Paradoxes of superfluid rotation

The phenomenon of superfluidity (as well as the related phenomenon of superconductivity) is of quantum nature and as such looks paradoxical from the standpoint of both classical physics and common sense. Suffice it to say that these phenomena imply the ability to flow without exhibiting viscosity or resistance (for this reason, for example, the circulation of a superconducting current within a closed circuit in the absence of external sources would last without damping for a period much in excess of the age of the Universe). At the same time, a number of unusual and quite unexpected features appear to be intrinsic to specific events of superfluid physics. Some of them will be considered in the present study.