Created on 27 July 1997.
Last modified on 5 August 2000.

Implementation Notes

Most of the illusions included here rely on effects that not all displays are capable of reproducing. If you have only a monochrome display, for example, none of the colour or contrast illusions will be very effective, and many will simply not work at all. Similarly, if your browser is running on a computer or terminal that has no local sound capability, the auditory illusions will be inaccessible.

Even when these obvious problems are not present, however, the effectiveness of a particular demo may still depend on the actual resolution and colour gamut of your monitor, the precision with which the timing of animation is maintained, and perhaps even the frequency response or your speakers. The default settings for each demonstration should be reasonably close, but you may need to experiment a bit with the various controls until you can see or hear the effect as described. In some cases, especially those that rely on small differences in hue or luminance, you may not be able to reproduce the illusion very effectively.

All of the interactive demonstrations were implemented using version 1.0.2 of the Java Development Kit (JDK). Although this kit provides a high degree of cross-platform consistency, there were nevertheless many minor differences in the behaviour of the same code when run using the same software (e.g., Netscape 3.1) on different platforms, or even using different software (e.g., Netscape and the JDK applet viewer) on the same platform. The demonstration programs have been tested with a modest variety of different configurations and platforms and, except for minor peculiarities involving resizing or windows and updating of slider bars, appear to work quite well. If for some reason a demo cannot be made to work adequately on your platform, of if your browser does not support Java, then you will have to make do with the static illustrations that accompany each illusion.

Scott Flinn (