Ron Eglash: The fractals at the heart of African designs

131,861 views ・ 2007-12-07

TED


請雙擊下方英文字幕播放視頻。

譯者: Joan Liu 審譯者: Nova Upinel Altesse
00:13
I want to start my story in Germany, in 1877,
0
13160
3000
我的故事要從1877年在德國
00:16
with a mathematician named Georg Cantor.
1
16160
2000
一位名叫Georg Cantor的數學家說起。
00:18
And Cantor decided he was going to take a line and erase the middle third of the line,
2
18160
5000
Cantor決定要把一個線段的中間三分之一擦掉,
00:23
and then take those two resulting lines and bring them back into the same process, a recursive process.
3
23160
5000
將頭尾兩端接起來再重複,如此週而復始。
00:28
So he starts out with one line, and then two,
4
28160
2000
所以他一開始有一條線段,然後有兩條,
00:30
and then four, and then 16, and so on.
5
30160
3000
接著有四條,然後有十六條,這樣繼續下去。
00:33
And if he does this an infinite number of times, which you can do in mathematics,
6
33160
3000
如果他做這個無限多次,在數學上是可以做到的,
00:36
he ends up with an infinite number of lines,
7
36160
2000
他就會有無限多條線段,
00:38
each of which has an infinite number of points in it.
8
38160
3000
其中每一條線段都有無限多點。
00:41
So he realized he had a set whose number of elements was larger than infinity.
9
41160
4000
所以他發現他會有一個比無限多還大的集合。
00:45
And this blew his mind. Literally. He checked into a sanitarium. (Laughter)
10
45160
3000
他為之瘋狂。真的。他進了療養院。(笑聲)
00:48
And when he came out of the sanitarium,
11
48160
2000
當他離開療養院時,
00:50
he was convinced that he had been put on earth to found transfinite set theory
12
50160
6000
他認為他來到地球是為了理解超限理論,
00:56
because the largest set of infinity would be God Himself.
13
56160
3000
因為最大的無限就是神。
00:59
He was a very religious man.
14
59160
1000
他是個非常虔誠的人。
01:00
He was a mathematician on a mission.
15
60160
2000
他是個有使命的數學家。
01:02
And other mathematicians did the same sort of thing.
16
62160
2000
而且其他數學家也做了類似的事情。
01:04
A Swedish mathematician, von Koch,
17
64160
2000
van Koch是個瑞典的數學家,
01:06
decided that instead of subtracting lines, he would add them.
18
66160
4000
他做了類似的事情,但是不用減法而改用加法。
01:10
And so he came up with this beautiful curve.
19
70160
2000
所以他得到了這漂亮的弧線。
01:12
And there's no particular reason why we have to start with this seed shape;
20
72160
3000
並沒有什麼特定的原因讓我們必須從這樣的種子圖形開始,
01:15
we can use any seed shape we like.
21
75160
4000
我們可以用任何的圖形作起始。
01:19
And I'll rearrange this and I'll stick this somewhere -- down there, OK --
22
79160
4000
我來重新整理一下,把這個放在某個地方--放到這裡,好--
01:23
and now upon iteration, that seed shape sort of unfolds into a very different looking structure.
23
83160
7000
經過無數重複後,種子圖形展開成一個非常不同的結構。
01:30
So these all have the property of self-similarity:
24
90160
2000
所以這些都有自體相似的特質:
01:32
the part looks like the whole.
25
92160
2000
各個部份跟整體相似。
01:34
It's the same pattern at many different scales.
26
94160
2000
在不同尺度上都是同一個圖形。
01:37
Now, mathematicians thought this was very strange
27
97160
2000
好,數學家覺得這很奇怪。
01:39
because as you shrink a ruler down, you measure a longer and longer length.
28
99160
5000
因為如果你把一把尺縮小,你量到的數據會越來越長。
01:44
And since they went through the iterations an infinite number of times,
29
104160
2000
然後因為重複了無限多次,
01:46
as the ruler shrinks down to infinity, the length goes to infinity.
30
106160
6000
量尺變成無限小,長度變成無限長。
01:52
This made no sense at all,
31
112160
1000
這不合理,
01:53
so they consigned these curves to the back of the math books.
32
113160
3000
所以他們把這個放在數學書籍最後面。
01:56
They said these are pathological curves, and we don't have to discuss them.
33
116160
4000
他們說這是有問題的曲線,所以我們不討論。
02:00
(Laughter)
34
120160
1000
(笑聲)
02:01
And that worked for a hundred years.
35
121160
2000
且成功的這麼做了一百年。
02:04
And then in 1977, Benoit Mandelbrot, a French mathematician,
36
124160
5000
然後在1977年,一個法國數學家Benoit Mandelbrot
02:09
realized that if you do computer graphics and used these shapes he called fractals,
37
129160
5000
發現如果利用電腦繪圖繪出這些他叫做碎形的圖樣,
02:14
you get the shapes of nature.
