112. Shortly after Serber started the short course, Oppenheimer took him aside and suggested that they should not be using the term “bomb.” There were too many workers milling around, and they could pick up the word and leak it outside. It was hard not to mention bomb, because that was what they were working on, but Serber substituted the word “gadget” in his lectures. Thus began the series of code-names describing the works of Los Alamos.