A droplet of helium, made to drift in a vacuum
Harris Lab, Yale University.
A drop of liquid helium cooled to an especially low temperature can be made to drift in a vacuum for an indefinitely very long time. In this state, it may function a robust mini-laboratory for basic physics.
At -269°C, liquid helium is already unusually cold for a liquid, however when it’s roughly 2 levels colder it turns into even stranger. At this temperature, quantum results make its viscosity vanish and switch it right into a superfluid. Charles Brown at …