(This exhibit is based upon an exhibit description included in the Exploratorium Cookbook series.)
The exhibit consists of six patterns, each the size of one sheet of paper 8.5"x11". The six patterns are labeled with different letters of the alphabet to allow reference to each individually. When looking at some of these patterns, most people will see a swirling or shimmering motion immediately around the solid centers.
|
|
|
|
|
|
The patterns are placed in random order on the exhibit stand. The patterns are a series of lines or narrow triangles emanating out from the center of a circle. Each pattern uses just one line or triangle repeated 120 times. Different widths of lines and triangles were used in different patterns to vary the effect and give the visitor a better opportunity to try to understand the phenomenon. One pattern was also laminated so that visitors could see what happens to the effect if they move the pattern.
The effect is easier to understand if one thinks in terms of the earliest video game, called Pong. It simulated ping pong, and was played on a television screen. The game boundary and center dividing line were constantly displayed in the same positions on the screen. After several hundred hours of use, people noticed that these lines were becoming permanently burnt into the screen because they always appeared in the same positions.
We see images that appear on our retinas. If an image were to appear on exactly the same position on the retina for a period of time, the brain might tend to ignore it in favor of other images that are moving. To avoid this possibility, our eyes are constantly moving ever so slightly. This is known as saccadic motion. This motion causes images to constantly change position very slightly on our retinas so that the images are superimposed on each other.
Normally we do not perceive this eye movement. A closely spaced high contrast alternating pattern is needed to allow us to observe the effect of the saccadic motion.
Return to GCSEC Sample Exhibits Page
Hosting of this site is generously provided by Choice.Net