Light conforms to certain rules. These rules are, for the most part, simple and sensible, but they create situations that can be counterintuitive or perplexing.

The activities for this topic focus on three of the rules: (a) light travels in a straight line; (b) the farther you are from a light source, the dimmer the light; and (c) the angle that a light beam makes when it hits a mirror (the angle of incidence) is the same size as the angle the beam makes when it bounces off the mirror (the angle of refraction).

• Alien Eyes. You explore how the images from your two eyes are slightly different because of parallax.

• Where Is the Player? (Requires Java.) You examine shadows; in particular, how multiple light sources produce shadows of differing darkness and length. (Also see the related activity Colored Shadows.)

• Fun House Mirrors. What makes you tall? What squishes you? Here you explore the effect of curved mirrors.