This video segment adapted from Shedding Light on Science illustrates how light changes speed, and thus direction, in a process known as refraction. Includes background reading and discussion questions. [2:05]

A detailed discussion of the nature of light, how it can travel through a vacuum, and how the speed of light is affected when light travels through a medium.

Students can study this article to help them understand the concept of refraction and index of refraction.

Here's a project that shows you how to use a laser pointer and some knowledge of physics to figure out the concentration of sugar dissolved in a liquid.

Think it takes expensive, sophisticated equipment to measure the speed of light? Think again. Outfit yourself with a simple handheld laser pointer, a protractor, and Jell-O, and you're ready to get started.

Biography of Willebrord Snell (1580-1626), a Dutch mathematician known best for his work in refractive indices.

Get a visual of convention currents with this activity. This activity allows students to observe the currents by bending light due to cold and warm water.

Lesson plan should be used for intermediate students. Students work in pairs or groups to create a shoe box that will bend light.