With a temperature below -268 degrees Celsius, liquid helium keeps MRI machines and particle accelerators properly cooled (yay!). Take liquid helium's temperature even lower than that, however, and things start to get a little less practical -- and a lot more weird.
At lower and lower temperatures, greater and greater fractions of liquid helium become superfluid. Superfluid helium can do some seemingly impossible things, like climb up the walls of containers or leak through pores that are too small for normal liquid helium to pass through. At this point, superfluid helium is demonstrating the effects of quantum physics, which makes it especially tantalizing to physicists. Now, in a new study, an international team of physicists has taken images of tiny droplets of superfluid helium, finding that even very small amounts of superfluid helium act unusually.