Skip to comments.Water not so squishy under pressure
Posted on 03/06/2012 1:09:39 AM PST by U-238
When squeezed to pressures and temperatures like those inside giant planets, water molecules are less squeezable than anticipated, defying a set of decades-old equations used to describe watery behavior over a range of conditions.
Studying how molecules behave in such environments will help scientists better understand the formation and composition of ice giants like Uranus and Neptune, as well as those being spotted in swarms by planet hunters. The new work, which appears in the March 2 Physical Review Letters, also suggests that textbooks about planetary interiors and magnetic fields may need reworking.
At this point, its worth putting together an accurate equation of state over the entire pressure range for planetary modelers to use, says Bill Nellis, a physicist at Harvard University. Nellis notes that while the new study has generated reliable data for the conditions in question, more work is needed to determine how the new numbers will tweak existing theories.
In the lab, scientists generated pressures reaching 700 gigapascals almost 7 million times the atmospheric pressure at the Earths surface using the Z machine, an accelerator at Sandia National Laboratories in Albuquerque, N.M. It really is a regime that we dont experience in our lives, says planetary scientist Jonathan Fortney of the University of California, Santa Cruz. Even at the bottom of the ocean.
(Excerpt) Read more at sciencenews.org ...
I love any article that uses the word “rejiggering”.
I just do.
Excuse me waitor, rejigger my scotch if you will.
Thanks U-238! It’s a quad-ping. This one is first, and going out to the very patient members of the APoD list, who put up with my procrastination and other sub-standard behavior. An “extra, extra” ping.
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Thanks. I really think what is interesting is at the core of these gas giants. If they have rocky cores, the immense pressure of the gas planets might lie a diamond about the size of planet Earth.
When squeezed to pressures and temperatures like those inside giant planets, water molecules are less squeezable than anticipated,'Less Squeezable', dang. I hate it when these guys get all technical.
Anywho, this is an odd coincidence as last night (Tuesday) on 'Universe' (H2 Channel) they had a program on 'water' and our Solar System. Specifically about Saturn's Moon Titan which is the only other body we know of with 'flowing liquid'. But on Titan it isn't water.
Titan is 'almost' like Earth in that respect and also that's it atmosphere is mostly Nitrogen and it has water (H2O. But on Titan the pressure is HUGH (don't know about any gigapascals) and due to the atmospheric pressure the 'water' is like Granite on Earth, it's that hard and compressed. And also because of that pressure the flowing liquid and lakes are Liquid Methane, and so is the 'rain'. And like Methane is on Earth, Oxygen is on Titan -- flammable. But on Titan Methane isn't flammable and we know on Earth it is.
The basic conclusion 'they' (numerous physicists who play segment hosts) all came to is that liquid water is really an unnatural state. It should be Solid like on Titan or a Gas like with Steam here. So finding any 'water earths' in the Universe is not likely as all the conditions are too exacting (and then I nodded off to my redcurrant nightmare of being butt-naked and in HS)
(just kidding, I'm really in a Firefight and have a gun (sometimes a pistol, sometimes a rifle) that won't fire at the 'bad guys').
[Hmm??? Maybe I did die in Vietnam after all?]
“The scientists, from Sandia and Germanys University of Rostock, did this by punching a dime-sized amount of water with small metal plates that had been magnetically accelerated to speeds of 27 kilometers per second. The resulting shock wave induced planetary core-like pressures; the scientists could then watch how the molecules in the sample reacted.
“The water was less compressible than expected, the researchers found, refusing to collapse into denser configurations. Instead, the molecules broke into charged fragments, forming a fluid capable of conducting electricity that behaves more like a weak metal, says study coauthor Marcus Knudson, a physicist at Sandia”
Very interesting experimental technique and result. I am a bit surprised that they infer that this is the first time that Water has been subjected to this pressure - I believed that it had been done many years ago in diamond anvil cells.
On second reflection - perhaps that has been done, and that the reason for the electrical properties is not the pressure, but the shock wave that this sample was subjected to. I don’t see how it would be possible to separate the effects of shock from the effects of the pressure using this technique.