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Letter: How to fool even those savvy about illusions

Published 9 April 2025

From Brian Reffin Smith, Berlin, Germany

On the idea of learning to be less fooled by optical illusions, I do some lecture-performances to illusion-savvy audiences about pataphysics, art, zombie theory and so on. I tell them they just can’t trust their brains, and build up to… the Müller-Lyer illusion, the one with two identical lines where one looks longer because of the direction of arrow heads. I ask them which is longer, and they can’t believe I am ending on this old cliché! Smirking, they yell that they are both the same. But this time, they aren’t. One is centimetres longer than the other. You can’t trust your brain. You can have similar fun with cognitive scientists by showing a version of the famous disappearing gorilla video, the original suitably credited, edited to have no gorilla (22 March, p 15).

The editor writes: See page 40 to read about the science of illusions

Issue no. 3538 published 12 April 2025

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