Theodore Lyman (English pronunciation: /ˈlaɪmən/; November 23, 1874 – October 11, 1954) was a U.S. physicist and spectroscopist, born in Boston. He graduated from Harvard in 1897, from which he also received his Ph.D. in 1900. He became an assistant professor in physics at Harvard, where he remained, becoming full professor in 1917, and where he was also director of the Jefferson Physical Laboratory (1908–17). Dr.