Thin Man (nuclear bomb) Thin Man (nuclear bomb) "Thin Man" was the code name for a proposed plutonium gun-type nuclear bomb using plutonium-239 which the United States was developing during the Manhattan Project. They aborted its development when they discovered that the spontaneous fission rate of their nuclear reactor-bred plutonium was too high for use in a gun-type design, due to the high concentration of the isotope plutonium-240. In 1942, prior to the Army taking over wartime atomic research, Robert Oppenheimer held conferences in Chicago in June and Berkeley, California, in July at which various engineers and physicists discussed nuclear bomb design issues. A
Cosmic bomb (phrase) uses the phrase several times in his 1973 novel "Gravity's Rainbow", which is set roughly in the period during which the term was current. The term rapidly fell into disuse as applied to weaponry, soon yielding to "atomic bomb" (which, in turn, was eventually to yield to "nuclear weapon"). In equestrian circles, it survived for many years in the racing career of a thoroughbred named "Cosmic Bomb" and in the pedigrees of horses he sired. More recently, the term has been applied to powerful energy surges from celestial objects known as magnetars. Cosmic bomb (phrase) "Cosmic bomb" was another name