A fun little caveat of that fact is that if you were able to make a 100% incompressible material you would violate causality. If the glass in your marbles did

A fun little caveat of that fact is that if you were able to make a 100% incompressible material you would violate causality. If the glass in your marbles did not compress at all then the "information" that you inserted your marble would reach the other end before it actually happened (faster than the speed of light)