Anybody else might shrug off these ice spikes as a meaningless hiccup in the preparation of a frosty beverage, but not Lenore and Windell at Evil Mad Scientist Laboratories!
Snowcrystals.com has a fairly detailed explanation of how these things form, and it's documented elsewhere as well. (Roughly speaking, supercooled water is pushed up through a hole, somewhat like magma forming a volcano.) It's relatively easy to form these in your freezer if you start with distilled water, but occasionally-- as in our case --they do occur with regular tap water.
"Compressed avi movie of a controlled ice spike growth experiment. The frame rate is about 50X normal time. The air temperature was -11.5C and the grid squares are 1 mm. The colours that appear on the ice surface toward the end of the video are potassium permanganate crystals sprinkled onto the ice. It looks as if there is evidence of a liquid layer on the surface, suggesting (though not conclusively) that there is some overflow at the spike orifice near the end of its growth. Movie made in the ice lab of Edward Lozowski at the University of Alberta. Movie by Lesley Hill, Russ Sampson and Edward Lozowski, with technical help by Kenny Lozowski. "
Actually, it depends on your freezer. In frost-free freezers, hot water won't make a difference. But if you're placing it on a large bed of frost, the hot water will serve to melt the frost and bed the tray down into the ice, providing a significant increase in contact area and resulting improvement of the thermal conductivity. Hence, it cools faster!
I've seen the exact opposite of this whilst casting molten aluminium into ingots. Since aluminium shrinks as it cools (unlike ice which expands) you get a sinkhole in the ingot.
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Why didn't they do a time lapse?
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Because they didn't expect this to happen!
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I looked for one on the web but couldn't find anything. Would be really cool to see one form.
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Very interesting. I probably would have not even thought twice about!
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Here's some video-
http://www.physics.utoronto.ca/~smorris/edl/icespikes/cube.mov
in quicktime movie format.
http://www.physics.utoronto.ca/~smorris/edl/icespikes/Lozowski_icespike.avi
another in compressed .avi format.
"Compressed avi movie of a controlled ice spike growth experiment. The frame rate is about 50X normal time. The air temperature was -11.5C and the grid squares are 1 mm. The colours that appear on the ice surface toward the end of the video are potassium permanganate crystals sprinkled onto the ice. It looks as if there is evidence of a liquid layer on the surface, suggesting (though not conclusively) that there is some overflow at the spike orifice near the end of its growth. Movie made in the ice lab of Edward Lozowski at the University of Alberta. Movie by Lesley Hill, Russ Sampson and Edward Lozowski, with technical help by Kenny Lozowski. "
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Thanks Volkemon, that second video is great.
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... This happened a couple times in my dorm fridge... Never could figure out how... Thanks for the post... I feel more informed!
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I can get them regularly by using hot tap water.
http://www.flickr.com/photos/andrew/sets/131633/
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Please tell me you're not one of those people putting hot tap water in your trays because you think it freezes faster....
Physics people...colder water is closer to freezing than hot water. Use cold water if you want quick cubes.
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Actually, it depends on your freezer. In frost-free freezers, hot water won't make a difference. But if you're placing it on a large bed of frost, the hot water will serve to melt the frost and bed the tray down into the ice, providing a significant increase in contact area and resulting improvement of the thermal conductivity. Hence, it cools faster!
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dave read this: http://www.math.ucr.edu/home/baez/physics/General/hot_water.html
I suspect he was experimenting, not for practical purposes..
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I've seen the exact opposite of this whilst casting molten aluminium into ingots. Since aluminium shrinks as it cools (unlike ice which expands) you get a sinkhole in the ingot.
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