A simple way to deduce the Planck equation of blackbody radiation emission

Abstract

The blackbody radiation equation, also known as the Planck equation, has proved to be a challenge for students starting their studies in the field of thermal radiation, and this article aims to overcome this difficulty by presenting it in a simplified way. First, the classical approach to the blackbody derivation performed by the scientist Max Planck will be presented, which uses the concept of entropy, related to the different forms of energy distribution, in a thermodynamic system, complexion, according to Planck. Next, the deduction of the blackbody equation is presented, without resorting to complex calculations, but rather simple ones, from the approach carried out by Richard Feynman. Therefore, the objective of this article is to present the blackbody radiation equation, using basic concepts of average energy, and how the equation can be deduced from simple numerical calculations, without losing sight of the phenomenological character.