| This very convincing model to illustrate the phenomenon
of polarization by reflection, in the apparatus collection at Kenyon College,
may have been built by Ritchie of Boston. Within its pleasing shape are
two serious errors in physics.
David Brewster (1781-1868) showed in 1814 that there was a relationship between the angle of incidence at which the light ray reflected from an interface is completely plane polarized: the index of refraction was equal to the tangent of the angle. In the model, the angle of incidence is 45°. The tangent of this angle is 1.000, and so the relative index of refraction is also 1.0000 But this means that there will be no reflection because there is no interface! At the upper surface, the lack of a reflected signal is also an error.
The shapes of the components of the incident wave are also wrong: they should be in phase.
REFERENCE: Thomas B. Greenslade, Jr., "A Brewster's Angle Mistake", Phys. Teach., 32, 188-119 (1994)
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