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 the dynamics of the sun.
Videos courtesy of William Irvine, Dustin Kleckner. Additional photos from NASA SDO, Annette Heist, “Knots” 1918, and thanks to Dude, for smoke rings.