How to Make a Color Spectrometer From a Cereal Box & CD

When you look at light, your eye sees only one color, but in reality there are many different bands of color in light. A spectrometer divides a light into its component bands. By looking at those different components, a scientist can figure out how the light is being produced and what gasses are between the light source and the observer.

Difficulty:

Moderately Easy

Instructions

Things You'll Need

• Cereal box Old CD Scissors Glue Tape Craft knife

1. Use a craft knife to cut a thin slit in the cereal box a few centimeters from the top of the box. It should be less than a millimeter wide, a couple centimeters across, and parallel to the top of the cereal box. Make it as straight as possible.

2. Cut into the cereal box at a 45-degree angle right across from the slit. You should cut open the edge and cut down into the box several centimeters. This is where you are going to put the compact disc.

3. The light comes through the slit and bounces off the CD, through the viewing window

   Cut a viewing hole above the diagonal slit. It should be about 2 centimeters square and be positioned so that light coming straight from the slit will reflect off of the compact disc at a right angle straight through the hole. See the illustration below for clarification.

4. Insert the compact disc into the diagonal cut so that the shiny side faces towards the slit. use tape or glue to hold it in the spectrometer.

5. Point the slit toward whatever light source you want to see. Look into the viewing screen.

Tips & Warnings

• The lower half of the cereal box is not needed. You can cut it off and cover the hole with cardboard if you want a more compact spectrometer.

Resources

• What Does a Spectrograph Do?