A class of illusion in which an object which is physically unrealizable is apparently depicted.
More than 100 papers have been written about impossible figures (Kulpa 1987), and Escher made extensive use of them in some of his well-known drawings.
Impossible Figure
See also
Ambihelical Hexnut, Freemish Crate, Home Plate, Illusion, Impossible Fork, Impossible Joinery, Impossible Torus, Klein Bottle, Necker Cube, Penrose Stairway, Penrose Triangle, TriboxExplore with Wolfram|Alpha
References
Cerf, C. "A Family of Impossible Figures Studied by Knot Theory." http://www.mi.sanu.ac.yu/vismath/cerf/.Cowan, T. M. "The Theory of Braids and the Analysis of Impossible Figures." J. Math. Psych. 11, 190-212, 1974.Cowan, T. M. "Supplementary Report: Braids, Side Segments, and Impossible Figures." J. Math. Psych. 16, 254-260, 1977.Cowan, T. M. "Organizing the Properties of Impossible Figures." Perception 6, 41-56, 1977.Cowan, T. M. and Pringle, R. "An Investigation of the Cues Responsible for Figure Impossibility." J. Exper. Psych. Human Perception Performance 4, 112-120, 1978.Cowan, T. M. "Turning the Penrose Triangle Inside Out." J. Math. Psych. 26, 252-262, 1982.Ernst, B. Adventures with Impossible Figures. Stradbroke, England: Tarquin, 1987.Harris, W. F. "Perceptual Singularities in Impossible Pictures Represent Screw Dislocations." South African J. Sci. 69, 10-13, 1973.Fineman, M. The Nature of Visual Illusion. New York: Dover, pp. 119-122, 1996.Jablan, S. "Impossible Figures." http://members.tripod.com/~modularity/impos.htm.Knuth, D. E. §7.2.2.3 in The Art of Computer Programming, Vol. 4. Pre-Fascicle 7A, p. 14, Dec. 5, 2024.Kulpa, Z. "Are Impossible Figures Possible?" Signal Processing 5, 201-220, 1983.Kulpa, Z. "Putting Order in the Impossible." Perception 16, 201-214, 1987.Rakov, D. "Impossible Objects." http://www.rakov.de/ARTE.HTM.Rausch, J. "Impossible Objects." http://www.johnrausch.com/PuzzleWorld/cat/io000.htm.Robinson, J. O. "Impossible Figures." In The Psychology of Visual Illusion. New York: Dover, p. 176, 1998.Sugihara, K. "Classification of Impossible Objects." Perception 11, 65-74, 1982.Terouanne, E. "Impossible Figures and Interpretations of Polyhedral Figures." J. Math. Psych. 27, 370-405, 1983.Terouanne, E. "On a Class of 'Impossible' Figures: A New Language for a New Analysis." J. Math. Psych. 22, 24-47, 1983.Thro, E. B. "Distinguishing Two Classes of Impossible Objects." Perception 12, 733-751, 1983.Wilson, R. "Stamp Corner: Impossible Figures." Math. Intell. 13, 80, 1991.Referenced on Wolfram|Alpha
Impossible FigureCite this as:
Weisstein, Eric W. "Impossible Figure." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/ImpossibleFigure.html