The notion of using a fission weapon to ignite a process of nuclear fusion can be dated back to September 1941, when it was first proposed by Enrico Fermi to his colleague Edward Teller during a discussion at Columbia University. At the first major theoretical conference on the development of an atomic bomb hosted by J. Robert Oppenheimer at the University of California, Berkeley in the summer of 1942, Teller directed the majority of the discussion towards this idea of a "Super" bomb.