I'm guessing it has to do with electron excitation, and the release of EM waves when the electrons fall back to their ground state, but I am want to learn more about this in detail. I've barely covered Maxwell's Equations and optics in a lower division general physics course, so there's a whole lot that I don't know. I would like to be able to answer questions like: - How do the laws of reflection and refraction arise from these interactions? I can understand that these laws come from ray optics, which are really macroscopic models of the behavior of light, but I'm sure there are microscopic explanations that are consistent with this as well. - How can one find out how much of the energy is refracted and how much is reflected? - If you had one atom, for instance, and you shined a beam of light at it, would the the falling of the electrons to their ground state result in dispersion of light in random directions, or is there a pattern to it? Perhaps I'm jumping the gun and these questions would soon be answered once I study modern physics.