Can You Put Your Head Through a Business Card?

Index. Business. Playing. Can You Put Your Head Through a Business Card?

Moebius Strip, Continuous, 2-Sided Strip with No Inside or Outside

Do you remember when you or your brother or your sister learned magic tricks?

I think, at some age, every child gets interested in magic. My brothers did. My sons did.

Some is sleight of hand that takes hours of practice so the audience can not to see how the trick works.

Some is done with props – a globe-within-a-globe to hide and then reveal a ball.

Telescoping magic wands that reveal a bouquet of flowers on command.

When Is Magic Really Science?

Some magic is really just science showing us the world in a new way.

That is what the putting-your-head-through-a-card trick is.

It is topology revealed in such a startling way that some children will want to learn more about this fascinating subject.

For everyone else, it’s just fun.

Challenge

Here’s the challenge.

Can you put your head through a business card (or an index card, or a playing card)?

You can, but your audience probably cannot.

You will need a card and a pair of scissors.

Instructions

Here is how you do it.

1. Fold the card in half across the width, not the length, so it is almost square.

2. First set of cuts: cut from the folded edge almost to the open edge about 1/8 inch from one end, to within 1/8 inch of the open edge.

Be sure not to cut all the way through to the other edge.

3. About 1/8 inch from the first cut, cut on the opposite side, from the open edge, almost to the folded edge, again, leaving about 1/8 inch uncut, this time on the folded edge side.

4. Keep this up, cutting on opposite sides of the card, to within an 1/8 of an inch from the other end.

5. Gently open up the card, separating the cut edges, until the card is unfolded.

6. Second set of cuts: not including either end, cut the folded seam all the way across on the inside strands.

7. It is very important not to cut the end seams, as these hold the final “necklace” together.

8. Open the paper up and it will fall into a large ring you can easily put your head through.

For a graphic view of the first set of cuts, click here. Note that this site, like several other Internet sites describing this trick, does not include the second, critical set of cuts.

Science

To understand why this works is to be introduced to a branch of mathematics called topology, the study of the spatial relationship between geographic features, especially their continuity and connectivity.

In this case, you are making a continuous piece of the original card with strategic cuts that allow you to stretch it out in an open circle, while it is still connected.

One of the first problems in the emerging field of topology was to figure out a route through a town in which you would cross each of seven bridges once and only once. This is the Seven Bridges of Koenigsburg problem.

The insight gained from developing an analytical method to prove that there was no solution to this problem was that it did not matter how far apart the bridges were, or how long, but how they were connected to riverbanks and islands. The graph developed to show these connections ultimately led to the branch of mathematics called topology.

Common uses of topology today are computer network layouts networks.and geographic information systems, such as those using Global Positioning System (GPS) data.

Do you remember any tricks you learned as a child that you can teach your grandchildren?

Do you remember the wonder of surprise when someone showed you something you thought was impossible?

What was it?

Frugal Fridays are fun activities to share with the grandchildren. Click here to follow our Frugal Friday posts in your Reader or click here to get all our posts by email.

To you and introducing your grandchildren to the wonders of the world.

Carol Covin, “Granny-Guru”

Author, “Who Gets to Name Grandma? The Wisdom of Mothers and Grandmothers”

http://newgrandmas.com

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