Sunlight strikes a piece of crown glass at an angle of incidence of 40.0o. Calculate the difference in the angle of refraction between a red (660 nm) and a violet (410 nm) ray within the glass. The index of refraction is n=1.520 for red and n=1.538 for violet light.? The ray now travels inside the glass. What is the minimum angle of incidence at which the red ray can hit the surface of the glass and become there totally internally reflected and not refracted?