Can anyone counter my argument that the photon energy is properly half of the generally accepted value? It is a short argument, as follows: Accepting the Planck hypothesis that the energy of the standing-wave electromagnetic modes of a cavity oscillator at thermodynamic equilibrium is E = n h nu (with n a non-negative integer, h the Planck constant, and nu the frequency of the mode), then recognizing that standing waves can't have momentum, but a photon always has momentum, and also that a standing wave is representable as a superposition of two oppositely-traveling waves of equal amplitude, then the minimum number of photons needed to change the energy of a standing wave by h nu is two. Therefore the energy of a single photon can be at most h nu / 2. I realize there is a lot of observation that seems to back up that the photon energy is h nu, so if that is correct, there must be something wrong with my argument. What is it that's wrong, then?