Sculpting the Impossible: Solid Renditions of Visual Illusions

Artists find mind-bending ways to bring impossible figures into three-dimensional reality

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In an impossible figure, seemingly real objects—or parts of objects—form geometric relations that physically cannot happen. Dutch artist M. C. Escher, for instance, depicted reversible staircases and perpetually flowing streams. Mathematical physicist Roger Penrose drew his famously impossible triangle, and visual scientist Dejan Todorović of the University of Belgrade in Serbia created a golden arch that won him third prize in the 2005 Best Illusion of the Year Contest. These effects challenge our hard-earned perception that the world around us follows certain, inviolable rules. They also reveal that our brains construct the feeling of a global percept—an overall picture of a particular item—by sewing together multiple local percepts. As long as the local relation between surfaces and objects follows the rules of nature, our brain doesn't seem to mind that the global percept is impossible.

Several contemporary sculptors have taken up the challenge of creating impossible art. That is, they are interested in shaping real-world 3-D objects that nonetheless appear to be impossible. Unlike classic monuments—such as the Lincoln Memorial in Washington, D.C.—which can be perceived by either sight or touch, impossible sculptures can be interpreted (or misinterpreted, as the case may be) only by the visual mind.

Stephen L. Macknik is a professor of opthalmology, neurology, and physiology and pharmacology at SUNY Downstate Medical Center in Brooklyn, N.Y. Along with Susana Martinez-Conde and Sandra Blakeslee, he is author of the Prisma Prize-winning Sleights of Mind. Their forthcoming book, Champions of Illusion, will be published by Scientific American/Farrar, Straus and Giroux.

More by Stephen L. Macknik

Susana Martinez-Conde is a professor of ophthalmology, neurology, and physiology and pharmacology at SUNY Downstate Health Sciences University in Brooklyn, N.Y. She is author of the Prisma Prize–winning Sleights of Mind, along with Stephen Macknik and Sandra Blakeslee, and of Champions of Illusion, along with Stephen Macknik.

More by Susana Martinez-Conde
SA Special Editions Vol 22 Issue 3sThis article was published with the title “Sculpting the Impossible: Solid Renditions of Visual Illusions” in SA Special Editions Vol. 22 No. 3s (), p. 86
doi:10.1038/scientificamericanillusions0913-86

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