TED-Ed
Adam Savage: How simple ideas lead to scientific discoveries
Filmed:
Readability: 3.6
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Adam Savage walks through two spectacular examples of profound scientific discoveries that came from simple, creative methods anyone could have followed -- Eratosthenes' calculation of the Earth's circumference around 200 BC and Hippolyte Fizeau's measurement of the speed of light in 1849. Find more TED-Ed videos on our new YouTube channel: youtube.com/TEDEd.
Adam Savage - Maker, critical thinker
Adam Savage is an internationally renowned television producer, host and public speaker. Full bio
Adam Savage is an internationally renowned television producer, host and public speaker. Full bio
Double-click the English transcript below to play the video.
（音樂）
擁有大腦的有趣之處在於
00:14
One of the funny things
about owning a brain
about owning a brain
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你無法控制大腦如何收集與保留
00:16
is that you have
no control over the things
no control over the things
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00:18
that it gathers and holds onto,
the facts and the stories.
the facts and the stories.
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事實和故事。而當你越來越老, 事情只會變得更糟
00:21
And as you get older, it only gets worse.
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有些事情會留在你的腦袋裡很多年
00:23
Things stick around for years sometimes
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你根本不知道為什麼會一直記著這些事
00:25
before you understand
why you're interested in them,
why you're interested in them,
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也不清楚到底是怎麼把它記起來的。
00:28
before you understand their import to you.
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以下我有三個例子
00:30
Here's three of mine.
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當理查 · 費曼還是一個小男孩, 住在皇后區
00:31
When Richard Feynman
was a young boy in Queens,
was a young boy in Queens,
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有一次他和他的父親去散步, 拉著他的玩具拖車
00:34
he went for a walk with his dad
and his wagon and a ball.
and his wagon and a ball.
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上面放了一個球。他注意到，當他拉車的時候
00:38
He noticed that when he pulled the wagon,
the ball went to the back of the wagon.
the ball went to the back of the wagon.
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球會往拖車後面跑
他問他的爸爸, "為什麼球會跑到拖車的後面呢？"
00:42
He asked his dad, "Why does
the ball go to the back of the wagon?"
the ball go to the back of the wagon?"
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他的父親說, "這是慣性。"
00:45
And his dad said, "That's inertia."
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他問說, "慣性是什麼？" 他的父親說, "啊。
00:47
He said, "What's inertia?"
And his dad said, "Ah.
And his dad said, "Ah.
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慣性是科學家們給的名稱
00:50
Inertia is the name that scientists give
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00:52
to the phenomenon of the ball
going to the back of the wagon."
going to the back of the wagon."
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用來描述球跑去拖車後面的這種現象。
但事實是, 沒有人真正知道這現象到底是怎麼一回事。"
00:55
(Laughter)
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00:57
"But in truth, nobody really knows."
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費曼後來取得了學位
01:00
Feynman went on to earn degrees
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在麻省理工學院、 普林斯頓大學, 他還解決了挑戰者號太空梭爆炸的謎團,
01:02
at MIT, Princeton, he solved
the Challenger disaster,
the Challenger disaster,
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他還得到了諾貝爾物理學獎,
01:05
he ended up winning
the Nobel Prize in Physics
the Nobel Prize in Physics
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因為他在描述亞原子粒子的運動方面的成就
01:08
for his Feynman diagrams, describing
the movement of subatomic particles.
the movement of subatomic particles.
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他把一切歸功於那次與他父親的對話
01:12
And he credits that conversation
with his father as giving him a sense
with his father as giving him a sense
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給了他一個啟發:
從最簡單的問題開始, 可以帶領你探索到人類知識的前鋒,
01:16
that the simplest questions could carry
you out to the edge of human knowledge,
you out to the edge of human knowledge,
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這就是他想做的
01:21
and that that's where he wanted to play.
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而他也如此做到了
01:23
And play he did.
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第二個例子, 艾拉托斯特尼是亞歷山大
一個偉大圖書館的第三任館長
一個偉大圖書館的第三任館長
01:25
Eratosthenes was the third librarian
at the great Library of Alexandria,
at the great Library of Alexandria,
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他在科學方面有很多貢獻。
01:29
and he made many contributions to science.
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其中最讓人津津樂道的
01:32
But the one he is most remembered for
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是在他當圖書館館長時, 收到了一封信
01:34
began in a letter that he received
as the librarian,
as the librarian,
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寄自亞歷山大城南邊的斯威尼特鎮。
01:37
from the town of Swenet,
which was south of Alexandria.
which was south of Alexandria.
