There are only two forces in the world, the sword and the spirit. In the long run, the sword will always be conquered by the spirit. - Napoleon Bonaparte
Chapter 8 - Irradiation and Brightness-Contrast In Optical Illusions
Many interesting and striking illusions owe their existence to contrasts in brightness. A dark line or spot will appear darker in general as the brightness of its environment is increased; or conversely, a white spot surrounded by a dark environment will appear brighter as the latter is darkened. In other words, black and white, when juxtaposed, mutually reinforce each other.
The visual phenomenon of irradiation (the apparent enlargement of a bright object when viewed against a dark background) does not strictly belong to this group, but it is so closely related to it and so dependent upon brightness-contrast that it is included.
Click the link below to start reading this chapter.
