The above circles are not moving, although they appear to be. The image comes from Clive Gifford’s book Eye Benders: The Science of Seeing and Believing.
The book, with its gallery of optical tricks, has been awarded the 2014 Royal Society Young People’s Book prize, which is judged by young readers.
Gifford says the motion illusion, above, was inspired by psychology professor Akiyoshi Kitaoka from the Ritsumeikan Asia Pacific University.
Gifford explains: “Most people can stop the illusion simply by concentrating upon and focusing on a single wheel in the image. The difference in luminance between different parts of the wheels and how your eyes repeatedly scan an image, a little like a twitchy digital camera continually autofocusing and adjusting the eye’s lens, are believed to be responsible for creating the illusion of the wheels turning round.”
See more images from Gifford’s book here.
Originally published by Cosmos as Seeing and believing
Katherine Kizilos
Katherine Kizilos is a staff writer at Cosmos.
Read science facts, not fiction...
There’s never been a more important time to explain the facts, cherish evidence-based knowledge and to showcase the latest scientific, technological and engineering breakthroughs. Cosmos is published by The Royal Institution of Australia, a charity dedicated to connecting people with the world of science. Financial contributions, however big or small, help us provide access to trusted science information at a time when the world needs it most. Please support us by making a donation or purchasing a subscription today.