Tying Water in a Knot

Reporting in the journal Nature Physics, William Irvine and Dustin Kleckner, physicists at the University of Chicago, describe the knotted fluid vortex they created in the lab -- a scientific first, they say. The knots resemble smoke rings -- except these are made of water, and they’re shaped like pretzels, not donuts. Understanding knottiness has extra-large applications, including untangling dynamics of the sun. More SciFri videos Untangling the Hairy Physics of Rapunzel: