The Klein bottle is a one-sided surface named after the great 19th-century mathematician Felix Klein, who was one of the first mathematicians to explore its unusual properties. The Klein bottle is formed from a square piece of paper by gluing opposite...

In mathematics, the Klein bottle is a certain non-orientable surface, i.e., a surface (a two-dimensional topological space) with no distinction between the "inside" and "outside" surfaces. Other related non-orientable objects are the Möbius strip and...