Sir Charles Galton Darwin, FRS (December 18, 1887 - December 13, 1962) was the English physicist grandson of Charles Darwin who served as director of the National Physical Laboratory (NPL) during World War II.

Darwin was born in Cambridge into a fine scientific dynasty, the son of the mathematician George Howard Darwin and his wife Maud du Puy , and the grandson of Charles Darwin. He was educated at Marlborough College and, in 1910, he graduated from Trinity College, Cambridge in mathematics. No doubt, his family connections helped him to secure an immediate post-graduate position at the Victoria University of Manchester, working under Ernest Rutherford and Niels Bohr on Rutherford's atomic theory. In 1912, his interests developed into using his mathematical skills assisting Henry Moseley on X-ray diffraction.

On the outbreak of World War I, he joined the Royal Engineers, where he worked on problems in ballistics, and later served in the Royal Flying Corps. From 1919 to 1922 he was a lecturer and fellow of Christ's College, Cambridge where he worked with R.H. Fowler on statistical mechanics and, what came to be known as, the Darwin-Fowler method . He then worked for a year at the California Institute of Technology before becoming Tait professor of natural philosophy at the University of Edinburgh in 1924, working on quantum optics and magneto-optic effects. He also anticipated some of P.A.M. Dirac's relativistic theory of the electron.

In 1936 Darwin became master of Christ's College, beginning his career as an active and able adminitrator, becoming director of the NPL on the approach of war in 1938. He served in the role into the post-war period, unafraid to seek improved laboratory performance through re-organisation, but spending much of the war years of scientific missions to the USA.

On his retirement, his attention turned to issues of population, genetics and eugenics, unsurprisingly given his familial inheritance. His conclusions were pessimistic and entailed a resigned belief in an inevitable Malthusian catastrophe, as described in his 1952 book The Next Million Years.

In later years he travelled widely, an enthusiastic collaborator across national borders and an able communicator of scientific ideas. He died in Cambridge.

Honours

• Fellow of the Royal Society - (1922)
• President of the Physical Society - (1941-1944)
• KBE - (1942)
• President of the Eugenics Society - (1953-1959)
• Honorary degrees from the University of Manchester, St Andrew's College and Trinity College, Dublin