The recent preprint titled "Time Dilation Test: No Deviation From Relativity Predictions Found" reports on a comprehensive test of time dilation utilizing a fiber network of optical clocks. The study, which involved clock comparisons between PTB and LNE-SYRTE, found no deviations from the predictions of relativity. It highlighted that time-variable gravity potential components induced by tidal forces from the Sun and Moon resulted in fractional frequency variations of approximately 1.3 × 10-17, which is comparable to the measurement uncertainty.
PREREQUISITESPhysicists, researchers in gravitational studies, and anyone interested in the experimental validation of general relativity will benefit from this discussion.
This effect is about as large as the uncertainty of the measurements: The tides from Sun and Moon are relevant.During the considered dates of clock com- paraisons, time-variable gravity potential components in- duced by tides give approximately diurnal peak-to-peak fractional frequency variations up to 1.3 × 10-17 between PTB and LNE-SYRTE, [...]