For 10 points, name this phenomenon in which light turns around when it hits an object, such as a mirror.
This phenomenon is not observed in a thin film if the thickness times the index of refraction is a half-integer multiple of wavelength. This phenomenon introduces "s-polarization" at an angle equal to the arctangent of the ratios of the indies of refraction, at Brewster's angle. It can be "specular" or "diffuse." Above the critical angle, the sparkle of diamonds occurs due to the "total internal" form of this phenomenon. In general, this phenomenon results in an angle symmetric to the angle of incidence, with respect to the normal. For 10 points, name this phenomenon in which light turns around when it hits an object, such as a mirror.
This phenomenon is not observed in a thin film if the thickness times the index of refraction is a half-integer multiple of wavelength.
reflection [or total internal reflection]