Robert C. Richardson
The Nobel Prize in Physics 1996
Born: 26 June 1937, Washington, D.C., USA
Died: 19 February 2013, Ithaca, NY, USA
Affiliation at the time of the award: Cornell University, Ithaca, NY, USA
Prize motivation: “for their discovery of superfluidity in helium-3”
Prize share: 1/3
When certain substances are cooled to extremely low temperatures, they become superfluid, flowing without any friction. This applies to helium-4, the most common form of helium, but for a long time the superfluidity of helium-3 was in dispute. The different types of helium are described by different quantum mechanical rules and equations under which helium-4 has a whole-number spin while helium-3 has a half-number spin. In 1972 Robert Richardson, David Lee, and Douglas Osheroff verified that helium-3 also becomes superfluid at extremely low temperatures.