Edward Teller When asked how he came to devote his life to the design of nuclear weapons, Edward Teller, who died on Tuesday at 95, used to recall how, as a boy he would lie awake at night doing mathematics problems in his head.
The image - of extreme intelligence and obliviousness to the outside world - is revealing. His abilities, which put him in the forefront of his generation's physicists, won him admirers; widespread misgivings about the way he applied them made him many opponents.
Teller was born to prosperous Hungarian Jews in Budapest in 1908. He showed great talent at mathematics and the piano, a lifelong passion. He studied at the Budapest Institute of Technology and then Karlsrühe, Munich - where he fell under a tram and lost his right foot - Leipzig and Gottingen universities. He took a degree in chemical engineering and a doctorate in physical chemistry, also studying with Niels Bohr in Copenhagen.
He married Augusta Harkanyi and, a passionate opponent of fascism and communism, emigrated to the US with her in 1935. After Bohr's 1939 report on atomic fission and President Franklin Roosevelt's call to scientists to help defend America, he took US citizenship and committed himself to the race to beat Germany, and later the Soviet Union, in developing nuclear arms.
That race, called the Manhattan Project, began in 1943 when Robert Oppenheimer, a brilliant physicist, began to establish Los Alamos in the New Mexico desert. Teller was one of the first of Oppenheimer's recruits and his theoretical work saw him later nicknamed "Father of the H Bomb", the first of which exploded in 1952.
Two years later he took the step which left him widely ostracised. At the hearings which led to the removal of Oppenheimer's security clearance, he said of his former boss: "I would feel personally more secure if public matters would rest in other hands."
In an apparent contradiction of earlier views Teller would later argue that the scientists should have suggested to President Truman that he drop bombs over Tokyo bay, not over the cities of Hiroshima and Nagasaki.
He was instrumental in the creation of the second US weapons laboratory at Livermore, California, concentrating on thermonuclear devices. He was its director for two years from 1958 and a professor at the University of California at Berkeley from 1953 to 1975.
Although he maintained scientists should keep apart from political decisions but cultivate political influence. He helped persuade President Ronald Reagan to pledge research funds for the "Star Wars" missile defence.
Pressed in 1995 on whether he was religious, he was equivocal. At the turn of the century, he said, scientists looked at the world as a machine and believed the laws of physics completely determined its behaviour. "They couldn't see then how an all-powerful god could have an influence." But since Einstein and quantum mechanics, he argued, "we know - although many intellectuals do not understand this - that the future is not determined. Now, if you want to believe in God, you have room for it."
Teller is survived by a son, a daughter.
Edward Teller: born January 15th, 1908; died September 9th, 2003.