These initial worries proved unfounded, as Oppenheimer played a crucial role in catalyzing this concentration of genius. An ascetic polymath who was equally comfortable discussing sonnets as he was cyclotrons, Oppenheimer had been put in charge at Los Alamos because he possessed expertise and charisma. In one case, the physicist Robert Serber, after hearing a single lecture from Oppenheimer, immediately left his role at Princeton to join Oppenheimer at Berkeley. When Oppenheimer relocated from Berkeley to Los Alamos, Serber followed.