Klein's bottle

A Klein bottle is a mathematical object that behaves like a surface with only one side and one edge, unlike a typical bottle with an inside and outside. It’s a four-dimensional shape that can be visualized as a loop passing through itself in higher dimensions, creating a continuous, seamless surface. When projected into three dimensions, it appears to intersect itself, but in four dimensions, it’s a non-intersecting, single-sided surface. Klein bottles are used to explore concepts in topology—they challenge our intuitive understanding of surfaces and boundaries and have applications in fields like physics and computer graphics.