Science Common Sense

238 - How does the principle of relativity affect time?

The principle of relativity, discovered by Albert Einstein, says that time can be different for people moving at different speeds. This is called time dilation.

Imagine you have a twin brother, and you both have identical clocks. You stay on Earth, but your brother travels to a spaceship going very, very fast. When he returns, you might notice that his clock is a bit slower than yours. That's because time passed slower for him on the spaceship because it was moving so fast.

This effect is very small and only happens at extremely high speeds, like those close to the speed of light. But it shows that time is not always the same everywhere, and it can change depending on how fast you're moving.