"It cries, because it doesn't know what is it all for..."

Helium gas is great fun at parties. Anyone can do the Donald Duck voice.

But at a temperature of -271C, helium undergoes a strange transformation, turning into helium II, a "superfluid".

If ordinary helium were a light beam, then helium II would be a laser. The helium atoms "line up" in a single quantum state, eliminating all viscosity. It can therefore flow through the smallest holes.

Even odder, it will not stay inside its vessel. It climbs the side of the jar, and "tears" of helium II flow down the outside.

This video of helium II experiments is in Polish, with rather off-beat English subtitles. It concludes:

"It cries, because it doesn't know what is it all for...".

For some reason, I find this strangely moving . I don't know why.