Underwater Wing (image)

Caption
When accelerated to more than 100 g in a specially prepared water tank, hydrofoils like these can generate knotted vortex loops. Physicists have unsuccessfully attempted to create knotted vortices in the laboratory for more than a century.
Credit
Robert Kozloff/University of Chicago
Usage Restrictions
News organizations may use this image in connection with reports about the work of Dustin Kleckner and William Irvine.