The “Doomsday Clock” is not really a timepiece. It is a metaphor marking civilization’s proximity to a self-induced conclusion adopted by scientists at the dawn of the Cold War. In 1947 the Bulletin of Atomic Scientists, the clock’s makers, set the time at 11:53 p.m., reflecting the danger of nuclear weapons, the sole province, at the time, of the United States. By 1953 with the introduction of an atomic bomb by the Soviet Union and testing of more powerful thermonuclear weapons by both America and Russia, the clock nudged to just two minutes away from humanity’s midnight.