A non-orientable surface with no inside or outside, living in 4D space
4D Rotation Controls
Non-orientableχ = 0No boundary
The Klein bottle is a closed surface that cannot be embedded in 3D without self-intersection. In 4D, it exists perfectly.
As we rotate through the 4D planes (XW, YW, ZW), watch how the apparent self-intersection slides through the surface — it's an artifact of projection, not a real crossing.
Unlike a Möbius strip (1 boundary), the Klein bottle has zero boundary.