Stokes, Sir George Gabriel, 1819–1903, British mathematician and physicist, b. Ireland, studied at Cambridge. From 1849 he was a professor of mathematics at Cambridge; he served as secretary (1854–85) and as president (1885–92) of the Royal Society. His researches, done in many fields, developed the modern theory of viscous fluids, revealed the nature of fluorescence, and helped to establish the composition of chlorophyll. The important work he did on the undulatory theory of light led to publication of his Dynamical Theory of Diffraction (1849). His other publications include Light (1884) and Natural Theology (1891).