quote:
I have seen it explained in the past, on this site (although finding this will take more time than I have, so sorry there's no link), that whilst from, say, our perspective, it takes a photon of light 8 minutes to travel from the sun to the earth, from the perspective of the photon, it takes no time at all. It is travelling spatially at the speed of light, and therefore from its perspective its movement through the dimension of time is zero (since spatial velocity plus velocity in time cannot exceed C). (In fact, it is always equal to C, for everything).
Not quite. From
our perspective, the photon takes 8 minutes to travel from sun to earth. But also from
our perspective, the photon does not age. If the photon carried a clock, the photon's clock would not move --from
our perspective.
From the
photon's perspective, the distance between sun and earth is contracted to zero, and the photon's trip happens instantly.
Edited by kbertsche, : Replaced second paragraph, which was wrong.