Turbulent, Fast-Spinning Black Holes Reveal How Gravity Can Act Like a Fluid

If you're flying near a black hole, you may be in for a bumpy ride. Scientists have taken a closer look at the massive forces surrounding black holes, and have found that the gravitational fields around them may just eddy and swirl, creating a turbulent region of space.

"There's a conjecture in physics-the holographic conjecture-which says gravity can be described as a field theory," said Luis Lehner, one of the researchers, in a news release. "And we also know that at high energies, field theories can be described with the mathematical tools we use to describe fluids. So it's a two-step dance: gravity equals field theory, and field theory equals fluids, so gravity equals fields equals fluids. That's called the gravity/fluids duality."

Essentially, the gravity/fluids duality means that gravity can act like a fluid. But if gravity can act like a fluid, does that mean that it can show turbulence? That's what scientists wanted to discover.

"For many years, the folklore among physicists was that gravity could not be turbulent," said Lehner in a news release. "Either there was a problem with the duality and gravity really can't be fully captured by a fluid description, or there was a new phenomenon in gravity and turbulent gravity really can exist."

In order to find out a bit more about the possibility of turbulent gravity, the researchers turned to fast-spinning black holes. Because spacetime around black holes is less viscous than the spacetime around other kinds of black holes, it increased the chanced of turbulence. The scientists also examined non-linear perturbations of the black holes.

So what did they find? It turns out that a non-linear perturbation analysis was exactly what was called for, and that spacetime did indeed become turbulent. This means that gravity is indeed capable of turbulence.

While this is interesting in and of itself, it doesn't just have implications for the depths of space. It also has implications for Earth-bound turbulence. If gravity can be treated as a fluid, then fluids could potentially be treated gravitationally.

"We've been stuck for 500 years on achieving a full understanding of turbulence," said Lehner in a news release. "This gravity/fluid correspondence tells us that there is a way to use gravitational tools and gravitational intuition to take a fresh look at turbulence. We may end up as stuck as we are in our standard approach, or we may end up shedding completely new light that helps the field go forward. It's very exciting."

The findings are published in the journal areXiv.