Entropy in classical electromagnetism

Dragan Poljak

A behaviour of a bunch of electrons moving with non-relativistic velocities is considered. The force on a single electron in such a cloud of electrons is composed from Lorentz forces due to the existence of other electrons and due to ist own radiated field (radiation reaction). Now using the laws of thermodynamics and assuming the initial velocities of electrons represented by a Maxwell-Boltzman distribution one may determine the entropy of of bunch of electrons.