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Israeli Scientists Freeze Water By Warming It
ccktech writes "As reported by NPR and Chemistry world, the journal Science has a paper by David Ehre, Etay Lavert, Meir Lahav, and Igor Lubomirsky [note: abstract online; payment required to read the full paper] of Israel's Weizmann Institute, who have figured out a way to freeze pure water by warming it up. The trick is that pure water has different freezing points depending on the electrical charge of the surface it resides on. They found out that a negatively charged surface causes water to freeze at a lower temperature than a positively charged surface. By putting water on the pyroelectric material Lithium Tantalate, which has a negative charge when cooler but a positive change when warmer; water would remain a liquid down to -17 degrees C., and then freeze when the substrate and water were warmed up and the charge changed to positive, where water freezes at -7 degrees C."
I thought pure water doesn't go solid, not until an impurity starts crystal formation that turns the water into a solid?
I don't remember the science story yesterday Physicists Discover How To Teleport Energy being called Japanese Physicists Discover How To Teleport Energy. Is the fact these scientists are Israeli title worthy?
I thought pure water doesn't go solid, not until an impurity starts crystal formation that turns the water into a solid?
This comment seems really unintuitive so I looked around a little. Ice can actually form entirely without crystallization, by cooling it to ~137 C in a matter of milliseconds. The article also mentions that "pure water, in the absence of any nucleating surface, can remain in a supercooled liquid state down to temperatures as low as -40C". I guess that means that pure water will begin crystallizing at this temperature anyway.