So i am taking the MOOC of Galitski et al on Exploring Quantum Physics. I like it. But i keep running into some difficulty with my understanding of what it means to quantize a static EM (or E or M) field: Is the field made up of photons? If so, are they somehow moving at the speed of light? (!) If not, what does it mean that they are (much!) slower? A particular variant of this question which would be: What is light in the brain? [end] has particular interest to me. So i have a suspicion we are somehow dealing with a set of (essentially harmonic?) oscillators here? So they have defined / definable photon energies etc? With regard to the level of math used in any possible reply, i am a mathematician and will attempt to deal with any level of math you can throw at me. Hmmm. This may be completely irrelevant, but i might regard answers which tell me something is infinite as being dubious. Infinity (even only countable infinity) is really large. Thank you for your attention.