When does water become compressed?

Question

Here on earth, water appears to be incompressible. We are told that black holes exist in space; these have enormous density so much so that whole solar systems collapse on themselves until they occupy a space no larger than pea. When do the laws of physics change and the apparently incompressible substances start to shrink?

Answer 1

Water is not incompressible. Water in deep oceans will be slightly more dense than at the surface because of the additional pressure it is under. Hydraulic devices are slightly more "cushioned" than ones made of, for instance, metal because of the compressibility of water.

However, the degree of compression seen in a liquid is obviously much less than of, say, a gas. Water is also less compressible than some liquids because its molecules are electrically charged (the oxygen is slightly negative, the hydrogens slightly positive), and the repulsion between the like charges helps push the molecules apart. However, the will be overcome by sufficient force.

Another odd thing about water is that it does not, as most liquids do, become solid when compressed (the first answer is wrong in this respect): that is because ice is LESS dense than water - this is again due to the charge separation across the molecule, which aligns the molecules into a lattice which is a less efficient way to stack them than could be achieved if they were uncharged.

There WILL be a change of state under sufficient force, though. There is probably an arrangement of the constituent atoms which allows them to pack more closely and is therefore more stable at very, VERY high pressures - the way graphite turns into diamond. However, I'm not aware that such a state has ever been created or observed.

Eventually, under the unimaginable gravity of a black hole, the pressure will be such that bonds between the atoms become irrelevant, and their nuclei are so close that they don't even resemble everyday matter - at which point it would be hard to call it "water" at all.

Answer 2

By saying that water is 'incompressible' i think we just mean that it would take a very large amount of pressure to compress it, and that this is not possible to do on Earth without special equipment or something.

The gravitational force from black holes is so incredibly huge, that it can compress pretty much anything. Basically, it comes down to the amount of force you can exert on something. Black holes can exert a hell of a huge one, simply because they are so massive. The laws of physics do not change, if you could provide enough force you can compress water, wherever it is.

Answer 3

those varieties of solutions are evaluations. If water must be compressed, truly there sould be revealed, peer reviewed lab consequences. i believe water to be infinitely incompressible, and that i've got hunted for examples of compression yet discovered no longer something yet theoretical extremes. in all probability from the comparable people who have not have been given any subject imagining spaceships traveling the cost of light.

Answer 4

Water is actually quite compressible, it just takes thousands of atmospheres of pressure to get much effect. The distance between molecules is rather large, but then the electrostatic repulsion becomes very large as the molecules get closer together. When the external forces or gravity are stronger than the electrostatic forces these substances collapse. Of course when they collapse too much, they have this nasty habit of going thermalnuclear. Don't try that at home.

Answer 5

There comes a point, called the critical point, where the temperature and pressure are so great that steam and liquid water are indistinguishable...this initiates the "plasma" state of a substance.

OH...and ice is NOT compressed water, the density of ice is actually less than that of water

Answer 6

to ciaragw........ice is not compressed water, water expands as it gets colder [to ice] AND as it gets warmer [to steam].
I'm unsure about actually compressing the stuff as compression always produces heat and so it should expand.
Good question all the same.

Answer 7

About the same time that the substances start to break down into their component particles.


Doug

Answer 8

you must understand they immense power and energy that a black hole posseses. the laws of physics change when lets say a star dies and huge amounts of energy is released.

Answer 9

Water is compressible. You don't need a black hole to compress it.

Answer 10

Just before it becomes depressed.