Fr.: loi de Rayleigh-Jeans
A classical law approximately describing the intensity of radiation emitted by a → blackbody. It states that this intensity is proportional to the temperature divided by the fourth power of the wavelength (8πkT/λ4). The Rayleigh-Jeans law is a good approximation to the experimentally verified Planck radiation formula only at long wavelengths. At short wavelengths it runs into a paradox named the → ultraviolet catastrophe.