Sir David Brewster KH PRSE FRS FSA(Scot) FSSA MICE (11 December 1781 – 10 February 1868) was a Scottish scientist, inventor, author, and academic administrator. In science he is principally remembered for his experimental work in physical optics, mostly concerned with the study of the polarization of light and including the discovery of Brewster's angle. He studied the birefringence of crystals under compression and discovered photoelasticity, thereby creating the field of optical mineralogy. For this work, William Whewell dubbed him the "father of modern experimental optics" and "the Johannes Kepler of optics." A pioneer in photography, Brewster invented an improved stereoscope, which he called "lenticular stereoscope" and which became the first portable 3D-viewing device. He also invented the binocular camera, two types of polarimeters, the polyzonal lens, the lighthouse illuminator, and the kaleidoscope. Brewster was a Presbyterian and walked arm in arm with his brother on the Disruption procession which formed the Free Church of Scotland. As a historian of science, Brewster focused on the life and work of his hero, Isaac Newton. Brewster published a detailed biography of Newton in 1831 and later became the first scientific historian to examine many of the papers in Newton's Nachlass. Brewster also wrote numerous works of popular science, and was one of the founders of the British Science Association, of which he was elected President in 1849. He became the public face of higher education in Scotland, serving as Principal of the University of St Andrews (1837–59) and later of the University of Edinburgh (1859–68). Brewster also edited the 18-volume Edinburgh Encyclopædia.