SphereEversion

Turns a sphere inside out: a smooth deformation (homotopy). During the eversion, the deformed sphere is allowed to intersect itself transversally, however, no creases or pinch points occur. Inspired by the following paper: Adam Bednorz, Witold Bednorz: "Analytic sphere eversion using ruled surfaces", Differential Geometry and its Applications 64:59-79, 2019. https://en.wikipedia.org/wiki/Sphere_eversion https://mathworld.wolfram.com/SphereEversion.html Written by Carsten Steger; 2020.