The Doomsday Clock is a symbolic clockface maintained since 1947 by the Board of Directors of the Bulletin of the Atomic Scientists at the University of Chicago. It uses the analogy of the human race being at a time that is “minutes to midnight” where midnight represents destruction by nuclear war. Since its introduction, the clock has appeared on the cover of each issue of the Bulletin of the Atomic Scientists. The first representation of the clock was produced in 1947, when artist Martyl Langsdorf, the wife of physicist, Alexander Langsdorf, Jr., who worked on the Manhattan Project, was asked by magazine cofounder Hyman Goldsmith to design a cover for the June issue.
The number of minutes before midnight, a measure of the degree of nuclear, environmental, and technological threats, is updated periodically. The clock is currently set to five minutes to midnight, having been advanced by two minutes on January 17, 200
The clock was started at seven minutes to midnight during the Cold War in 1947, and has subsequently been advanced or rewound at intervals, depending on the state of the world and the prospects for nuclear war. Its setting is relatively arbitrary, set by the Board of Directors at the Bulletin of the Atomic Scientists in response to global affairs. The setting of the clock has not always been fast enough to cope with the speed of global events, either; one of the closest periods to nuclear war, the Cuban Missile Crisis in 1962, reached its head and resolution in a number of weeks, and the clock either could not be changed or was not changed to reflect any of this at the time. Nevertheless, the changing of the clock usually does provoke attention.
The official announcement of the most recent change to five minutes to midnight took place on January 17, 2007 at 14:30 hours GMT.