The Einstein–Szilard Letter
Also called: Einstein letter
In August 1939 Einstein signed a letter drafted by Szilard warning President Roosevelt that Nazi Germany might build an atomic bomb first and that the United States should speed up its own research.
Written by Leó Szilárd and signed by Albert Einstein. · Public domain · Source
The Hungarian-born physicist Leo Szilard had been thinking about nuclear chain reactions since 1933 and, hearing of fission, feared Nazi Germany would build a bomb first; Germany’s halt to uranium exports from occupied Czechoslovakia alarmed him. In July 1939 he visited Einstein at his summer house in Peconic, Long Island, and persuaded him to warn the president in the name of the world’s most famous scientist.
The letter Einstein signed on 2 August said that "extremely powerful bombs of a new type" might be made with uranium and that Germany might already be working on them. It reached Roosevelt through his adviser Alexander Sachs on 11 October, after the Second World War had begun, and Roosevelt set up an Advisory Committee on Uranium. Einstein is said to have later called signing it "the one great mistake" of his life.
