gestalt (13. 431)

Via Clive Thompson’s latest linkfest (lots more to discover there), we discover this catalogue of scores of visual phenomena and optical illusions catalogued and indexed by one Michael Bach, polymath and ophthalmologist. Each entry includes details about the provenance and with an explanation of what’s going on perception-wise, including how to unsee it. Furthermore, unlike this sample GIF of Roget’s Palisade, the illusion first described by the author of the eponymous thesaurus though his take on the mechanism behind the illusion does not quite fit with the current understanding of what’s classed as the rolling shutter effect, the animations that Bach has created can be paused, the colours denuded and sped up or slowed down. Let us know your favourites and what you find most befuddling.