A wonderful little example of supercooling occurred in front of my very eyes last night.
Supercooling is a state of matter where a fluid is cooled below its freezing point, but for whatever reason, fails to actually solidify. Pilots encounter this phenomenon as “icing” in the air, and ground dwellers as freezing rain or “ice storms”. Yesterday it happened in my hand on a much larger scale.
The ingredients: a 500mL bottle of spring water and its thirty friends, a manly deep freezer, some electricity, and a few weeks’ time.
The outcome: almost every bottle of water is translucent and frozen solid with ice. Two bottles, from somewhere in the middle of the pile of frozen bottles, look and feel completely liquid, right up to bubbles of air moving around freely.
Yet, shake one around just a little more vigorously. Suddenly, within the span of one second, a translucent mass of ice forms from top to bottom. It turns to a hard slush, as subsequent drink confirms. Disbelieving that supercooling on this scale is likely, shake the second bottle the same way, in front of four adult observers. The same thing happens. Wonderful stuff.