Can someone explain to me why all models of an EM wave (or photon) are always shown in-phase? Isn't the total energy of a photon stored in the two oscillating fields? And isn't the total energy of a photon constant (according to conservation of energy)? If so then an in-phase model of perpendicular fields describes a wave in which, at the beginning of every new cycle, the strength of E+B = 0, meaning the total energy at that instant in time is 0. See http://www.astronomynotes.com/light/emanim.gif It would seem to me that in order for the strength of E+B, and thus the total energy, to be constant the two fields would have to be out of phase by a factor of Pi/2. Am I incorrect in my understanding of the relationship between the two fields E & B and the total energy?