Osheroff, Douglas Dean (1945-…), is an American physicist who specializes in ultralow temperature physics. In 1972, he was one of a team of physicists who discovered that helium-3, a rare type of helium, becomes a superfluid when it is extremely cold. A superfluid is an exotic state of matter that acts like a liquid that flows absolutely freely. The team had to cool the helium-3 to about two-thousandths of a degree Celsius above absolute zero. Absolute zero is the lowest temperature that scientists believe is possible. For this discovery, Osheroff shared the 1996 Nobel prize for physics with colleagues David Lee and Robert Richardson.
Osheroff grew up in Aberdeen, a small logging town in Washington, and was interested in scientific gadgets from a very young age. Osheroff earned a bachelor’s degree in physics at the California Institute of Technology, (Caltech). In his final year, he worked in the department’s low-temperature laboratory. He then went to Cornell University in New York to work for his master’s and doctor’s degrees. During his first year at Cornell, he worked with David Lee, head of the low temperature laboratory.
In November 1971, the laboratory team was experimenting with helium-3 cooled so close to absolute zero that it was partly solid and partly liquid. Helium-3 is a type of helium in which the nucleus of the atom consists of two protons and one neutron, instead of the usual two protons and two neutrons. The material behaved strangely. In one experiment, the pressure was steadily changed over time. Osheroff noticed small jumps in the graph of pressure. During 1972, the team established that the jumps in pressure were due to changes in the helium-3, marking its change to a superfluid. The team had discovered the first of three superfluid phases of liquid helium-3. Because the atoms in superfluid helium-3 lose all their randomness and move in a coordinated manner at a temperature only fractionally above absolute zero, the fluid is able to flow up and out of an open container. Although its behavior was complex, they were able to account for it in terms of a theory of physics called the BCS theory. The theory explains superconductivity (the loss of electrical resistance by some materials when cooled to extremly low temperatures).
Osheroff continued his studies of superfluid helium-3 when he moved to Bell Laboratories, then the research department of the Bell Telephone Company, in Murray Hill, New Jersey, in 1972. He found the behavior of helium-3 to be much more complex than that of helium-4, which was already known. He went on to study the structure of solid helium-3. Osheroff continued in the same areas of research when he moved to Stanford University in 1987. He served as chair of the Stanford physics department from 1993 to 1996.
In March 2003, Osheroff was appointed to a United States federal board to investigate the breakup of the space shuttle Columbia. On Feb. 1, 2003, the shuttle had broken apart over Texas as it reentered Earth’s atmosphere. All seven crew members died.
