The Earth’s gravity is strong enough to keep The Moon, an immense celestial body, from flying off into space. It is also weak enough to allow us to jump and throw things in the air. How does this work?

Question

Similarly, why does The Moon’s gravity affect the tides but won’t, for example, cause a paperclip to slide across a desk?

In: Physics

Answer 1

There isn’t anything strong pushing the moon away, so gravity would pull it down immediately if it wasn’t moving.

It is moving sideways fast enough that gravity just makes it move in a circle instead. If you throw a ball, it goes in a curve until it hits the ground, if you throw it faster, it goes further before the curve that the surface of earth has and the curve the ball follows meet. If it goes fast enough, the curve of the ball never runs into the earth, and comes all the way back around.