National Museum of Nuclear Science & History
Jay Wechsler enlisted in the Army in 1943 and spent several months at Oak Ridge working as an Army construction engineer, In the winter of 1943, he was suddenly transferred to Los Alamos, where he began working directly with Otto Frisch.
Dr. Karl Larsen worked at Massachusetts Institute of Technology during the Manahattan Project. While there, he conducted heavy-water research by spectrum analysis, which was one of the prerequisites to the early atomic bombs.