Turbulence: A Nexus of Creative Possibilities
Some of the most interesting thinking happens at the edges of disciplines, where a scientist’s instinct meets an artist’s eye, and neither has the whole answer. The Simons Foundation’s Open Interval program builds on that premise. This fall, we’re inviting trios to take on one of nature’s great unsolved problems: turbulence.
Scientifically speaking, turbulence is a compelling starting point for the next Open Interval program because of its mysterious qualities: It is a force of havoc that resists a single definition, feels relatable in large and small ways, and shows up in many basic science research contexts. In mathematics and physics, it remains an unsolved problem, a scientific leviathan that has been the subject of intense study for over a century.
According to many researchers, you tend to know it when you see it. (Or, when on an airplane, you know it when you feel it.) It is a phenomenon more readily recognized in experience than captured in a single intuitive definition. However, it has some critical, defining properties, such as an ‘energy cascade’ that produces disordered motion across scales. For example, when you pour milk into your morning coffee and dip a spoon into your cup, you introduce energy on a large scale, creating a plume that breaks down into progressively smaller eddies. This turbulent mixing makes changes at all scales, down to the molecular level, until the coffee and milk are fully mixed.
Turbulence is with us in our kitchens every day as we boil and stir liquids, just as it is in winds, flames, tidal currents and just about everywhere, always. In 1922, the physicist Lewis Fry Richardson described the phenomenon of the cascade into eddies in a limerick: “Big whorls have little whorls that feed on their velocity. Little whorls have lesser whorls, and so on to viscosity.”
Turbulence is scale-invariant, meaning it creates patterns that look or behave similarly regardless of the scale at which we observe them. Zooming in or out does not fundamentally change the properties of those patterns. Swirling coffee can resemble a storm’s winds or the ocean’s currents, even though these systems operate at vastly different scales. The turbulence we experience on an airplane occurs at a scale our bodies can feel, but turbulent motion extends across a much wider range: for instance, in oceans, clouds, the atmosphere and in the formation of celestial bodies. Climate and weather models grapple with the unpredictability of turbulence in these systems.
Researchers are exploring systems at different scales and identifying turbulent motion more broadly. For example, quantum physicists might observe turbulence in collective electron flow, which can be modeled using equations originally developed for fluids, such as the Navier–Stokes equations.
Microbiological research shows that in some systems, for instance, when enough bacteria pack together, they start churning in coordinated swirls — a kind of living turbulence driven by the push and pull of neighboring cells. In these systems, biological material generates its own energy rather than being disturbed by a cascade. Neuroscientists are beginning to model how patterns of brain activity unfold across multiple scales simultaneously, sometimes exhibiting dynamics that resemble turbulence. Accounting for this complexity may offer new ways of understanding how information flows through the brain.
At its heart, turbulence is about connection: particles influencing each other in chains of cause and effect so tangled that the whole system becomes extraordinarily difficult to predict. It is a nominally destructive, chaotic force, yet also fundamental to nature. We cannot wait to see what creative collaborations will emerge as part of the upcoming Open Interval program.
Click here to learn more about the next Open Interval program’s timeline, eligibility and format.
If you have any questions, please email [email protected].
With gratitude to the many Simons Foundation staff and researchers at the foundation’s Flatiron Institute who offered their perspectives on turbulence, especially Drummond Fielding, Blakesley Burkhart, Jasmin Imran Alsous, Neha Wadia, Olivier Gingras, Joshua Pughe-Sanford, Michael Shelley and David Spergel.
