In A.D. 1858, German mathematicians Mobius and john cleese Ting discovered that the paper tape loop made by twisting a piece of paper 180 and then gluing the two ends together has magical properties.
Mosubi ring is a geometric figure with faces and edges in three-dimensional space, which can be embedded in four-dimensional space "flat". The basic structure of Mosubi ring is to take a piece of paper tape, rotate it by 180 degrees, and connect it with the other end. In order to prove that the Mosubi ring has only one face, take any point on the ring with a pen and draw a straight line along the ring. It can be found that the straight line can reach the back of the starting point without crossing the side.