Researchers have discovered new properties of supercooled water. It has long been known that clean water with no particulates that is placed in a smooth enough container can be cooled below its freezing point of 0 C (32 F) without freezing.
They found certain forms of particles hitting the water can microscopically (subatomically) cause it to freeze if it’s supercooled first. Some particles (neutrons) but not others (gamma rays) trigger freezing.
This could lead to better detectors for nuclear weapons in cargo for homeland security, understanding cloud formation, and providing clues as to how certain mammalian species hibernate, supercooling their blood somehow.