07-13E

The possibility of calculating the black body radiation spectrum density proceeding from the classical physical ideas is considered. The consideration of electromagnetic radiation energy as a set of standing wave energies in the volume restricted by mirror walls is shown to enable calculating the black body radiation spectrum using the equilibrium state maximum probability statistical hypothesis. It is a very interesting result from the point of view of quantum physics since the existence of Planck's constant is proved within the framework of classical physics. But the classical solution looks simpler as it doesn't introduce zero oscillation of the vacuum, that is, infinite energy in the definite volume.