Color-changing fibers help reveal mysteries of how knots work
Deciding whether a knot is fit to be tied just got a bit more scientific. Some knots are stronger than others, but scientists have struggled to explain why. Now, with the help of color-changing fibers, researchers have developed simple mathematical rules that can determine the relative strength of various knots based only on the knots’ topology — the geometry of how the knot is tied. “Despite the fact that [knots] have been around for thousands of years, not much is known about why they work the way they do,” says applied mathematician Vishal Patil of MIT. To better understand the simplest knots, Patil and colleagues studied color-changing fibers, with hues that reveal areas of greater and lesser strain in a knotted strand. The strain seen in knots in those fibers agreed with the strain calculated in the researchers’ computer simulations — which also estimate the relative strength of different knots — the researchers report in the Jan. 3 Science. The team used that simulation...