormalcar.Theothersixteenwheelssitinpairsonfouroftheaxles.Thismakesthevehiclesafer.
An articulated truck
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