Blackbody tawg thiab nws

Nws hu ua ib tug dub lub cev xws li vim hais tias nws absorbs tag nrho cov caij nplooj zeeg nyob rau hauv nws (los yog es nws) tawg nyob rau hauv qhov pom spectrum thiab tshaj. Tab sis yog hais tias tus cev tsis rhuab, lub zog yog rov tawm txim liab rov qab. Qhov no tawg yog tawm txim liab los ntawm ib tug dub lub cev, nws yog ib yam uas kev txaus siab. Tus thawj cov me nyuam kawm nws cov khoom tau nqa tawm ua ntej lub rov tshwm sim ntawm tus qauv xwb.

Nyob rau hauv thaum ntxov 19th caug xyoo, Dzhon Lesli experimented muaj ntau yam tshuaj. Raws li nws muab tawm, tsis tsuas dub muaj hmoov quav absorbs tag nrho cov teeb meem nyob rau ntawm nws pom lub teeb. Nws faib nyob rau hauv lub infrared ntau yog muaj zog tshaj li lwm yam, sib zog tshuaj. Nws yog lub tshav kub tawg uas yog txawv los ntawm tag nrho cov lwm yam ntau yam khoom. Lub tawg blackbody equilibrium, homogeneous, muaj yog tsis muaj lub zog hloov lwm lub tsev thiab nyob rau hauv lub cev kub. Thaum ib tug txaus siab kub ntawm tus kwv lub thermal tawg yog ua pom, thiab ces tej cev xws li ib tug blackbody acquires xim.

Qhov no cim kwv uas emits tsuas ib tug tej yam hom ntawm lub zog, yuav tsis tsis nyiam xim. Txij li thaum peb tham txog thermal tawg, cov thawj cov qauv thiab theories txog yuav ua li cas lub spectrum yuav tsum zoo li, nws tau tau npaj nyob rau hauv lub moj khaum ntawm thermodynamics. Classical thermodynamics yuav txiav txim dab tsi wavelength yuav tsum ib tug tshaj plaws ntawm hluav taws xob ntawm ib tug muab kub, nyob rau hauv uas cov kev taw qhia thiab ntau npaum li cas nws yuav mus nyob rau cua sov thiab cua txias. Txawm li cas los, nws ua tsis tau tejyam rau koj twv seb yuav ua li cas lub zog faib nyob rau hauv lub spectrum ntawm ib tug blackbody ntawm tag nrho cov wavelengths, thiab nyob rau hauv particular, nyob rau hauv lub ultraviolet ntau yam.

Raws li lub ntsiab ntawm classical thermodynamics, lub zog muaj peev xwm yuav tawm txim liab los ntawm tej yam feem, xws li raws li me me raws li xav. Tab sis rau ib tug dub lub cev yuav emit ntawm luv luv wavelengths, lub zog ntawm ib co ntawm nws cov hais yuav tsum yog heev loj, thiab nws yuav tau ncaim mus infinity nyob rau hauv lub teb ntawm ultra-luv luv tsis. Nyob rau hauv kev muaj tiag qhov no yog tsis tau, muaj ib infinity nyob rau hauv qhov sib npaug thiab yog hu ua tus ultraviolet teeb meem. Tsuas yog Planck lub theory uas zog yuav tawm txim liab nyob rau hauv discrete feem - quanta - pab kom daws tau qhov teeb meem. Niaj hnub no thermodynamics sib npaug yog tshwj xeeb no ntawm qhov sib npaug ntawm quantum physics.

Keeb xeeb ib tug dub lub cev sawv cev raws li ib tug kab noj hniav nrog ib tug nqiam qhib. Tawg sab nraum txais mus rau hauv xws li ib tug kab noj hniav thiab absorbed los ntawm cov phab ntsa. Nyob rau spectrum ntawm cov tawg, uas yuav tsum tau muaj ib tug dub lub cev, nyob rau hauv cov ntaub ntawv no, zoo ib yam li cov emission spectrum ntawm lub qhov tsua nkag, qhov zoo qhov, ib lub qhov rais nyob rau hauv ib tug maub chav tsev nyob rau ib hnub ci hnub, etc. Tab sis feem ntau ntawm tag nrho cov nrog nws tib spectra ntawm cosmic microwave tom qab tawg ntawm lub ntug thiab cov hnub qub, nrog rau lub hnub.

Nws yog muaj kev ruaj ntseg hais tias ntau tshaj ib tug kev kwv uas hais muaj ntau energies, qhov ntau nws yuav zoo li blackbody tawg. zog faib nkhaus nyob rau hauv lub spectrum ntawm ib tug blackbody qhia lub statistical regularities nyob rau hauv lub system ntawm hais, nrog qhov txawv tsuas hais tias cov zog kis tau rau hauv lub sis ntawm discrete.