In A.D. 1858, the German mathematician Mobius (1790 ~ 1868) discovered that a piece of paper twisted by 180 was magically bonded at both ends. Because ordinary paper has two sides (that is, a double-sided surface), one front and one back, and the two sides can be painted with different colors; And such a paper tape has only one side (that is, one side), and a bug can crawl all over it without crossing its edge! This magical single-sided paper tape discovered by Mobius is called Mobius tape. The video produced by researchers Douglas Arnold and Jonathan Rogenis of the University of Minnesota describes the profound and interesting phenomenon of Mobius transformation in simple language.