Reply to comment on `Poynting flux in the neighbourhood of a point charge in arbitrary motion and the radiative power losses'

Abstract

Doubts have been expressed in a comment (Eur. J. Phys., 39, 018001, 2018), about the tenability of the formulation for radiative losses in our recent published work (Eur. J. Phys., 37, 045210, 2016). We provide our reply to the comment. In particular, it is pointed out that one need to clearly distinguish between the rate of the energy-momentum being carried by the electromagnetic radiation to far-off space, and that of the mechanical energy-momentum losses being incurred by the radiating charge. It is also demonstrated that while the Poynting flux is always positive through a spherical surface centred on the retarded position of the charge, it could surprisingly be negative through a surface centred on the "present" position of the charge. It is further shown that the mysterious Schott term, hitherto thought in literature to arise from some acceleration-dependent energy in fields, is actually nothing but the difference in rate of change of energy in self-fields of the charge between the retarded and present times.