George Stokes. Portrait of Sir George Gabriel Stokes (1819-1903), Irish mathematician and physicist. After graduating from Cambridge University, Stokes became a professor of mathematics there. Stokes was the first person to study the Sun's composition by studying its light through a spectrometer. He deduced an equation (Stoke's law) describing the motion of a small sphere falling through a viscous medium. He also derived laws, subsequently named after him, describing fluorescence and integral operations in vector calculus. He was appointed President of the Royal Society of London in 1885.