kogasa, 1 year ago (edited 1 year ago)

This is an interesting question. Instant acceleration is mathematically implausible, but I don’t know if there’s a better physical interpretation for what happens to a bouncing photon. I’m guessing this is one of those “less particle, more wave” situations where the instantaneous velocity of the photon is undefined.

According to some random internet sources, reflection is the not-quite-instantaneous process of the photon being absorbed and then emitted by the electrons in the mirror.