Demonstration of total internal reflection using a prism.

This demo is best accomplished by passing the prism to each student in the class.

• "Lucite" is written on the bottom of the prism, as shown in the image below, at left. It should be pointed out that while the bottom of the prism is somewhat opaque, the other two sides are transparent, as can be seen when looking the other sides.
• Hold the prism so that when you look through the prism you see the inverted letters written on the bottom (with Γ to the left).
• Slowly rotate the prism (away from you); as you continue to rotate, the letters will appear correctly oriented due to total internal reflection (below, right).
• If you continue to rotate beyond this point, the letters will disappear, and you'll be able to see directly through the prism (you'll probably see your fingers holding the prism)

LDL-B4. The prism is about 4" or 5" long.