Eponymously named for a Scottish physicist is, for ten points, what angle of incidence at which all light reflected from a surface is polarized?
This law accounts for why sunglasses work so well at the beach.  Equal to 53 degrees for an air-water interface, it is given by the inverse tangent of the ratio of the refractive indices.  Eponymously named for a Scottish physicist is, for ten points, what angle of incidence at which all light reflected from a surface is polarized?
This law accounts for why sunglasses work so well at the beach.  
Brewster's law or angle (prompt on "polarization" on a first-sentence buzz)