He also made substantial contributions to gamma ray spectroscopy, leading to the use of radioactive tracers to locate tumors and other disorders. (He shared the prize with Rudolf Ludwig M??ssbauer of Germany.)en.wikipedia.org/wiki/Robert_Hofstadter1961 Charles H. Mason, founder of the Church of God in Christen.wikipedia.org/wiki/Charles_Harrison_Mason1998 Esther Rolle (b 1920) American actress of