That is helpful, and interesting, though I think I remain a bit confused about the idea of 'moving through time' and especially 'moving through time quickly/slowly'. Does this imply some sort of meta-time, in which we can measure the speed at which one travels through time?
And I think I still have my original question: if a photon travels through space at c, and therefore doesn't travel through time at all, is the photon at its starting and its final position at the same moment? If so, in what sense did it travel through space at all?
Does this imply some sort of meta-time, in which we can measure the speed at which one travels through time?
No it doesn't. Remember, in relativity, time is relative to a frame of reference. So when I talk about a moving object traveling slowly through time, I'm not relativizing its time to some meta-time, I'm relativizing time as measured by that object (say by a clock carried by the object) to time as measured by me (someone who is stationary in the relevant frame of reference). So an object moving slowly through time (relative to my frame of reference...
Haven't had one of these for awhile. This thread is for questions or comments that you've felt silly about not knowing/understanding. Let's try to exchange info that seems obvious, knowing that due to the illusion of transparency it really isn't so obvious!