What you need: paper, scissors and tape

HOW TO MAKE A MÖBIUS STRIP….HOW TO MAKE A MÖBIUS STRIP….

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Möbius strip was named after the famous German astronomer and mathematician August Ferdinand Möbius (1790-1868), who was a pioneer in the field of topology. He came up with his 'strip' inSeptember 1858 M.C. Esch

SO… WHAT IS A MÖBIUS STRIP?

Most surfaces have two sides – like a sheet of paper – you can paint each side with a different colour. AMöbius strip doesn't have a front or a back. The top and the bottom are the same. The twist in the strip connects what was the top to the bottom, making one big side and only one edge.

1. First, cut out a long, thin strip of paper (about 3cm wide).

2. Holding it the tall way, label the top left corner "A" the top right corner "B" the bottom left corner "C" and the bottom right corner "D“.

3. Give the strip a twist and tape the two ends together so that "A" touches "D" and "B" touches "C“.

4. Draw a line around the strip (in the middle). What happens?

5. Use the scissors to cut along the line you drew. How many bands do you have now?

6. Take another strip of paper and twist it twice. Tape it closed. Cut it in the middle, the same as before. What happens?

Why did the chicken cross theMöbiusstrip?

To get to the same side.

What do they do with them?

What do they do with them?

Giant Möbius Strips have been used as

conveyor belts (to make them last longer, since

"each side" gets the same amount of wear) and as continuous-loop

recording tapes (to double the playing time). In the 1960'sSandia Laboratories

used Möbius Strips in the design of versatile

electronic resistors. Free-style skiers have christened one of their

acrobatic stunts theMöbius Flip.

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The famous artist, M.C. Escher, used mathematical themes in some of his work,

including a Möbius parade of ants. His flight of swans looks like it might be a Möbius Strip, but

it's not. Can you see why not?

Using a piece of cardboard about ¼ of the size of an A4 piece of paper, make three cuts in the index card that go almost to the top of the card.

Try to pull on both of the ends of the index card at the same time, ripping it so that the middle part falls to the ground. Impossible, huh?

Did you knowthat you can't fold a

piece of paper in half more than eight

times, no matter how big the paper is?

Go on… try it.

Why is this?There are two reasons why it's impossible to do this: First, it's almost impossible to make two cuts that are exactly even. So, when you pull both sides, one side will almost always break first.

Second, it's almost impossible to pull equally on both sides. So, the side you pull on with more force, or pull on first, will rip first.

Try this with a different sized piece of paper and see what happens.

pull pull

Take a piece of A4 paper and cut it in half. Using one of the pieces see if you can you cut a hole in it big enough for you to climb through without breaking it.

Q. Which side of a chicken has the most feathers?

A. The outside!

Q. What do you call a chicken who crossed the road, rolls around in the dirt, and crosses the road again?

A. A dirty double-crosser!

Invisible InkStuff you need: paper, toothpick, lemon juice and a heat source (like a lamp or a toaster).

Dip the toothpick in lemon juice and write a secret message on a piece of paper. Let the paper dry for a couple of hours.

Then hold it over a lamp or toaster to warm it up. The message will magically appear.

How this works:After the lemon juice dries, a residue of organic solids is left behind on the paper. When heated, the solids darken and reveal the writing.

Experiment with other liquids such as orange juice, apple juice and milk. Do they work as well as lemon juice? Also try different kinds of paper. Which types of paper work best? Does more absorbent paper such as newspaper work as well as less absorbent paper such as notebook paper?

cut

Stuff you need: Ruler, newspapersWhat you do: Slide a ruler underneith several flat sheets of newspaper, until only 5cm of the ruler sticks out. Strike the ruler suddenly with a thick roll of (additional) newspaper. The ruler and flat sheets of newspaper will stay in place.How it works:Air pressure on top of the newspaper keeps the ruler in place. If the ruler is slowly pressed down, the newspaper will lift. But if the ruler is struck hard, air cannot move out of the way fastenough and holds the ruler in place.

Try changing the length of ruler that sticks out from beneath the newspaper. What is the maximum distance that the ruler can stick out before the newspaper can no longer hold down the ruler. Put more newspapers on the first several sheets of newspaper. Which holds the ruler to the tabletop better: (a) stacking the paper straight up and down on top of each other or (2) overlapping the papers on top of each other?

All you need, cardboard, scissors, several pieces of paper of different sizes

Can’t huh! Ok – try cutting it this way instead.

First fold the paper in half length ways.

Make a cut along the fold – be careful not to cut all the way to the ends, leave a space on either side.

Make cuts as indicated on the diagram below. Be careful NOT to cut all the way through the paper.

Try different sizes of paper. Try making the cuts closer together and see what happens.