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這封信提到的一件事, 一直在艾拉托斯特尼的心中揮之不去
01:41
The letter included this fact
that stuck in Eratosthenes' mind,
that stuck in Eratosthenes' mind,
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寫信的人說, 當他在夏至的中午
01:44
and the fact was that the writer said,
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望進一口深井的時候
01:46
at noon on the solstice,
when he looked down this deep well,
when he looked down this deep well,
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他可以看到井底的水面, 有陽光反射, 而且他的頭
01:49
he could see his reflection at the bottom,
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01:51
and he could also see
that his head was blocking the sun.
that his head was blocking the sun.
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正好可以擋住太陽。
而我應該告訴你,
關於克里斯多夫 · 哥倫布
發現地球是球形的這回事
關於克里斯多夫 · 哥倫布
發現地球是球形的這回事
01:54
I should tell you -- the idea
that Christopher Columbus
that Christopher Columbus
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根本就是胡扯。完全不正確。
01:57
discovered that the world
is spherical is total bull.
is spherical is total bull.
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事實上, 受過教育的人都知道地球是圓的
01:59
It's not true at all.
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02:00
In fact, everyone who was educated
understood that the world was spherical
understood that the world was spherical
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因為在亞里斯多德的年代, 他就已證明了這事
02:04
since Aristotle's time.
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只靠簡單的觀察。
02:05
Aristotle had proved it
with a simple observation.
with a simple observation.
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他注意到, 每次在月亮上看到地球的影子(月食)
02:07
He noticed that every time you saw
the Earth's shadow on the Moon,
the Earth's shadow on the Moon,
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影子是圓的
而唯一能每次都造成圓影的形狀
02:11
it was circular,
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02:12
and the only shape that constantly
creates a circular shadow
creates a circular shadow
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就是一個球體, 所以證明地球是圓的。
02:15
is a sphere, Q.E.D. the Earth is round.
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但沒有人知道地球有多大
02:18
But nobody knew how big it was
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直到艾拉托斯特尼有了這封信跟井的這回事。
02:19
until Eratosthenes got
this letter with this fact.
this letter with this fact.
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他想到太陽是斯威尼特鎮的正上方
02:23
So he understood that the sun
was directly above the city of Swenet,
was directly above the city of Swenet,
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因為向井下頭看, 這是一條直線
02:26
because looking down a well,
it was a straight line
it was a straight line
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從太陽經過寫信者的頭, 一路到井底。
02:29
all the way down the well,
right past the guy's head up to the sun.
right past the guy's head up to the sun.
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艾拉托斯特尼知道另一個事實。
02:33
Eratosthenes knew another fact.
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他知道在亞歷山大城當地立了一根棍子
02:34
He knew that a stick stuck
in the ground in Alexandria
in the ground in Alexandria
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在同一時間、 同一天中午,
02:37
at the same time
and the same day, at noon,
and the same day, at noon,
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太陽正在天頂的時候
02:40
the sun's zenith, on the solstice,
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陽光照出的棍子的陰影與鉛直線偏了 7.2 度。
02:42
the sun cast a shadow that showed
that it was 7.2 degrees off-axis.
that it was 7.2 degrees off-axis.
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現在, 如果你知道一個圓的圓心角
02:49
If you know the circumference of a circle,
and you have two points on it,
and you have two points on it,
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還有圓上的兩個點
你只要知道這兩點之間的距離
02:53
all you need to know is the distance
between those two points,
between those two points,
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就可以推算出圓周長。
02:56
and you can extrapolate the circumference.
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360 度除以 7.2 度等於 50。
02:58
360 degrees divided by 7.2 equals 50.
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我知道正好整除有些太巧了,
讓人有點懷疑這個故事的可信度
讓人有點懷疑這個故事的可信度
03:02
I know it's a little bit
of a round number,
of a round number,
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但這是一個好故事, 所以我們會繼續談下去。
03:04
and it makes me suspicious
of this story too,
of this story too,
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03:06
but it's a good story,
so we'll continue with it.
so we'll continue with it.
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他需要知道斯威尼特鎮
和亞歷山大城之間的距離
和亞歷山大城之間的距離
03:08
He needed to know the distance
between Swenet and Alexandria,
between Swenet and Alexandria,
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這是容易的, 因為艾拉托斯特尼很擅長地理學。
03:11
which is good because Eratosthenes
was good at geography.
was good at geography.
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事實上, 地理學這個名詞就是他發明的。
03:15
In fact, he invented the word geography.
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斯威尼特鎮 和亞歷山大之間的道路
03:17
(Laughter)
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03:19
The road between Swenet and Alexandria
was a road of commerce,
was a road of commerce,
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是一條經商者常走的路,
經商者需要知道路程要多久。
03:22
and commerce needed to know
how long it took to get there.
how long it took to get there.
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所以實際的距離很重要,
所以他也非常精確地知道
所以他也非常精確地知道
03:25
It needed to know the exact distance,
so he knew very precisely
so he knew very precisely
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這兩個城市之間的距離是 500 英哩。
03:28
that the distance between
the two cities was 500 miles.
the two cities was 500 miles.
