June 1: The Doomsday Clock

The Bulletin of Atomic Scientists, co-founded by physicist Hyman Goldsmith and botanist and biophysicist Eugene Rabinowitch in 1945, published its Doomsday Clock, with its hands set to seven minutes to midnight, for the first time on this date in 1947. The clock was meant to warn of the dangers of nuclear annihilation; it was moved one minute closer to midnight the following year after the first Soviet nuclear test. Now set at five minutes to midnight, the clock symbolizes additional threats to humankind such as climate change and dangerous emerging technologies. The Bulletin of Atomic Scientists has continued to publish through the years, with contributors who have included Albert Einstein, Léo Szilárd, J. Robert Oppenheimer, Harold Urey, and Max Born, among many other notable scientists. The decision to move the hands of the clock — which have been moved twenty times since its inception — is made each autumn by the Bulletin’s Science and Security Board at the Doomsday Clock Symposium, and announced each January. The closest it has been set to midnight is by two minutes in 1953, when both the U.S. and the USSR were conducting thermonuclear tests; the furthest was seventeen minutes in 1991, when the Strategic Arms Reduction Treaty was signed and the Soviet Union dissolved as a unified country. “The illusion that tens of thousands of nuclear weapons are a guarantor of national security has been stripped away.” —Bulletin of the Atomic Scientists, 1991