I was interested in understanding the behavior of the disk particularly in vacuum and in a superfluid.
I Know that Euler's disk in vacuum runs slightly longer than usual and that most of the dissipation of energy is due to rolling friction. Suppose it was suspended in a superfluid. since they have (If I understand correctly) 0 viscosity, is running Euler's disk in a superfluid the same thing as running it in a vacuum?
Furthermore, what would be an example of an extremely smooth surface? IE is there a limit to how smooth you can make surfaces?