The Limb of the Sun

  Open with LBRY

Also, why do some flames look hollow? Thanks to http://www.audible.com/minutephysics for sponsoring this video.

More information about:

Limb darkening – https://en.wikipedia.org/wiki/Limb_darkening

Optical Depth – https://en.wikipedia.org/wiki/Optical_depth

Limb darkening – http://spiff.rit.edu/classes/phys440/lectures/limb/limb.html

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https://www.youtube.com/watch?v=ur0fATmsVoc