S C I E N C E C E N T E R

Transcription

1 IT SPINS BEFORE YOUR EYES But your brain makes a beautiful film out of it. With a special spinning drum with slits a zoetrope you can make your own cinema. Together you can make some crazy drawings and let them spin. Now who s fooling who? WHAT DO YOU NEED? Materials: Thick black paper (A4 size) White paper Paper cup Round pencil with eraser at the end Thumbtack Contact adhesive Glue Tools: Pencil Ruler Scissors Big pair of compasses White pencil Colored pencils or markers BUILDING PLAN Before he starts building, a builder of exhibits first makes a building plan of the exhibit. That s what you are going to do too. A building plan shows how something is made and how big it will be. First look at the photo and the drawings under How are you going to make it? This will give you an idea of what the exhibit will look like and how it should be constructed. Tips: 1. You can read the text accompanying the drawings already. 2. If the materials for your exhibit are already available, it s a good idea to have a look at them too. Under What do you need? you can see all the materials and tools that you need. But the list of materials does not show exactly how much of them you will need. You will know that only when you have decided how big the exhibit will be. So first decide with your pal how big the exhibit should be and how you are going to draw it. Discuss your plan with your teacher. 1

2 Now use a pencil and ruler to make a building plan in your workbook. You both make your own building plan in your workbooks, but you do it in the same way. You make the drawing to scale 1:2. This means that one centimeter in the drawing is really two centimeters in real life. So if your real zoetrope is forty centimeters high, it is twenty centimeters high in the drawing. Write the real measurements next to the different parts. For this, use the description under How are you going to make it? You are going to show the building plan to the rest of your class. Tell them how you plan to build the exhibit. Ask the other children and the teacher what they think of the building plan. Maybe they have an idea to make it even better. Show your improved building plan to the teacher. When he or she has approved your drawing, you can start making the list of materials together. LIST OF MATERIALS The building plan is ready, so you now know the size of all the materials and you can count how many of each part you need. Make the list of materials in your workbook and give the list to your teacher. Ask him or her where you can get these things. Then you can really start building! HOW ARE YOU GOING TO MAKE IT? To build an exhibit together you have to discuss a lot and make agreements. How are you going to tackle it? Who does what? Divide up the different tasks as fairly as possible. Try to work together as much as possible, so that you both get some experience of building. If you come across a difficult word, look it up in a dictionary. 1. First you are going to make the zoetrope. To do this, you use a big pair of compasses to make a circle with a diameter of 14 centimeters on the black paper. Cut the circle out. This is the bottom of the zoetrope. 2. Fold the other sheet of black paper (A4 size) in half lengthways. Cut it through the middle along the fold. Cut off a piece measuring 19 centimeters from one of the strips. Paste this piece lengthways on the other half of the black paper. Do this with glue. Spread glue over 2 centimeters of one of the pieces of paper and stick the other strip to it. You now have a strip of paper 46.5 centimeters long and 10.5 centimeters wide. Leave it to dry. 2

3 3. You are now going to make a gluing edge. Take the long strip of black paper. Use a white pencil and a ruler to draw a long line over the length of the paper, 1 centimeter from the edge. In the strip you have thus created, draw short lines to the edge of the paper; these should be 1.5 centimeters apart. Cut these short lines to make separate pieces and then fold these upwards. 4. Opposite the gluing edge, draw another line with a white pencil and a ruler, but now 3 centimeters from the edge. Again, draw short lines on this strip with the white pencil, but now every 4 centimeters. You now cut out slits around these lines as shown in the drawing. The slits will be about 3 millimeters wide, so cut about 1½ millimeters to the left and right of the stripe. 5. Now take the round bottom. Spread glue around the edge to a depth of 1 centimeter. Take the black paper with the gluing edge folded upwards. Glue this onto the bottom as shown in the drawing. Where the ends of the strip overlap, glue them together. 6. Take a paper cup and make a hole in the center of the bottom with the sharp end of a pencil with an eraser on the end. Push the pencil through the bottom. 7. Pull the pencil out again. In the centre of the bottom of the zoetrope is a small hole left by the compasses. Prick this through with a thumbtack. Then push the thumbtack into the eraser on the end of the pencil. 3

4 8. Now push the cup over the pencil. Glue the upper edge in the center of the bottom of the zoetrope. Make sure that the zoetrope spins well. 9. Now you are going to make the film. You can use the drawing on the next page for this. First copy the drawing and color it. Make sure that you use the same color for the parts of the drawing that will change their position. Then cut out the drawing and paste it into the zoetrope. Schuif nu de beker over het potlood heen. Plak de bovenrand vast in het midden van de onderkant van de zoötroop. Zorg dat de zoötroop goed kan draaien. HOW DOES IT WORK? The exhibit is ready. It works like this: hold the pencil of the zoetrope firmly in one hand. Give the zoetrope a spin with the other hand. Look through the slits. What do you see? WHAT DO YOU SEE HAPPENING? Now look for the science behind the exhibit. This exhibit is about the zoetrope. Do the research below. Write the answers in your workbook under Research report Do you see every drawing very clearly? Do you still see that they are different drawings? 2. And what happens if you give it a faster or slower spin? Now make your own film for the zoetrope. For this, you need two strips of white paper that are 6 centimeters wide. You make them like this: using a pencil and ruler, draw a line along the long side of the white paper 6 centimeters from the edge. Repeat this on the other (long) side. Cut both strips off. Make a gluing edge of 2 centimeters on one of the two strips and paste the two strips together with glue. On the long strip, you now draw a maximum of 12 pictures, each of which differs a bit from the last one. For example, a clown juggling balls. Make sure that the drawings are equally distanced from each other. To do this, divide the paper strip into equal spaces with a pencil. You are going to draw in these. You can erase the lines marking the spaces afterwards. However, you just make sure that the drawings make sense. When they are moving, the balls that the clown is juggling must always move in the same direction. The clown looks exactly the same in every drawing! You must also make sure that the first drawing and the last one fit each other. Are the drawings ready? Place the strip of paper in the zoetrope. Was the film successful? 4

5 fitting strip fitting strip 5

6 WHAT S THE ANSWER? Now you are going to find information about the zoetrope and film. You can look for information in the school media library, the library or the Internet. Go to and then to primary school pupils and click on links. Under the title of your exhibit, you will find a number of websites with background information. Answer the questions below and write the answers in your workbook under Research report 2. Operation: How should you operate a zoetrope? How should you look to see the film? Science: There are separate drawings on the paper strip on the inside of the zoetrope. Why do you see one moving thing or figure when you spin the zoetrope? Invention: Who invented the zoetrope? When was that? Application: Actually the zoetrope is a forerunner of the modern film. Today s cinema films work in the same way. Can you explain how that works? Let your teacher read your answers. 6