Barberpole illusion

Imagine you are holding a red and white pole vertically in front of you. Raising your eyes to the top and then to the bottom of the pole, you get the feeling that the colors of the bands are spiraling around the pole as if it is rotating in space. This perception is the barberpole illusion.

It's like when you run through a spinning tunnel in the park and the walls appear to spin around you. The same thing happens with the barberpole: as you move your eyes up and down, the stripes seem to move in a spiral-like motion, when in reality they are just straight lines. This is because the stripes are constantly shifting direction at each intersection, and your brain struggles to keep up with the change.

Our brains process visual information quickly and efficiently by making assumptions about what we see. The barberpole illusion is a great example of how our brains can be tricked into believing something that isn't there. So even though it may seem like the barberpole is spinning, it's not really moving at all!