Klein Bottle

A Klein bottle is a mathematical shape that has only one surface and no edges. Imagine taking a flat piece of paper, rolling it into a cylinder, and then connecting the ends in a way that twists through itself. Unlike a regular bottle, a Klein bottle has no inside or outside – it's all one continuous surface. While it's impossible to create a perfect Klein bottle in our three-dimensional world, it's a popular concept in mathematics for exploring the ideas of surfaces and dimensions. The Klein bottle was first described in 1882 by the mathematician Felix Klein.