Kopie van Penrose Stairway
The Penrose stairs or Penrose steps, also dubbed the impossible staircase, is an impossible object created by Lionel Penrose and his son Roger Penrose. Bedankt Ivan de Winne!
An impossible figure in which a stairway in the shape of a square appears to circulate indefinitely while still possessing normal steps (Penrose and Penrose 1958).
The Dutch artist M. C. Escher included a Penrose stairway in his mind-bending illustration "Ascending and Descending"