John Desmond Bernal

John Desmond Bernal (1901 to 1971) was an Irish scientist who pioneered the use of X-ray crystallography in molecular biology, turning a method for reading the arrangement of atoms in solid crystals into a tool for studying the large molecules of living matter. That approach to determining structure from diffraction patterns became a foundation for later work on proteins and other biological materials, and it makes his career a bridge between materials science and the life sciences. Alongside his laboratory work he published extensively on the history of science and wrote popular books on science and society, arguing for the social role of research. He was also a communist activist and a member of the Communist Party of Great Britain.