3 ms·
> They are measuring the difference in earth's gravitational field at two locations separated by a millimeter. Just in case there is anyone here who didn't rea
by hanoz 5y ago
> They are measuring the difference in earth's gravitational field at two locations separated by a millimeter.
Just in case there is anyone here who didn't read the article (surely not?), for whom this summary might not convey the full astoundingness of the procedure, what they are actually measuring is the difference in the passage of time itself, due to gravity, when a millimeter higher up than the other.
- trhway 5y agoMy favorite experiment in that vain is https://en.wikipedia.org/wiki/Pound%E2%80%93Rebka_experiment https://en.wikipedia.org/wiki/Pound%E2%80%93Rebka_experiment - using loudspeakers to cause Doppler to compensate for redshift. 1959 - 22m, 2021 - 1 mm, a Moore's law for such measurements seems to be "doubling precision about each 4 years".