To Do And Notice

Notice that the spiral seems to be either moving away from you or towards you depending on the direction of its spin.

Stare at the center of the spiral for about 30 seconds. Look up at a wall. Notice that the wall seems to be rushing toward

you or away from you, opposite of what the spiral was doing.


What's Going On?

Mechanisms in your eye and brain detect inward and outward motion. When something is standing still, the receptors

detecting inward motion are in balance with the receptors detecting outward motion.


What else can I do?

The Squirming Palm exhibit also demonstrates a similar phenomenon

What if the animation is playing too slow to see the effect?

Results of this experiment may vary depending on your computer's processing speed, the amount of RAM allocated to

your browser and the colordepth your monitor is set to.


You can increase animation performance by:

  • Switching your monitor's color depth to 256 colors
  • Closing other open applications
  • Allocating more RAM to your web browser

The Depth Spinner is also available as a downloadable application for the Mac OS. Depth Spinner 2.1 Beta for the Mac OS (845k hqx)

©1998 The Exploratorium