Planck's radiation law

noun

, Physics.

1. the law that energy associated with electromagnetic radiation, 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.

Word History and Origins

Origin of Planck's radiation law¹

First recorded in 1905–10; named after M. K. E. Planck