The Relativity of Time Explained

Added: 2026-06-01

[00:00:00]Einstein said that time is relative.

[00:00:03]But what does that actually mean?

[00:00:05]It means that each person measures time according to their own path through space-time. [music] And that path mainly depends on two things, gravity and speed.

[00:00:15]Near an object with a lot of mass, like a star or a black hole, space-time curves more.

[00:00:21]And in that curvature, clocks tick more slowly >> [music] >> than they do in a region with weaker gravity.

[00:00:28]The same happens with speed.

[00:00:30]>> [music] >> If someone travels extremely fast, their clock can tick more slowly than the clock of someone who followed a different path.

[00:00:38]But here's the strangest part.

[00:00:41]You wouldn't notice your own time slowing down.

[00:00:44]For you, 1 second >> [music] >> would still feel like 1 second.

[00:00:48]The difference only appears when you compare your clock with someone else's, someone who experienced different gravity [music] or moved at a different speed.

[00:00:57]That's when you could discover that while only 1 hour passed for you, much more time passed for them.