I love this optical illusion on the Daily Mail’s website.
“Although it may seem impossible to believe, the squares marked ‘A’ and ‘B’ are actually exactly the same shade of grey.”
Lesson 1: question everything.
This amazing illusion was created by Edward H Adelson from the Massachusetts Institute of Technology. Although it may seem impossible to believe, the squares marked ‘A’ and ‘B’ are actually exactly the same shade of grey! Your eyes and brain are constantly trying to figure out the colour of the objects around you, and in doing so automatically compensate for shadows. The square marked ‘B’ is in the shadow cast by the green cylinder, while the square marked ‘A’ is outside of the shadow. Your eyes and brain see that the two squares are the same shade of grey, but then think, ‘Hold on – if a square in a shadow reflects the same amount of light as a square outside of the shadow, then in reality it must be a much lighter shade of grey.’ As a result, your brain alters your perception of the image so that you see what it thinks is out there in the real world.
Having cut two holes in a piece of paper and placed them over the two squares, “A” actually is slightly darker than “B”. At least, on my screen.
Lesson 2: don’t believe everything in the Daily Mail.