Make a Salad Spinner Zoetrope
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The theme for this week’s Unplugged Project was wheel. I searched around for ideas and came up with this one which sounded really interesting: a zoetrope!
What is a zoetrope you ask? (I didn’t know what it was either.) A zoetrope works on the same principle as a flipbook, one of those little books where you flip the pages and it looks like an image is moving, but it uses a rotating cylinder to produce the illusion of movement.
I like this definition from Wikipedia: “A zoetrope is a device that produces an illusion of action from a rapid succession of static pictures.” The word zoetrope comes from the Greek zoe (life) and trope (turn), so it is really a “wheel of life,” perfect for our theme!
I found instructions for making a zoetrope many different ways: using a round camembert cheese box, a PVC pipe, a straw and a printout, a paper plate, and ice cream containers. We originally made up our own version out of black poster board, an old CD, a small lazy susan, and lots of tape. It was OK, but a bit wobbly.
Then I found a totally ingenious person who made one out of a salad spinner! Why didn’t I think of that? We absolutely had to try it and the result was AWESOME! It is an easy project that produces a maximum “wow factor.” Try it, here’s how:
Use electrical tape to tape off the slits on the salad spinner basket leaving every third slit open. We used 3/4″ electrical tape and that just happened to be exactly the right size for the job.
For images, the salad spinner genius used cutouts of the phases of the moon from a calendar. Very clever but I decided to draw my own pictures.
On a piece of white paper I marked off a series of 3/4″ x 3/4″ squares.
Then, using a black Sharpie, I drew a face with a changing mouth and waving hair, making each image slightly different than the previous one.
The tedious part was cutting out all 26 images and taping them in sequence to the blocked off areas of the inside of the salad spinner.
Finally, using a clump of rolled up tape, stick your zoetrope onto the overturned lid of the salad spinner, centering it as best you can. The zoetrope will be sitting on the rotating disk, and the salad spinner handle will be underneath.
Now for the fun: spin and look through the slots to see the “movie!” The view is best if you shine a bright light into the bowl of the zoetrope.
Hopefully you’ll see from this little 10 second video that we made, how cool this project really was!
Let’s not forget THE SCIENCE:
So how do flipbooks, zoetropes, thaumatropes (a rotating card with a different picture on each side, the pictures appear to combine when card is spun), cartoons, and old time film movies actually work? Many people still believe in the “persistence of vision” theory, in which it is thought that an image remains in the eye for a certain time after the image source is actually gone (ie. the optic nerve is the cause). Apparently that theory is no longer in favor these days. A more popular theory at the moment involves something called Beta movement where the brain itself apparently combines rapidly flashing images thus forming a perception of movement (ie. the brain is the cause). It seems that no one really understands any of this completely, but here are a few informative links if you are interested:
The Myth of Persistence of Vision, by Joseph and Barbara Anderson
Lectures: Visual Perception 8 – The Moving Image
FIELD TRIP:
You can visit a real zoetrope at the following museums:
V&A Museum of Childhood, London, UK
The Ghibli Museum, Tokyo, Japan
Great Lakes Science Center, Cleveland, Ohio, USA
Headwaters Science Center, Bemidji, MN, USA
Have fun!
(Be sure to visit the links to other people’s wheel Unplugged Projects on last Monday’s Weekly Unplugged Project post.)
that went very fast…for about 6 inches. I think the axle needs work, as does the length of the rubber band. It was fun, even though our model obviously needs improvements.
Themocracy