Mathematical Impressions: Can You Turn a Rubber Band into a Knot? [Video]

Theory suggests it is impossible, but geometer George Hart shows that the band's thickness can help you solve this puzzle

Join Our Community of Science Lovers!

From Simons Science News (find original story here).

The mathematics of knot theory says that a simple loop and a trefoil are fundamentally different knots. But is that all there is to the question? How can you take a rubber band and turn it into a knot?

Knot theory is the study of knots and their diagrams. It includes techniques for characterizing how knots can be transformed in three-dimensional space and tests for determining when two different-looking knots are actually equivalent. A good introduction is “The Knot Book” by Colin Adams, which explains in detail the “Jones polynomial” mentioned in the video.


On supporting science journalism

If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.


More videos from the Mathematical Impressions series.

It’s Time to Stand Up for Science

If you enjoyed this article, I’d like to ask for your support. Scientific American has served as an advocate for science and industry for 180 years, and right now may be the most critical moment in that two-century history.

I’ve been a Scientific American subscriber since I was 12 years old, and it helped shape the way I look at the world. SciAm always educates and delights me, and inspires a sense of awe for our vast, beautiful universe. I hope it does that for you, too.

If you subscribe to Scientific American, you help ensure that our coverage is centered on meaningful research and discovery; that we have the resources to report on the decisions that threaten labs across the U.S.; and that we support both budding and working scientists at a time when the value of science itself too often goes unrecognized.

In return, you get essential news, captivating podcasts, brilliant infographics, can't-miss newsletters, must-watch videos, challenging games, and the science world's best writing and reporting. You can even gift someone a subscription.

There has never been a more important time for us to stand up and show why science matters. I hope you’ll support us in that mission.

Thank you,

David M. Ewalt, Editor in Chief, Scientific American

Subscribe