Physics in Color
Overview
Learn about the physics of color and how our eyes perceive different colors. Explore the difference between primary colors of light and primary colors of pigments, and observe how colors combine in real time.
Materials
Cardboard tube (such as a toilet paper roll)
Piece of parchment paper (larger than the opening of the tube)
Piece of aluminum foil (larger than the opening of the tube)
2 rubber bands
Toothpick
Red light source
Green light source
Blue light source
Instructions
Place the parchment paper over one end of the tube, stretching it as smoothly as possible.
Secure the parchment paper with a rubber band.
Repeat the process on the opposite end using the aluminum foil.
Use a toothpick to poke small holes or create a design in the foil.
Turn on only the red and green lights. Hold the tube at arm's length and look through it. Notice how the colors combine to create yellow.
Turn on only the red and blue lights. Observe the magenta color formed where the lights overlap.
Turn on only the green and blue lights. Observe the cyan color created by the overlap.
Finally, turn on all three lights. Notice how the overlapping colors appear white.
What’s Happening?
Light follows a different color-mixing system than paint. Red, green, and blue are the primary colors of light. When combined, they create new colors—and when all three overlap, they produce white light.
