Why Our Brains Think These Shapes Are Circles And Squares At The Same Time

How will you ever trust a mirror again after seeing this?

Kokichi Sugihara , a professor at Meiji University in Japan, won second prize in the international Best Illusion of the Year Contest  last week for creating a brand-new visual illusion in which a perfectly rectangular shape appears circular when reflected in a mirror.

So how does this fascinating "ambiguous cylinder illusion" work? 

Sugihara has found a class of peculiar shapes made up of irregular sections that can look like either rectangles or circles depending on the viewer's perspective. 

"The direct views of the objects and their mirror images generate quite different interpretations of the 3D shapes," Sugihara explains  on the contest's website.

"We cannot correct our interpretations, although we logically know that they come from the same objects," he adds. "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,"

Pretty confusing, right? Luckily, anything that an engineer makes can be reversed engineered. And that's exactly what's happening on the Make Anything // 3D Printing YouTube channel. Check out more details on how this illusion works:

Sugihara has previously blown our minds with other award-winning illusions including a structure that seems to defy gravity  and a precursor to his new illusion -- a miniature garage roof that changes shapes in a mirror. 

The annual Best Illusion of the Year Contest showcases new illusions created by the research community. An international panel of judges rates the submissions to narrow them to the top 10, then a winner is selected using an online vote.