We have proposed a prequantum physics, itself founded on classical mechanics completed by the existence of an universal cloud of tiny particles noted U. These U particle command the mass, variable, of electron, neutron, proton, and atom particles noted M. The “shocks” between U and M particles in the cloud, with screen effect, give birth to electrical forces among charged particles with very small differences between attractive and repulsive forces, and to certain gravitational forces. This cloud with the electromagnetic waves propagating thus recalls an ether, yet much different regarding its effects on the inertial mass of any particle within it. The electromagnetic wave and the photon look like if they were born from a statistical mechanics induced by the universal cloud, and their status, in this regard, may be compared to the status conferred by atomics to a temperature or a pressure. The wave transversality is explained. By the same token, one understands why the photon, a vectorial bearer of a statistical information, may thus describe a particle as well as a wave.