atom-bombHungarian physicist Leó Szilárd was born on this date in 1898. After fleeing from Berlin to London as the Nazis came to power in 1933, Szilárd conceived and patented the idea of a nuclear chain reaction (he also patented, with Enrico Fermi, the first nuclear reactor). At Columbia University five years later, he and Fermi and a team of physicists created the first example of human-made nuclear fission. In 1939, Szilárd obtained his friend Albert Einstein’s signature on a letter to President Franklin Delano Roosevelt warning about Nazi nuclear research and urging the U.S. to develop an atomic bomb. This letter led directly to the establishment of the Manhattan Project, on which Szilárd worked. He strongly opposed using the Bomb on human targets, however — urging instead a demonstration detonation — and became a outspoken advocate of nuclear disarmament.
We turned the switch, saw the flashes, watched for ten minutes, then switched everything off and went home. That night I knew the world was headed for sorrow.” — Leo Szilard commenting on the first nuclear chain reaction