Science fiction collectors may well look a the two images below and think they’re both Richard Powers’ artwork, so prominent on the covers of science fiction titles in the mid-20th Century. Powers worked often for Ballantine in the 1950s and later, always refining the style he first exhibited when doing covers for Doubleday in the 1940s. The top image here is from one of the Doubleday titles, but I think of Powers most for his Ballantine work. His paintings could make a paperback rack into a moody, mysterious experience, a display of artistry that moved from the surreal to the purely abstract. At his best, Powers’ renderings seemed to draw out the wonder of the mind-bending fiction they encased.

What we have in the second image, though, is not abstract art but the manifestation of what is being described as “the world’s largest turbulence simulation.” The work comes from a project described in a new paper in Nature Astronomy, where lead author James Beattie describes his investigations at the Canadian Institute for Theoretical Astrophysics, where he is probing magnetism and turbulence as they occur in the interstellar medium. In this image, Beattie’s caption describes “…the fractal structure of the density, shown in yellow, black and red, and magnetic field, shown in white.”

And while Beattie may or may not be familiar with Richard Powers, he does have an eye for the art that this kind of turbulence can produce, saying:

“I love doing turbulence research because of its universality. It looks the same whether you’re looking at the plasma between galaxies, within galaxies, within the solar system, in a cup of coffee or in Van Gogh’s The Starry Night. There’s something very romantic about how it appears at all these different levels…”

And honestly, doesn’t this remind you of Powers?

What Beattie and team have produced, using the computing muscle of the SuperMUC-NG supercomputer at the Leibniz Supercomputing Centre in Germany, is helping us better understand the nature of the interstellar medium. In particular, it is a computer simulation that explores the interactions of magnetism and turbulence in the ISM, which addresses magnetism at the galactic level as well as individual astrophysical phenomena such as star formation. Beattie’s team is international in scope, with co-authors at Princeton University, Australian National University, Universität Heidelberg; the Center for Astrophysics, Harvard & Smithsonian; Harvard University; and the Bavarian Academy of Sciences and Humanities.

So what is the turbulence Beattie is describing? The phenomenon is ubiquitous, showing up in everything from cream swirling in a black cup of coffee to ocean currents to particles moving in chaotic flows in the solar wind. We can produce ultra-high vacuums on Earth, but even in these there are far more particles than are found in the average sample of the ISM. Despite the fact that so few particles exist in the ISM, though, their motions do generate a magnetic field, one that the researchers liken to the motion of our Earth’s molten core which generates the magnetic field that protects us.

The galactic magnetic field is weak indeed, but it can be modeled for the first time at a level of accuracy that is both scalable and high in resolution. At its highest setting, Beattie’s simulation can depict a volume of space 30 light years to a side, but can be scaled down by a factor of 5000 to explore smaller spaces. The latter has implications for how we study the solar wind, which not only produces ‘space weather’ but is also a factor in certain space sail concepts that use superconducting rings to produce a strong magnetic field that can harness the solar wind as thrust.

Always keep in mind that we have anything but a uniform interstellar medium. Some of the early writing about Robert Bussard’s ramjet concepts noted that a design that harnessed interstellar hydrogen would thrive best in dense star-forming regions, where hydrogen would be plentiful. The Bussard concept has fallen on hard times given issues with drag that seem to knock it out of contention, but magsail work remains interesting both as a way of harnessing solar wind particles or braking against the same upon entering a destination stellar system. So the more we can learn about the extreme density variations in the ISM, the better we can envision future interstellar flight.

Moreover, star formation is implicated in the same model. The better our simulations of interstellar turbulence, the more we can learn about the magnetic forces that push outward against the collapse of a nebula that will eventually produce one or more stars. And the model the team has developed stacks up well when run against actual data from the solar wind, which points to short term gains in the forecasting of space weather, the ‘rain’ of charged particles that affects both Earth and spacecraft.

The ubiquity of chaotic turbulence and its coupling with the galaxy’s ambient magnetic fields makes its study all the more provocative. Both generating and scattering off the plasma phenomena known as Alfvén waves, cosmic rays are strongly affected. From the paper:

In the cold (T ≈ 10 K) molecular phase of the ISM, [turbulence] changes the ionization state of the plasma by controlling the diffusion of cosmic rays [1–5], gives rise to the filamentary structures that shape and structure the initial conditions for star formation [6, 7], and through turbulent and magnetic support, changes the rate at which the cold plasma converts mass density into stars [8–13].

So there is plenty to work with here. And a brief return to van Gogh’s ‘The Starry Night,’ which Beattie mentioned in the quote above. Come to find that the author and co-author Neco Kriel (Queensland University of Technology) have produced a paper on the subject called “Is The Starry Night Turbulent?” The goal was to learn whether the night sky in this famous painting “has a power spectrum that resembles a supersonic turbulent flow.” And indeed, “‘The Starry Night’ does exhibit some similarities to turbulence, which happens to be responsible for the real, observable, starry night sky.”

Which I think only means that van Gogh was turning what he saw into art, recognizable to us precisely because it did reflect the night sky he was observing. Still, it’s fun to see these methods, which draw on deep research into turbulent interactions, applied to a cultural icon. I wonder what Beattie’s team would dig out of a deep dive into Powers’ work in the century after van Gogh?

Image: van Gogh’s ‘The Starry Night’ is Figure 1 in Beattie’s paper with Kriel. Caption: Vincent van Gogh’s The Starry Night, accessed from WallpapersWide.com (2018). We see eddies painted through the starry night sky that resemble the structures comparable to what we see in turbulent flows.”

The paper is Beattie et al., “The spectrum of magnetized turbulence in the interstellar medium,” Nature Astronomy 13 May 2025 (abstract / preprint). The paper on van Gogh is Beattie & Kriel, “Is The Starry Night Turbulent?” available as a preprint.