Everything that I've read about GR says that gravity is caused because mass wants to "slide" down the warping of ST like a marble falling to the center of a warped trampoline. But the marble falls because of gravity! We are trying to find out what gravity is! Some articles explain that moving masses (and light) always follow the shortest path and that makes them look as if they are falling. But if you drop a ball, then it was never moving (through space) in the first place! So why should it all of a sudden start moveing through the curves of ST? I've been wondering about this for a long time, could someone please help?