38
134160
2000
你可以得到自然界的圖形。
02:16
You get the human lungs, you get acacia trees, you get ferns,
39
136160
4000
你可以得到人類的肺圖形、刺槐、蕨類,
02:20
you get these beautiful natural forms.
40
140160
2000
你可以得到這些美麗的大自然形狀。
02:22
If you take your thumb and your index finger and look right where they meet --
41
142160
4000
如果你看你大拇指和食指交界的地方--
02:26
go ahead and do that now --
42
146160
2000
拿起來看看--
02:28
-- and relax your hand, you'll see a crinkle,
43
148160
3000
手放鬆,你會看到波紋,
02:31
and then a wrinkle within the crinkle, and a crinkle within the wrinkle. Right?
44
151160
3000
波紋中有皺紋,皺紋中有波紋。對吧?
02:34
Your body is covered with fractals.
45
154160
2000
你們全身都被碎形包覆著。
02:36
The mathematicians who were saying these were pathologically useless shapes?
46
156160
3000
而這些數學家竟然說這些是有問題且無意義的圖形?
02:39
They were breathing those words with fractal lungs.
47
159160
2000
他們正在用碎形組成的肺說這些話。
02:41
It's very ironic. And I'll show you a little natural recursion here.
48
161160
4000
這是非常諷刺的。我可以給你們看一些自然的循環。
02:45
Again, we just take these lines and recursively replace them with the whole shape.
49
165160
5000
再次的,我們將這些線段作重複。
02:50
So here's the second iteration, and the third, fourth and so on.
50
170160
5000
這是第二次重複、第三次、第四次...
02:55
So nature has this self-similar structure.
51
175160
2000
大自然有這樣的自體相似結構。
02:57
Nature uses self-organizing systems.
52
177160
2000
大自然利用自體組織系統。
02:59
Now in the 1980s, I happened to notice
53
179160
3000
在1980年代我發現
03:02
that if you look at an aerial photograph of an African village, you see fractals.
54
182160
4000
如果看這個非洲村落的空照圖,你會看到碎形。
03:06
And I thought, "This is fabulous! I wonder why?"
55
186160
4000
我就想:「這太好了!我想要知道為什麼?」
03:10
And of course I had to go to Africa and ask folks why.
56
190160
2000
所以當然我要去非洲問那些人為什麼。
03:12
So I got a Fulbright scholarship to just travel around Africa for a year
57
192160
6000
所以我拿了Fulbright獎學金去非洲旅行一年
03:18
asking people why they were building fractals,
58
198160
2000
問當地人為什麼要建造碎形。
03:20
which is a great job if you can get it.
59
200160
2000
其實是個很不錯的工作如果你可以拿到這個工作。
03:22
(Laughter)
60
202160
1000
(笑聲)
03:23
And so I finally got to this city, and I'd done a little fractal model for the city
61
203160
7000
所以我終於到達了這個城市。我做了一個這個城市的小型碎形模型,
03:30
just to see how it would sort of unfold --
62
210160
3000
讓我可以更瞭解如何展開的--
03:33
but when I got there, I got to the palace of the chief,
63
213160
3000
我到了那裡,找到酋長的宮殿,
03:36
and my French is not very good; I said something like,
64
216160
3000
我的法文不大好,我說了像是這樣的話:「
03:39
"I am a mathematician and I would like to stand on your roof."
65
219160
3000
我是個數學家,我想要站到你的屋頂上。」
03:42
But he was really cool about it, and he took me up there,
66
222160
3000
但他覺得沒問題,然後帶我上去,
03:45
and we talked about fractals.
67
225160
1000
然後我們聊了一下碎形。
03:46
And he said, "Oh yeah, yeah! We knew about a rectangle within a rectangle,
68
226160
3000
他說:「喔對對,我們知道這個長方形裡面的長方形,
03:49
we know all about that."
69
229160
2000
我們知道那個。」
03:51
And it turns out the royal insignia has a rectangle within a rectangle within a rectangle,
70
231160
4000
而且事實上皇家徽章就是長方形裡面有長方形有長方形,
03:55
and the path through that palace is actually this spiral here.
71
235160
4000
且皇宮中的走廊也是這樣迴旋著的。
03:59
And as you go through the path, you have to get more and more polite.
72
239160
4000
而且順著這些走廊走下去,你必須越來越有禮貌。
04:03
So they're mapping the social scaling onto the geometric scaling;
73
243160
3000
所以他們是用這樣幾何縮放的方式來建立社會地位,
04:06
it's a conscious pattern. It is not unconscious like a termite mound fractal.
74
246160
5000
是故意這麼做的,並不是像飛蟻丘那樣無意識的。
04:11
This is a village in southern Zambia.
75
251160
2000
這是在南尚比亞的一個村莊。
04:13
The Ba-ila built this village about 400 meters in diameter.
76
253160
4000
Ba-Ila人建造了一個直徑約400公尺的村莊。
04:17
You have a huge ring.
