Why do strings tie themselves in knots?

Spontaneous knotting of an agitated string

Physicists tumbled bits of string in a spinning box thousands of times to see how often they tie themselves in knots.

Raymer, D. M., & Smith, D. E. · Proceedings of the National Academy of Sciences, 2007

Ig Nobel 2008

The researchers dropped a single piece of string into a box, spun it around for a few seconds, then opened it up to check for knots. They did this thousands of times with different lengths.

Longer strings knotted very often, and quickly, forming all sorts of different knots. Proof at last that your headphones and fairy lights aren’t out to get you; they’re just obeying statistics.

the verdict

Tangles are a law of nature. Forgive your fairy lights.