ghwellsjr
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You are mixing up time dilation (which is frame dependent and arbitrary) with what observers see (which is relativistic Doppler and not dependent on any arbitrarily selected frame).GAsahi said:Same difference, you are mixing up mutual time dilation (the way the two observers see each other moving) with the calculation of total elapsed time (the circular variant of the twins paradox).
Einstein went on to describe:
Einstein was talking about the slow transport of a clock but in this thread it is a fast transport so the only difference is that the clock zipping around the equator will be ticking much more slowly than one at the equator.Thence we conclude that a balance-clock at the equator must go more slowly, by a very small amount, than a precisely similar clock situated at one of the poles under otherwise identical conditions.
Now, if each clock could actually see the other one (without the curvature of the Earth getting in the way), then the zipping one would see the one at the pole as ticking much more quickly all the time and the one at the pole would see the one zipping around as ticking much more slowly all the time. In the Earth's inertial frame, all the time dilation occurs for the zipping clock and it is constant. You can pick a non-inertial frame in which the zipping clock is at rest and the clock at the pole is running faster, not slower, and it is constant. Since the distance between the pole clock and the zipping clock is constant, the relativistic Doppler and the "time dilation" can be made the same.
But in this thread, the stationary clock is not at the pole but at the equator which complicates things. For one, each clock will only be able to see the other one during a small portion of the time when they are close together. During this brief period of time, you can approximate the relative motion as mutual and they each see the other ones clock as ticking faster while approaching then slower while retreating but the time dilation, based on two different approximately inertial frames for each clock will determine that the other clock is ticking much more slowly (I presume this is what HallsofIvy meant in post #21). And if they could see through the earth, they would each continue to see the other ones clock fluctuating in its tick rate, but on average, the zipping clock would see the station clock as going faster than its own and the station clock would see the zipping clock as going slower than its own. That's why I said in post #20 "on average".
I believe uniqueland wanted to avoid all these complications, especially of not being able to see the other one during the entire orbit and so he introduced a couple webcams. Now it will depend on where the mutual antenna is located as to how much fluctuation would be seen by each observer. I mentally put this antenna above the Earth's pole to eliminate any fluctuation but to be more general, I allowed for the antenna or antennas to be located anywhere and so I included "on average".
I'm really sorry that you had to make me go into all these gory details as they have nothing to do with what uniqueland is asking about and I hope it doesn't undo all the work I have been doing in trying to help him understand the answers to his questions.