Analysis of information sources in references of the Wikipedia article "Ice skating" in English language version.
Most studies so far were performed at temperatures well above 240 K (−33 °C) and report the presence of a liquid or quasiliquid layer on ice. Those studies that went below this temperature do not suggest a liquid-like layer.
Professor Somorjai's findings indicate that ice itself is slippery. You don't need to melt the ice to skate on it, or need a layer of water as a lubricant to help slide along the ice... the "quasi-fluid" or "water-like" layer exists on the surface of the ice and may be thicker or thinner depending on temperature. At about 250 degrees below zero Fahrenheit (−157 °C), the ice has a slippery layer one molecule thick. As the ice is warmed, the number of these slippery layers increases.
Most studies so far were performed at temperatures well above 240 K (−33 °C) and report the presence of a liquid or quasiliquid layer on ice. Those studies that went below this temperature do not suggest a liquid-like layer.
It used to be thought ... that the reason skaters can glide gracefully across the ice is because the pressure they exert on the sharp blades creates a thin layer of liquid on top of the ice... More recent research has shown, though, that this property isn't why skaters can slide on the ice... It turns out that at the very surface of the ice, water molecules exist in a state somewhere between a pure liquid and a pure solid. It's not exactly water – but it's like water. The atoms in this layer are 100,000 times more mobile than the atoms [deeper] in the ice, but they're still 25 times less mobile than atoms in water. So it's like proto-water, and that's what we're really skimming on.
It used to be thought ... that the reason skaters can glide gracefully across the ice is because the pressure they exert on the sharp blades creates a thin layer of liquid on top of the ice... More recent research has shown, though, that this property isn't why skaters can slide on the ice... It turns out that at the very surface of the ice, water molecules exist in a state somewhere between a pure liquid and a pure solid. It's not exactly water – but it's like water. The atoms in this layer are 100,000 times more mobile than the atoms [deeper] in the ice, but they're still 25 times less mobile than atoms in water. So it's like proto-water, and that's what we're really skimming on.
Professor Somorjai's findings indicate that ice itself is slippery. You don't need to melt the ice to skate on it, or need a layer of water as a lubricant to help slide along the ice... the "quasi-fluid" or "water-like" layer exists on the surface of the ice and may be thicker or thinner depending on temperature. At about 250 degrees below zero Fahrenheit (−157 °C), the ice has a slippery layer one molecule thick. As the ice is warmed, the number of these slippery layers increases.