Happy Birthday Bear Cake

PIRA: 6J11.30

Overview:

This demo illustrates the physics of persistence of vision. As the dome rapidly rotates, the distinct yellow and blue stripes become blurred into continuous bands of color. This occurs because the human eye retains an image for a brief moment after the actual object has moved or disappeared. When the dome spins fast enough, the successive images of each stripe are presented to the eye before the previous image has completely faded from the retina, causing our brain to perceive them as a continuous, unbroken pattern surrounding the stationary bear. This optical illusion demonstrates how our visual system integrates rapidly changing visual information.

Materials:

Just the bear in the birthday cake toy.

Setup:

There is no set-up for this demo.

How to:

Press the button and allow the cake to spin around the the bear.

Safety:

Must be at least 3 years old to operate.