At what temperature did ice turn into water?

Water can be liquid at minus 130 degrees

Umeå - Under normal conditions, water boils at 100 degrees Celsius and freezes to ice at zero degrees Celsius. A Swedish physicist has now succeeded in producing sluggishly flowing water at minus 130 ° C - under extremely high pressure. The previously only theoretically postulated form of water could also occur on other, colder celestial bodies, writes Ove Andersson from Umeå University in the "Proceedings of the National Academy of Sciences" (PNAS).

Even if water normally crystallizes to ice at 0 °, the liquid can be retained from water well into the minus range. The so-called super-cooled water becomes denser with increasing cold, and becomes less dense as it heats up. To obtain the ultra-viscous water, the researcher exposed crystalline water ice to a pressure of 1.3 gigapascals (GPa) at around minus 140 ° C. As a result, the crystal structure collapsed and amorphous ice formed with a random arrangement of the water molecules. As the temperature increased and the pressure decreased to one GPa, the ice turned into sluggishly flowing water. So it was liquid at minus 130 ° C.

"The water is like normal water, but its density is 35 percent higher and the water molecules move relatively slowly. This means that the viscosity is high," says Andersson. Such deviations from the norm - such as supercooled water, for example - have been known for years, but there is no general explanation for them. "The answer could lie in how the properties of water are influenced when it is exposed to high pressure," says the physicist. (red)