Scientists have managed to bring liquid water to the lowest temperature possible without it turning into ice, and no, it’s not by cooling it to just above its freezing point,
How do you keep water liquid in freezing temperatures?
We know that water freezes at 0 degrees Celsius (or 32 degrees Fahrenheit, or 272 Kelvin). We may also think that that’s the coldest that liquid water can go before turning to ice, and to a certain extent, we’re right. However, if you have access to the kind of equipment that some scientists do, you’ll be able to cool liquid water to down to -42.55 degrees Celsius (or -44.59 degrees Fahrenheit, or 230.6 Kelvin). That’s far past the “usual” freezing point of water, but a team of researchers have managed to formulate a technique that allowed them to keep water in its liquid state even at that subzero temperature.
“Supercooled” water remains liquid even far past the freezing point, revealing the bizarre ways that water behaves when subjected to such temperatures.
Droplets in a vacuum becoming a singularity
The truth is, laboratory conditions aren’t always necessary for water to stay liquid even when the temperature drops to way below zero. Water has been found to naturally be able to stay liquid in a temperature of -35 degrees Celsius in the atmosphere. We already know that water has the tendency to bend the rules of its own behavior, but somewhere around these very low temperatures, water achieves a sort of strange mathematical state, called a “singularity”.
Two research teams may have been able to reach this singularity.
“Yet what sort of singularity might water be approaching still represents an unresolved puzzle that has prompted the formulation of conflicting scenarios to interpret its origin,” one team wrote in their study on the matter. Members of this particular team first tracked the diameter of microscopic droplets of water in a vacuum, then lit them up with lasers. With this technique, the researchers were able to take very precise measurements.
The second team, meanwhile, examined how supercooled water shifted between two different liquid states. With x-ray lasers, the researchers were able to show how water behaved in a confused manner of sorts after being subjected to extremely low temperatures. According to the research paper, the water seemed unable to decide whether it wanted to be low density or high density, thus embodying a singularity.
We won't actually be seeing waves or splashes of subzero temperature liquid water anytime soon.
So what did these teams do to keep water liquid while in extreme subzero temperatures? Like the first group, the second group placed microscopic water droplets into a vacuum as well. The smaller the droplet of water, the colder it can be while still retaining its liquid state. Making the droplets smaller and smaller lowers pressure, which makes the particles on the surface of the droplets evaporate. This then leads to a significant drop in temperature.
Determining the temperature of droplets was also quite the challenge. It wasn’t just a matter of sticking a thermometer in there and taking note of the temperature reading. Instead, the researchers took note of changes in the droplets’ diameter in the vacuum. Using a mathematical formula, the researchers were able to use the diameters to figure out the temperature of the droplets.
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