British physicist. His pioneering work in the field of X-ray crystallography enabled the structure of many complex molecules to be elucidated.
Bernal came from an Irish farming family. Brought up as a Catholic, he was educated at Stonyhurst and Cambridge, where he abandoned Catholicism and became (1923) an active member of the Communist Party. After Cambridge, Bernal spent four years at the Royal Institution in London learning the practical details of X-ray crystallography from Sir William Bragg. When he returned to Cambridge in 1927 he planned a research programme to reveal the complete three-dimensional structure of complex molecules, including those found exclusively in living organisms, by the techniques of X-ray crystallography.
In 1933 Bernal succeeded in obtaining photographs of single-crystal proteins and went on to study the tobacco mosaic virus. It was not, however, Bernal's own achievements in crystallography, as much as those of his pupils and colleagues, such as Dorothy Hodgkin and Max Perutz, that brought about the revolution in biochemistry and launched the subject of molecular biology.
In 1937 Bernal was appointed professor of physics at Birkbeck College, London. His attempts to develop the department were interrupted by the outbreak of World War II. Despite his known membership of the Communist Party, and against the advice of the security forces, Bernal spent much of the war as adviser to Earl Mountbatten. In 1945 he returned to Birkbeck College and in 1963 was appointed to a chair of crystallography. In the same year he suffered a stroke and although he continued to work for some time, a second and more severe stroke in 1965 paralysed him down one side and virtually ended Bernal's scientific life. His books include The Social Function of Science (1939), Science in History (1954), World Without War (1958), and The Origin of Life (1967).
Subjects: Science and Mathematics — Contemporary History (Post 1945).