A bizarre optical illusion showing two sets of seemingly different chess pieces is baffling internet users.
The image has gone viral after being posted by science journalist Tom Chivers on Twitter, with the post racking up more than 2,000 likes.
Despite the recent interest in the illusion, the image was actually created by researchers Barton Anderson, from the University of New South Wales, Australia, and Jonathan Winawer, who is now with New York University, for a 2005 study published in the journal Nature.
The illusion shows two sets of chess pieces in a smoky environment: one which appears to be white, and another that looks to be black.
The seemingly white set is placed in an environment of mostly black smoke, while the seemingly black is placed in one featuring mostly lighter smoke.
But while the two sets of chess pieces look different, the truth is they are actually identical—meaning that each piece is the same as the corresponding one below it. The fact they look different is simply an illusion.
Every piece has “the same pattern of shades as its counterpart,” Chivers said in a reply to his post. “If you screenshot a tiny spot from any one of them and its partner, they’ll be the same shade.”
Unsurprisingly, the illusion has caused some shock and confusion among social media users in the comments below Chivers’ post.
“Absolutely no way are these the same col.. THEY FLIPPING WELL ARE, YOU KNOW!” said one Twitter user, Gareth Ebenezer.
“That’s flipping voodoo there. Are you a witch doctor?” another user said.
“I do not like this. (in the best way possible),” said another.
So why do people see the two chess sets as different when they are in fact the same?
The reason is that the way our brain processes the lightness of a given object is highly dependent on the context in which that object is embedded. Thus, the brain can be fooled into thinking that the chess pieces are different purely because of the environment they are embedded in.
This is not the only illusion to have caught the interest of internet users recently. A picture of a cat apparently “floating” over a sofa has gone viral, leaving social media users stunned.
The picture was first shared on the sub-Reddit r/confusing_perspective on Sunday, by a Redditor who goes by the username Flamind666 and has garnered more than 18.7k upvotes and almost 100 comments to date.