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Einstein’s General Relativity and Your Age

Albert Einstein’s 1915 theory of general relativity proposes an effect called time dilation. This means that you would age slightly slower or faster depending on the gravitational field, an effect that can be measured with atomic clocks located at different elevations. NIST scientists have used atomic clocks as sensors to measure general relativity more and more precisely. A 2022 experiment measured time dilation at the smallest scale ever, showing that two tiny clocks in the same cloud of atoms, separated by just a millimeter or the width of a sharp pencil tip, tick at different rates. A 2010 experiment measured it by comparing two independent atomic clocks, one positioned 33 centimeters (about 1 foot) above the other.

Infographic titled "Einstein's General Relativity and Your Age" shows your age on Jupiter, the Moon, Mount Everest, etc.
Credit: N. Hanacek/NIST
Created February 11, 2022, Updated February 16, 2022