For many optical illusions, there’s a life cycle on a person-to-person basis, and it’s often pretty short (see exhibit A: the black and blue or white and gold dress). First, the observer sees the illusion and is fooled by it. Then, they discover why it provides the effect it does, and once they know that, they can revisit the illusion from a new perspective, one that lets them see behind the curtain and no longer be affected by it in the same way. Then there’s the Ames Window, which remains weird as heck all the time, even after you’ve seen it debunked in multiple ways.

The illusion got its name from Adelbert Ames Jr., the scientist who invented the illusion in 1946 (despite the video saying it was 1951). In a recently shared clip from the vintage Australian program The Curiosity Show, Dr. Deane Hutton introduces the Ames window, first demonstrating the window in its initial state. When rotated at a consistent rate on a turntable, the window appears to be changing the direction of its rotation, even though its movement remains regular and unchanged. Hutton explains it’s because the Ames window is actually a trapezoid, but since our brains are so used to seeing rectangular windows, some cognitive dissonance fools us. Hutton’s attempts to stop the illusion from working only make things stranger: He’s able to make it look like a matchbox is rotating around the window, and like a ruler is passing right through it.

It’s a fascinating illusion, so watch it for yourself in the video above, and if you know of any other illusions that are similarly confusing, share them in the comments below!

Featured Image: CuriosityShow