Science Porn

[Alex K]

In this episode of sciency gifs





^^^ EXPLAIN ^^^

The speed of light is different in glass than in air. That leads to a change in direction when the light enters/exits - because neighboring lightwaves get shifted in speed a bit later than others if the beam of light they make up does not enter the glass nicely perpendicular, and that leads to a change of the orientation of the waves.

Since the speed of light in materials usually depends on the frequency of the wave, roughly speaking bc the electrons in the material can follow some frequencies more easily than others, the amount of change in direction depends on frequency, i.e. color.

Here is an illustration why going into a slower medium at some angle leads to a change in direction


Because of the reduced speed in the glass, the distance AE is shorter than BC, so the beam changes direction.