Brewster’s angle is the angle at which light of a certain polarisation won’t reflect off a surface. The resulting reflection will then be made up of only light from a single polarisation (p-polarised). This little optical quirk is how polarised lenses remove lots of scattered reflections in photographs and why polarised sunglasses are so much better when lounging by the seaside. However, rather than just being something that makes sunny days even better, it also provides a neat trick for visualising things that would otherwise be invisible to other analytical methods. Brewster’s angle for water is approximately 53.1°, which is calculated Continue reading →