Optical Illusion Science Project

An optical illusion is first of all an illusion. An illusion is a false understanding of information perceived from reality. Optical means that it pertains to the sense of vision. The oldest optical illusion ever to exist is the rainbow. It is a refraction of sunlight through the prism of raindrops.

Much more complicated is one of mankind’s oldest optical illusions, called an anamorphosis. This is an image reproduced in a distorted way that can only be seen logically with the aid of some visual instrument, such as a cylindrical mirror. This kind of illusion has been used since the 14th century in Europe. Spies have used it to camouflage sensitive information; artists have used it to exercise their perspectives and architects have used it to convince their public that they’ve built structures which they haven’t. In the Renaissance these optical illusions were produced by knowledgeable mathematicians and scientists. Geometrical algorithms produce anamorphic art. The planar and conical cases are quite elementary. However cylindrical ones test a artist’s or mathematician’s ability to a greater degree. The mathematical association was lost in the subsequent centuries. Currently, scientists at Guelph University in Ontario, Canada have re-discovered the transform equations needed for producing anamorphs.

In the arts, an image created with this technique can appear extremely difficult to comprehend. Or perhaps, in some case, the items are just slightly skewed. The concept of perspective didn’t exist in European art until the 14th century. With perspective came play; the artist began to manipulate images to create illusions.

A sixteenth century painter named Hans Holbein, the Younger (1497-1543), painted one of the most famous examples of an anamorphosis. His painting called "The Ambassadors," is one of two men standing in front of tables full of books, instruments, and globes. At the bottom, Holbein painted what turns out to be a grinning skull when the painting is slanted the right way.

With anamorphosis, the viewer must change his or her perception of the painting or image in order to comprehend it. This is often done with mirrors. It can also be done by relaxing and squinting the eyes to see a concealed image, or by stepping aside and viewing the picture from a different position.

Anamorphosis can be done with a rather tedious graphing technique. However, it is enjoying resurgence in popularity. Have a go at it.

Begin with two sheets of graph paper. The first graph paper should be ruled into squares. The second one should be ruled into the same number of trapezoids. A trapezoid is a four sided, four angled (quadrilateral) plane that has two parallel lines and two non-parallel lines.

Draw the picture on the square grid.

Carefully draw the corresponding part of the picture on the corresponding trapezoid. Stretch each line as necessary to fill the grid and make the lines touch each other at either end of the boxes.

The end result should be a distorted version of the original picture. In this case, all you need to do is tilt the distorted picture at the proper angle in order to be able to see the original image. Play with it.