On fundamental properties of the classical electromagnetic zero-point radiation and its implications

There is a classical theory that can explain various quantum phenomena including the Casimir effect, the van der Waals force, the blackbody radiation, and so forth [1]. The classical theory is called "stochastic electrodynamics (SED)" and only the difference from conventional classical physics is the choice of the boundary condition for Maxwell equations. It requires random electromagnetic radiation called "zero-point field (ZPF)," which exists throughout space even at zero temperature. Thus, the ZPF is thought to be an universal background field which corresponds to the vacuum ground state in the language of quantum electrodynamics.; In this paper, the fundamental properties, especially the symmetries, of the ZPF are studied at first. It is found that the requirement of the Lorentz invariance of the field might be incompatible with the formulation of classical electrodynamics. Secondly, the behavior of unrestricted charged particle immersed in the ZPF is considered. Unlike other random radiation fields, the ZPF is found to produce no Einstein-Hopf drag on a particle modeled as Planck oscillator. It is also shown that the speed of the particle approaches to the speed of light when equilibrium is achieved in thermal bath of the ZPF background. Finally, the new development of SED on the theory of inertia is examined. It is found that, under certain conditions, an accelerated body in the ZPF experiences counteractive force which may be identified as the inertia. The ZPF-induced mass is shown to have the velocity dependence exactly the same as the prediction given by relativistic mechanics.