That law replaced another which failed due to the equipartition theorem, which Ehrenfest called the ultraviolet catastrophe.
Laboratory models for these entities include hohlraums, which are covered in a nickel phosphorus alloy. One of the early methods of modeling these entities involved calculating the number of standing waves inside and summing all possible modes over the volume. One equation governing these contains a term with the fifth power of the wavelength in the denominator, and instead of integrating that law the Sakuma-Hattori equation is often used instead. That law replaced another which failed due to the equipartition theorem, which Ehrenfest called the ultraviolet catastrophe. Kirchoff's law of these states that their emissivity is 1. These entities have luminosity proportional to the fourth power of temperature in the Stefan-Boltzman law. For 10 points, name these perfect thermal emitters equivalent to a hole in an oven which are modeled by the incorrect Rayleigh-Jeans and more correct Planck's Law.
Laboratory models for these entities include hohlraums, which are covered in a nickel phosphorus alloy.
Blackbodies 