David Lee was born on Jan. 20, 1931, in Rye, N.Y. He graduated from Rye High School in 1948 and earned a bachelor's degree from Harvard University in 1952. Between 1952 and 1954 he served in the United States Army.

Within his first year out of the Army, Lee completed a master's degree in physics from the University of Connecticut. Four years later, while completing a Ph.D. in physics at Yale, he was recruited into Cornell University's new low-temperature physics laboratory.

At that time, scientists at Cornell University were racing with scientists at the University of California at San Diego to discover the temperature at which helium-3 becomes a nuclear magnet. In the fall of 1971 Lee and his two partners in the lab, Douglas Osheroff and Robert Richardson, thought they had discovered the point at which this phase transition of solid helium-3 occurred, and they published an article in Nature describing their findings. On closer observation by Osheroff, however, they realized that they had instead stumbled upon something entirely different: at extremely low temperatures, helium-3 becomes a superfluid.

Superfluids are very special forms of liquids which have no inner friction, or viscosity. At the time of Lee, Osheroff, and Richardson's discovery, it was known that helium-4 was a superfluid at low temperatures, but no one had yet been able to make a superfluid out of helium-3. It was at only 0.002 degree above absolute zero that superfluidity in helium-3 was obtained.

The scientists corrected their earlier Nature article and conducted more experiments that showed them that superfluid helium-3 was a very unusual substance. It had magnetic properties and a different structure than had been expected. Perhaps most importantly, superfluid helium-3 seemed to exhibit quantum properties, which allowed the researchers to observe subatomic effects on a macroscopic scale. In addition, they theorized that the superfluid might hold the key to hypothetical objects called cosmic strings, which were thought to have been responsible for the condensation of matter into galaxies during the creation of the universe. On a more practical level, superfluid helium-3 helped in the development of magnetic resonance imaging, a noninvasive procedure used to see into the body.

Lee, Osheroff, and Richardson won the Simon Memorial Prize of the British Physical Society in 1976 and the Buckley Prize of the American Physical Society in 1981 for their discovery of superfluid helium-3. Lee also won two separate Guggenheim fellowships. He was elected a fellow of the American Academy of Arts and Sciences in 1990 and a member of the National Academy of Sciences in 1991.

In 1996, Lee and his two 1971 teammates won the Nobel prize in physics. They had been nominated for the award by numerous scientists for more than 15 years.