Disappearing Act

Click the "animate shape" box to start or stop a shape's movement across the colored background. You can also move a shape by clicking and dragging.

What do you see when you stop the shape inside the colored background? What if it's only partially inside?

Experiment with different shapes and backgrounds, starting and stopping in different places.

Many animals, including humans, have specialized brain cells that detect motion. These cells receive information from light-sensitive cells at the back of the eye. As an object moves past your eyes, some of your light-sensitive cells experience rapid changes in light and dark, triggering your motion detector cells.

It's no accident that many animals have evolved a sensitivity to motion. In the wild, anything that moves is potentially predator or prey. An animal's survival depends on it ability to detect motion quickly.

This online exhibit is still under development
comments or suggestions e-mail: Lowell Robinson

The museum version of this exhibit was originally developed by Professor Ken Nakayama of Harvard University.