Water freezes at zero degrees Celsius or 32 degrees Fahrenheit, right? While that’s water’s freezing point, under certain conditions liquid water can be supercooled – and still be liquid. Two groups of scientists recently uncovered new details about supercooled water, showing there could still be a lot we don’t know about this fairly common substance.
Water just got weirder. We know supercooled water drops can exist naturally in the planet’s atmosphere, at temperatures as low as negative 35 degrees Celsius, according to Gizmodo. It isn’t easy for scientists to measure the temperature of supercooled water droplets, but a team led by Goethe University Frankfurt pioneered a new technique – for drops as small as a micrometer – that shows liquid water can exist at negative 42.55 degrees Celsius. Their research was published in Physical Review Letters earlier this month, with scientists at institutions in Germany, Italy, France, and Spain contributing.
Meanwhile, Stockholm University published other groundbreaking research on supercooled water last month in Science – and here’s where things get really weird. The scientists found that at normal pressure and a temperature of negative 44 degrees Celsius, water “can exist as two distinct liquids with different ways to bind the water molecules. The water can not decide what shape to be in without fluctuating between these two,” per the university’s press release. They explained it’s similar to how we may be unable to make up our minds on a decision and go back and forth over different options. They discovered many of water’s weird properties “reach a maximum at negative 44 degrees Celsius.”
Supercooled water may be a cool topic, but why should you care? Physics said in their synopsis of the Goethe University Frankfurt research, “Knowing when water freezes and when it stays liquid at these low temperatures could improve understanding of atmospheric ice formation and help researchers develop more reliable climate models.”