The faster the journey through space, the shorter the journey through time.

The time dilation equation describes how elapsed time depends on relative motion, one of the most striking consequences of special relativity. It shows that a moving clock runs slower relative to an observer who sees that clock in motion. At everyday speeds the difference is vanishingly small, but as velocity approaches the speed of light, the effect becomes dramatic. Time itself is not universal; different observers can measure different intervals between the same events. The prediction has been repeatedly confirmed with precise clocks and fast-moving particles. It is used primarily in particle physics, satellite navigation, and relativistic astrophysics.