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Physics Hall · EXH-0004
How can white light become a rainbow?
A narrow white beam leaves a prism as several colored paths.
Start the experience01
What should you look for?
What did the colored rays do?
- 01All rays bent at the surfaces
- 02Colors left at slightly different angles
- 03Changing the light angle moved the spectrum
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Why does this happen?
Refraction changes direction
Light changes speed at a boundary between materials, so its path usually bends.
Dispersion separates colors
Each wavelength refracts by a slightly different amount. Violet and red therefore leave along different paths.
The SVG ray paths are a qualitative angle model, not an optical design calculator.
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Move it before reading the answer
Angle and material change the path. The prism separates colors already present in white light; it does not create them.