Science4All (english)'s video: The Poincar conjecture Relativity 21

Could a universe without border, not go on and on forever? Poincaré not only gave an answer, he also proposed a fundamental conjecture... Poincaré Conjecture and Homotopy | Science4All Article http://www.science4all.org/le-nguyen-hoang/poincare-conjecture/ Can you glue opposite edges of a square? Nash's embedding | Science4All 7 https://www.youtube.com/watch?v=Bx0MOMvUxS8 What's wrong with that map? Spherical Geometry | Science4All 9 https://www.youtube.com/watch?v=SZsz3EchTA0 Topology | MyWhyU https://www.youtube.com/watch?v=p2ofJPh2yMw https://www.youtube.com/watch?v=n8Sb29BSZcY https://www.youtube.com/watch?v=29LoQVbEa7w Poincaré Conjecture | Numberphile https://www.youtube.com/watch?v=GItmC9lxeco Ricci Flow | Numberphile https://www.youtube.com/watch?v=hwOCqA9Xw6A Euler’s Formula and the Utilities Problem | Science4All Article http://www.science4all.org/le-nguyen-hoang/eulers-formula-and-the-utilities-problem/ Homotopy Type Theory and Higher Inductive Types | Science4All Article http://www.science4all.org/le-nguyen-hoang/homotopy-type-theory/