the law that energy associated with electromagnetic radiation, as light, is composed of discrete quanta of energy, each quantum equal to Planck's constant times the corresponding frequency of the radiation: the fundamental law of quantum mechanics.
2.
the law giving the spectral distribution of radiation from a blackbody.
Also called Planck radiation formula, Planck's law.
Origin of Planck's radiation law
1905-1910
First recorded in 1905-10; named after M. K. E. Planck