Tuesday, April 24, 2007

Supercooling

wiki: Supercooling is the process of chilling a liquid below its freezing point, without it becoming solid. A liquid below its freezing point will crystallize in the presence of a seed crystal or nucleus around which a crystal structure can form. However, lacking any such nucleus, the liquid phase can be maintained all the way down to the temperature at which crystal homogeneous nucleation occurs. The homogeneous nucleation can occur above the glass transition where the system is an amorphous—that is, non-crystalline—solid. Water has a freezing point of 273.15 K (0 °C or 32 °F) but can be supercooled at standard pressure down to its crystal homogeneous nucleation at almost 231 K (−42 °C).
I would have thought the water would already freeze in the container when agitated, but apparently you can pour supercooled water.

4 comments:

annom said...

Supercool! We should try this at home!

pimp-a-lot bear said...

indeed supercool!

I wonder how cold this sample is. he /she is holding the bottle with his /her bare hands.

cybrbeast said...

The text at the youtube page says:
"In this installment we see supercooled water to -21C / -6F and pour it our into a bowl. It pours out as a liquid and turns to slush, forming ropelike peaks."
But I find this hard to believe. -21C should turn into very solid ice, not a slush?
I'd say it was only a few degrees below zero.

pimp-a-lot bear said...

I totally agree! It doesn't look like -21 degrees Celcius.