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One of the most remarkable aspects[br]of the human brain

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is its ability to recognize patterns[br]and describe them.

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Among the hardest patterns[br]we've tried to understand

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is the concept of[br]turbulent flow in fluid dynamics.

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The German physicist[br]Werner Heisenberg said,

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"When I meet God,[br]I'm going to ask him two questions:

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why relativity and why turbulence?

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I really believe he will have[br]an answer for the first."

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As difficult as turbulence is[br]to understand mathematically,

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we can use art to depict the way it looks.

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In June 1889, Vincent van Gogh[br]painted the view just before sunrise

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from the window of his room[br]at the Saint-Paul-de-Mausole asylum

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in Saint-Rémy-de-Provence,

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where he'd admitted himself after[br]mutilating his own ear

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in a psychotic episode.

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In "The Starry Night,"[br]his circular brushstrokes

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create a night sky filled[br]with swirling clouds and eddies of stars.

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Van Gogh and other Impressionists[br]represented light in a different way

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than their predecessors,

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seeming to capture[br]its motion, for instance,

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across sun-dappled waters,

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or here in star light[br]that twinkles and melts

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through milky waves of blue night sky.

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The effect is caused by luminance,

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the intensity of the light[br]in the colors on the canvas.

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The more primitive part[br]of our visual cortex,

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which sees light contrast[br]and motion, but not color,

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will blend two differently[br]colored areas together

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if they have the same luminance.

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But our brains' primate subdivision

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will see the contrasting colors[br]without blending.

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With these two interpretations[br]happening at once,

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the light in many Impressionist works[br]seems to pulse, flicker and radiate oddly.

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That's how this[br]and other Impressionist works

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use quickly executed[br]prominent brushstrokes

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to capture something strikingly real[br]about how light moves.

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Sixty years later, Russian[br]mathematician Andrey Kolmogorov

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furthered our mathematical[br]understanding of turbulence

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when he proposed that energy[br]in a turbulent fluid at length R

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varies in proportion to[br]the 5/3rds power of R.

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Experimental measurements show Kolmogorov

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was remarkably close[br]to the way turbulent flow works,

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although a complete description[br]of turbulence

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remains one of the unsolved[br]problems in physics.

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A turbulent flow is self-similar[br]if there is an energy cascade.

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In other words, big eddies[br]transfer their energy to smaller eddies,

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which do likewise at other scales.

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Examples of this include[br]Jupiter's Great Red Spot,

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cloud formations[br]and interstellar dust particles.

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In 2004, using the Hubble Space Telescope,

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scientists saw the eddies of a distant[br]cloud of dust and gas around a star,

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and it reminded them[br]of Van Gogh's "Starry Night."

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This motivated scientists[br]from Mexico, Spain and England

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to study the luminance[br]in Van Gogh's paintings in detail.

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They discovered that there is a distinct[br]pattern of turbulent fluid structures

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close to Kolmogorov's equation[br]hidden in many of Van Gogh's paintings.

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The researchers digitized the paintings,

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and measured how brightness varies[br]between any two pixels.

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From the curves measured[br]for pixel separations,

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they concluded that paintings from[br]Van Gogh's period of psychotic agitation

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behave remarkably similar[br]to fluid turbulence.

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His self-portrait with a pipe, from[br]a calmer period in Van Gogh's life,

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showed no sign of this correspondence.

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And neither did other artists' work

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that seemed equally[br]turbulent at first glance,

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like Munch's "The Scream."

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While it's too easy to say[br]Van Gogh's turbulent genius

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enabled him to depict turbulence,

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it's also far too difficult to accurately[br]express the rousing beauty of the fact

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that in a period of intense suffering,

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Van Gogh was somehow[br]able to perceive and represent

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one of the most supremely[br]difficult concepts

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nature has ever brought before mankind,

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and to unite his unique mind's eye

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with the deepest mysteries[br]of movement, fluid and light.