Principle of relativity

The principle of relativity is a big idea that says that everyone experiences the same physical laws and rules of the universe regardless of how fast they are moving or where they are located. It means that if two people look at the same scene, both will agree on what they see, even if one of them is moving really fast. For example, if two people are standing on the ground, both will see an airplane fly over them. The person in the airplane will also see the people and have the same experience they do. All the while, everyone is moving, but no one feels like they are going anywhere. This idea helps explain a lot of the weird things we experience in the universe, like why time slows down when you are moving very fast.