Matthew Meselson anticipated a lecture that night in 1954 when he heard Linus Pauling's slippety-slap footfall outside the lab. Meselson, then a graduate student in Pauling's lab at Caltech, had neglected his lab duties to organize scientists against atmospheric nuclear testing.
Instead of a dressing-down, Pauling told him a story: A man asked Socrates what he considered the best job for an old man. 'Politics,' Socrates responded. And for a young man? 'Science.'
Meselson took Socrates' advice: in 1958, he and Frank Stahl demonstrated the semi-conservative replication of DNA. Later in life, he campaigned against chemical and biological weapons.
Pauling heeded likewise, first winning the Nobel Prize in Chemistry in 1953, and later becoming science's most prominent activist against nuclear weapons testing, a movement which led to the 1963 ban on above-ground testing and Pauling's Nobel Peace prize.
--Sam Jaffe
