Post by Chris M. ThomassonPost by Chris M. ThomassonPost by sobriquetHi!
https://www.desmos.com/3d/t5fsaljsmh
The shape is comprised of 12 pyramids that come in two varieties, but
they all appear to have the same volume.
It looks like a unit 5-gon in the xy plane at (x, y, 0) with each
vertex connected to two points, at (0, 0, -1) and (0, 0, 1)?
Not quite... Like two 5 gons one on the xy plane and one on the xz plane
rotated by pi / 2. I need to take a closer look and try to recreate it
on my end. Fun. Thanks for the post. Might have some more time tonight.
It's the shape with the biggest volume one can obtain with 8 vertices on
the unit sphere.
I got the coordinates for the vertices from the paper referenced in the
recent Matt Parker video about the shape.
https://www.ams.org/journals/mcom/1963-17-082/S0025-5718-63-99183-X/S0025-5718-63-99183-X.pdf
When I computed the volume of the shape that has an isosceles
triangle as the base for the pyramid, it seemed to give the
impression that it's a twelfth of the total volume, implying
that the other pyramid shape with a scalene triangle base has
the same volume.
https://www.desmos.com/calculator/stjrx6qsxt