In 1938, Russian physicist Pyotr Leonidovich Kapitsa discovered that helium-4 has almost no viscosity at temperatures near absolute zero, a phenomenon now called superfluidity. This phenomenon is related to Bose–Einstein condensation. In 1972, the same phenomenon was observed in helium-3, but at temperatures much closer to absolute zero, by American physicists Douglas D. Osheroff, David M. Lee, and Robert C. Richardson. The phenomenon in helium-3 is thought to be related to pairing of helium-3 fermions to make bosons, in analogy to Cooper pairs of electrons producing superconductivity.
In 1938 Russian physicist Pyotr Leonidovich Kapitsa discovered that helium-4 has almost no viscosity at temperatures near absolute zero a phenomenon now called superfluidity This phenomenon is related to Bose–Einstein condensation In 1972 the same phenomenon was observed in helium-3 but at temperatures much closer to absolute zero by American physicists Douglas D Osheroff David M Lee and Robert C Richardson The phenomenon in helium-3 is thought to be related to pairing of helium-3 fermions to make bosons in analogy to Cooper pairs of electrons producing superconductivity