77
257160
2000
首先你有一個很大的圈圈。
04:19
The rings that represent the family enclosures get larger and larger as you go towards the back,
78
259160
6000
這些代表家族的圈圈越往後面越大,
04:26
and then you have the chief's ring here towards the back
79
266160
4000
在後面這邊有酋長的圈圈,
04:30
and then the chief's immediate family in that ring.
80
270160
3000
圈圈旁邊是酋長的家人圈。
04:33
So here's a little fractal model for it.
81
273160
1000
所以這是個小型的碎形模型。
04:34
Here's one house with the sacred altar,
82
274160
3000
這裡是一棟擁有神檀的屋子。
04:37
here's the house of houses, the family enclosure,
83
277160
3000
這裡是房子的房子,家庭圈圈,
04:40
with the humans here where the sacred altar would be,
84
280160
3000
這邊神壇的位置有人在,
04:43
and then here's the village as a whole --
85
283160
2000
這是整個村莊--
04:45
a ring of ring of rings with the chief's extended family here, the chief's immediate family here,
86
285160
5000
一圈一圈地在這裡,這是酋長的遠親,這裡是酋長的近親--
04:50
and here there's a tiny village only this big.
87
290160
3000
而這裡是一個非常小只有這麼大的村莊。
04:53
Now you might wonder, how can people fit in a tiny village only this big?
88
293160
4000
你們可能會問,這麼小的村莊怎麼住得下人?
04:57
That's because they're spirit people. It's the ancestors.
89
297160
3000
那是因為這些是神魂人物,是祖先們。
05:00
And of course the spirit people have a little miniature village in their village, right?
90
300160
5000
而且當然的這迷你的村落裡有另一個更小的村落,對吧?
05:05
So it's just like Georg Cantor said, the recursion continues forever.
91
305160
3000
所以就像Georg Cantor說的,一再地重複著。
05:08
This is in the Mandara mountains, near the Nigerian border in Cameroon, Mokoulek.
92
308160
4000
這是在奈吉利亞邊界Mokoulek地區Cameroon的Mandara山中的景象。
05:12
I saw this diagram drawn by a French architect,
93
312160
3000
我看到這幅法國建築家畫的圖,
05:15
and I thought, "Wow! What a beautiful fractal!"
94
315160
2000
然後我想:「哇!真是漂亮的碎形阿!」
05:17
So I tried to come up with a seed shape, which, upon iteration, would unfold into this thing.
95
317160
6000
所以我試著找出一個種子圖形在經過重複後可以展開成這樣的東西。
05:23
I came up with this structure here.
96
323160
2000
我想到這樣的一個結構。
05:25
Let's see, first iteration, second, third, fourth.
97
325160
4000
讓我們看看,第一次重複、第二次、第三次、第四次。
05:29
Now, after I did the simulation,
98
329160
2000
經過模擬後,
05:31
I realized the whole village kind of spirals around, just like this,
99
331160
3000
我發現整個村莊像螺旋般環繞著,就像這樣,
05:34
and here's that replicating line -- a self-replicating line that unfolds into the fractal.
100
334160
6000
且這邊是重複線:一條融入到碎形裡的自我複製線。
05:40
Well, I noticed that line is about where the only square building in the village is at.
101
340160
5000
我發現這也是整個村莊唯一一棟正方形建築物所在地。
05:45
So, when I got to the village,
102
345160
2000
所以我到了這個村莊,
05:47
I said, "Can you take me to the square building?
103
347160
2000
我問:「你可以帶我到這棟正方形建築那裡嗎?
05:49
I think something's going on there."
104
349160
2000
我覺得那裡有些什麼東西。」
05:51
And they said, "Well, we can take you there, but you can't go inside
105
351160
3000
他們說:「恩,我們可以帶你去那裡,但你不能進去,
05:54
because that's the sacred altar, where we do sacrifices every year
106
354160
3000
因為那是聖壇也就是我們每年為了
05:57
to keep up those annual cycles of fertility for the fields."
107
357160
3000
保持土地肥沃做祭祀的地方。」
06:00
And I started to realize that the cycles of fertility
108
360160
2000
我開始瞭解到這肥沃土壤的循環
06:02
were just like the recursive cycles in the geometric algorithm that builds this.
109
362160
4000
就跟建造這個的幾何算式循環一樣。
06:06
And the recursion in some of these villages continues down into very tiny scales.
110
366160
4000
且這樣的循環一直延續到非常小的尺度。
06:10
So here's a Nankani village in Mali.
111
370160
2000
這裡是Mali的一個Nankani村莊。
06:12
And you can see, you go inside the family enclosure --
112
372160
3000
你們可以看到,人們可以進到家庭圈圈中--
06:15
you go inside and here's pots in the fireplace, stacked recursively.
113
375160
4000
你可以進去然後這裡是壁爐中的鍋子,也是循環堆疊的。
06:19
Here's calabashes that Issa was just showing us,
114
379160
4000
這是Issa剛剛給我們看得葫蘆,
06:23
and they're stacked recursively.
