May 24, 2082, Neptune’s moon Triton: The hero of one of my novels, Nick, tries to move a block of ice weighing 80 kg (176 lbs). But it’s damn hard, even with Triton’s low force of gravity. “On Earth, the ice would slide because its bottom would melt due to the pressure, like under the blade of a skate, but it’s too cold for that here,” Nick thinks.
A mistake, a Swedish reader just wrote to me. The idea that ice skating works because ice melts under pressure and then forms a lubricating layer is old. Ice does in fact heat up under pressure, but not nearly enough or fast enough to melt and create a lubricating layer. My mistake: I read the idea somewhere and didn’t review it again for accuracy while I was writing.
There’s a lot more to it than just a lubricating layer. Ice skating is one of the rare everyday phenomena that have not been definitively explained yet by science. You already know, of course, that it works, and best results are given at a temperature of -7 °C, which is why the ice in sports arenas is kept at that temperature. But it also works at temperatures below -20 °C, where water no longer melts due to pressure.