A New Twist on the Möbius Strip

ScienceNow : Cut a thin strip from a piece of paper, twist it, and connect the two loose ends. You’ll end up with a Möbius strip, a graceful bracelet that oddly has only one side, as you can easily demonstrate by running your finger around it. Now try the same thing with the much wider strip of paper. Why is it harder to connect the ends? Mathematicians now have a precise answer.