# Superfluid Fountain

I was wondering how a super fluid fountain can flow indefinitely without violating energy conservation.

• At any temperature below the lambda point (2.2K) liquid helium is a mixture of a superfluid and a normal fluid. The superfluid fraction goes to zero as $T\to T_c$. If you set up a temperature gradient, then the normal fluid flows to low T, and the superfluid flows to high T. This is why the superfluid flows into the heated pipe. The seal ensures that the normal fluid cannot get out, and you get the fountain effect. – Thomas Jun 16 '15 at 18:44