WEBVTT

00:00:07.040 --> 00:00:10.023
One of the most remarkable aspects
of the human brain

00:00:10.023 --> 00:00:13.675
is its ability to recognize patterns
and describe them.

00:00:13.675 --> 00:00:16.355
Among the hardest patterns
we've tried to undestand

00:00:16.355 --> 00:00:20.789
is the concept of
turbulent flow in fluid dynamics.

00:00:20.789 --> 00:00:23.296
The German physicist
Werner Heisenberg said,

00:00:23.296 --> 00:00:27.381
"When I meet God, I'm going to ask him
two questions:

00:00:27.381 --> 00:00:30.842
why relativity and why turbulence?

00:00:30.842 --> 00:00:34.932
I really believe he will have 
an answer for the first."

00:00:34.932 --> 00:00:38.304
As difficult as turbulence is to
understand mathematically,

00:00:38.304 --> 00:00:42.194
we can use art to depict the way it looks.

00:00:42.194 --> 00:00:47.308
In June 1889, Vincent van Gogh painted
the view just before sunrise

00:00:47.308 --> 00:00:51.659
from the window of his room at the
Saint-Paul-de Mausole asylum

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

00:00:53.588 --> 00:00:56.840
where he'd admitted himself after
mutilating his own ear

00:00:56.840 --> 00:00:59.312
in a psychotic episode.

00:00:59.312 --> 00:01:02.056
In "The Starry Night,"
his circular brushstrokes

00:01:02.056 --> 00:01:07.827
create a night sky filled with
swirling clouds and eddies of stars.

00:01:07.827 --> 00:01:11.748
Van Gogh and other Impressionists
represented light in a different way

00:01:11.748 --> 00:01:14.872
than their predecessors,
seeming to capture its motion,

00:01:14.872 --> 00:01:17.860
for instance, across sun-dappled waters,

00:01:17.860 --> 00:01:21.530
or here in star light that 
twinkles and melts

00:01:21.530 --> 00:01:24.844
through milky waves of blue night sky.

00:01:24.844 --> 00:01:27.415
The effect is caused my luminance,

00:01:27.415 --> 00:01:31.104
the intensity of the light in the colors 
on the canvas.

00:01:31.104 --> 00:01:33.632
The more primitive part of our
visual cortex,

00:01:33.632 --> 00:01:37.578
which sees light contrast and motion,
but not color,

00:01:37.578 --> 00:01:40.627
will blend two differently 
colored areas together

00:01:40.627 --> 00:01:42.973
if they have the same luminance.

00:01:42.973 --> 00:01:45.352
But our brains primate
subdivision

00:01:45.352 --> 00:01:48.506
will see the contrasting colors
without blending.

00:01:48.506 --> 00:01:51.457
With these two interpretations
happening at once,

00:01:51.457 --> 00:01:57.898
the light in many Impressionist works
seems to pulse, flicker and radiate oddly.

00:01:57.898 --> 00:02:01.489
That's how this and other Impressionist
works use quickly executed

00:02:01.489 --> 00:02:05.163
prominent brushstrokes to capture
something strikingly real

00:02:05.163 --> 00:02:07.533
about how light moves.

00:02:07.533 --> 00:02:11.206
60 years later, Russian mathematician
Andrey Kolmogorov

00:02:11.206 --> 00:02:13.787
furthered our mathematical 
understanding of turbulence

00:02:13.787 --> 00:02:18.157
when he proposed that energy in a
turbulent fluid at length R

00:02:18.157 --> 00:02:22.491
varies in proportion to 
the 5/3rds power of R.

00:02:22.491 --> 00:02:24.414
Experimental measurements
show Kolmogorov

00:02:24.414 --> 00:02:27.804
was remarkably close to the 
way turbulent flow works,

00:02:27.804 --> 00:02:30.441
although a complete description of
turbulence remains

00:02:30.441 --> 00:02:33.304
one of the unsolved problems in physics.

00:02:33.304 --> 00:02:37.515
A turbulent flow is self-similar
if there is an energy cascade.

00:02:37.515 --> 00:02:41.123
In ther words, big eddies
transfer their energy to smaller eddies,

00:02:41.123 --> 00:02:43.941
which do likewise at other scales.

00:02:43.941 --> 00:02:47.504
Examples of this include Jupiter's
great red spot,

00:02:47.504 --> 00:02:51.408
cloud formations and
interstellar dust particles.

00:02:51.408 --> 00:02:54.909
In 2004, using the Hubble Space Telescope,

00:02:54.909 --> 00:03:00.171
scientists saw the eddies of a distant
cloud of dust and gas around a star,

00:03:00.171 --> 00:03:03.842
and it reminded them of Van Gogh's 
"Starry Night."

00:03:03.842 --> 00:03:07.193
This motivated scientists from Mexico, 
Spain and England

00:03:07.193 --> 00:03:11.387
to study the luminence in Van Gogh's
paintings in detail.

00:03:11.387 --> 00:03:15.700
They discovered that there is a distinct
pattern of turbulent fluid structures

00:03:15.700 --> 00:03:20.801
close to Kolmogorov's equation
hidden in many of Van Gogh's paintings.

00:03:20.801 --> 00:03:23.224
The researchers digitized the paintings,

00:03:23.224 --> 00:03:26.970
and measured how brightness varies between
any two pixels.

00:03:26.970 --> 00:03:29.689
From the curves measured for
pixel separations,

00:03:29.689 --> 00:03:34.455
they concluded that paintings from
Van Gogh's period of psychotic agitation

00:03:34.455 --> 00:03:37.945
behave remarkably similar 
to fluid turbulence.

00:03:37.945 --> 00:03:41.998
His self-portait with a pipe, from
a calmer period in Van Gogh's life,

00:03:41.998 --> 00:03:44.488
showed no sign of this correspondence.

00:03:44.488 --> 00:03:49.595
And neither did other artists' work that
seemed equally turbulent at first glance,

00:03:49.595 --> 00:03:51.648
like Munch's 'The Scream."

00:03:51.648 --> 00:03:54.696
While it's too easy to say Van Gogh's
turbulent genius

00:03:54.696 --> 00:03:57.092
enabled him to depict turbulence,

00:03:57.092 --> 00:04:02.026
it's also far too difficult to accurately
express the rousing beauty of the fact

00:04:02.026 --> 00:04:04.477
that in a period of intense suffering,

00:04:04.477 --> 00:04:07.931
Van Gogh was somehow able to
perceive and represent

00:04:07.931 --> 00:04:10.360
one of the most supremely 
difficult concepts

00:04:10.360 --> 00:04:13.621
nature has ever brought before mankind,

00:04:13.621 --> 00:04:15.760
and to unite his unique mind's eye

00:04:15.760 --> 00:04:20.368
with the deepest mysteries
of movement, fluid and light.