115
383160
2000
它們也是循環堆疊的。
06:25
Now, the tiniest calabash in here keeps the woman's soul.
116
385160
2000
這裡,最小的葫蘆裡面保存著女人的靈魂。
06:27
And when she dies, they have a ceremony
117
387160
2000
她離開人世時,他們有一個儀式
06:29
where they break this stack called the zalanga and her soul goes off to eternity.
118
389160
5000
會打壞這個叫做zalanga的的堆疊讓她的靈魂可以達到永恆。
06:34
Once again, infinity is important.
119
394160
3000
再次的,無限是非常重要的。
06:38
Now, you might ask yourself three questions at this point.
120
398160
4000
到此,你們可能會問自己三個問題。
06:42
Aren't these scaling patterns just universal to all indigenous architecture?
121
402160
4000
這樣的不同尺度間呼應的圖形不是在每個原始建築中都存在嗎?
06:46
And that was actually my original hypothesis.
122
406160
2000
這事實上是我一開始的假設。
06:48
When I first saw those African fractals,
123
408160
2000
當我第一次看到非洲碎形時,
06:50
I thought, "Wow, so any indigenous group that doesn't have a state society,
124
410160
4000
我想:「哇,所以任何一個沒有制式的階層結構的的原始族群
06:54
that sort of hierarchy, must have a kind of bottom-up architecture."
125
414160
3000
都應該有類似的自下而上的建築形態。」
06:57
But that turns out not to be true.
126
417160
2000
但後來發現這是不正確的。
06:59
I started collecting aerial photographs of Native American and South Pacific architecture;
127
419160
4000
我開始蒐集美國原住民和南太平洋建築的空照圖,
07:03
only the African ones were fractal.
128
423160
2000
只有非洲的有碎形。
07:05
And if you think about it, all these different societies have different geometric design themes that they use.
129
425160
6000
而且如果你仔細想,這些不同的文民都有不同的幾何設計主題。
07:11
So Native Americans use a combination of circular symmetry and fourfold symmetry.
130
431160
6000
美國原住民用了圓形對稱和四方對稱的組合。
07:17
You can see on the pottery and the baskets.
131
437160
2000
你可以在陶器和籃子上看出來。
07:19
Here's an aerial photograph of one of the Anasazi ruins;
132
439160
3000
這是Anasazi殘骸的空照圖。
07:22
you can see it's circular at the largest scale, but it's rectangular at the smaller scale, right?
133
442160
5000
你們可以看到在大尺度上是圓環的,但在較小的尺度上是長方形的,對吧?
07:27
It is not the same pattern at two different scales.
134
447160
4000
在這兩個尺度上不是一樣的圖形。
07:31
Second, you might ask,
135
451160
1000
第二,你可能會問:
07:32
"Well, Dr. Eglash, aren't you ignoring the diversity of African cultures?"
136
452160
3000
「恩,Eglash博士,你是不是忽略了非洲文化的多樣性?」
07:36
And three times, the answer is no.
137
456160
2000
第三次的,答案是否定的。
07:38
First of all, I agree with Mudimbe's wonderful book, "The Invention of Africa,"
138
458160
4000
首先,我完全贊同Mudimbe在他很棒的書《非洲創立》中寫到
07:42
that Africa is an artificial invention of first colonialism,
139
462160
3000
非洲是個是個人類殖明主義的開始,
07:45
and then oppositional movements.
140
465160
2000
接著是對抗性運動。
07:47
No, because a widely shared design practice doesn't necessarily give you a unity of culture --
141
467160
5000
不,因為一個廣泛被使用的設計並不代表文化上是統一的,
07:52
and it definitely is not "in the DNA."
142
472160
3000
亦不代表是包含在DNA中的。
07:55
And finally, the fractals have self-similarity --
143
475160
2000
而且這些碎形是自體相似的,
07:57
so they're similar to themselves, but they're not necessarily similar to each other --
144
477160
4000
也就是說他們跟自己像而跟其它的碎形不像,
08:01
you see very different uses for fractals.
145
481160
2000
你可以看到非常不同的碎形使用方式。
08:03
It's a shared technology in Africa.
146
483160
2000
這是在非洲的一個共同的科技。
08:06
And finally, well, isn't this just intuition?
147
486160
3000
最後,恩,會不會這只是直覺?
08:09
It's not really mathematical knowledge.
148
489160
2000
事實上跟數學知識一點關係都沒有?
08:11
Africans can't possibly really be using fractal geometry, right?
149
491160
3000
非洲人不可能真的使用碎形幾何對吧?
08:14
It wasn't invented until the 1970s.
150
494160
2000
碎形幾何一直到1970年代才發明的。
08:17
Well, it's true that some African fractals are, as far as I'm concerned, just pure intuition.
151
497160
5000
是的,我認為非洲碎形有很大一部份是直覺。
08:22
So some of these things, I'd wander around the streets of Dakar
152
502160
3000
有時候我會在Dakar的街上遊蕩
08:25
asking people, "What's the algorithm? What's the rule for making this?"
