I don't know... atomic clocks are approaching precision that can measure the effects of time dilation due to gravity on the order of inches. They have to take i

I don't know... atomic clocks are approaching precision that can measure the effects of time dilation due to gravity on the order of inches. They have to take into account daily tectonic tides. > The precision of current optical clocks is astounding. You may have heard that time goes more slowly when gravity is strong due to general relativity. Optical clocks are so sensitive they can measure the different flows of time 2cm apart in height. If I lay a book on the table, the bottom of the book is slightly closer to the center of the Earth than the top, so experiences slightly stronger gravity. This difference is measurable with an optical clock. Optical clocks are so sensitive we can no longer average the time of multiple clocks together—the ground you or a clock are sitting on typically rises and falls by ~5cm a day due to land tides. The seismic motion of the ground currently limits our ability to measure time. https://arstechnica.com/science/2021/01/a-curious-observers-guide-to-quantum-mechanics-pt-2-the-particle-melting-pot/ https://arstechnica.com/science/2021/01/a-curious-observers-...