Take it slow, polaritons are a new concept for me. Anyways, I'm trying to get some intuition for excitation polaritons having mass. Is this a quantity that we could directly measure, at least in theory if not practically? How would we separate the mass of the polariton itself from the mass of the particles that are creating the polariton? Are the things causing polaritons always seperate from the polaritons themselves, or are they sometimes a "part" of the polariton? I'm thinking here specifically of a situation like a photon interacting with some EM field, is the photon still a seperate entity? Sorry for the barrage. Most of the stuff I've dug up so far is written a little above my pay grade so I'm trying to get a better handle on it.