A droplet of helium, made to float in a vacuum
Harris Lab, Yale University.
A drop of liquid helium cooled to an extremely low temperature can be made to float in a vacuum for an indefinitely long time. In this state, it could serve as a powerful mini-laboratory for fundamental physics.
At -269°C, liquid helium is already strangely cold for a liquid, but when it is approximately 2 degrees colder it becomes even stranger. At this temperature, quantum effects make its viscosity vanish and turn it into a superfluid. Charles Brown at …