Friedman, Jerome I (1930– )

US physicist who, with Henry Way Kendall and Richard E Taylor, was awarded the Nobel Prize for Physics in 1990 for their pioneering investigations into high-energy electrons colliding with protons and neutrons. These were important in developing the quark model of particle physics.

In 1970, Friedman, Taylor, and Kendall led a team working at the Stanford Linear Accelerator Center (SLAC) in California. Their experiments involved bombarding protons (and later neutrons) with high-energy electrons. They knew from earlier experiments that the proton had a small but finite volume and believed that high-energy electrons would suffer only small deflections as they passed through the protons. However they found that the electrons were sometimes scattered through large angles inside the proton.

This result was interpreted by theorists James D Bjorken and Richard P Feynman. They suggested that the electrons were hitting hard pointlike objects inside the proton. These objects were soon shown to be quarks, particles whose existence had been proposed independently by Murray Gell-Mann and George Zweig in 1964. Today quarks are recognized as amongst the most fundamental building blocks of matter.

Friedman was born in Chicago, Illinois, USA, and educated at the University of Chicago, where he completed his doctorate in 1956. In 1957 he joined the High-Energy Physics laboratory at Stanford University, California, as a research associate and learned the techniques used in electron scattering experiments. At Stanford he began his long association with Henry Kendall and became acquainted with Richard Taylor. In 1960 he went to the physics department of the Massachusetts Insitute of Technology (MIT). Kendall joined his research group in 1961. In 1963 Friedman and Kendall began a collaboration with Taylor and others at Stanford to develop electron scattering facilities at the Stanford Linear Accelerator Center. In 1980 he became director of the laboratory for nuclear science at MIT and then served as head of the physics department 1983–88, when he returned to full-time teaching and research.