Theory of relativity

The Theory of Relativity is a scientific theory that explains how the universe works. Basically, it's a way of understanding what happens when objects move very fast, and how space and time work in relation to each other. So, when something moves very quickly, or is large in size, it affects the space and time around it. For example, imagine that you and your friend line up against a wall. You're standing still while your friend starts to move away from you. As your friend moves farther away, the space between you two increases and time passes by more slowly for your friend than it does for you. The Theory of Relativity explains the effects of this.