Naked Science Forum
Non Life Sciences => Technology => Topic started by: Karsten on 09/01/2009 00:13:15
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Another question I have been carrying with me far too long. I am glad to have found you folks.
I believe there are several theories out there in regard to what makes an ice skate glide. All rely on a thin layer of water. Can it be so cold that this does not work any longer? Can a skate be too wide/long for certain temperatures to inhibit skating or at least not allow skating as fast as with another skate? Is really cold ice slower? Is really, really, really cold ice unskateable with normal skates?
Karsten
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I have my opinion on this but.......
Why not make some ice in the freezer at -20 C and experiment. Use a shallow tray and see how a smooth metal object(also frozen down to -20 OR NOT or even heated to various temps) glides and see what happens as the ice warms up. Might be handy to have a few 'sliders' at different temps and more than one tray of ice.
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i would think if the ice were too cold the skate may not be able to cut in enough to get a grip and glide ..properly.... Now I really no nothing of the temp..but when you watch olympic ice skaters the ice is hard but also soft enough that you see some of the icshavings skater behind them and you see the trails quite easily.. now those blades are hard and sharp.. so the do cut in some!
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I expect there is an effect, but the pressure per unit area on an ice skate is quite large and will probably melt the iceimmediately under the blade. I am not a good skater, but did skate on an open-air rink in Russia in below -10C. Below this it just gets too cold (below -20C say) and you don't actually want to be out in it, skating or not.
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I was one day skating in Inzell, Austria on the speed skating rink and could SEE the effects of the skate on the ice. A skater was skating in front of me and when we were heading into the sun I could see a thin line of water shimmering right behind the skate. A few feet later it disappeared without trace. It had frozen again. This is something you can only witness with speed skates. The blade has a rectangular cross-section and they do not dig in unless they are put on edge (unlike hockey and figure skates which are hollow ground and dig in no matter which angle the blade is set on the ice). Speed skates do not damage the ice very much. As a matter of fact, that one day there were about 50 speed skaters on the oval and the ice looked like new even after one hour of skating until ONE person with hockey skates got lost and skated around the oval ONCE. It looked like a tank had gone through. The secret to the speed of speed skates seems to be that they don't dig in at all when set straight. They don't track like other skates. They glide on water and you can slide sideways easily if the skate is set perpendicular on the ice. But yes, for turns they need to dig in a bit and on colder days that seems to work less well. At least at the pathetic speeds I was able to reach.
I began wondering that day in Inzell: Asides from it being wicked uncomfortable to skate at really, really low temperatures, what happens when it gets so cold that the water does not melt anymore under a skate, and what temperatures are we talking about? I don't think that -20 is enough. Colder ice is considered "faster" by some people. Colder meaning - 10 rather than -5. But what if it is - 40 or colder? While it occasionally drops this low here, I am not up for an experiment. Not curious enough I guess. I want to know from others. When does it stop getting "faster" (however that is determined)? What is the ideal temperature for ice for breaking speed skating records for long-distance?
Karsten