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Some Simple Optics

Refraction
Refraction occurs when light travels from one medium crosses a boundary and enters another medium of different properties. For example, light traveling from air to water. The amount of refraction (or bending) can be calculated using Snell's Law.

niSini = nrSinr

where
i = angle of incidence
r = angle of refraction
nr/ni = index of refraction




Reflection
Reflection occurs when the light hits the surface and bounces back at a certain angle. These angles can also be calculated with one important fact.

angle of incidence = angle of reflection

where
i = angle of incidence
l = angle of reflection


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