Kragen's technique for inventing new kinds of software or new applications of existing software seems to me to have been invented by Ramon Llull. The difference is that Llull, according to Martin Gardner, was aiming at getting people to think about ideas such as "God's greatness is good" and "God's goodness is great", where Kragen is aiming at getting people to think about ideas like "we could combine BitTorrent and xwd" or "we could combine Wiki and Google Maps". But I almost think that Kragen's program ought to carry a credit to Llull.
David Chess pointed to an actual vision researcher's fantastic page of optical illusions, many of which I hadn't seen before and several of which were apparently discovered only recently. (Many of them seem to require Flash, Java, or other exotic things, but a few are simple animated GIFs.) This is really fun.
David refers to the rapid colored afterimage in particular, which I found amazing; I'm also impressed by the contrast gain control. If you're on a machine with a Flash player, I also recommend the rotating spokes.
The optical illusion home page quotes Purkinje: "Illusions of the senses tell us the truth about perception." This weekend I heard a reading by Michael Chorost, the author of Rebuilt: How Becoming Part Computer Made Me More Human Books, which had just been reviewed by Annalee in Techsploitation. Chorost, who uses a cochlear implant, says that losing and regaining a sense -- with the mediation of technology and with the mediation of software -- shows that perception is not what we assume it is. I guess the rest of us may have to rely on optical illusions to do that.
