Compression of water

[Wso]

Can water be compressed? I have heard multiple conflicting views on this. Assuming that you could compress water, could you compress it to a point where any further compression would not be possible? If so then could you make a tube, full of water, and push the water from one end and have the force traverse the length of the tube instantaneously? Compression waves can't happen in water, unless I'm mistaken. I'm more then a bit confused on this and wasn't entirely sure where to post this. I hope posting this here is alright, as it has to do with faster then light data sending and the physics of water.

Edited April 9, 2014 by Wso

[MigL]

You can compress water vapour, liquid water and even solid water ( ice ) to varying degrees.

Compression waves happen in water, not instantaneously, but at the speed of sound.

Ever hear water hammer in pipes ?

 

This question may be better posted in classical physics.

Edited April 9, 2014 by MigL

[John Cuthber]

To be fair, it's a valid point.

If the compressibility of water was actually zero the speed of sound would be infinite- violating relativity.

 

When they say iut's incompressible, they mean the compressibility is too small to bother with in most calculations or measurements.

[Wso]

Thanks for the replies so far, they were very helpful. So is there a point of maximum compression? Or does the amount of energy required to further compress anything increase exponentially?

[studiot]

One of the things I suggest you need to clarify is what exactly you mean by "compress"

 

Do you mean reduce the volume, with or without additional stress, or do you mean apply a compressive stress, with or without change of volume?

Edited April 11, 2014 by studiot

[Sensei]

So is there a point of maximum compression?

 

After reaching some threshold compression, matter will change to plasma (nucleus and electrons are free), and nuclear fusion will start up (at least for initial H₂O).

Water will no longer be water, but mixture of protons and Oxygen nucleus and electrons.

But it needs cosmic scale amount of matter to create enough pressure. Some estimate that Jupiter would need 50-75 times of its current mass to ignite and become star.

For instance Sun core has density 150 g/cm^3, which is 150 times denser than water density on Earth (and 7.7 times denser than gold 19.3 g/cm^3).

Average distance between particles will be much much smaller.

Edited April 11, 2014 by Sensei

[Bignose]

There are good references for the compressibility of water on its wikipedia page: http://en.wikipedia.org/wiki/Properties_of_water

 

As above, real actual physical water is compressible, at least some small amount. The real art of answering scientific questions is to know when it is appropriate to use certain assumptions or not. In general, the assumption of treating water as incompressible will introduce such a small percentage of error, that it is completely acceptable. But, in certain very high pressure and high temperature applications, it may needed to be accounted for. I don't have much other advice other than you need experience to know when it is and isn't ok to use those assumptions.

[Wso]

Unless I'm mistaken compression waves among atoms are just the atoms getting very close, but not touching. So if the electrons in the atoms are repealing eachother, then by the time you compress something to the point of plasma, where unless I'm mistaken all the electrons are on the outside of the plasma body, then how could compression waves travel? Would the neucleus of each atom repel away from eachother? If this isn't how compression waves travel (with electrons repealing eachother and thus their atoms apart from eachother in a wave) then please correct me.

[Sensei]

Would the neucleus of each atom repel away from eachother?

 

Yes. Nucleus possessing the same electric charge (f.e. positive and positive) will be repelling.

 

Typical human made plasma wants to expand in the all directions in vacuum.

Therefore we need to surround it by very strong magnets/electromagnets, which will be pushing plasma from all directions and it won't touch device's walls (that would melt it).

http://fire.pppl.gov/KSTAR_First_Plasma_Photos.png

 

Nucleus of matter and nucleus of antimatter will attract.

 

There is even exotic human made matter where antiproton is orbiting for a while Helium-4 nucleus (so role of electron is taken by antiproton).

Then after a while antiproton and nucleus are annihilating.

Edited April 11, 2014 by Sensei