153
505160
3000
問當地人:「這背後的算式是什麼?規則是什麼?」
08:28
and they'd say,
154
508160
1000
他們會說:「
08:29
"Well, we just make it that way because it looks pretty, stupid." (Laughter)
155
509160
3000
我們把它建造成這樣所以好看阿!你這個笨蛋。」(笑聲)
08:32
But sometimes, that's not the case.
156
512160
3000
但有些時候不是這樣的。
08:35
In some cases, there would actually be algorithms, and very sophisticated algorithms.
157
515160
5000
有些時候,背後真的有算式,且是非常複雜的算式。
08:40
So in Manghetu sculpture, you'd see this recursive geometry.
158
520160
3000
你可以在Manghetu的雕像上看到重複的幾何圖形。
08:43
In Ethiopian crosses, you see this wonderful unfolding of the shape.
159
523160
5000
在Ehiopian的十字架上也可以看到這些無限展開的形狀。
08:48
In Angola, the Chokwe people draw lines in the sand,
160
528160
4000
在Angola,Chokwe人會在沙上畫線,
08:52
and it's what the German mathematician Euler called a graph;
161
532160
3000
也就是德國數學家Euler叫做圖像的東西。
08:55
we now call it an Eulerian path --
162
535160
2000
我們把它叫做Eulerian道路--
08:57
you can never lift your stylus from the surface
163
537160
2000
你永遠不可以將你的筆從表面上提起,
08:59
and you can never go over the same line twice.
164
539160
3000
也不可以重複同一條線段。
09:02
But they do it recursively, and they do it with an age-grade system,
165
542160
3000
但他們可以重複地這個做,且以一個年紀劃分的方式這麼做,
09:05
so the little kids learn this one, and then the older kids learn this one,
166
545160
3000
所以小朋友會學這個,大一點的學這個,
09:08
then the next age-grade initiation, you learn this one.
167
548160
3000
在大一點的學這個。
09:11
And with each iteration of that algorithm,
168
551160
3000
而且在每一次重複這些算式時
09:14
you learn the iterations of the myth.
169
554160
2000
他們會學這些重複背後的意義。
09:16
You learn the next level of knowledge.
170
556160
2000
他們會學到下一層的知識。
09:19
And finally, all over Africa, you see this board game.
171
559160
2000
最後,在整個非洲你都可以看到這樣的棋盤遊戲。
09:21
It's called Owari in Ghana, where I studied it;
172
561160
3000
這遊戲在我研究的加那叫作Owari,
09:24
it's called Mancala here on the East Coast, Bao in Kenya, Sogo elsewhere.
173
564160
5000
在東岸叫做Mancaia,在肯亞叫做Bao,在其他地方叫做Sogo。
09:29
Well, you see self-organizing patterns that spontaneously occur in this board game.
174
569160
5000
你可以在這些棋盤遊戲中看到自體重複的圖形。
09:34
And the folks in Ghana knew about these self-organizing patterns
175
574160
3000
在加那的人知道這些圖形,
09:37
and would use them strategically.
176
577160
2000
且會有策略地運用它們。
09:39
So this is very conscious knowledge.
177
579160
2000
所以是個有意識的知識。
09:41
Here's a wonderful fractal.
178
581160
2000
這是個很棒的碎形。
09:43
Anywhere you go in the Sahel, you'll see this windscreen.
179
583160
4000
在Sahel的各個地方,你都可以看到這樣的擋風玻璃。
09:47
And of course fences around the world are all Cartesian, all strictly linear.
180
587160
4000
當然的世界上任何籬笆都是笛卡爾式的,都是直線的。
09:51
But here in Africa, you've got these nonlinear scaling fences.
181
591160
4000
但在非洲,你也可以看到這些不是直線的籬笆。
09:55
So I tracked down one of the folks who makes these things,
182
595160
2000
所以我找到設計這些籬笆的人,
09:57
this guy in Mali just outside of Bamako, and I asked him,
183
597160
4000
他是一個住在Bamako外面的Mali的人,我問他:
10:01
"How come you're making fractal fences? Because nobody else is."
184
601160
2000
「為什麼你用碎形法製造籬笆?因為沒有其他人這麼做。」
10:03
And his answer was very interesting.
185
603160
2000
他的答覆非常有趣。
10:05
He said, "Well, if I lived in the jungle, I would only use the long rows of straw
186
605160
5000
他說:「恩,當我走在叢林中時,我只會用長條的稻草,
10:10
because they're very quick and they're very cheap.
187
610160
2000
因為使用它們既快又便宜。
10:12
It doesn't take much time, doesn't take much straw."
188
612160
3000
不需要花太多時間且不需要太多稻草。」
10:15
He said, "but wind and dust goes through pretty easily.
189
615160
2000
他說:「但風和塵土很容易穿過。
10:17
Now, the tight rows up at the very top, they really hold out the wind and dust.
