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Refraction

When a light ray slows down and changes direction as a result of passing through different mediums – such as water or air.
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Aberrations

Default thumbnail: three prisms splitting light on a surface
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Dispersion

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Snell's Law, Reflection, and Refraction

Default thumbnail: three prisms splitting light on a surface
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What is a Rainbow?

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Why do the Stars Twinkle?

Default thumbnail: three prisms splitting light on a surface
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