Compact Diffraction Grating CD Spectroscope Light Analyzer
An engaging, screen-free learning activity that builds real-world creativity and critical thinking for kids aged 8 to 13.
Materials Needed
- • Clean cardboard paper towel tube (1 unit)
- • Blank recordable CD or DVD disc (1 unit)
- • Black construction paper (1 sheet)
- • Clear packing tape and scissors (1 roll/unit)
- • Household light sources (LED, incandescent, fluorescent) (ambient access)
Pro Tips
- → A compact disc contains microscopic spiral data tracks that act as a high-precision diffraction grating.
- → Peel the metallic foil off an old CD using clear packing tape to reveal a clear diffraction window.
- → Tape the CD wedge over the viewing hole of a cardboard tube with a razor-thin light slit at the far end to split household light into sharp rainbow emission bands.
Safety First
Never look directly at the sun; analyze indirect sunlight reflected off clouds or household bulbs.
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Step-by-Step Instructions
Step 1
Peel the reflective metallic foil layer off an old blank CD using packing tape to isolate a clear transparent plastic disc.
Step 2
Cut a 1 mm narrow slit in a black paper disc and tape it securely over one end of a paper towel tube.
Step 3
Cut a 30-degree angled viewing peephole at the opposite end and tape a piece of the clear diffraction disc over it.
Step 4
Point the slit toward a lamp and look through the diffraction window to observe illuminated rainbow emission lines.