Mobius Strip - A Strange Surprise
Take a strip of paper, join the ends so you have a band. This is a very simple object with 2 surfaces.
Take a strip of paper, but give it 1 half twist before joining the ends. This is the famous Mobius Strip. Despite how it looks it only has 1 surface. Does a half twist clockwise give the same object as a half twist counter clockwise, or are these two different objects?
But things get strange fast..
Take a strip of paper, but give it 4 half twists before joining the ends. This has 2 surfaces. Now play around with it for a while. At some point it will suddenly "flip" into a double thickness band with 1 half twist. In other words it flips into a double thickness Mobius Strip. One surface has gone, and so have 3 half twists!
Content written and posted by Ken Abbott firstname.lastname@example.org