The namesake of a petition that attempted to block the use of the atomic bomb against Japan, he later became so disillusioned with his work that he dropped out of physics altogether, and spent the last decades of his life as a biologist.   
In 1934 he obtained a patent for the nuclear chain reaction, which he immediately assigned to the British Admiralty.   The namesake of a petition that attempted to block the use of the atomic bomb against Japan, he later became so disillusioned with his work that he dropped out of physics altogether, and spent the last decades of his life as a biologist.   For 10 points name this influential Manhattan Project physicist, who is perhaps best known as the real author of Einstein's letter to FDR urging research into nuclear weapons.
In 1934 he obtained a patent for the nuclear chain reaction, which he immediately assigned to the British Admiralty.   
Leo Szilard