It was also done with planes flying around the world. https://en.m.wikipedia.org/wiki/Hafele–Keating_experiment https://en.m.wikipedia.org/wiki/Hafele–Keating_

It was also done with planes flying around the world. https://en.m.wikipedia.org/wiki/Hafele–Keating_experiment https://en.m.wikipedia.org/wiki/Hafele–Keating_experiment > The Hafele–Keating experiment was a test of the theory of relativity. In October 1971, Joseph C. Hafele, a physicist, and Richard E. Keating, an astronomer, took four cesium-beam atomic clocks aboard commercial airliners. They flew twice around the world, first eastward, then westward, and compared the clocks against others that remained at the United States Naval Observatory. When reunited, the three sets of clocks were found to disagree with one another, and their differences were consistent with the predictions of special and general relativity. —— Also, GPS wouldn’t work without understanding relativity because the clocks in the satellites move faster (I think?) than the ones here on Earth.