How does the penrose steps work

In Goldstein, E. Sage Publications, Inc. Penrose, L. Impossible objects: A special type of illusion. British Journal of Psychology , 49, pp. Wikipedia contributors 23 April Home Explore Illusions Penrose Stairs. Penrose Stairs Impossible staircase. The positioning of the stairs is impossible - they seem to forever ascend in one direction and descend in the other.

Instructions Note how the stairs appear to continiously ascend when tracing round their path in one direction and descend in the other, yet if one were to complete a circuit one would end up back at the same level that one began. Effect You will see something which appears physically possible yet which you know is not. Penrose Stairs. Escher subsequently wrote back to Penrose and Penrose see Ernst : A few months ago, a friend of mine sent me a photocopy of your article References Ernst, Bruno July , "Penrose Stairs" in F.

Macpherson ed. Escher then discovered the Penrose stairs in the following year and made his now famous lithography Klimmen en dalen Ascending and Descending in March Penrose and Escher were informed of each other's work that same year. Escher developed the theme further in his print Waterval Waterfall , which appeared in In their original article the Penroses noted that "each part of the structure is acceptable as representing a flight of steps but the connexions are such that the picture, as a whole, is inconsistent: the steps continually descend in a clockwise direction.

Optical Illusions Wiki Explore. Optical Illusions. Escher's Ascending and Descending which shows numerous monks laboriously climbing up and down the same steps. By distorting perspective in the two dimensional illustration, the impossibility of the Staircase is removed, and it often takes new viewers a little time to realize that something is not quite right.

The same illusion can be pulled off by cleverly photographing a carefully built sculpture. From most angles such a structure will look like nonsense, but if viewed from just the right position, the faults are hidden and the impossible apparently created.

An extraordinary example of this is provided by Andrew Lipson, a self proclaimed nerd, mathematician, and computer programmer, who, along with Daniel Shiu, built a rendition of Ascending and Descending out of the ever-popular LEGO toy bricks. Lipson's explanation on his webpage should satisfy all but the most demanding LEGO-nerd.

Descriptions of some of the pieces used to build the model as well as many photographs of the work-in-progress are provided and help explain just how Lipson and Shiu achieved the illusion. Many other people have built and photographed their own impossible Staircases; and, while true Penrose Staircases cannot function in the real world, we see that three-dimensional representations can be tricked into being. And, of course, through clever camerawork Christopher Nolan is able to put a Penrose Staircase on the big screen.

The illusion appears twice in the film, actually, but the second time is probably overlooked even more often then when it is first explained.