Each group needs:

• A mailing tube about 2 in (5 cm) in diameter and about 1 ft (30 cm) long. (Note: To save cost, a tube could also be made by rolling stiff paper into a tube and taping it together.)
• A card-mounted diffraction viewer (available from Edmund Scientifics)
• Three index cards, cut in half
• 4-6 6" lengths of masking or cellophane tape

For groups to share:

• Various light sources: a flashlight, a camping lantern, yellow streetlights (sodium produces the color), blue streetlights (mercury vapor produces the color), neon signs, and slide projector lamps. Note: students can also look at the solar spectrum by looking at the light from the sun reflected off of white paper. Students should NOT look directly as the sun, as serious injury to the eye may occur.
• Various materials to place in front of the light source for the second part of the activity. These materials should include at least one of each: transparent (clear plastic), translucent (wax paper), opaque (cardboard), and reflective (mirror).