 Hafele-Keating experiment

The Hafele–Keating experiment, conducted in 1971 by physicists Joseph Hafele and Richard Keating, was designed to test the effects of time dilation as predicted by Albert Einstein’s theory of relativity. The experiment involved flying atomic clocks on commercial airliners around the world, both eastward and westward, and then comparing the time recorded by these clocks with those left stationary on the ground.