English: Central part of sphere eversion (turning inside out) process flattened with folds along a square, cut out of doubly colored paper (red/green). The depicted part is homeomorphic to a cylinder/collar/bottleneck, to be glued to two spheres opposite oriented. The middle stage is the Morin surface, with both sides equally privileged. The left stage can be easily unfolded to a green (outer side) sphere, the right - red. The middle stage has removed four flat triangles to see the folds underneath, the triangles can be shifted above of beneath the surface to proceed to the left/right. Note the quadruple intersection in the center, double intersections along diagonals and fold annihilation at the vertices of the inner square (midpoints of sides of the outer square).
English: Central part of sphere eversion (turning inside out) process flattened with folds along a square, cut out of doubly colored paper (red/green). The depicted part is homeomorphic to a cylinder/collar/bottleneck, to be glued to two spheres opposite oriented. The middle stage is the Morin surface, with both sides equally privileged. The left stage can be easily unfolded to a green (outer side) sphere, the right - red. The middle stage has removed four flat triangles to see the folds underneath, the triangles can be shifted above of beneath the surface to proceed to the left/right. Note the quadruple intersection in the center, double intersections along diagonals and fold annihilation at the vertices of the inner square (midpoints of sides of the outer square).
to share – to copy, distribute and transmit the work
to remix – to adapt the work
Under the following conditions:
attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
https://creativecommons.org/licenses/by/4.0CC BY 4.0 Creative Commons Attribution 4.0 truetrue
This image was uploaded as part of Wiki Science Competition 2019.