One of the most mind-bending aspects of Albert Einstein s Theory of Relativity is time dilation. Time moves more slowly for a person in motion compared to a person at rest. This effect also applies in gravitational fields. Someone closer to a gravitationally-dense body like a black hole would be subject to a slowdown in time compared to others farther away. Mind you, life wouldn t proceed in slow motion for these people. Everything would seem normal within their own frames of reference. The relative differences would only be noticed when everybody meets up.
In our own existence, we really don t have to concern ourselves with time dilation. Relatively speaking, humans move much too slowly to ever notice it. However, physicists finely tuned into the tinest ticks of time have observed dilation in a very human activity: international air travel.