Time dilation is a phenomenon predicted by Einstein's theory of relativity that states time can appear to pass differently for objects in motion relative to each other. When an object or a person travels at speeds close to the speed of light, they experience time dilation.
According to the theory of relativity, as an object's velocity approaches the speed of light, time for that object appears to slow down relative to an observer who is at rest. This means that for a person traveling close to the speed of light, time would appear to pass more slowly compared to an observer who is stationary.
As an object's velocity increases, its relative time dilation becomes more significant. At speeds that are only a fraction of the speed of light, the effect is negligible and difficult to observe. However, as the object's speed approaches the speed of light, the time dilation becomes more pronounced.
For example, imagine a scenario where an astronaut travels in a spaceship at a speed close to the speed of light for a certain duration. When the astronaut returns to Earth, they would find that less time has passed for them compared to people who remained on Earth. In other words, the astronaut would have aged less than their Earth-bound counterparts.
This phenomenon has been experimentally verified and is an important aspect of modern physics. It has practical implications, particularly for systems that rely on accurate timekeeping, such as GPS satellites, which must account for time dilation effects to function accurately.
In summary, time dilation is the effect of time appearing to pass more slowly for objects traveling close to the speed of light relative to observers who are at rest. It is a consequence of Einstein's theory of relativity and has been experimentally confirmed.