# This 3D Optical Illusion Will Make You Question The Shape of Reality

### May 03, 2018

Things are not what they seem. If you ever needed proof, there's an arrow we could show you, one that points to a different kind of truth.

But be warned – once you've seen it, you'll never look at the world quite the same way again, thanks to the mind-melting brilliance of Japanese mathematician and optical illusionist Kokichi Sugihara.

Okay, back to the arrow. Taken from a Japanese toy set inspired by Sugihara's mathematical explorations, it looks to be a simple, white arrow, mounted on a handsome wooden stand, and it's pointing clearly to the right.

There's no question about it. No signal has ever been less ambiguous than this arrow pointing directly right.

But wait a second, if you swivel the arrow around 180 degrees, what should happen? It should now be pointing to the left, right? Right.

Except it doesn't.

If you swivel this particular arrow around, it somehow keeps pointing to the right. Again, and again, and again.

It never changes direction, and with every impossible turn, a fresh mind melts somewhere around the world.

This optical illusion – just one of many of Sugihara's mathematically designed deceptions – has been making the rounds on the internet this week, courtesy of an Instagram video by the user physicsfun.

After showing the unreal swivels, his video gives us a glimpse of what's really happening. A hand picks up the arrow and shows what it looks like from directly above.

All of a sudden we can see that the arrow is actually a different 3D shape when viewed from overhead, revealing previously hidden contours that warp your perception when you view the object from certain angles.

To prove the point – and show just how powerful the illusion is – the video then introduces a mirror, which brain-breakingly shows a reflected arrow, only this reflected one is pointed in the exact opposite direction to the original arrow.

Left is right, right is left, and frankly we have no idea anymore – all we know for certain is that our brains are royally screwed.

What's so amazing about this illusion is that even when its workings are revealed to you, your eyes and brain instantly fool you again when the arrow is placed back on the table – unable to resist the diversion of the strange shape's curves.

If you like that, you'll love an even more bewildering example of the same visual mischief, in what Sugihara calls his 'ambiguous cylinder illusion':

In this one, we're not dealing with arrows, but with a configuration of square-looking prisms, which actually turn out to be perfect cylinders. Or is it the other way around?

Even more confusingly, some of these geometrical shape-shifters seem to be inter-linked with one another, but their reflections suggest otherwise, depicting clearly separated objects.

"The direct views of the objects and their mirror images generate quite different interpretations of the 3D shapes," Sugihara explained back in 2016.

"We cannot correct our interpretations, although we logically know that they come from the same objects. Even if the object is rotated in front of a viewer, it is difficult to understand the true shape of the object, and thus the illusion does not disappear."

That's right, Sugihara. The only thing that seems to have disappeared around here is my fleeting certainty in the shape of known reality, but hey, that's okay.

10/10, would have brain melted again.