Refraction ntawm lub teeb - lub keeb kwm ntawm lub cev tswvyim

Thiaj thiab refraction ntawm lub teeb hais txog cov lub cev phenomena, qhib raws li ib tug tshwm sim ntawm soj ntsuam ncaj qha, tsis muaj kev kuaj thwmsim. Rau cov thawj lub sij hawm peb yuav sib tham txog nws nyob rau hauv ancient Greece, tiam sis feem ntau physicists yog inclined xav hais tias qhov no fact twb paub ua ntej. Cia li thawj tus paub txog yuav ua kom muab ib tug zajlus kom piav rau ib tug xov tooj ntawm empirically tsim tseeb los ua Cleomedes, uas nyob rau hauv qhov kuv pua AD nyob rau hauv dab tsi yog tam sim no tim Nkij teb chaws. Ua ntej nws, Euclid piav no phenomenon los tsom kwm ib lub nplhaib dag nyob rau hauv qab ntawm lub hub, uas yog nyob rau lwm lub nws yog tsis pom mus rau saib, tab sis yog tias koj pib pouring cov dej mus rau ib tug lub tshob rau dej, ces tom qab ib co sij hawm tsis muaj kev hloov lub kaum sab xis ntawm view ntawm lub observer yuav pom dag nyob rau hauv qab ntawm lub kho kom zoo nkauj. Tab sis raws li ib tug ncauj lus kom ntxaws qhia txog qhov no Euclid tseem tsis tau muab tus thawj tus paub txog los kawm nyob rau hauv kom meej lub refraction yog suav tias yog Cleomedes.

Cov kev kawm ntawm nws kev tshawb no yog refraction nyob rau hauv dej - nws yog muab sau tias yog ib tug ntev pas dipped nyob rau hauv cov dej thiaj li hais tias ib tug tej yam yog ib feem tseem nyob rau hauv tus nto, muaj ib tug quas refraction ntawm lub interface ntawm huab cua thiab dej. Tab sis nyob rau hauv qhov tseeb, lub pas tseem lawm, li no yog vim li cas rau qhov no kho qhov muag zoo nyob rau hauv lub nrig txog kev pom deception?

Tshuaj ntsuam no phenomenon zoo dua Cleomedes sau tseg hais tias yog lub teeb beam nkag mus rau los ntawm ib tug tsawg tuab nruab nrab mus rau ib tug ntau ntom, thaum muaj oblique kev taw qhia (uas yog, muaj lub kaum sab xis txheeb ze rau thaj tsam ntawm lub ob xov xwm), qhov nruab nrab muaj ib tug kev kub ceev, deflects nws mus rau lub sheer cov kev taw qhia.

Nws yog ib tug uas zoo sib xws refraction nws piav qhia peev xwm mus saib lub hnub rau tej lub sij hawm tom qab hnub poob.

Cleomedes muab tsuas cov feem ntau cov kev cov yam ntxwv ntawm cov refraction ntawm lub teeb thiab piav xwb nyob rau hauv daim ntawv ntawm tej yam txheej thaum ub thwmsim, muab, Txawm li cas los, ib tug ncaj tiav daim duab ntawm lub dav cai ntawm tus txheej txheem no. Tom qab ntawd lwm Greek kawm, uas nyob ib xyoo tom qab Cleomedes, txuas ntxiv tshawb fawb, pib los ntawm nws cov thawj ntawm, thiab yuav luag tuaj ze rau unraveling cov kev cai ntawm physics, uas refracts lub teeb beam.

Muaj sufficiently loj tus naj npawb ntawm thwmsim, Klavdiy Ptolemey tau tsim kom muaj lub approximate lub uas lub teeb yog refracted nyob rau hauv ib tug ib puag ncig. Yog li, rau refraction tshwm sim nyob rau hauv cov kev hloov ntawm lub beam tob nyob rau hauv cov dej iav, lub kaum sab xis ntawm refraction yog 0,88 lub kaum sab xis ntawm cov xwm txheej. Rau lwm kua, qhov no tus nqi yog hloov - rau saum huab cua thiab dej, nws yog sib npaug zos rau 0,76, thiab huab cua thiab iav 0,67.

Tab sis rau tag nrho cov tsev lag luam ntawm cov kev cai, uas sau lub refraction ntawm lub teeb, coj ib tug ob peb ntau centuries. Ntau tshaj ib tiam ntawm zaum koom nyob rau hauv kev txhim kho ntawm uas twb muaj lawm paub, thiab qhov kawg version ntawm refraction mis yog ntaus nqi mus rau René Descartes, tus naas ej Fabkis physicist-naturalist.

Nyob rau hauv cov thawj version ntawm lub Dutch paub txog W. Snell lub mis rau xam lub kaum sab xis ntawm cov xwm txheej zoo li nram no:

n = kev txhaum (a) / txoj kev txhaum (b).

Nyob rau hauv lwm yam lus, lub refractive index ntawm lub teeb beam rau ob txog xov xwm yog qhov thiab tsis hloov hlo xwm thiab yog tus piv ntawm cov sine ntawm lub kaum sab xis ntawm cov xwm txheej mus rau lub sine ntawm lub kaum sab xis ntawm refraction.

Thaum kawg ua tiav qhov kev tshawb fawb thiab cov hauj lwm ntawm lub refraction ntawm lub teeb beam thaum ntaus los ntawm ib tug nruab nrab mus rau lwm lub, raws li tau hais tias, Rene Dekart. Nws piv nws kuj ceeb tias txoj cai characterizes lub essence ntawm lub teeb refraction txheej txheem, muab piv nws nrog ib tug ya pob nyob rau hauv cov huab cua. Yog hais tias nws yog thaum lub sij hawm nws lub davhlau encounters ib cov ntaub so ntswg, heev lub teeb thiab nyias, li ntawd, ib qho yooj yim mus ua txhaum nws thiab mus txuas ntxiv mus, nws cia li poob ib co ntawm nws cov thawj ceev, thiab me ntsis hloov lub kaum sab xis ntawm lub davhlau.