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Snell's Law

Refraction of light between two media.

Formula

n1sin⁡θ1=n2sin⁡θ2n_1\sin\theta_1 = n_2\sin\theta_2

Variables

nRefractive indices
\thetaAngles

Example

Light from air (n=1) into water (n=1.33) at 30° bends to θ ≈ 22°.

Did You Know?

Snell's law explains why a straw looks bent in a glass of water — light changes speed as it enters.

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