Re:Scientists find way to make water freeze at boiling tempe...
by soperj on Tuesday November 29, 2016 @01:20AM
(#13061258)
This reminds me of an experiment my physics teacher did in gr.12. The way he explained it was that water would boil when there was a temperature delta, so he boiled some water in a test tube, to eliminate most of the air in the tube, and then plugged it and removed it from the heat. Let it cool down and then put it on ice. It looked like full rolling boil. I've never tried it again since.
Re:Scientists find way to make water freeze at boiling tempe...
by dhimes on Tuesday November 29, 2016 @07:37AM
(#13062650)
The boiling point depends on pressure. It sounds like he reduced the pressure in the testtube be getting the air out and letting the water vapor condense- then the liquid boiled. Clever.
Re:Scientists find way to make water freeze at boiling tempe...
by james_a_craig on Tuesday November 29, 2016 @02:08AM
(#13061406)
I wonder if the forced phase-change the confinement causes applies to other contexts? Could we use a similar trick to force superconductive materials into their low-temperature superconductive phase at higher temperatures?
Re:Scientists find way to make water freeze at boiling tempe...
by bskdjx on Tuesday November 29, 2016 @07:41AM
(#13062663)
Yes, somehow.
What they technically did is raise the chemical potential, mu, of the gas phase (the phase with the lowest mu wins). TL/DR, but I'm not too impressed from a theoretical POV.
The problem to replicate this is "what do you do to raise the mu of the non super-conducting phase?". That's not trivial as many things raise the mu of the super conducting phase instead, like applied magnetic fields.
What they technically did is raise the chemical potential, mu, of the gas phase (the phase with the lowest mu wins). TL/DR, but I'm not too impressed from a theoretical POV.
The problem to replicate this is "what do you do to raise the mu of the non super-conducting phase?". That's not trivial as many things raise the mu of the super conducting phase instead, like applied magnetic fields.
Looks like plenty of ranges where boiling water can freeze with a pressure change.