Combined with Cauchy's equation, this equation implies material dispersion. For calcium carbonate, the o-ray follows this equation, but the e-ray does not. While birefringence can result in violation of this law, by setting the time derivative of path length to zero, (*) Fermat's principle of least time can be used to derive this equation. It can be used to calculate the angle where, instead of passing through, light is reflected off the boundary of the two mediums.  Lig
Combined with Cauchy's equation, this equation implies material dispersion. For calcium carbonate, the o-ray follows this equation, but the e-ray does not. While birefringence can result in violation of this law, by setting the time derivative of path length to zero, (*) Fermat's principle of least time can be used to derive this equation. It can be used to calculate the angle where, instead of passing through, light is reflected off the boundary of the two mediums.  Light entering at that critical angle undergoes total internal reflection. For 10 points, name this equation that states that the ratio of the sines of the angles of incidence is proportional to the reciprocal ratio of the indices of refraction.
Combined with Cauchy's equation, this equation implies material dispersion.
{Snell's} law