Michael Riordan is an Adjunct Professor of Physics at University of California Santa Cruz. He is also Assistant to the Director at the Stanford Linear Accelerator Center. After earning his Ph.D. from the Massachusetts Institute of Technology in 1973, he researched particle physics at Massachusetts Institute of Technology and University of Rochester. Riordan began researching the history of physics in the 1980s. He has written or co-authored books on the discovery of quarks, on dark matter, and on the invention of the transistor. In 2002, he received the American Institute of Physics Gemant Award.