Scientist’s applause for van Gogh
Why is The Starry Night so cherished by scientists?
It is always a special delight to find scientist valuing art, artist understanding science, or really any other kind of cross-disciplinary celebration and solidarity. After all, humanities are at the core of our human interests in this world; whether we pursue a chemistry or literature career makes no difference. Contrary to a popular assumption that science is in essence for utility and that the scientist is aiming mainly at technology, the focus on practicality and serviceability are rather under the scope of applied sciences in my opinion, such as medicine and engineering. The scientist is after the wonder, the inapplicable useless mystery.
A nice reminder of intersections between art and science, or rather their continuity with one and other, is Neil de-Grasse Tyson’s honouring of the famous “Starry Night” painting of Vincent van Gogh. Acclaimed astrophysicist and host of the popular StarTalk podcast show does not miss any chance to talk about The Starry Night. His fascination with this painting comes from the human representation of the reality filtered through emotions, which he says is the artist’s work. Because we don’t need the artist to depict the reality in exactitude, we have the technology to show us how the universe looks like from the Earth with accuracy. De-Grasse Tyson wants to know how the sky felt like, not how it looked like, hence his praise for van Gogh.
The Starry Night reveals a few facts about the sky that van Gogh saw through his window from the Saint-Paul de Mausole Asylum where he was staying at the time. First, de-Grasse Tyson elaborates, we know that he painted this early in the morning, before the dawn. This is deduced by the angle of the moon with respect to the horizon, considering that he was situated in the northern hemisphere. Second, one of the stars in the painting — the brightest and lowest one, is Venus. Planets are the first to appear in the sky at night time, however they can be also present in the dawn.
Another very curious scientific aspect about the swirling clouds in van Gogh’s painting was revealed by a study conducted by two physicists in Australia. Though still not peer-reviewed, their findings were made available in 2019 at arXiv.org. Here, James Beattie and Neco Kriel compare the turbulent features of molecular clouds (where stars are born) and van Gogh’s brush strokes. The authors pose the question, “Is The Starry Night turbulent?”
“The painting portrays a night sky full of stars, with eddies (spirals) both large and small. Kolmogorov (1941)’s description of subsonic, incompressible turbulence gives a model for turbulence that involves eddies interacting on many length scales, and so the question has been asked: is The Starry Night turbulent?”
Turbulence is a type of flow in which the fluid (either liquid or gas) fluctuates irregularly as opposed to laminar flow where it moves in layers. Turbulent flow is present in everyday life: the air flow at the tips of the wings of a plane, currents in the ocean, blood flow in the arteries etc.. One of the first people to describe and study turbulent flow was Leonardo da Vinci. In 1941, the Soviet mathematician Kolmogorov described the phenomenon mathematically, and this was the model that researchers used to determine if van Gogh’s painting resembled turbulent flow. However it is important to note that even Kolmogorov’s equation is not a complete description of turbulence.
The resemblance between the spiral clouds in the Dutch painting and the turbulent flow was actually established first in 2008 in a study led by Jose Luis Aragón from the National Autonomous University of Mexico. However, the study didn’t confirm wether the swirls in the painting followed Kolmogorov’s theory of turbulent flow exactly, since the researchers took an approximation.
The original idea of comparing van Gogh’s turbulent sky came from a NASA release in 2004, as a result of a new image taken by the Hubble Telescope showing the star V838 Monocerotis:
“This image resembling Vincent van Gogh’s painting, ‘Starry Night’, is Hubble’s latest view of an expanding halo of light around a distant star, named V838 Monocerotis (V838 Mon).”
This excited some researchers at the time, among whom Aragón and his team who undertook the first study to see if van Gogh’s turbulent clouds approximated Kolmogorov’s theory of turbulence. Finally last year, this was put to a more meticulous test, and Beattie and Kriel confirmed that van Gogh somehow nailed it. They conclude in the 2019 paper:
“These realisations support the case that The Starry Night is a depiction of a turbulent flow.”
There is a lovely TED-Ed animation by Natalya St. Clair walking us through the discovery of “The maths behind van Gogh’s ‘Starry Night’” where fluid dynamics meet the troubled artist. Here, one can appreciate the contrast yet proximity between the unanswerables: Can turbulent flow in fluid dynamics be understood and described completely? How can an artist in the last year of his life in a mental asylum produce one of the most popular and replicated art works? How could he depict a physical reality that is so hard for scientists to describe?
According to de-Grasse Tyson, what makes this painting extraordinary is that it is the background that gives the name to the title. In other words, van Gogh didn’t protagonise the village, or the Cypress tree in the foreground of his painting; he called his masterpiece “The Starry Night”, honouring the celestial and thus giving birth to the cosmos as the main theme of an art work.
A life-long educator of science in all kind of platforms de-Grasse Tyson gives his big applause to van Gogh:
“Cosmic discovery does not become mainstream until the artists embrace the fruits of that discovery.”
