In 1968-69, commuting between MIT and California, he conducted experiments with Henry W. Kendall and Richard E. Taylor at the Stanford Linear Accelerator Center which gave the first experimental evidence that protons had an internal structure, later known to be quarks. For this, Friedman, Kendall and Taylor shared the 1990 Nobel Prize in Physics. He is an Institute Professor at the Massachusetts Institute of Technology. Friedman is also a member of the Board of Sponsors of the Bulletin of the Atomic Scientists.