Incidentally, we once found a similar equation [to the total energy for photons with energy .h-bar.omega in blackbody radiation] … That is one of the marvelous miracles of … [e.g., photons] which do not interact with each other … into this state there can be put either … up to any number n of particles, one … such an oscillator we mean a dynamic system … There is no way to make up your … by giving how many photons there are in … So in the future we can speak either … the energy level associated with a particular mode …
Google-1
Google-2
Copyright clearance needed for quotation.