Reveal the amazing colors hidden in soap bubbles by creating an observatory. This science experiment for kids explores interference colors on a bubble – colors created when two sets of light waves interfere and combine to make colors brighter or cancel each other out to remove colors from the mixture.

Conduct the science experiment below to discover the interference colors on soap bubbles:


  • Small clear plastic lid
  • Clear plastic tape
  • Flashlight
  • Bubble solution (combine 1 gallon of water and 2/3 cup dishwashing soap)
  • Spoon
  • Straw
  • Dark room


  • Tape the plastic lid over the end of the flashlight the light shines from.
  • Turn the flashlight on and hold it so the light shines straight up.
  • Dip a finger in the bubble solution and wet the lid. Put a spoonful of bubble solution on the lid. With a straw, blow one big bubble to make a bubble dome that covers the entire lid.
  • Turn off the lights and hold the flashlight so that the bottom of the bubble dome is just above your eyebrows.
  • Watch the swirling colors. If you put the wet straw into the bubble dome and blow very gently, you can move the colors around.
  • Watch the colors. How many do you see? If you watch a bubble for a few minutes, do the colors change? What colors do you see right before the bubble pops? Do you ever see black and white polka dots?