Consider the following variation of the twin paradox:
A clock or a biological system ultimately is an electromagnetic system. First, let’s devise a new time measuring device. Imagine a tank of water with a spout on the bottom. The spout has a control mechanism that will release a single drop of water into a vacuum tube. At the bottom of the tube is a sensor that detects when the drop hits it. A wire connecting the sensor at the bottom with the spout control at the top then signals the spout to drop the next drop of water. The system is calibrated such that each drop measures precisely one second of time. Let’s refer to this time measuring device as a gravity clock.
Our gravity clock almost entirely eliminates EM from the timing mechanism (at the surface of the Earth the E&M component along the signal wire makes up 1.6e-8s (4.9/c) of each second).
Now empty the Universe save for 2 instances of Earth. On each of these Earths we place one normal clock (an EM clock) and one gravity clock. Both Earths are in the same inertial frame and all 4 clocks are synchronized.
We now attach rockets to one of the Earth’s and accelerate it and its clocks to near the speed of light.
It seems to me that the “time” dilation is caused by the longer round trip time of photons (or virtual photons) moving between charges. Since, the gravity clock (very nearly) eliminates electromagnetism from its timing mechanism, it will largely be unaffected by the shifting frame.
If the wandering Earth is returned to the stationary Earth (again at near the speed of light), then the two clocks on the stationary Earth will be still be in sync, and I suspect the gravity clock on the wandering Earth will largely be in sync with the stationary clocks (aside from the effect of the signal along wire), while the wandering electromagnetic clock will vary fully as predicted by the Lorentz transformation.
First, is there any reason to believe that this would not be the case; that the gravity clock would actually be affected in the same way as the EM clock?
If not, is it really accurate to describe this situation as “time” dilating (as opposed to say the animation rate of EM systems dilating)?
EDIT: Apologies for not noticing it earlier, but this question: (Time dilation only on electromagnetic force?) is essentially the same as mine. Although, I don't think either of the answers indicate whether any experiment has shown that a gravity clock is affected by "time" dilation.