Take a sheet of printer paper and cut a one inch strip from the long side. Get ready to tape the ends together to make a loop but wait a moment.
Before you tape them, turn one end over (180 degrees) and tape the ends that way. You’ve taped the bottom to the top.
You are now holding a very special loop of paper.
A moment ago, that strip of paper had two sides and (if taped in a normal loop) two long edges. Your loop has only one side and one edge!
Prove this by writing an “S” for “start” and drawing a line down the middle of the strip. Do this carefully, scooting the paper along as you go. Keep your line running down the middle of the strip and make sure you never lift your pencil.
Suddenly, you’ll find yourself back at the “S” where you started, without ever turning the paper over. Your strip has only one side.
If you’re careful, you can run a yellow highlighter along the edge of the strip. Without ever lifting your marker, you’ll find yourself back where you started. Your strip has only one edge.
If you have a curious young scientist, let him or her think about this one for a while.
Oh, one other thing. What do you imagine will happen if you cut along that pencil line you drew down the middle? Think about it a moment and give it a try.
The Mobius strip, first discovered in 1858, is part of a field of study called topology and has a few more interesting properties that you can look into later on your own.
A search on Google and Youtube will keep you busy.
For now, though, here’s a riddle…
Why did the chicken cross the Mobius strip?
To get to the other… oh, wait. Never mind.