Traditional long sword dancing is an art form that produces stable patterns of interwoven segments. These structures, sometimes called “popsicle stick bombs,” are surprisingly rich mathematically and raise subtle difficulties for those attempting to analyze their stability. Dancers look for sequences of movements that will produce a desired configuration, an algorithmic question that is particularly challenging if the arms and swords are required to maintain a simple closed loop during the dance.
The standard reference on traditional dances is Ivor Allsop, “Longsword Dances from Traditional and Manuscript Sources” (Northern Harmony, 1996).
For a stability analysis, see Walter Whiteley, “Rigidity and Polarity II: Weaving Lines and Tensegrity Frameworks,” Geometriae Dedicata 30, no. 3 (1989), pp. 255-279.
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.
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.
