While driving on the freeway I noticed my car’s reflection in the “baby moon” hubcap of the truck next to me and got to wondering (uh oh).
Does the fact that a reflective surface is moving have any effect on the light that strikes it? If I were standing next to an extremely long, perfect mirror that was passing me at 500,000mph, would my reflected image be offset before it hit my retina?
I’m missing something obvious here, aren’t I.
Peace,
mangeorge
You’re not missing something. In fact you’re noticing something about the special nature of light. Light doesn’t behave the same as waves that travel through a medium and experiments such as the Michelson-Morley interferometer are very similar to you observing your reflection in a hubcap.
No, I think you’re right. Photons are objects. They will travel for a time with the atoms that “sling” them back at you.
Now THAT’s some good science! H-yup, yup, yup…
To clarify what tshirts is saying:
When a photon “bounces off of” an object, it’s not actually the same photon coming off as it was going in (Yes, I know that you can’t really define whether two photons are the “same” or not. Bear with me here.). What happens is that a photon hits an atom in the mirror and is absorbed, causeing one of the electrons in that atom to go to a higher energy state. After a very short but nonzero period of time, that electron decays back into the ground state, giving off a photon. If the mirror is moving, then the atom will move a very short distance while that electron is excited, so the emitted photon won’t come from quite the same place as the incoming photon was absorbed. On the macroscopic scale, I imagine that the effect of this would be a slight displacement of the image in the mirror.
Before anyone starts complaining about the effect this would have on the gedanken experiments that Einstein used to think up special relativity, remember that (being a physicist), Einstein was using special idealized mirrors, which have zero time lag between incidence and reflection.