Christopher Nolan’s film Inception features a classic optical illusion called the Penrose staircase, which folds back upon itself in space. World-renowned puzzlemaker and LEGO constructor Eric Harshbarger takes us for a walk on the stairs.
“Forever Ascending,” by Eric Harshbarger
The popular film
Inception provides its viewers with many twists and turns in both storytelling and visuals. From dreams within dreams and mirror-induced Droste effects to mazes and cityscapes that fold upon themselves, the movie keeps the audience engaged and continuously looking for more. With so much going on (and so much left unanswered), it is understandable that some of the details might slip by the moviegoer.
Still from Inception, courtesy of Warner Bros. Pictures
One such detail is an optical illusion that is brought to the screen in the form of an ever-ascending staircase. It is introduced by Arthur (Joseph Gordon-Levitt) to Ariadne (Ellen Page) as a way to construct a never-ending dreamscape within an otherwise finite world. The moment plays out quickly, and, as with many of director Christopher Nolan’s scenes, it is assumed that the audience will keep up. If it was not clear what exactly was going on, then allow me to re-introduce you to the notion of the Penrose Staircase.
The illusion takes its name from a father and son duo of mathematicians, Lionel and Roger Penrose, who introduced the impossible object in a 1958 paper. The Staircase cannot be constructed in three dimensional reality due to its property that the steps forever carry the traveler upward in a loop. The same steps are traversed, but, impossibly, after the first time around (or second, or third…) one ends up back at the beginning, and the whole journey starts again. One can turn around on the stairs and descend, as well, with the same effect—continually treading the same ground, over and over.
While impossible to build in our real world, that has not stopped mathematicians and artists from depicting the Penrose Staircase as an optical illusion. The most famous example is M. C. 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.
M.C. Escher's Ascending and Descending
