George Uhlenbeck, Hendrik Kramers, and Samuel Goudsmit around 1928 in Ann Arbor.
George Eugene Uhlenbeck (December 6, 1900 – October 31, 1988) was a Dutch/U.S. (Indonesian-born) physicist. He introduced the concept of electron spin, which posits that electrons rotate on an axis, with Samuel Abraham Goudsmit, for which they were awarded the Max Planck medal in 1964. Uhlenbeck was also awarded the Lorentz Medal in 1970 and Wolf Prize in Physics in 1979.
He was a student of Austrian physicist and mathematician Paul Ehrenfest.