Posted on February 12, 2018
What I had initially thought was an ordinary photo of my wife walking down a wide stairway turned out to be a rather interesting example of an optical illusion. The high concrete wall on her right had been partially painted with a dark grey paint which gives the illusion that the stairs could be going up. Also worth mentioning is that the lighter grey in the upper right of the picture is not some distant foggy vista. It’s still the wall!