Watch a Mathematician Effortlessly Fit a Large Circular Disk Through a Smaller Square Hole

Math Illusion

Screenshot: YouTube

Can a large circular disk fit through a small square hole? When you first picture it, it seems impossible. But thanks to Stanford University mathematician Tadashi Tokieda, you'll see that it is possible and easier than you might think. In an enlightening video by Numberphile, he demonstrates this illusion by using a cork coaster and a sheet of paper with a square hole cut into the middle of it. By folding the paper a certain way, the hole suddenly becomes large enough for the coaster to easily pass through the opening.

“I didn’t stretch, let alone tear,” Tokieda shares, “and yet when I fold the sheet back in a judicious way, the coaster does go through the square that is bigger than the hole. How is this possible?”

Tokieda then goes into a detailed explanation of how he’s able to make the coaster fit. “It has to do with the intrinsic, or inner dimension, of this piece of paper, which is two dimensions, and the fact that this sheet evolves, or flourishes, in the ambient three-dimensional space,” he says. “There is some elbow room, there is some ambient space.”

If that still leaves you scratching your head, be sure to watch how Tokieda folds the paper. He does so in a specific manner that transforms the sheet from two to three dimensions. In doing that, he brings two sides of a square together and forms a larger opening for which the coaster can pass through without a problem.

Scroll down to see Tokieda in action. Then, try it for yourself!

It seems like a large circular disk cannot fit into a smaller square hole, right? Watch how mathematician Tadashi Tokieda proves the math illusion possible:

h/t: [IFL Science!]

Related Articles:

These 10 Spellbinding Optical Illusions Are Considered the Best of 2019

You Need to Shake Your Head to See the Hidden Animal in This Optical Illusion

Perplexing Optical Illusion Stumps the Internet with 12 Disappearing Dots

Science Experiment Shows How 25,000 Random Dice Neatly Assemble into Perfect Circles

Sara Barnes

Sara Barnes is a Staff Editor at My Modern Met and Manager of My Modern Met Store. She is a graduate of the Maryland Institute College of Art where she earned her BFA in Illustration and MFA in Illustration Practice. Sara is also an embroidery illustrator and writer living in Seattle, Washington. She runs Bear&Bean, a studio where she stitches pet portraits and other beloved creatures. She chronicles the creativity of others through her website Brown Paper Bag and newsletter, Orts. Her latest book is Threads of Treasure: How to Make, Mend, and Find Meaning Through Thread, published in 2014. Sara’s work has been recognized in Be Creative With Workbox, Embroidery Magazine, American Illustration, on Iron and Wine’s album Beast Epic, among others. When she’s not stitching or writing, Sara enjoys planning things that bring together the craft community. She is the co-founder of Camp Craftaway, a day camp for crafty adults with hands-on workshops in the Seattle area.
Become a
My Modern Met Member
As a member, you'll join us in our effort to support the arts.
Become a Member
Explore member benefits