It was 1945 and a group of young male scientists affiliated with elite universities across the United States greeted colleagues in the secure location. As director of the atomic bomb project, Oppenheimer had an exceedingly difficult challenge on which to focus his brilliant yet troubled mind, and although his security clearance was delayed due to his communist affiliations, project work did not pause. Indeed, Hempelmann's physics and mathematical knowledge appeared strikingly anemic, as he had found it necessary to stop his physics because he did not feel he had sufficient mathematical background to allow him to pursue his studies further. Beginning in World War II, US military officials arranged for a team of young scientists including Oppenheimer, Warren, Friedell, Kennedy, Hempelmann, Wahl, Stone, Langham, and Hamilton to conduct and oversee human radiation experiments in the effort to develop radiological weapons technology, and the groups' efforts would extend well into the Cold War.