Robert Walker, 85; Physicist Worked on the Manhattan Project

Robert Walker, 85, a retired Caltech physics professor who worked on the Manhattan Project, died of a suspected heart attack Wednesday at his home near Tesuque, N.M.

A native of St. Louis with a bachelor’s degree from the University of Chicago, Walker was a doctoral student at Cornell University when he joined the effort to produce the atomic bomb. He worked at the Los Alamos and University of Chicago laboratories of the Manhattan Project, building pressure gauges to measure the size of the blasts.

Walker was on the Caltech faculty from 1949 until his retirement in 1981, specializing in experimental high-energy physics and working on the university’s synchrotron. He was the principal investigator under Caltech’s contract with the Department of Energy and its predecessor agencies to do experimental and theoretical research in elementary particle physics.

The physicist, working with Jon Mathews, co-wrote the textbook “Mathematical Methods of Physics.” Walker spent his retirement years building harpsichords.