Make: Technology on Your Time Volume 26

TOYS, TRICKS, AND TEASERS

By Donald Simanek, recreational physicist

Kinetic Illusion Toys

Deceive the eye with impossible falling motion.

VISUAL ILLUSIONS COME IN MANY FORMS. The most common are flat pictures, cleverly made so they seem to show something that’s impossible in reality. A smaller category is the kinetic illusion, an illusion caused by motion of real objects.

Jacob’s Ladder

Let’s look at two kinetic illusion toys, one well-known, one not so well-known. Both give illusions of something continuously falling that doesn’t really fall.

The folk toy called “Jacob’s ladder” is also known as “magic tablets,” “Chinese blocks,” or “klick-klack” ...