So assume you have disk in space with a ball on it, the disk rotates and the ball flies off in a in a spiral (viewed from the disk). Thing is if we are in a space with no other matter, then who is to say what the non-moving frame of reference is. I could therefore say the disk is a my reference frame in which case the space around me is constantly spinning, however space is empty so the ball shouldn't feel any sort of force at all.. This obviously does not work. So in other words, how is spinning "space" any different from stationary "space"?