- Empty paper towel roll
- Scissors or craft knife
- Blank or old CD
- Small piece of cardboard or cardstock
- Paint or stickers (to decorate)
- If you decided that you want to paint your paper towel roll, do this first and allow it to dry.
- This next step is for adults only! With your scissors or craft knife, cut a small slit at a 45 degree angle near the bottom of the paper towel roll. Next, cut out a small hole, just large enough to look into, directly across from the slit you just made.
- Place one end of your paper towel roll on your cardboard or cardstock and trace around it. Cut it out.
- Now, cut a small rectangle into the center of that cardboard or cardstock circle.
- You can now tape this circle onto the top of your spectroscope.
- Place your old or blank CD into the slit near the bottom of the spectroscope with the shiny side facing up.
- Your spectroscope is now complete! Use it outside, with the top facing the sky and look into your viewing hole. You will see a rainbow!
Why does this happen?
- Because the CD is a mirror with spiral tracks over the surface.
- Because these spiral tracks are evenly spaced apart, they separate colours making a rainbow!
- The CD then reflects this rainbow to your eye!