190
617160
4000
最上層很緊的那排可以擋住風和塵土。
10:21
But it takes a lot of time, and it takes a lot of straw because they're really tight."
191
621160
5000
但這需要花很多時間、很多稻草,因為他們需要非常緊。」
10:26
"Now," he said, "we know from experience
192
626160
2000
「現在」他說:「我們從經驗中得知,
10:28
that the farther up from the ground you go, the stronger the wind blows."
193
628160
5000
越高的地方風越強。」
10:33
Right? It's just like a cost-benefit analysis.
194
633160
3000
對吧?就有點像是成本效益分析。
10:36
And I measured out the lengths of straw,
195
636160
2000
我量了稻草的長度,
10:38
put it on a log-log plot, got the scaling exponent,
196
638160
2000
把它放進對數圖形,得到尺度指數,
10:40
and it almost exactly matches the scaling exponent for the relationship between wind speed and height
197
640160
5000
發現他幾乎完全和風速工程書上的
10:45
in the wind engineering handbook.
198
645160
1000
風速與高度的指數相同。
10:46
So these guys are right on target for a practical use of scaling technology.
199
646160
5000
這些人在利用尺度科技上正中目標。
10:51
The most complex example of an algorithmic approach to fractals that I found
200
651160
5000
我找到最復雜的算式碎形
10:56
was actually not in geometry, it was in a symbolic code,
201
656160
2000
並不是幾何圖形,而是符號象徵,
10:58
and this was Bamana sand divination.
202
658160
3000
而這是在Bamana的沙占卜。
11:01
And the same divination system is found all over Africa.
203
661160
3000
在整個非洲都有同樣的占卜系統。
11:04
You can find it on the East Coast as well as the West Coast,
204
664160
5000
你可以在東岸西岸都找得到這個占卜,
11:09
and often the symbols are very well preserved,
205
669160
2000
而且大部份的時候這些符號是保存得很好的。
11:11
so each of these symbols has four bits -- it's a four-bit binary word --
206
671160
6000
每一個符號有四個小部份:是四個二進法組成的字。
11:17
you draw these lines in the sand randomly, and then you count off,
207
677160
5000
你隨意畫這些線,然後數一下,
11:22
and if it's an odd number, you put down one stroke,
208
682160
2000
如果是奇數,就畫一條線;
11:24
and if it's an even number, you put down two strokes.
209
684160
2000
如果是偶數,就畫兩條線。
11:26
And they did this very rapidly,
210
686160
3000
且他們很迅速地這麼做,
11:29
and I couldn't understand where they were getting --
211
689160
2000
我無法瞭解他們怎麼做到的,
11:31
they only did the randomness four times --
212
691160
2000
他們在隨意的部份只做了四次,
11:33
I couldn't understand where they were getting the other 12 symbols.
213
693160
2000
我不懂他們另外十二個符號怎麼來的。
11:35
And they wouldn't tell me.
214
695160
2000
他們也不告訴我。
11:37
They said, "No, no, I can't tell you about this."
215
697160
2000
他們說:「不不,我不能告訴你這個。」
11:39
And I said, "Well look, I'll pay you, you can be my teacher,
216
699160
2000
然後我說:「恩,我可以付你錢,你可以當我的老師,
11:41
and I'll come each day and pay you."
217
701160
2000
然後我可以每天來付你學費。」
11:43
They said, "It's not a matter of money. This is a religious matter."
218
703160
3000
他們說:「這不是錢的問題。這是宗教問題。」
11:46
And finally, out of desperation, I said,
219
706160
1000
最後在絕望中我說:「
11:47
"Well, let me explain Georg Cantor in 1877."
220
707160
3000
恩,讓我來解釋一下1877年的Georg Cantor。」
11:50
And I started explaining why I was there in Africa,
221
710160
4000
所以我開始解釋我為什麼會在非洲,
11:54
and they got very excited when they saw the Cantor set.
222
714160
2000
他們看了Cantor組合後非常興奮。
11:56
And one of them said, "Come here. I think I can help you out here."
223
716160
4000
他們之中其中一個說:「過來,我想我可以幫你一些。」
12:00
And so he took me through the initiation ritual for a Bamana priest.
224
720160
5000
所以他代Bamana牧師帶我走過了一連串的起始儀式。
12:05
And of course, I was only interested in the math,
225
725160
2000
當然的,我只對數學的部份有興趣,
12:07
so the whole time, he kept shaking his head going,
226
727160
2000
所以整個過程,他一直搖頭說:
12:09
"You know, I didn't learn it this way."
227
729160
1000
「我不是這樣學的。」
12:10
But I had to sleep with a kola nut next to my bed, buried in sand,
228
730160
4000
但我必須在床邊放一顆埋在沙裡的可樂果,
12:14
and give seven coins to seven lepers and so on.
229
734160
3000
然後給七個痲瘋病人七個銅板之類的事情。
12:17
And finally, he revealed the truth of the matter.
230
737160
4000
最後,他終於告訴我這後面的祕密。
12:22
And it turns out it's a pseudo-random number generator using deterministic chaos.
