10 Mind Melting Illusions (And Exactly How They Work)

10. The Shifting Square

Stare at the black dot and your brain will swear to you that the square is moving, but your brain is a filthy liar.

There are all sorts of complicated explanations as to how this illusion occurs. The people who made it would tell you that it's down to the "configurations of drifting Gabors that are stationary can give rise to dramatic global motion percepts", but there's an easier way to think about it.

Your eyes and brain don't record the world around you like a film camera - that would be way too much information to take in. What it does is takes in the key elements of a scene and extrapolates the rest using what it knows about the rest of the world. This is the basis of a lot of optical illusions, as the rules of the physical, 3D world don't necessarily apply.

A good analogue for this one would be to imagine a car, driving behind a row of trees. You catch small glimpses between the branches, but your brain infers the smooth motion of the car. The same is happening here, your brain is making its best guess at the motion of the points, but is getting is disastrously wrong.