Nail Polish Rainbow

Rainbows can be seen in many places besides the sky. Maybe you’ve seen them in your sprinklers or reflected off of oil. This experiment explains why that is.

Materials

  • Clear nail polish
  • A tin foil pan
  • Black construction paper
  • Water
  • Paper Towels

Directions

  1. Put the black construction paper in the tin foil pan.
  2. Fill the pan about halfway with water. Make sure that the paper stays on the bottom of the pan.
  3. Drip a single drop of nail polish into the water and let it sit for 10-30 seconds. Notice how the nail polish expands over the paper. What colors do you see?
  4. Wait five minutes to let the nail polish dry.
  5. Making sure to avoid the nail polish, reach into the water and grab the edges of the paper. Lift it out slowly and allow the paper to touch the nail polish.
  6. Lay the paper onto a paper towel to let it dry.
  7. Think about why so many colors came from clear nail polish.

Explanation

This experiment shows refraction. As light travels through thicker substances, it tends to slow down and give off a greater wavelength. The change in wavelength is what changes the color that gets reflected back to us. Since nail polish is thicker than air, refraction occurs. The nail polish gets thinner and thinner as it spreads across the water, so different wavelengths, and thus colors, are shown.