A CD – cereal box spectrometer

A CD – cereal box spectrometer… Jerry writes –

A simple spectrometer can be built from a CD and a box. Cut a slit on one side of the box. Place the CD on the other side with about 60 degree angle. Look down into the openning on the box. The slit should not be too wide, otherwise the spectrum lines will be blurred. It should not be too narrow either, otherwise the spectrum is too dim. I use a 0.2mm wide slit.