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Q & A: Supercooled Water

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Most recent answer: 01/27/2011
My husband went to a house that had been froze up since the middle of December. Every thing in this house was froze. Pipes and toilet and any thing that could freeze was froze. Sitting on the table was an unopened bottle of water which was still in liquid form .How can water in pipes and in the toilet freeze and not this bottle of unopened water?
- Nadine Shampine (age 63)


In order to freeze into ice, the water has to form an ordered crystal lattice structure, which it ordinarily does not do unless it has something to freeze "around," often called a nucleus or seed crystal. Ordinary water has lots of impurities in it like dust around which it can freeze, so the water in your ice trays has no problem. However, an unopened (which is the key quality, here) bottle of water contains little to no particles that are large enough around which the water can form a crystal (the bottled water was probably filtered to make it this pure). In fact, this is the entire basis around the science of cloud seeding, the process of "inspiring" clouds to rain by pumping dust into them. When clouds contain high amounts of supercooled water, we can use dry ice (silver iodide is commonly used as well) to "seed" the clouds with crystals in order for the water to cling to them, and then fall as snow, then melt again into rain.

There are some really cool videos on youtube demonstrating this supercooling effect, like this one:

Others have asked questions like yours, so here's a link to the answers to their questions:,


(published on 01/27/2011)

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