Okay, I have been wondering this for a long time. The question concerns buoyancy of objects in water. Question: Imagine you have a balloon filled with air. Imagine the balloon has virtually zero mass, but actually has a virtually infinite hardness. You could replace the balloon with a force field or sorts, like star trek. So, will the hypothetical balloon float? The arrangement in itself would have less mass than water; so by this reasoning it will float. But it has infinite hardness and therefore cannot bend in the expected way (if you were to hold a real balloon by the filling point underwater, it would stretch out as you go deeper and deeper). So the water can have no direct or indirect interaction with the mass inside the balloon. So will the balloon float? If not, has as hardness been accounted for in buoyancy calculations?