Saturday, September 01, 2007

Trick #10: Afghan Bands

Also known as "The Perplexing Mystery Of The Moebius Bands", this is a self-working trick that seems to defy logic! A loop is cut in half lengthwise, but instead of two loops, you have one long loop! You try again, but now instead of two separate loops you have two loops linked together! Even you will be amazed when it happens!

REQUIREMENTS: A strip of newspaper or cloth cut about 4" wide by 3' long. Cut it so the the grain runs with the length of the strip. Paste or glue.

Moebius strips are a mathematical oddity that can be used in magic to produce unbelievable results. Basically, a moebius strip is a loop which has been cut at one point, given a half twist, and reconnected. It now has only one side and one edge. I know that sounds weird, but try making a simple moebius strip out of a 2" wide strip of newspaper, and run your finger around the edge. It will first go around the outside of the loop, then when it reaches the twist it will go all the way around the inside of the loop, and when it reaches the twist again, it will go all the way around the outside again. It literally has only one side, or edge.

To prepare the trick: Take your strip of cloth or paper (if you use cloth make sure it is easily tearable). At one end cut a slit about 3" long down the middle of the band. At the other end cut another slit along the middle about 1 inch long (Figure 1).

Bring the ends of the cloth or paper together to make a loop. But, before you connect the ends with glue, give one of the 3 inch slits a half twist (Figure 2), and the other 3 inch slit a full twist (Figure 3). Then, glue the ends together as in Figure 3.

To perform the trick: Take the prepared loop and tear it down the middle into two loops (Figure 4). You will now have one loop with a half twist in it, and one loop with a full twist.

Now, for the really weird part. When you take the loop with the full twist in it and tear it down the middle, everyone expects you to get another two complete loops, AND YOU DO... ONLY THEY'RE LINKED TOGETHER as in Figure 5!
And, when you take the loop with the half twist and tear that loop down the middle, instead of two separate loops or two connected loops, YOU JUST GET ONE BIG LOOP! (Figure 6)

Try it and see

NOTE: It is important when you cut or tear the bands thay you stay in the center all throughout the cut. Start the tear at one end, or place the scissors in, and then carefully cut in a straight line, staying in the center of the band and working your way around the center of the entire band until you reach the point where you began.

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