There a few interesting phenomena that occur once we get to near 0 K temperature. One of these interesting phenomena is superfluid. A popular example of a superfluid material is liquid helium near 0K. Both isotopes of helium 3He and 4He can form super fluid at very low temperatures. Superfluidity is characterized by having 0 or almost zero viscosity, meaning that the fluid can move upon a surface without losing kinetic energy. A superfluid vortex would last forever.
Liquid helium earns superfluid properties once its temperature goes under a temperature called the lambda point. These properties were first discovered in 1937 by Pytor Kapitsa, who published a paper about it in January 1938. While he was attempting to measure the thermal conductivity of liquid helium, he was running the liquid through a gap between two discs and measured the flow rate of the liquid. He noticed that the flow increased rapidly after going below a certain temperature. The flow rate of the superfluid helium also does not change as a function of pressure, and no viscosity formula at the time was able to give a tangible value for its viscosity.
There is a behaviour that is observed in superfluids that has yet to be adequately explained. As seen in the video if you have a superfluid in a cup the fluid can flow up against gravity and climb up the wall of the glass. The extremely low viscosity helps explaining the phenomenon, but still doesn’t help explaining it fully. An interesting thought that emerges after observing this behavior is that if we have a superfluid fountain it would flow forever without the need of external forces.
Superfluidity is just one of the interesting properties that can be observed near 0 K, having 0 viscosity allows for a lot of crazy behaviors such as: an infinitely flowing fountain, and a vortex that keeps on rotating forever. This property, along with other properties like superconductivity, shows that with just manipulating temperature a whole new range of possibilities open up.
— Moayad
