Gravity Probe A

Gravity Probe A was an experiment conducted in 1976 by NASA to test Einstein's theory of general relativity, specifically how gravity affects time. The experiment involved placing a highly precise atomic clock on a spacecraft in orbit around Earth and comparing its time to an identical clock on Earth. Because of Earth's gravity, time runs slightly slower closer to Earth. The measurements confirmed that the clock in orbit ticked faster than the one on Earth, aligning with Einstein's prediction. This experiment provided a crucial test of how gravity influences time, strengthening our understanding of the fundamental nature of gravity and spacetime.