Pacman has been going around and around for so long  that he has worn the wooden object!  This object has the same properties as the Möbius strip.  It's got only one side.  Just try to follow Pacman's track,  you'll find that he will eventually come back  to exactly the same spot.  But he will come very near to this spot  three times before reaching it at last.  But Pacman won't stop there, of course.  He will keep going around and around...

Making a Möbius strip is very easy!

1. Cut a strip along the length of the sheet of paper, say 3 cm wide.
2. Make a ring by joining the ends of the strip, but don't glue anything yet!
3. Now here's the trick: twist one of the ends, half a turn.
4. Now you can glue the two ends.

This strip has interesting properties!

• It has only one side
Take a pen and start drawing a line in the middle, just like a line in the middle of the road. See what happens? You get back to the starting point, but if you were to cut the ring so as to come back to the original strip, you would get a strip marked on both sides. So the Möbius strip has neither inside, nor outside.
This property is masterfully demonstrated by M. C. Escher in "Möbius Strip II".

• It has only one edge
Try to follow the edge with your finger, starting at the place where the two ends have been glued to one another. Once more you'll get back to the starting point, but before getting there, your finger will meet the seam across from the starting point.