Neo-Hertzian Electromagnetism

On the propagation of inhomogeneous waves

“…The question of the photon mass has been reviewed in the literature [29-311. For a = 1 we obtain the particular value m = 3.3 X g. A recent experiment realised by Crandall [32] set a bound on the photon mass: m S 8 X g. It is not well known that there are different formulations of Maxwell's equations published in the literature [33,34], depending on the choice of the grid and the meaning given to the partial time derivatives. A point that now deserves special attention is the question of the significance of the grid on which the equations (52) are specified.…”