Puas txij li hnub kawm ntawv, peb paub tias qhov ceev ntawm lub teeb, raws li Einstein txoj cai, yog qhov siab tshaj plaws hauv lub Ntiaj Teb. Lub teeb tawm ntawm lub hnub mus rau lub ntiaj teb hauv 8 feeb, uas yog kwv yees li 150,000,000 km. Nws tsuas yog siv sijhawm 6 teev kom ncav cuag Neptune, tab sis nws yuav siv sijhawm ntau xyoo rau lub dav hlau kom kov yeej qhov kev ncua deb. Tab sis tsis yog txhua tus paub tias tus nqi ntawm qhov ceev tuaj yeem sib txawv heev nyob ntawm qhov nruab nrab uas lub teeb hla.
Formula rau lub teeb nrawm
Paub qhov ceev ntawm lub teeb hauv lub tshuab nqus tsev (c ≈ 310 8 m / s), peb tuaj yeem txiav txim siab nws hauv lwm cov xov xwm raws li lawv qhov ntsuas qhov ntsuas n. Cov mis loj heev rau kev ceev ntawm lub teeb zoo ib yam li cov kev cai ntawm mechanics los ntawm physics, los yog theej, lub ntsiab lus ntawm kev ncua sij hawm thiab qhov ceev ntawm ib yam khoom.
Piv txwv li, peb coj iav, qhov ntsuas qhov ntsuas qhov ntsuas yog 1.5. Raws li cov qauv ntawm qhov ceev ntawm lub teeb, v=c\n, peb tau txais tias qhov ceev ntawm qhov nruab nrab no yog kwv yees li 200,000 km / s.. Yog hais tias peb noj cov kua, xws li dej, ces qhov ceev ntawm propagation ntawm photons (me me ntawm lub teeb) nyob rau hauv nws yog 226,000 km / s nrog ib tug refractive index ntawm 1.33.
Formula rau lub teeb nrawm hauv huab cua
Cua kuj yog qhov nruab nrab. Yog li ntawd, nws muaj qhov hu ua optical ntom. Yog hais tias nyob rau hauv lub tshuab nqus tsev photons tsis ntsib obstacles ntawm lawv txoj kev, ces nyob rau hauv ib tug nruab nrab lawv siv ib co sij hawm rau excitation ntawm atomic hais. Qhov denser ib puag ncig, ntau lub sij hawm nws yuav siv sij hawm rau qhov kev zoo siab heev. Lub refractive index (n) nyob rau hauv huab cua yog 1.000292. Thiab qhov ntawd tsis deb ntawm qhov txwv ntawm 299,792,458 m/s.
Asmeskas cov kws tshawb fawb tau tswj hwm kom qeeb lub teeb nrawm kom yuav luag xoom. Ntau tshaj 1/299,792,458 sec. lub teeb nrawm tsis tuaj yeem kov yeej. Qhov tseeb yog hais tias lub teeb yog tib yam electromagnetic yoj li x-rays, xov tooj cua tsis muaj cua sov. Qhov txawv tsuas yog qhov txawv ntawm wavelength thiab zaus.
Qhov tseeb nthuav yog qhov tsis muaj huab hwm coj hauv photon, thiab qhov no qhia tias tsis muaj sijhawm rau cov khoom no. Cias muab, rau ib tug photon uas tau yug los ob peb lab, los yog txawm billions xyoo dhau los, tsis yog ib tug thib ob ntawm lub sij hawm tau dhau mus.
