How the index of refraction arises, and why it depends on color.
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Looking Glass Universe videos on the index of refraction:
   • I don't know why light slows down in ...  

Much of this video is based on the following Feynmann lecture
https://www.feynmanlectures.caltech.e...

The explanation for why the phase of a wave produced by a plane of oscillating charges is a quarter phase behind the wave of a charge in the center of that plane, and hence a quarter phase behind that of a light wave inducing the oscillations, is given in the previous chapter:
https://www.feynmanlectures.caltech.e...

Sections:
0:00 - The standard explanation
3:14 - The plan
5:09 - Phase kicks
8:25 - What causes light?
13:20 - Adding waves
16:40 - Modeling the charge oscillation
20:59 - The driven harmonic oscillator
26:57 - End notes

Thanks to these viewers for their contributions to translations
German: Ole
Hebrew: Alon Altman, Omer Tuchfeld
Hindi: Saurabh
Portuguese: @doryhelioaires
Urdu: Momini0

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These animations are largely made using a custom Python library, manim. See the FAQ comments here:
https://3b1b.co/faq#manim
https://github.com/3b1b/manim
https://github.com/ManimCommunity/manim/

All code for specific videos is visible here:
https://github.com/3b1b/videos/

The music is by Vincent Rubinetti.
https://www.vincentrubinetti.com
https://vincerubinetti.bandcamp.com/a...
https://open.spotify.com/album/1dVyjw...

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