231
742160
4000
事實上這是一個偽渾沌的產生數字的過程。
12:26
When you have a four-bit symbol, you then put it together with another one sideways.
232
746160
6000
當你有一個四位符號,你把它們並排排起來。
12:32
So even plus odd gives you odd.
233
752160
2000
所以偶數加奇數會得到奇數。
12:34
Odd plus even gives you odd.
234
754160
2000
奇數加偶數會得到奇數。
12:36
Even plus even gives you even. Odd plus odd gives you even.
235
756160
3000
偶數加偶數會得到偶數。奇數加奇數得到偶數。
12:39
It's addition modulo 2, just like in the parity bit check on your computer.
236
759160
4000
這是加法定理,就像是電腦裡的配對法一樣。
12:43
And then you take this symbol, and you put it back in
237
763160
4000
然後你拿所得到的符號,再放回去,
12:47
so it's a self-generating diversity of symbols.
238
767160
2000
就得到一個自我生成的多樣性符號。
12:49
They're truly using a kind of deterministic chaos in doing this.
239
769160
4000
他們真的在使用決定性混度來產生這些符號。
12:53
Now, because it's a binary code,
240
773160
2000
好,因為是二進位符號,
12:55
you can actually implement this in hardware --
241
775160
2000
事實上你可以將這個置入到硬體裡面--
12:57
what a fantastic teaching tool that should be in African engineering schools.
242
777160
5000
多麼適合給非洲工程學校的教材阿!
13:02
And the most interesting thing I found out about it was historical.
243
782160
3000
我發現最有趣的是它的歷史。
13:05
In the 12th century, Hugo of Santalla brought it from Islamic mystics into Spain.
244
785160
6000
在十二世紀,Santalla的Hugu將這個從西班牙的回教傳統中引進的。
13:11
And there it entered into the alchemy community as geomancy:
245
791160
6000
在那裡,碎形以看風水的身分
13:17
divination through the earth.
246
797160
2000
進入了煉金術的世界。
13:19
This is a geomantic chart drawn for King Richard II in 1390.
247
799160
5000
這是1390年理查國王二世所畫的幾何圖表。
13:24
Leibniz, the German mathematician,
248
804160
3000
德國數學家Leibniz在他的論文中
13:27
talked about geomancy in his dissertation called "De Combinatoria."
249
807160
4000
提到「De Combinatoria」的幾何性。
13:31
And he said, "Well, instead of using one stroke and two strokes,
250
811160
4000
他說:「恩,讓我們用零和一取代
13:35
let's use a one and a zero, and we can count by powers of two."
251
815160
4000
一條線和兩條線,這樣我們可以以二的指數數下去。」
13:39
Right? Ones and zeros, the binary code.
252
819160
2000
對吧?零和一,二進位法。
13:41
George Boole took Leibniz's binary code and created Boolean algebra,
253
821160
3000
George Boole拿了Leibniz的二進位法而創造了Boolean算式,
13:44
and John von Neumann took Boolean algebra and created the digital computer.
254
824160
3000
然後John von Neumann拿了Boolean算式而創造了數位電腦。
13:47
So all these little PDAs and laptops --
255
827160
3000
所以這些掌上型電腦和筆記型電腦--
13:50
every digital circuit in the world -- started in Africa.
256
830160
3000
所有利用數位迴路的東西--都是從非洲開始的。
13:53
And I know Brian Eno says there's not enough Africa in computers,
257
833160
5000
我知道Brian Eno說非洲的電腦不夠,
13:58
but you know, I don't think there's enough African history in Brian Eno.
258
838160
5000
但你知道嗎?我覺得Brian Eno的非洲歷史知識不夠。
14:03
(Laughter) (Applause)
259
843160
3000
(掌聲)
14:06
So let me end with just a few words about applications that we've found for this.
260
846160
4000
所以讓我在結束前談談我們做的一些程式。
14:10
And you can go to our website,
261
850160
2000
你們可以到我們的網站,
14:12
the applets are all free; they just run in the browser.
262
852160
2000
使用免費在瀏覽器中始用的程式。
14:14
Anybody in the world can use them.
263
854160
2000
世界上任何人都可以使用它。
14:16
The National Science Foundation's Broadening Participation in Computing program
264
856160
5000
美國國家科學基金會的擴大計算機計畫
14:21
recently awarded us a grant to make a programmable version of these design tools,
265
861160
7000
最近給我們一筆經費來設計一個可編輯的設計工具,
14:28
so hopefully in three years, anybody'll be able to go on the Web
266
868160
2000
希望在三年內,任何人都可以上網
14:30
and create their own simulations and their own artifacts.
267
870160
3000
去作自己的模擬和設計自己的藝品。
14:33
We've focused in the U.S. on African-American students as well as Native American and Latino.
268
873160
5000
我們把重點放在美國和非裔美國學生和美國原住民和西班牙裔。
14:38
We've found statistically significant improvement with children using this software in a mathematics class
269
878160
6000
相較於沒有使用這些程式的控制組,
14:44
in comparison with a control group that did not have the software.
