Digsy Posted June 21, 2007 Share Posted June 21, 2007 Fair enough, I get funny things go on with my thermal testing at work so could have believed it was true. On a more interesting note, Digs, have you added that 't' into your sig? I'm sure it wasn't our lord and saviour mentioned in there before!! Hey - what's more interesting than physics? I added the "t" myself - after Ian C hillariously pointed out that I accidentally called CW "Christ" in a post a few weeks ago. Quote Link to comment Share on other sites More sharing options...
paul_y3k Posted June 21, 2007 Share Posted June 21, 2007 the hot water thing .... I know that those little kart thingys they use at ice rinks use hot not cold water ? Quote Link to comment Share on other sites More sharing options...
michael Posted June 21, 2007 Author Share Posted June 21, 2007 the hot water thing .... I know that those little kart thingys they use at ice rinks use hot not cold water ? A Zamboni, you are correct, apparently warmer water gives a smoother surface. Quote Link to comment Share on other sites More sharing options...
chilli Posted June 21, 2007 Share Posted June 21, 2007 I think there might be something in the water thing tbh but it's in very specific circumstances. I wonder if it would happen with pure water... http://adsabs.harvard.edu/abs/1995AmJPh..63..882A "Temperature measurements taken near vessel walls show that initially hot water may well begin to freeze quicker than cold. This is not, as previously surmised, due to the cooling history of the water (e.g., air expulsion during heating). Rather, supercooling virtually always takes place. On those occasions where the cold water supercools sufficiently more than the hot the Mpemba scenario is the following: The hot water supercools, but only slightly, before spontaneously freezing. Superficially it looks completely frozen. The cold water (in larger volume than that of the hot sample) supercools to a lower local temperature than the hot before it spontaneously freezes. This scenario can occur more often for ambient cooling temperatures between -6 °C and -12 °C." it would appear the hot water may freeze first, but at a higher temperature. After all the states of matter, solid, liquid and gas form at particular temperatures only with everything else is equal, and temperature itself is only a statistical measurement Quote Link to comment Share on other sites More sharing options...
Thorin Posted June 21, 2007 Share Posted June 21, 2007 What temperature does water freeze at then? http://f0rked.com/articles/supercooling Quote Link to comment Share on other sites More sharing options...
chilli Posted June 21, 2007 Share Posted June 21, 2007 What temperature does water freeze at then? http://f0rked.com/articles/supercooling yes exactly, quite amazing isn't it. The state transition from liquid to solid is like the formation of a crystal, needs something to get it started, to seed it. Quote Link to comment Share on other sites More sharing options...
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