Doomsday device

A doomsday device is a hypothetical construction — usually a weapon — which could destroy all life on the Earth, or destroy the Earth itself (bringing "doomsday", a term used for the end of planet Earth).

Doomsday devices have been present in literature and art especially in the 20th century, when advances in science and technology made world destruction (or at least the eradication of all human life) a credible scenario. Many classics in the genre of science fiction take up the theme in this respect.

After the advent of nuclear weapons, especially hydrogen bombs, they have usually been the dominant components of doomsday devices. RAND strategist Herman Kahn, collaborating with risk analyst Ian Harold Brown, proposed a "Doomsday Machine" in the 1950s which 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. Such a scheme, fictional as it was, epitomized for many the extremes of the suicidal logic behind the strategy of mutually assured destruction, and it was famously parodied in the Stanley Kubrick film from 1964, Dr. Strangelove or: How I Learned to Stop Worrying and Love the Bomb. It is also a main topic of the movie Beneath the Planet of the Apes, in parallel with the species extermination theme. Most such models either rely on the fact that hydrogen bombs can be made arbitrarily large (see Teller–Ulam design) or that they can be "salted" with materials designed to create long-lasting and hazardous fallout (e.g.; a cobalt bomb).

Other fictional devices of this nature are made by aliens to kill off mankind, or all life on earth, for various reasons, ranging from 'saving' the earth from mankind's destructive nature to invasion of the planet to simply them being a genocidal kind.