1
00:00:06,841 --> 00:00:09,999
One of the most remarkable aspects
of the human brain

2
00:00:10,023 --> 00:00:13,651
is its ability to recognize patterns
and describe them.

3
00:00:13,675 --> 00:00:16,331
Among the hardest patterns
we've tried to understand

4
00:00:16,355 --> 00:00:20,765
is the concept of
turbulent flow in fluid dynamics.

5
00:00:20,789 --> 00:00:23,272
The German physicist
Werner Heisenberg said,

6
00:00:23,296 --> 00:00:27,357
"When I meet God,
I'm going to ask him two questions:

7
00:00:27,381 --> 00:00:30,818
why relativity and why turbulence?

8
00:00:30,842 --> 00:00:34,908
I really believe he will have
an answer for the first."

9
00:00:34,932 --> 00:00:38,280
As difficult as turbulence is
to understand mathematically,

10
00:00:38,304 --> 00:00:42,170
we can use art to depict the way it looks.

11
00:00:42,194 --> 00:00:47,284
In June 1889, Vincent van Gogh
painted the view just before sunrise

12
00:00:47,308 --> 00:00:51,635
from the window of his room
at the Saint-Paul-de-Mausole asylum

13
00:00:51,659 --> 00:00:53,564
in Saint-Rémy-de-Provence,

14
00:00:53,588 --> 00:00:56,816
where he'd admitted himself after
mutilating his own ear

15
00:00:56,840 --> 00:00:58,415
in a psychotic episode.

16
00:00:59,312 --> 00:01:02,032
In "The Starry Night,"
his circular brushstrokes

17
00:01:02,056 --> 00:01:07,803
create a night sky filled
with swirling clouds and eddies of stars.

18
00:01:07,827 --> 00:01:11,724
Van Gogh and other Impressionists
represented light in a different way

19
00:01:11,748 --> 00:01:12,955
than their predecessors,

20
00:01:12,979 --> 00:01:15,749
seeming to capture
its motion, for instance,

21
00:01:15,773 --> 00:01:17,836
across sun-dappled waters,

22
00:01:17,860 --> 00:01:21,506
or here in star light
that twinkles and melts

23
00:01:21,530 --> 00:01:23,919
through milky waves of blue night sky.

24
00:01:24,844 --> 00:01:27,391
The effect is caused by luminance,

25
00:01:27,415 --> 00:01:30,916
the intensity of the light
in the colors on the canvas.

26
00:01:30,940 --> 00:01:33,608
The more primitive part
of our visual cortex,

27
00:01:33,632 --> 00:01:37,554
which sees light contrast
and motion, but not color,

28
00:01:37,578 --> 00:01:40,603
will blend two differently
colored areas together

29
00:01:40,627 --> 00:01:42,949
if they have the same luminance.

30
00:01:42,973 --> 00:01:45,328
But our brains' primate subdivision

31
00:01:45,352 --> 00:01:48,482
will see the contrasting colors
without blending.

32
00:01:48,506 --> 00:01:51,433
With these two interpretations
happening at once,

33
00:01:51,457 --> 00:01:57,005
the light in many Impressionist works
seems to pulse, flicker and radiate oddly.

34
00:01:57,898 --> 00:02:00,200
That's how this
and other Impressionist works

35
00:02:00,225 --> 00:02:03,042
use quickly executed
prominent brushstrokes

36
00:02:03,067 --> 00:02:06,733
to capture something strikingly real
about how light moves.

37
00:02:07,702 --> 00:02:11,182
60 years later, Russian
mathematician Andrey Kolmogorov

38
00:02:11,206 --> 00:02:13,763
furthered our mathematical
understanding of turbulence

39
00:02:13,787 --> 00:02:18,133
when he proposed that energy
in a turbulent fluid at length R

40
00:02:18,157 --> 00:02:22,467
varies in proportion to
the 5/3rds power of R.

41
00:02:22,491 --> 00:02:24,444
Experimental measurements show Kolmogorov

42
00:02:24,469 --> 00:02:27,632
was remarkably close
to the way turbulent flow works,

43
00:02:27,656 --> 00:02:29,788
although a complete description
of turbulence

44
00:02:29,811 --> 00:02:32,576
remains one of the unsolved
problems in physics.

45
00:02:33,181 --> 00:02:37,491
A turbulent flow is self-similar
if there is an energy cascade.

46
00:02:37,515 --> 00:02:41,099
In other words, big eddies
transfer their energy to smaller eddies,

47
00:02:41,123 --> 00:02:43,174
which do likewise at other scales.

48
00:02:43,921 --> 00:02:47,204
Examples of this include
Jupiter's Great Red Spot,

49
00:02:47,228 --> 00:02:50,568
cloud formations
and interstellar dust particles.

50
00:02:51,671 --> 00:02:54,885
In 2004, using the Hubble Space Telescope,

51
00:02:54,909 --> 00:02:59,907
scientists saw the eddies of a distant
cloud of dust and gas around a star,

52
00:02:59,931 --> 00:03:02,857
and it reminded them
of Van Gogh's "Starry Night."

53
00:03:03,961 --> 00:03:07,169
This motivated scientists
from Mexico, Spain and England

54
00:03:07,193 --> 00:03:10,570
to study the luminance
in Van Gogh's paintings in detail.

55
00:03:11,421 --> 00:03:15,676
They discovered that there is a distinct
pattern of turbulent fluid structures

56
00:03:15,700 --> 00:03:20,014
close to Kolmogorov's equation
hidden in many of Van Gogh's paintings.

57
00:03:20,998 --> 00:03:23,200
The researchers digitized the paintings,

58
00:03:23,224 --> 00:03:26,946
and measured how brightness varies
between any two pixels.

59
00:03:26,970 --> 00:03:29,665
From the curves measured
for pixel separations,

60
00:03:29,689 --> 00:03:34,431
they concluded that paintings from
Van Gogh's period of psychotic agitation

61
00:03:34,455 --> 00:03:37,137
behave remarkably similar
to fluid turbulence.

62
00:03:37,987 --> 00:03:41,974
His self-portrait with a pipe, from
a calmer period in Van Gogh's life,

63
00:03:41,999 --> 00:03:43,860
showed no sign of this correspondence.

64
00:03:44,313 --> 00:03:46,787
And neither did other artists' work

65
00:03:46,811 --> 00:03:49,337
that seemed equally
turbulent at first glance,

66
00:03:49,362 --> 00:03:50,977
like Munch's "The Scream."

67
00:03:51,418 --> 00:03:54,672
While it's too easy to say
Van Gogh's turbulent genius

68
00:03:54,696 --> 00:03:57,068
enabled him to depict turbulence,

69
00:03:57,092 --> 00:04:02,002
it's also far too difficult to accurately
express the rousing beauty of the fact

70
00:04:02,026 --> 00:04:04,453
that in a period of intense suffering,

71
00:04:04,477 --> 00:04:07,907
Van Gogh was somehow
able to perceive and represent

72
00:04:07,931 --> 00:04:10,336
one of the most supremely
difficult concepts

73
00:04:10,360 --> 00:04:13,597
nature has ever brought before mankind,

74
00:04:13,621 --> 00:04:15,736
and to unite his unique mind's eye

75
00:04:15,760 --> 00:04:19,926
with the deepest mysteries
of movement, fluid and light.