4 ms·

And from the photon's frame of reference the photo itself doesn't move at all.

• baddox 9y ago
  That part is actually harder for me to understand. The photon experiences no passage of time, right? And yet it does move through space. Or would you say that, from the reference point of a photo, there is no movement in time or space? Or perhaps it’s better to just say that the concept of reference points hits an asymptote at velocity c, so it simply doesn’t make sense to talk about the reference frame of a photon.
  • jcims 9y ago
    Can photons interact? If they can, what happens when you have two photons cancelling each other out at different distances from their origin? From the photon reference frame, both were emitted and absorbed at T=0, but in our reference frames they were emitted at different times. Does that somehow link the emission time of the two given that there is a reference frame in which they are equivalent?
• luk32 9y ago
  This is trivial. From one's frames of reference this very one is always stationary =]. What is interesting from photon's frame of reference is the image of the rest of the world.