Summer is a time for the kids to get outside and play. And yet, Mother Nature doesn’t always cooperate. Sometimes she sends us heat advisories, thunderstorms, or plain old rainy days. Bah! This brings us to today’s Adventure in Learning: it’s part science, part history, part art, and a fabulous indoor activity for those days Mother Nature just isn’t feeling it.
Plus, we’ve added a twist to make today’s activity great for July 4 barbecues and celebrations!
The History and Science of Thaumatropes
Thaumatropes were invented by a 19th century British physician named John Ayrton Paris. He was curious about the retina and its ability to retain an image. So, he created a simple device to test it. He took a card and placed an image on one side, and a different image on the other. Then he tied strings to each side of the card and spun it fast to test the retina’s abilities.
The retina is the part of the eye that acts kind of like a screen. It’s incredibly light sensitive. That’s why when you stare at a bright light and look away, you’re left with spotty vision. More importantly, it’s responsible for taking visual information and sending it up to the brain for processing. The brain figures out what the image is and what it means. Now, while the retina is excellent at sending the info super fast (it is an electric impulse after all) there’s still a bit of delay. It’s small, but, it’s there.
That’s where the science behind the thaumatrope comes in. It plays with that teeny tiny delay, causing your brain to turn two images into one. It’s basically how movies work—films are actually a bunch of single images, that when shown together in super quick succession, make it look like pictures are moving.
Now that we have some of the history and science behind this illusion, let’s get to it. These toys are easy to make and even the youngest kids will get a kick out of them.
- card stock or thin cardboard
- hole punch
- string or rubber bands
- Cut a rectangle out of the card stock.
- Draw a set of colorful fireworks on one side of the card.
- Now, flip the card over so the drawing you just drew is upside down. Draw a second set of fireworks on the new blank side.
- Punch two holes on either side of the card; left and right.
- Attach a piece of string or rubber band through each hole and tie it in a double knot.
- Now roll the pieces of string between your thumb and forefinger to make the card flip back and forth. The two images become one. Cool, right?
After the kids get the hang of it, have them experiment with other drawings.