University of Chicago physicists have succeeding in creating a vortex knot -- a feat akin to tying a smoke ring into a knot. Linked and knotted vortex loops have existed in theory for more than a century, but creating them in the laboratory had previously eluded scientists.
Vortex knots should, in principle, be persistent, stable phenomena. "The unexpected thing is that they're not," said Dustin Kleckner, a postdoctoral scientist at UChicago's James Franck Institute. "They seem to break up in a particular way. They stretch themselves, which is a weird behavior."