"Seeing is believing." "A picture is worth a thousand words." But sometimes our eyes deceive us, and what we see is only what our brain expects to see. Optical illusions are amusing, but they also teach us a lot about how our brain works in conjunction with our eyes to create vision. Are you ready for some fun science?
The fabulous hands-on science museum from San Francisco presents a gallery of thirteen illusions (many powered by Shockwave and QuickTime) to play with and learn from. You'll find the Cafï¿½ Wall Illusion on other sites as well, but here you get to interact with it and watch the distortion come and go. "The Cafï¿½ Wall Illusion was first described by Dr. Richard Gregory. Dr. Gregory is a good friend of the Exploratorium and director of The Exploratory Hands On Science Museum in Bristol, England. Dr. Gregory observed this curious effect in a pattern of tiles on a cafï¿½ wall in Bristol and has kindly granted us permission to display his picture of this cafï¿½."
Have you ever seen a Magic Eye picture? Nine years ago they ignited a craze and sold more than twenty-five million books between 1992 and 1995. Although the buzz has died down, the Magic Eye company is still around. Once you learn how to focus your eyes, a three-dimensional object will appear floating above the original image. Can't see it? Help is only a click away ï¿½ look for the link titled "Need help viewing 3d?" Another fun difference between a printed Magic Eye picture and this online archive, is that clicking on the picture itself reveals the hidden answer.
My very first reaction was "Wow!" and then it got better and better. Sand Lot Science is my pick of the day with over one hundred online exhibits. In addition to dozens of interactive illusions, unique clicks include Do-It-Yourself Projects ("Six easy-to-do optical illusion projects in Adobe PDF format to tempt the curious.") and a Typography Section. "Here is a familiar word with the top half missing. Can you read the word anyway? Place your mouse over the top half of the word. Now the bottom half goes away. Try to read the word both ways! Which is easier?"