ITHACA, N.Y. (AP) — Robert C. Richardson, a Cornell University professor who shared a Nobel Prize for a key discovery in experimental physics, has died. He was 75.

Cornell says Richardson died Tuesday in Ithaca from complications of a heart attack.

Richardson and fellow Cornell researchers David Lee and Douglas Osheroff were awarded the Nobel in 1996 for their 1971 work on low-temperature physics involving the isotope helium-3. The work has contributed to research ranging from microscopic matter to astrophysics.

Richardson was born in Washington, D.C., earned his bachelors and masters degrees in physics at Virginia Polytechnic Institute and a doctorate at Duke University, where he studied with the physicist Horst Meyer and later served as a trustee.

He joined Cornell in 1968 and was named Floyd R. Newman Professor of Physics in 1987.