I saw a video on youtube or somewhere which showed that Helium somewhere around 4-5 degrees near Subzero, becomes a supercritical fluid i.e. it has 0 viscosity. And the video showed that the liquid was coming out of the glass by climbing up the walls. I'm pretty surprised by this.. and some people said that this could be used to make perpetual motion machines, which, however I am totally against [I'd rather believe in a Flying Spaghetti Monster]. so, if the fluid is to climb by itself, it needs a force that counteracts gravity. And that force purely will act, as the glass or the container walls cease to apply any force on the fluid. As such, I think that the force is caused by inter-molecular repulsions. However, if we build something like a perpetual motion machine [not exactly perpetual], and the fluid continuously flows up and down. Then owing to work done by inner charges, the energy of the fluid must decrease after successive flows. In that case, the temperature of the fluid must decrease. If we continue to do it, maybe at a point, the temperature may near sub zero. We might be able to reach the lowest temperatures ever. What are your views on this?