Nuclear Fission

“Now I am become Death, the destroyer of worlds.” — J. Robert Oppenheimer, quoting the Bhagavad Gita

The discovery that splitting an atomic nucleus could release vast quantities of energy changed the course of human history. Nuclear fission offered the promise of limitless energy and the terror of total annihilation — twin legacies that continue to shape global politics.

Unlocks

• Wonders: Manhattan Project

Historical Background

Nuclear fission was discovered in 1938 by German chemists Otto Hahn and Fritz Strassmann, with the theoretical explanation provided by Lise Meitner and Otto Frisch. The realisation that a chain reaction of splitting uranium atoms could release enormous energy — and that Nazi Germany might be pursuing such a weapon — prompted Albert Einstein’s famous letter to President Roosevelt in 1939, warning of the military implications.

The result was the Manhattan Project, the largest scientific undertaking in history up to that point. Under the direction of J. Robert Oppenheimer, a team of physicists and engineers at Los Alamos, New Mexico, designed and built the first atomic bombs. The Trinity test on 16 July 1945 confirmed the weapon’s terrifying power, and the bombings of Hiroshima and Nagasaki the following month killed over 200,000 people and brought about Japan’s surrender. The nuclear age had begun. The subsequent arms race between the United States and the Soviet Union defined the Cold War, and the doctrine of mutually assured destruction created a paradoxical peace — the most destructive weapons ever devised may have prevented a third world war.