(testing signal)

Month: December 2018

But why is a sphere’s surface area four times its shadow?

The formula is no mere coincidence.
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Discussion on Reddit: https://www.reddit.com/r/3Blue1Brown/comments/a2gqo0/but_why_is_a_spheres_surface_area_four_times_its/

The first proof goes back to Greek times, due to Archimedes, who was charmed by the fact that a sphere has 2/3 the volume of a cylinder encompassing it, and 2/3 the surface area as well (if you consider the caps). Check out this video for another beautiful animation of that first proof:

Calculus series:

Thanks to these folks for letting me use their images at the end:
https://www.youtube.com/user/vlogbrothers…