# Movement

Movement
Movement, or motion, is the state of changing something's position--that is, changing where something is. A flying bird or a walking person are moving, because they change where they are from one place to another. There are many kinds of science and math related to movement.
For example, thanks to Albert Einstein, we know that all "position" is relative. This means that everything's position depends on where they exist in relation to other things. For example, a ball is 5 feet away from a box, 3 feet away from a chair, and a foot away from a table. According to Einstein, the ball's position means how far the ball is from other things, so by telling you how far the ball was from other things, I told you its position. An object's "movement" is also relative. Its movement depends on where it is in relation to other things and where it's going to in relation to other things.
There are many things involved in movement, such as speed, velocity, acceleration, gravity, magnetic attraction and repulsion, friction, and inertia. Also, work is needed to produce movement.