In the quantum world, dark matter particles can merge into a single superfluid droplet — a state where matter flows without friction, like an ideal fluid. When near a black hole, this droplet doesn’t just disappear into it but twists into stable vortices, like water swirling around a rock in a stream. Scientists found that the most stable ones are a dense central clump and a vortex encircling the hole. The latter can persist for years if the particles attract each other weakly: a balance of forces prevents it from falling apart.
The twist: these vortices affect the rotation of galaxies and even make the black hole wobble, generating a distinct “ringing” in gravitational waves — ripples in spacetime. And if the particles attract too strongly, the vortex collapses — scientists calculated a precise boundary for this collapse.
At ultralow temperatures, a special quantum fluid can behave as a single giant particle; when spun, it forms tiny tornado-like vortices — in labs, these are created using lasers.