Moebius

If you cut a Moebius strip in half, it does not split in half but stays in one piece. If you cut it to a third of its height, you have to make two turns before completing the cut and you get two pieces, linked together: one is a Moebius strip (the central one, in green in the animation), the other (in yellow) is a cylinder with two half twists. 

The animation, by sliding the yellow ribbon over the green central part, shows that a cylinder with two half twists is, naturally, a double covering of the Moebius strip.

Note: The idea and description is by Maria Dedò. The animation was created in 2018, on the occasion of a conference in Bari.

 90 total views,  1 views today