6) Liquid Helium
Image VIA
Liquid helium has zero viscosity, it’s basically the opposite of treacle. If you freeze helium hundreds of degrees below zero it becomes a liquid, but not just any old liquid, it becomes a liquid that completely ignores gravity. It can flow up hill and produce weird perpetual, never ending fountains.
The fountain in the video below is caused by a temperature gradient, the liquid helium just flows against gravity because it’ does not care at all, it does what it likes. No one tells a superfluid what to do:
