[time-nuts] WWV Doppler Shift

[Tom Van Baak]

Jim Lux wrote:
> I'm not sure I understand why the slowing due to spin happens to exactly 
> match the speedup from altitude.

Right. It's not obvious to me either. I've been looking some time for the right book, article, or web page to hand out when people ask that question. The same goes for a rotating planet made of foam vs. water vs. diamond question. It's possible that separating "SR" and "GR", as newcomers to relativity (me too) often do, is itself the problem in this case. When two things magically equal or cancel there's usually a deeper reason.

Let me encourage you ask around JPL over the months and see if any of your relativistic geodesy friends has a clean answer. Web searches on topics of relativity tend to have poor SNR. That said, to start with, see if one these links helps more than it hurts:

https://arxiv.org/pdf/gr-qc/0501034.pdf

https://physics.stackexchange.com/questions/126919/does-time-move-slower-at-the-equator

https://thatsmaths.files.wordpress.com/2012/11/two-clocks1.pdf

If you (and Steve, Donald, Bob, et al.) have half an hour to study these, let me know what you think. I've been down this rabbit hole myself.

The good news in this case is that we know what the right answer is. Any number of legacy and modern experiments show altitude is a factor in atomic clock rate but not latitude. The bad news is I / we don't have a convincing one sentence explanation for it.

/tvb