Physicists use 3-D printing and tiny bubbles to capture twisted-up water
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Swirling rings of fluid have for the first time been tied in a knot. Physicists accomplished the feat with the help of some unlikely lab tools: YouTube videos of dolphins and a 3-D printer.
“It’s a remarkable experiment,” says Carlo Barenghi, a mathematician and physicist at Newcastle University in England. The creation of these knotted vortices in