5 ms·
Moving the emitters affects the pace of time for them.
by Tagbert 3y ago
Moving the emitters affects the pace of time for them.
- AnimalMuppet 3y agoRight, so move them at identical speeds, with identical acceleration profiles.
- rjp0008 3y agoIf you do this, the clocks will be in the same place, it would have to be opposite acceleration profiles to get them moving away from each other.
- JumpCrisscross 3y ago> move them at identical speeds, with identical acceleration profiles Now do GR.
- AnimalMuppet 3y agoThat's the reason for the identical acceleration profiles. Which is totally obvious, so I suspect that means that I missed your point. Could you clarify?
- JumpCrisscross 3y agoMass and energy curve spacetime. So you could accelerate two clocks identically and still have to correct for nearby mass and energy.
- AnimalMuppet 3y agoWell, sure. I was thinking of stations that are a few tens of km apart on a flat region of Earth, so I don't think that would be much of an issue.
- lazide 3y agoDepends on how many digits of precision
- adgjlsfhk1 3y agothe assumption that time dilation is identical for the same acceleration profiles is equivalent to an assumption of the 1 way speed of light. if you do the full math with a non constant light speed, you find that degree of asymmetry in the 1 way speed of light directly cancels the difference in time dilation
- AnimalMuppet 3y agoHow can that work? I can control both how hard I accelerate, and how far I go with constant velocity. So I can control how much of the clock skew is due to acceleration time dilation. That can't match the speed difference for all possible experimental setups. For experiment 1, say I accelerate the clocks at 0.1 g for 10 seconds, then drive with constant velocity for 1 hour, then decelerate at 0.1 g for 10 seconds. That acceleration time dilation exactly matches the change in propagation time due to the difference in c? Fine, I'll give you that. So for experiment 2, I drive at constant velocity for two hours. I've kept the acceleration time dilation the same as in experiment 1, but doubled the distance. If the change in propagation time matched in experiment 1, it can't match now. Or, for experiment 3, I accelerate at 0.1 g for five seconds, reaching 1/4 of the previous velocity, then drive for two hours. Now the propagation difference is the same as in experiment 1, but the acceleration time dilation is different. So how is this going to come out "you can't tell" in all three experiments?
- adgjlsfhk1 3y ago> then drive with constant velocity for 1 hour 1 hour according to who's clock? The point is that if the 1 way speed of light is different, the clocks traveling in opposite directs will measure the 1 hour passing at different speeds.
- AnimalMuppet 3y agoThe (non-GR) time dilation rate difference will be proportional to v^2/c^2 (neglecting 4th order terms and higher). The total time dilation difference will be that times the time in transit, which is d/v (with d being the distance traveled). So the total time dilation difference will be proportional to vd/c^2. By making the velocity small, I can make that term as small as I want. But what if I don't know what c is? Doesn't matter. I know it's much, much larger than the velocity I'm moving at. So I don't buy the "according to who's clock" argument. I can make it so that it doesn't matter, just by going slow enough.