Time dilation

In the theory o relativity, time dilation is a difference o elapsed time atween twa events as measurt bi observers either muivin relative tae ilk ither or differently situatit frae a gravitational mass or masses.

Time dilation explains why twa wirkin clocks will report different times efter different accelerations. For example, ISS astronauts return from missions havin aged slichtly less nor thay would hae been if thay haed remained on Yird, an GPS satellites wirk acause thay adjust for seemilar bendin o spacetime tae coordinate wi seestems on Yird.