SUMMARY
In 30 seconds
This short introduction explains how light changes direction in glass and why different frequencies separate in a prism.
- 1Light in glassLight travels more slowly in glass than in vacuum.
- 2RefractionA beam entering at an angle changes direction.
- 3DispersionDifferent frequencies bend differently and separate.
Takeaways
- Light changes direction at an interface when it enters at an angle.
- Glass slows different frequencies by different amounts.
- White light contains components with different spectral colors.
TopicsPhysics
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01
Refraction and dispersion
The speaker introduces how a prism separates white light.
The speaker starts with a common explanation of a prism: light travels more slowly in glass, and a beam entering the glass at an angle changes direction, a phenomenon called refraction.
White light can be represented as a mixture of different frequencies, corresponding to spectral colors. Glass affects their speeds differently, so they refract by different amounts and spread into a rainbow.
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