It is the force of gravity that holds the Moon as it revolves around the Earth. We can investigate this by the following easy GRAVITY EXPERIMENT.

(1) Take a tennis ball and wrap an elastic band around it a few times. (2) Attach one end of a reasonable length of string to the ``elastic-banded ball''. (3) Make sure you have plenty of room for the next bit. Grab the string at the other end from the ball and start to swing it around your head. (4) Provided you are swinging the ball fast enough, you should be able to trace out a horizontal circle above your head.