Arthur Jeffrey Dempster

Arthur Jeffrey Dempster (August 14, 1886 - March 11, 1950) was a Canadian-American physicist best known for his work in mass spectrometry and his discovery of the uranium isotope U. Dempster was born in Toronto, Canada. He received his bachelor's and master's degrees at the University of Toronto in 1909 and 1910, respectively. He travelled to study in Germany, and then left at the outset of World War I for the United States; there he received his Ph.D. in physics at the University of Chicago. Dempster then joined the physics faculty there in 1916, teaching and researching until his death in 1950, interrupted only during World War II, when he worked on the secret Manhattan Project to develop the world's first nuclear weapons. From 1943...