Spaghetti-thin shoelaces, sturdy hawsers, silk cravats — all are routinely tied in knots. So too, physicists believe, are water, air and the liquid iron churning in Earth’s outer core. Knots twist and turn in the particle pathways of turbulent fluids, as stable in some cases as a sailor’s handiwork. For decades, scientists have suspected the rules governing these knots could offer clues for untangling turbulence — one of the last great unknowns of classical physics — but any order exhibited by the knots was lost in the surrounding chaos.
Now, with deft new tools at their fingertips, physicists are beginning to master the art of tying knots in fluids and other flowable entities, such as electromagnetic fields, enabling controlled study of their behavior. 'Now that we have these knots, we can measure the shape of them in 3-D; we can look at the flow field around them,' said William Irvine, a physicist at the University of Chicago. 'We can really figure out what the rules of the game are.'
Read more on Quanta Magazine website.