You Won’t Believe Your Eyes: STEAMStacks Optical Illusions

In November and December, look for this fun activity at your local SJPL branch. Recommended for children 8 and above,  the one-hour program involves making crafts that explore how  things like light, color, and patterns can play tricks on your eyes.  It’s a science and art project all rolled into one!

Actually, it’s three projects. Make your own to take home:

The word thaumatrope is derived from Greek words meaning “miracle turner.”  It’s a disk with a picture on either side (for example, a bird on one side and a cage on the other). When the disk is twirled rapidly, your eyes see the two pictures as one (e.g., the bird looks like it is inside the cage). This is due to a phenomenon known as “persistence of vision.”


Benham's DiskBenham’s Disk
In 1895, the British journalist and toymaker Charles Benham invented a black and  white patterned top. When you spin it, you might see different colors. Not  everyone sees the same colors, and some people don’t see colors at all.

Nobody quite knows how this works. Although we know that black is the absence  of all colors and white is the presence of all colors, we’re not quite sure what it is about the pattern on the disk that causes the color receptors in our eyes (called “cones”) to see different colors when we spin the disk.

Magic Picture
Create a picture frame that holds two completely different pictures. You will see only one of the pictures from one side of the frame, and the other picture from the other side.  You’ve created your own optical illusion, just like a stage magician performing a trick!

Check out the catalog for some of the great books on optical illusions in the library’s collection. And check out our event page to find out when you make these optical illusions for yourself!

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