1898-1964. Hungarian-born US physicist who,
in 1934, was one of the first scientists to
realize that nuclear fission, or atom
splitting, could lead to a chain reaction
releasing enormous amounts of instantaneous
energy. He emigrated to the USA in 1938 and
there influenced Einstein to advise President
Roosevelt to begin the nuclear arms
programme. In post-war years he turned his
attention to the newly emerging field of
molecular biology.