Penrose staircase

English

Penrose staircase

Etymology

After a drawing by Lionel Penrose and Roger Penrose.

Noun

Penrose staircase (plural Penrose staircases)

1. An impossible loop of endlessly ascending and descending stairs, or an optical illusion appearing to be one.
   • 1984 February, Monte Davis, “Profile of Benoit B. Mandelbrot”, in Omni, →ISSN, page 9:

     Can you make a fractal equivalent of the “Auditory Penrose Staircase,” the illusion of a steadily descending tone, by zooming in on a fractal as it branches?

   • 1989, Martin Gardner, Penrose Tiles to Trapdoor Ciphers: ...And the Return of Dr. Matrix, New York: Freeman, →ISBN, →OL:

     They are the inventors of the famous "Penrose staircase" that goes round and round without getting higher; Escher depicted it in his lithograph "Ascending and Descending."

   • 2010, Diana Deutsch, “The Paradox of Pitch Circularity”, in Acoustics Today, volume 6, number 3, →DOI, pages 8–14:

     This pitch paradox has been used to accompany numerous videos of bouncing balls, stick men, and other objects traversing the Penrose staircase, with each step accompanied by a step along the Shepard scale.

Synonyms

• Penrose stairs
• Penrose steps

Translations

Penrose stairs — see Penrose stairs