Diffraction ntawm lub teeb: lus nug thiab lus teb

Teeb tau yeej ib txwm tau ib tug mysterious thiab txaus nyiam rau tib neeg. Nws twb txuam nrog rau ntau dua powers. Lub teeb muab lub neej - thiab cov neeg to taub nws txij ancient sij hawm. Ntawv pov thawj - lub cult ntawm lub teeb qhov chaw - lub hnub. Thiab vim hais tias tag nrho cov tshwm sim hais tias txiv neej yuav tsis tau piav nyob rau hauv lub hauv paus ntawm txoj kev paub hais tias twb nyob nws lawg hlob hlob. Ib tug ntawm cov phenomena, uas yog feem ntau attentive neeg pom - lub diffraction ntawm lub teeb. Yuav ua li cas yog nws?

Phenomenon yuav pom tus kheej, yog tias kuv nco ib tug duab tshav ntawm lub teeb los ntawm lub vos qhib thiab saib ib qhov chaw ntawm lub teeb uas muaj dhau los ntawm nws. Peb pom tau tias nyob ib ncig ntawm tus ciam teb - alternating tsaus ntuj nti thiab lub teeb kab txaij. Vim li cas peb pom ib daim duab ntawm nws?

Lub fact tias cov tsis nyob hauv cov ntsiab lus nyob ib ncig ntawm qhov chaw txhawb txhua lwm yam, thiab ib co, on qhov tsis tooj, yog nyob rau hauv tsis sib xws, thiab yog li ntawd rho txhua lwm yam tawm. Cov kev geometric ciaj ciam ntawm lub resulting qauv yog nyob rau hauv lub wavelength (yog li ntawd rau tsis muaj liab thiab ntsuab lub teeb yuav txawv diffraction qauv) thiab txoj kab uas hla ntawm lub teeb beam. Nws ua ib tug cylindrical lub khob hliav qab. Qhov no yog qhov diffraction ntawm lub teeb. Tab sis lub phenomenon ntawm tus sis uas tsis yog hu ua cuam. Qhov no lub npe tshwm sim nyob rau hauv lub xyoo pua puv 19. Cuam thiab diffraction ntawm lub teeb - phenomena uas yog feem ntau piav nyob rau hauv physics phau ntawv.

Yuav ua li cas yog cov tswv yim rau daim ntawv thov ntawm no lub cev tshwm sim? Nws nqa mus rau hauv tus account thaum tsim kho qhov muag pab kiag li lawm (cov koob yees duab, rub kom pom loj, telescopes), vim hais tias tag nrho lawv muaj ib tug lens uas txwv nws cov ntug teeb beam.

Paub qhov txawv diffraction nyob rau hauv lub nyob ze cheeb tsam (lub point ntawm uas poob qhob beam ze rau ib tug lub chaw khuam siab). Qhov no tshwm sim yog lub npe ntawm tus Fresnel diffraction. Tab sis yog hais tias tus diffraction yog nyob rau hauv lub deb teb (interacting rays yog ze li ntawm thaum uas tig mus), tus physicist yuav hu nws lub Fraunhofer diffraction. Nws muaj ib tug xav paub cov cov khoom teejtug: yog hais tias lub qhov yog txaus loj, ces diffraction yuav nyob twj ywm invisible.

Tsis tas li ntawd nyob rau hauv cov phau ntawv nyeem ntawm physics peb yuav ntsib nrog lub sij hawm diffraction grating. Yuav ua li cas yog nws? Kho qhov muag ntaus ntawv, uas yog ib tug tshab los yog xav phaj nrog thov thaum uas tig mus strokes. Thaum nws kis tau los ntawm lub teeb dawb, yuav pom qhov kev sib cais ntawm lub teeb spectrum. Yog, lub ntxaij ntoo yuav dawb lias nyob rau hauv zaj sawv xim. Prism muab tsuas yog ib spectrum, thiab hniav nyiaj hniav kub - ib tug ob peb. Nws tsis yog ib tug, vim hais tias cov teeb yog phua rau hauv kab teeb tsim nyob rau hauv txawv bands, thiab ntev lub spectra, ntau dua qhov lub tawg kaum sab xis ntawm txawv los ntawm cov thawj coj.

Txawm li cas los, vim hais tias koj muaj peev xwm kis tau los ntawm cov grille tsis tau tsuas yog lub teeb dawb. Tab sis kuj lub teeb kis tau los ntawm ib yam khoom uas. Qhov no txoj kev no yog hu ua spectral tsom xam thiab qhia txog cov muaj pes tsawg leeg ntawm qhov kev kuaj. Raws li yuav ua li cas lub rays sab laug tom qab dhau los ntawm lub diffraction grating, nws tseem tau mus pom dab tsi tus kws tshawb fawb yog kev soj ntsuam txog nrog.

Thiab koj, dhau lawm, tau pom ib tug diffraction grating, cia li pom. Tsis ntseeg? Thaum ntawd yog thaum lub sij hawm tas los koj tau tuav tus tsav mus rau lub computer. Nws ua si beautifully tag nrho cov xim ntawm tus zaj sawv. Koj tau pom, tsis muaj realizing nws, lub phenomenon ntawm lub teeb diffraction. Lub cheeb tsam nyob rau disk uas cov ntaub ntawv yog me me hillocks (li tus tsav yog li ntawd rhiab rau kev puas tsuaj), thiab cov ntaubntawv povthawj siv yog ua nyob rau hauv ib lub voj voog, ces tus laser disc nto - ib tug khoom grating.

Txawm li cas los, xav txog lub diffraction phenomenon zoo dua. Thiab nrhiav seb yog dab tsi lub diffraction ntawm lub teeb, yog hais tias peb piav qhia txog nyob rau hauv cov lus yooj yim. Yog li ntawd, yog hais tias tus rays tau raws li ib tug impermeable teeb meem, lub teeb rays dua nyob ze ntawm lub heev ntug ntawm nws, tsis txhob mus txoj kev, tsis raws li yog hais khoov nyob ib ncig ntawm obstacles lawv tau raws li nyob rau hauv txoj kev. Los ntawm tus txheej txheem no, tus yoj yog tau siab khoov nyob ib ncig ntawm cov khoom uas yog tsis ntau tshaj nws ntev.

Nce qib nyob rau hauv txoj kev tshawb no ntawm physics!