You're probably really upset that all you have so far is a simple little ray model of light. When do we get to the good stuff, you say? How about now? As a bonus, you get to look at lots of pretty colors. This chapter addresses how light can be modeled as a series of waves. These waves consist of changing electric and magnetic fields that can travel through empty space, as well as through other mediums. Different frequencies of light waves correspond to different colors of light. White light is composed of all the colors of visible light. Visible light is just a small portion of the entire spectrum of electromagnetic waves.