incompressible fluid vs indestructible container

[gkathellar]

We discover Ice XVII.

[Satinavian]

You would end up with a cube full of water at a 10atm pressure, comparable to a depth of 100 meters in the ocean. That's not nearly enough to crush a freediver, but enough to give them decompression sickness should you dismiss the forcecage!

But that's only because of that wussy pressure limit. If you removed that pressure limit, you'd have increasingly dense, high-pressure liquid water, followed by increasingly dense, exotic forms of ice, followed by a series of exciting phases of degenerate matter, all the way to neutron matter and beyond. Needless to say, any non-indestructible object inside the forcecage would be crushed by the overwhelming pressure.

Midway through the process, you'd also get nuclear fusion, the resulting gamma radiation obliterating the surrounding area (since forcecage doesn't stop electromagnetic radiation from getting through).

Man, this should totally be a xkcd "What if" scenario.

Well, if the forcecage really let's through gases, there might be a state where the added energy from pressing even more water into the cube is enough to force water through the the forcecage in the form of steam so that you end up with a cube of constant steam streams puring out from all sides.