PLANCK RADIATION LAW


Meaning of PLANCK RADIATION LAW in English

noun

Usage: usually capitalized P

Etymology: after Max K. E. L. Planck

1. : a law in physics: radiant energy arising from processes within atoms or molecules is emitted in finite quanta each of which is equal to the product of the radiation frequency by a universal constant h — see planck constant

2. : a law in physics: the energy density of radiation within a blackbody cavity at absolute temperature T in terms of the wavelength λ is given by ΔPλ = (8πhc)/(λ 5 [e hc/(KλT) - 1]) Δλ where ΔPλ is the energy density within a given small wavelength interval Δλ, h is the Planck constant, and c the speed of light, all quantities being in cgs units

Webster's New International English Dictionary.      Новый международный словарь английского языка Webster.