David Brewster

Born in Scotland in 1781, Brewster spent decades at the bench studying how light behaves under pressure, through crystals, in polarized states. He discovered Brewster's angle and founded optical mineralogy by watching crystals compress. The kaleidoscope and the lenticular stereoscope - the first handheld 3D viewer - both came from his workshop, along with lighthouse illuminators and two kinds of polarimeters. A devout Presbyterian, he marched in the Disruption of 1843 that birthed the Free Church of Scotland. He worshipped Isaac Newton, published a major biography in 1831, and became the first scholar to dig through Newton's unpublished papers. He edited the 18-volume Edinburgh Encyclopædia, co-founded the British Science Association, and led it in 1849. He spent his final three decades running universities - St Andrews, then Edinburgh - and died in 1868 as the public face of Scottish higher learning.