I frequently get little pointy protrusions sticking up from the surface of some ice cubes that I make in my freezer. Some of them are about 1/4" high and cone-shaped, 2 or 3 per tray, but often one is very slender, over 1" tall, and sticking up at a slight angle. They seem to point toward the more substantial section of the metal rack about 2" above.
Is there some sort of electrical charge that is attracting the water molecules during the crystalization process? Or is there a simpler explanation?
Yeah, it’s a bit simpler. [ol][li]Ice tends to form at the edges first, and then fill in towards the center.Water expands as it freezes.[/ol][/li]
Because of these two conditions, there is frequenty a hole in the center of the ice on the surface, and as the water freezes, it exerts pressure upwards, forcing water out, where it freezes.
It doesn’t happen every time. I see it maybe once a week or every other week. And I go through two or three trays of ice a day when I’m in my apartment. It’s a pretty rare occurrence.
Almost everything contracts as the temperature drops. Water contracts as it cools down to 4*C, at which point, the crystals start growing large enough to push the other molecules further away. One of the many quirks that water has that make life (as we know it) possible.
