I know the title sounds stupid, but I have a serious question. If you look at the simulations for the massive structures in the universe, there are great voids and large areas of matter in between them. The matter parts of the universe contain gravitation objects with large masses, and from the simulations it looks like these areas have sucked all of the matter out of the voids, which is why they are voids, technically low density vacuums. So the question is two fold, 1) at what pressure/temperature can a vacuum exist at before the matter in it is destroyed/changed to something else? 2) If an area within the 'void' moves, the vacuum pressure where it moves away from increases, if there is a maximum vacuum pressure (at which vacuum become void) then the surrounding space would attempt to fill the void, which it couldn't do because this would create more void. So could we consider these great 'voids' to be inelastic in nature? Could the 'voids' be considered as a single (soft/hard) body, which increases in elasticity nearer the edges? What does that do to the dark matter problem if we consider the 'voids' to be immense solid bodies that slowly rotate?