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Registered Member #193
Joined: Fri Feb 17 2006, 07:04AM
Location: sheffield
Posts: 1022
The idea of ice melting under skaters is a myth. The effect of pressure on freezing point is only about a hundredth of a degree per atmosphere. With something like a couple of hundred pounds of skater on a blade a tenth of an inch thick and a foot long the melting point would only rise by about a quarter of a degree. So unless the ice was between 0 and -0.25 C to begin with it wouldn't melt. It's perfectly possible to skate at 20 below. At that temperature the ice would only melt if the pressure were something like 2000 atmospheres or 30000PSI. I dont think that skates would get anything like that pressure.
Registered Member #498
Joined: Sun Nov 19 2006, 06:00PM
Location: Bay Area
Posts: 19
Well, way back when (around the 30s or 40s), some scientist filled a 4-inch-thick bombshell with water, screwed on the cap, and left it outside in the snow for a night.
He came back in the morning and the thing had a nice neat crack all the way around.
Registered Member #27
Joined: Fri Feb 03 2006, 02:20AM
Location: Hyperborea
Posts: 2058
Some sports have a minimum width of 2.9 mm in the safety regulations and they work fine. A chair sledge has a much wider blade and it works fine too, both on ice and snow.
The rubbing action is probably much more important than the pressure itself.
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The molecular force of water expansion
