Have you seen this illusion? The ambiguous cylinder was a finalist (2nd prize) in the 2016 best illusion of the year contest.
The direct views of the objects and their mirror images generate quite different interpretations of the 3D shapes. They look like vertical cylinders, but their sections appear to be different; in one view they appear to be rectangles, while in the other view they appear to be circles. We cannot correct our interpretations although we logically know that they come from the same objects. Even if the object is rotated in front of a viewer, it is difficult to understand the true shape of the object, and thus the illusion does not disappear.
Title: Ambiguous Cylinder Illusion
Author: Kokichi Sugihara
Institution: Meiji University, Japan
Here’s how it works: The actual shape is neither circular nor square, but can appear to be either depending on the angle at which you view it.
This shows the true shape:
Dr. Sugihara Kukichi, an engineering professor at Japan’s Meiji University, created this trick for the 2016 Illusion of the Year competition (he placed second). That is a thing. I have verified it. It’s sponsored by the Neural Correlate Society, a non-profit that supports research into the relationship between perception and cognition. This kind of seems like Dr. Kukichi’s “thing”; though his ambiguous cylinder illusion has been blowing up the interwebs since it was first posted on Reddit five days ago, the Japanese professor has made a career of dealing with objects that absolutely screw with our minds when put in front of a mirror. His latest series is called “Impossible Objects,” and it’s a new class of objects that seemingly disappear when placed in front of a mirror.
Bonus points for commenting any real-world uses you can imagine.