Van wie was Margot Heinemann?

John Desmond Bernal (; 10 May 1901 – 15 September 1971) was an Irish scientist who pioneered the use of X-ray crystallography in molecular biology. He published extensively on the history of science. In addition, Bernal wrote popular books on science and society. He was a communist activist and a member of the Communist Party of Great Britain (CPGB).