0:00:07.040,0:00:10.023
One of the most remarkable aspects[br]of the human brain

0:00:10.023,0:00:13.675
is its ability to recognize patterns[br]and describe them.

0:00:13.675,0:00:16.355
Among the hardest patterns[br]we've tried to undestand

0:00:16.355,0:00:20.789
is the concept of[br]turbulent flow in fluid dynamics.

0:00:20.789,0:00:23.296
The German physicist[br]Werner Heisenberg said,

0:00:23.296,0:00:27.381
"When I meet God, I'm going to ask him[br]two questions:

0:00:27.381,0:00:30.842
why relativity and why turbulence?

0:00:30.842,0:00:34.932
I really believe he will have [br]an answer for the first."

0:00:34.932,0:00:38.304
As difficult as turbulence is to[br]understand mathematically,

0:00:38.304,0:00:42.194
we can use art to depict the way it looks.

0:00:42.194,0:00:47.308
In June 1889, Vincent van Gogh painted[br]the view just before sunrise

0:00:47.308,0:00:51.659
from the window of his room at the[br]Saint-Paul-de Mausole asylum

0:00:51.659,0:00:53.588
in Saint-Rémy-de-Provence,

0:00:53.588,0:00:56.840
where he'd admitted himself after[br]mutilating his own ear

0:00:56.840,0:00:59.312
in a psychotic episode.

0:00:59.312,0:01:02.056
In "The Starry Night,"[br]his circular brushstrokes

0:01:02.056,0:01:07.827
create a night sky filled with[br]swirling clouds and eddies of stars.

0:01:07.827,0:01:11.748
Van Gogh and other Impressionists[br]represented light in a different way

0:01:11.748,0:01:14.872
than their predecessors,[br]seeming to capture its motion,

0:01:14.872,0:01:17.860
for instance, across sun-dappled waters,

0:01:17.860,0:01:21.530
or here in star light that [br]twinkles and melts

0:01:21.530,0:01:24.844
through milky waves of blue night sky.

0:01:24.844,0:01:27.415
The effect is caused my luminance,

0:01:27.415,0:01:31.104
the intensity of the light in the colors [br]on the canvas.

0:01:31.104,0:01:33.632
The more primitive part of our[br]visual cortex,

0:01:33.632,0:01:37.578
which sees light contrast and motion,[br]but not color,

0:01:37.578,0:01:40.627
will blend two differently [br]colored areas together

0:01:40.627,0:01:42.973
if they have the same luminance.

0:01:42.973,0:01:45.352
But our brains primate[br]subdivision

0:01:45.352,0:01:48.506
will see the contrasting colors[br]without blending.

0:01:48.506,0:01:51.457
With these two interpretations[br]happening at once,

0:01:51.457,0:01:57.898
the light in many Impressionist works[br]seems to pulse, flicker and radiate oddly.

0:01:57.898,0:02:01.489
That's how this and other Impressionist[br]works use quickly executed

0:02:01.489,0:02:05.163
prominent brushstrokes to capture[br]something strikingly real

0:02:05.163,0:02:07.533
about how light moves.

0:02:07.533,0:02:11.206
60 years later, Russian mathematician[br]Andrey Kolmogorov

0:02:11.206,0:02:13.787
furthered our mathematical [br]understanding of turbulence

0:02:13.787,0:02:18.157
when he proposed that energy in a[br]turbulent fluid at length R

0:02:18.157,0:02:22.491
varies in proportion to [br]the 5/3rds power of R.

0:02:22.491,0:02:24.414
Experimental measurements[br]show Kolmogorov

0:02:24.414,0:02:27.804
was remarkably close to the [br]way turbulent flow works,

0:02:27.804,0:02:30.441
although a complete description of[br]turbulence remains

0:02:30.441,0:02:33.304
one of the unsolved problems in physics.

0:02:33.304,0:02:37.515
A turbulent flow is self-similar[br]if there is an energy cascade.

0:02:37.515,0:02:41.123
In ther words, big eddies[br]transfer their energy to smaller eddies,

0:02:41.123,0:02:43.941
which do likewise at other scales.

0:02:43.941,0:02:47.504
Examples of this include Jupiter's[br]great red spot,

0:02:47.504,0:02:51.408
cloud formations and[br]interstellar dust particles.

0:02:51.408,0:02:54.909
In 2004, using the Hubble Space Telescope,

0:02:54.909,0:03:00.171
scientists saw the eddies of a distant[br]cloud of dust and gas around a star,

0:03:00.171,0:03:03.842
and it reminded them of Van Gogh's [br]"Starry Night."

0:03:03.842,0:03:07.193
This motivated scientists from Mexico, [br]Spain and England

0:03:07.193,0:03:11.387
to study the luminence in Van Gogh's[br]paintings in detail.

0:03:11.387,0:03:15.700
They discovered that there is a distinct[br]pattern of turbulent fluid structures

0:03:15.700,0:03:20.801
close to Kolmogorov's equation[br]hidden in many of Van Gogh's paintings.

0:03:20.801,0:03:23.224
The researchers digitized the paintings,

0:03:23.224,0:03:26.970
and measured how brightness varies between[br]any two pixels.

0:03:26.970,0:03:29.689
From the curves measured for[br]pixel separations,

0:03:29.689,0:03:34.455
they concluded that paintings from[br]Van Gogh's period of psychotic agitation

0:03:34.455,0:03:37.945
behave remarkably similar [br]to fluid turbulence.

0:03:37.945,0:03:41.998
His self-portait with a pipe, from[br]a calmer period in Van Gogh's life,

0:03:41.998,0:03:44.488
showed no sign of this correspondence.

0:03:44.488,0:03:49.595
And neither did other artists' work that[br]seemed equally turbulent at first glance,

0:03:49.595,0:03:51.648
like Munch's 'The Scream."

0:03:51.648,0:03:54.696
While it's too easy to say Van Gogh's[br]turbulent genius

0:03:54.696,0:03:57.092
enabled him to depict turbulence,

0:03:57.092,0:04:02.026
it's also far too difficult to accurately[br]express the rousing beauty of the fact

0:04:02.026,0:04:04.477
that in a period of intense suffering,

0:04:04.477,0:04:07.931
Van Gogh was somehow able to[br]perceive and represent

0:04:07.931,0:04:10.360
one of the most supremely [br]difficult concepts

0:04:10.360,0:04:13.621
nature has ever brought before mankind,

0:04:13.621,0:04:15.760
and to unite his unique mind's eye

0:04:15.760,0:04:20.368
with the deepest mysteries[br]of movement, fluid and light.