[mehrdadn]

Amazing. They observe fractional frequency changes of around 4.1E-17. Thanks for sharing the links!

[ta1234567890]

Couldn't see that number in the info at the link above, is that from the full article?

[mehrdadn]

Yeah: "The two measurements consist of approximately 100,000 s of low-height data and 40,000 s of high-height data, and the clocks exhibit (Fig. 3) a fractional frequency change of (4.1 ± 1.6) × 10^−17."