270
884160
3000
我們發現有使用的孩子在數學課尚有顯著地進步。
14:47
So it's really very successful teaching children that they have a heritage that's about mathematics,
271
887160
6000
所以教孩子們他們有數學的傳統是非常有效的,
14:53
that it's not just about singing and dancing.
272
893160
4000
讓他們知道他們的傳統不只是唱歌與跳舞而已。
14:57
We've started a pilot program in Ghana.
273
897160
3000
我們也在加納開始了一個前驅計畫,
15:00
We got a small seed grant, just to see if folks would be willing to work with us on this;
274
900160
5000
我們拿到一小筆經費,只為了知道當地的人們有沒有興趣跟我們合作,
15:05
we're very excited about the future possibilities for that.
275
905160
3000
我們對於這個計畫的未來性感到興奮。
15:08
We've also been working in design.
276
908160
2000
我們也在設計上下工夫。
15:10
I didn't put his name up here -- my colleague, Kerry, in Kenya, has come up with this great idea
277
910160
5000
我沒有把他的名字放上去--我的同事Kerry在肯亞想到一個很棒的點子,
15:15
for using fractal structure for postal address in villages that have fractal structure,
278
915160
5000
就是用碎形結構在碎形村莊中作郵遞區號,
15:20
because if you try to impose a grid structure postal system on a fractal village,
279
920160
4000
因為如果你想要將格子式的郵遞區號放入碎形的村莊中
15:24
it doesn't quite fit.
280
924160
2000
是不大適合的。
15:26
Bernard Tschumi at Columbia University has finished using this in a design for a museum of African art.
281
926160
5000
哥倫比亞大學的Bernard Tschumi已經成功的利用碎形設計了一個非洲藝術博物館。
15:31
David Hughes at Ohio State University has written a primer on Afrocentric architecture
282
931160
8000
Ohio州立大學的David Hughes也寫了一本關於非洲中心建築的入門書籍,
15:39
in which he's used some of these fractal structures.
283
939160
2000
裡面包括了一些碎形結構。
15:41
And finally, I just wanted to point out that this idea of self-organization,
284
941160
5000
最後,我想要指出這個自體組織的想法,
15:46
as we heard earlier, it's in the brain.
285
946160
2000
就像我們早些兒聽到的,是在腦裡面的。
15:48
It's in the -- it's in Google's search engine.
286
948160
5000
這是在,有在Google的搜尋引擎中。
15:53
Actually, the reason that Google was such a success
287
953160
2000
事實上,Google之所以這麼成功就是
15:55
is because they were the first ones to take advantage of the self-organizing properties of the web.
288
955160
4000
因為他是前幾個使用自體組織的優點建構的。
15:59
It's in ecological sustainability.
289
959160
2000
這是存在於生態持續性的。
16:01
It's in the developmental power of entrepreneurship,
290
961160
2000
這也是創業精神中發展的動力,
16:03
the ethical power of democracy.
291
963160
2000
民主的道德力量。
16:06
It's also in some bad things.
292
966160
2000
它也存在於一些不大好的東西當中。
16:08
Self-organization is why the AIDS virus is spreading so fast.
293
968160
3000
自體組織是為什麼愛滋病可以如此迅速的擴散。
16:11
And if you don't think that capitalism, which is self-organizing, can have destructive effects,
294
971160
4000
而且如果你覺得資本主義,也是一種自體組織,不會有破壞性的影響的話,
16:15
you haven't opened your eyes enough.
295
975160
2000
你看得還不夠多。
16:17
So we need to think about, as was spoken earlier,
296
977160
4000
所以我們需要想想,就像我們之前說的,
16:21
the traditional African methods for doing self-organization.
297
981160
2000
這個非洲的自體組織的方式。
16:23
These are robust algorithms.
298
983160
2000
這是非常有力的計算方法。
16:26
These are ways of doing self-organization -- of doing entrepreneurship --
299
986160
3000
自體組織有很多種方式--就像創業一樣--
16:29
that are gentle, that are egalitarian.
300
989160
2000
可以是溫柔的,可以是平均的。
16:31
So if we want to find a better way of doing that kind of work,
301
991160
4000
所以如果我們想要找到一個更好的方式來做這件事情,
16:35
we need look only no farther than Africa to find these robust self-organizing algorithms.
302
995160
5000
我們只需要找到非洲這些強而有力的自體組織算式就夠了。
16:40
Thank you.
303
1000160
1000
謝謝。
關於本網站

本網站將向您介紹對學習英語有用的 YouTube 視頻。 您將看到來自世界各地的一流教師教授的英語課程。 雙擊每個視頻頁面上顯示的英文字幕,從那裡播放視頻。 字幕與視頻播放同步滾動。 如果您有任何意見或要求,請使用此聯繫表與我們聯繫。

https://forms.gle/WvT1wiN1qDtmnspy7