Use the overhead projector or a
slide projector and diffraction grating to project a white light
spectrum. Place the glass filter over part
of the
slit so the absorption spectrum can be compared with the
continuous spectrum.
Or use the showcase bulb and distribute slide-mounted diffraction
gratings.
For a broadband absorption spectrum, use a theater gel from the Rosco
swatch
book, or tidy bowl, or a glow doodler.
NOTES
Alternatively, illuminate
the room with one of the low pressure sodium lamps and display the view
using a video camera and didymium glass filter. The filter
absorbs the sodium yellow lines, so the room looks rightly
colored. Didymium is used in glass-blower's
glasses to filter out the sodium lines in hot glass.
