3 ms·
It's not. It's about closed surfaces, which include the surface of spheres, oblate spheres, footballs, pencils, and airplanes.
by IAmBroom 1y ago
It's not. It's about closed surfaces, which include the surface of spheres, oblate spheres, footballs, pencils, and airplanes.
- orlandpm 1y agoWell, all these closed surfaces you mention are (topologically) spheres. The theorem doesn’t apply to some other closed surfaces, like the torus, which does admit a continuous non-vanishing vector field.