Enlarge / Researchers captured the decay of a quantum knot (left), which untied itself after a few microseconds and eventually turned into a spin vortex (right). (credit: Tuomas Ollikainen/Aalto University) The same team who tied the first "quantum knots" in a superfluid several years ago have now discovered that the knots decay, or "untie" themselves, fairly soon after forming, before turning into a vortex.