Whereelsebesidesthekitchencanyoufindwedges?Let’sgoona “wedgeshunt” andfindout.Youwon’thavetolook far.

Justcheckoutalmostanygarageortoolbox.Nailsarewedges.So arethumbtacksandpushpins.Theyarelikethetinesofafork.Afterthesewedgesaredrivenintoamaterial,suchaswoodorcork,frictionholdstheminplace.That’showawoodenchairstaystogether.Andthat’showyourlatestandgreatestsciencereportstayspinnedtothebulletin board.

Lotsofgardenequipmentismadeofwedges.Theseincludethebladesofshovels,hoes,andweedingtools—prettymuchanythingdesignedtodig.Wedgesaregreatforcutting,too,likethebladesoflawnmowersandgarden shears.

Wanttothinkbigger?Howaboutthebladeofabulldozerandtheplowsonfarmequipment?Snowplowsusewedgestoscrapesnowoffroads.Theshapeofthewedgeallowstheplowtoreachbeneaththesnowandliftoffthe road.

Somewedgesareeasytosee,andyoucantellrightawayhowtheywork.Forinstance,youcanseehowasculptorusesachiseltobreakoffbitsof rock while creating astatue.Butsometoolshavewedgeshiddeninsidethem.You can’t seethewedges,yetthetoolcouldn’tworkwithoutthem.Oneofthesetoolsissomethingyouprobablyuseevery day.It’sonpants,jackets,bookbags,andlotsofotherthings.Canyouguesswhatitis?It’sa zipper!

Youwouldn’tbeabletoapplyenoughforcewithonlyyourfingerstointerlockthetwosidesofazipper.Butit’seasywithwedges.Whenyoupulluponthezipper,smallwedgesinsidethesliderpushtheteethtogether.Whenyoupulldown,anotherwedgeseparatestheteeth,likeatinyaxesplitting wood.

Sofar,mostofthewedgesyouhavereadaboutcutthroughsolid matter,likewood,soil,andfood.Butliquidsandgasesarematter,too.Dowedgescutthroughthismatter?Sure,justlookat thefrontofaboat.Thewedgeshapeofthebowletstheboatslicethroughthewaterwith ease.

Designersofallkindsofvehiclestakeadvantageofwedges.Haveyouevernoticedhowthefrontofcars,planes,andtrainsusuallyarenarrowerthantherestofthevehicle?Thatgeneralwedge shapemakesiteasierforthevehicletopushawayalloftheairparticlesasitmoves.Thenitcangofaster,uselesseffort,andthereforeuseless fuel.

Shapingvehicleslikewedgesisagreatidea,butallwe’redoingisfollowingnature’slead.Manyanimalshaveasleekwedgeshapethathelpsthemmoveswiftly.Birdbeaksareagreatexample.Soarethesleekshapesofdolphinsandmostsharks.Theirtaperedbodyhelpsgivethemthespeedwithless effort.

Nowthatyouknowsomethingaboutwedges,thinkaboutsomewaysyoumightusethissimplemachineonacamping trip.

Here’saquestiontojumpstartyourthinking:Whatwouldyouusetoroastmarshmallowsoverthatcampfireyouhelped start?