Physics 312 Lecture: "Dispersion and Total Internal Reflection" Apr 17, 1998

The index of reflection of material changes with wavelength
- Long wavelengths get refracted a little
- Short wavelengths get refracted a lot
One consequence is that light of different wavelengths is bent through different angles when it passes from one medium to another: dispersion
When light of different wavelengths is spread out, the result is a spectrum
When material is vaporized and heated, it absorbs and/or emits light of very specific wavelengths; each element has its unique set of wavelengths
If light passes from a medium with high index of refraction to one with a low index of refraction, at a glancing angle, it may fail to pierce the interface: total internal reflection

Total internal reflection occurs when

                 (n1 / n2) * sin(theta1) > 1

This lecture discusses material in Chapter 35 of Serway.