Place the disk with the narrow edge on the glass surface. If you now turn the disk on the glass, it loses almost no energy through friction. On the contrary: it even rotates faster from second to second. In the end, it buzzes and only stops with a bang after about two minutes.
Further viewsof the exhibit "Euler's disk"
Further informationson the exhibit "Euler's disk"
With ordinary coins, the turning pleasure is unfortunately short-lived until the fall. But here we have a thick, large stainless steel disk with rounded edges on a hard glass plate. Its surface is strongly polished so that it offers almost no resistance. The glass plate also has a lower resistivity than, for example, a wooden table top.