Van Gogh’s technique in ‘The Starry Night’ evokes a striking sense of movement in the sky, prompting researchers to explore how it compares to real atmospheric physics. Experts in marine sciences and fluid dynamics studied the painting to reveal what they term the hidden turbulence present in the work. They analyzed the brushstrokes to understand the shape, energy, and scaling of atmospheric qualities that are usually undetectable, using the varying brightness of paint colors as a proxy for the kinetic energy associated with actual movement.
Vincent van Gogh’s artwork “The Starry Night” illustrates a dynamic blue sky filled with a bright yellow moon and twinkling stars. The sky bursts with colors and distinct forms, with each star appearing to shimmer, encapsulated in rippling yellow, reminiscent of reflections on water.
Van Gogh’s strokes create such a believable impression of sky motion that atmospheric scientists have contemplated the extent to which they mirror the physics of the real sky. While they can’t quantify the atmospheric movement in the artwork, they can measure the brushstrokes.
In a paper published this week in Physics of Fluids by AIP Publishing, a team of researchers from China and France specialized in marine sciences and fluid dynamics examined Van Gogh’s work to uncover what they consider hidden turbulence within the artist’s sky portrayal.
“The scale of the paint strokes was key,” remarked author Yongxiang Huang. “By utilizing a high-resolution digital image, we were able to measure the size of the brushstrokes accurately and compare them to the scales predicted by turbulence theories.”
To uncover hidden turbulence, the researchers likened the brushstrokes in the painting to leaves caught in a gust of wind, investigating the shape, energy, and scaling of atmospheric traits, which are typically imperceptible. They interpreted the varying paint colors’ brightness or luminance as a representation of the kinetic energy related to physical motion.
“This reveals a profound and instinctive understanding of natural phenomena,” Huang stated. “Van Gogh’s meticulous portrayal of turbulence might stem from observing cloud movements and the atmosphere or from an inherent ability to capture the sky’s dynamism.”
The research examined the spatial dimensions of 14 prominent swirling forms in the painting to determine if they correspond with the cascading energy theory, which illustrates the transfer of kinetic energy from larger to smaller turbulent flows in the atmosphere.
They found that the overall composition aligns with Kolmogorov’s law, which predicts patterns of atmospheric movement and scale based on measured inertial energy. By further investigating the intricacies of the paint strokes themselves, where brightness varies across the canvas, the researchers identified a connection to Batchelor’s scaling, which explains energy dynamics in small-scale, passive scalar turbulence linked to atmospheric movements.
Discovering both types of scaling in a single atmospheric system is quite uncommon and served as a significant motivator for their research.
“Turbulence is thought to be a fundamental characteristic of high Reynolds flows, which are primarily influenced by inertia. However, recent observations have noted turbulence-like behaviors in various flow systems across a broad spectrum of spatial scales, particularly in cases of low Reynolds numbers where viscosity plays a more significant role,” Huang explained.
“It appears to be time to propose a new definition of turbulence that encompasses a wider range of scenarios.”
