Since the 1954 Castle Bravo thermonuclear weapon test demonstrated the feasibility of making arbitrarily large nuclear devices which could cover vast areas with radioactive fallout by rendering anything around them intensely radioactive , nuclear weapons theorists such as Leo Szilard conceived of a doomsday machine , a massive thermonuclear device surrounded by hundreds of tons of cobalt which , when detonated , would create massive amounts of Cobalt-60 , rendering most of the Earth too radioactive to support life . RAND strategist Herman Kahn postulated that Soviet or US nuclear decision makers might choose to build a doomsday machine that would consist of a computer linked to a stockpile of hydrogen bombs , programmed to detonate them all and bathe the planet in nuclear fallout at the signal of an impending nuclear attack from another nation
Castle Bravo
Castle Bravo
Doomsday device