
Scientists Build Atomic Clocks Accurate Enough to Measure Changes in Spacetime - Varcht
https://gizmodo.com/scientists-build-atomic-clocks-accurate-enough-to-measu-1830715349
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jhayward
> _But characterizing the clocks this well meant that the ytterbium clocks
> could detect how Earth’s gravity had slowed time, accurately determining
> their location in the Earth’s gravitational field to within a centimeter._

This is amazing to me. There was an article published 4 or so years ago that
predicted a satellite network of quantum entangled clocks that would yield
similar resolution throughout the entire volume of the earth.

Essentially, such an ultra-GPS constellation would be able to determine the
density of any centimeter-sized volume anywhere within the earth. It's nice to
see regular progress to such a goal.

