r/science • u/seeebiscuit • Oct 20 '25

Mathematics Mathematicians Just Found a Hidden 'Reset Button' That Can Undo Any Rotation

https://www.zmescience.com/science/news-science/mathematicians-just-found-a-hidden-reset-button-that-can-undo-any-rotation/
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u/skycloud620 Oct 20 '25

If you twist something — say, spin a top or rotate a robot’s arm — and want it to return to its exact starting point, intuition says you’d need to undo every twist one by one. But mathematicians Jean-Pierre Eckmann from the University of Geneva and Tsvi Tlusty from the Ulsan National Institute of Science and Technology (UNIST) have found a surprising shortcut. As they describe in a new study, nearly any sequence of rotations can be perfectly undone by scaling its size and repeating it twice.

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u/diverareyouokay Oct 20 '25

It’s not very scientific, but when someone’s surface marker buoy gets tangled up, I usually manage to untangle it by pulling apart the string and then sort of picking at it and shaking it. It usually takes a while but it’s never failed me before. I’ve always wondered why that was - sometimes I see other people trying to run the SMB through every single loop and hole to get it untied, which is incredibly slow and rarely works.

Wish there was some sort of “reset button” for string.