So consider the usual pop-science spacetime model, a bowling ball on a trampoline. Apparently, the ball should sink into the trampoline, causing a dip in the fabric which causes nearby objects to fall towards the ball, and so on and so forth. In this analogy the trampoline fabric is the fabric of spacetime and the attraction of other masses to the dip in the fabric is gravity.
However, this model requires that whatever mass is being considered as the gravity well is itself sinking into the fabric. How can something sink into the fabric when a) the fabric is 3 dimensional and b) there's no force of gravity to cause the ball to sink?
What's pulling the yellow ball into the fabric?
