Theory
Think of space time like a pond, the water being space time it self. If you throw a rock in in it, it creates a "hole" and this hole is analogous to gravity. If you throw a rock that is big enough, you will get the hole, and little extra water will lift from the surface. This little extra removed from the surface violates the 1st law of thermodynamics, Matter cannot be created or destroyed. If that little extra was never returned, sent to another dimension, lets say a 5th, the pond will try to fill it self back up. If you haven't caught on yet, what is the riddle?