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乘上 50 倍, 就是 25,000 英哩,
03:31
Multiply that times 50, you get 25,000,
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03:34
which is within one percent
of the actual diameter of the Earth.
of the actual diameter of the Earth.
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這跟地球實際的大小只有 1% 的誤差。
在二千二百年前, 他就能做到這樣的事。
03:38
He did this 2,200 years ago.
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現在, 我們生活在一個時代,
03:42
Now, we live in an age where
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03:44
multi-billion-dollar pieces of machinery
are looking for the Higgs boson.
are looking for the Higgs boson.
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價值數十億元的設備正在尋找希格斯玻色子。
我們發現可能比光速更快的粒子
03:48
We're discovering particles
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03:50
that may travel faster
than the speed of light,
than the speed of light,
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而所有的這些發現都是靠著
03:52
and all of these discoveries
are made possible
are made possible
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在過去幾十年中所發展出來的科技。
03:55
by technology that's been developed
in the last few decades.
in the last few decades.
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但在人類歷史的大多數時間,
03:58
But for most of human history,
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我們只能靠我們的眼睛和耳朵,
還有思考能力, 來發現新事物。
還有思考能力, 來發現新事物。
04:01
we had to discover these things using
our eyes and our ears and our minds.
our eyes and our ears and our minds.
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阿曼德斐索是在巴黎的實驗物理學家。
04:06
Armand Fizeau was
an experimental physicist in Paris.
an experimental physicist in Paris.
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他的專長是精煉和確認其他人的研究結果,
04:10
His specialty was actually refining
and confirming other people's results,
and confirming other people's results,
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這聽起來可能有點的遜,
04:15
and this might sound
like a bit of an also-ran,
like a bit of an also-ran,
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但事實上, 這就是科學的靈魂
04:17
but in fact, this is the soul of science,
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因為若不能獨立的被重複驗證,
就不能被稱為科學事實。
就不能被稱為科學事實。
04:19
because there is no such thing as a fact
that cannot be independently corroborated.
that cannot be independently corroborated.
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他很熟悉伽利略的一個實驗
04:23
And he was familiar
with Galileo's experiments
with Galileo's experiments
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是關於光是不是有速度的。
04:26
in trying to determine
whether or not light had a speed.
whether or not light had a speed.
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伽利略曾做了這個特別的實驗
04:29
Galileo had worked out this
really wonderful experiment
really wonderful experiment
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他和他的助手各拿了一盞燈,
04:32
where he and his assistant had a lamp,
each one of them was holding a lamp.
each one of them was holding a lamp.
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當伽利略打開他的燈,
他的助手看到光後,
也同樣地打開燈。
他的助手看到光後,
也同樣地打開燈。
04:36
Galileo would open his lamp,
and his assistant would open his.
and his assistant would open his.
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他們把時間抓得很準。
04:39
They got the timing down really good.
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他們只管自己的開燈時機。
然後他們站在兩個山頭
然後他們站在兩個山頭
04:41
They just knew their timing.
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04:42
And then they stood at two hilltops,
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相距兩英里, 兩人做一樣的事情,
04:44
two miles distant,
and they did the same thing,
and they did the same thing,
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伽利略的假設是, 如果光有一個特定的速度,
04:47
on the assumption from Galileo
that if light had a discernible speed,
that if light had a discernible speed,
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他應該會注意到在從他的助手燈回來的光的延遲。
04:50
he'd notice a delay in the light
coming back from his assistant's lamp.
coming back from his assistant's lamp.
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但光的速度對伽利略來說太快了。
04:53
But light was too fast for Galileo.
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他對光的速度的臆測差了好幾個數量級 (10的n次方)
04:56
He was off by several orders
of magnitude when he assumed
of magnitude when he assumed
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他猜測光大概只比聲音的速度快 10 倍。
04:58
that light was roughly ten times
as fast as the speed of sound.
as fast as the speed of sound.
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斐索聽說了這個實驗。他住在巴黎,
05:02
Fizeau was aware of this experiment.
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05:04
He lived in Paris, and he set up
two experimental stations,
two experimental stations,
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他設立了兩個實驗站
相距大約五英里半,
05:09
roughly 5.5 miles distant, in Paris.
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在巴黎。他解決了伽利略的實驗中的問題,
05:12
And he solved this problem of Galileo's,
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他只用了一塊相對來說很小的設備。
05:14
and he did it with a really relatively
trivial piece of equipment.
trivial piece of equipment.
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他用的就像這個。
05:19
He did it with one of these.
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我先把遙控器收起來,
05:21
I'm going to put away
the clicker for a second
the clicker for a second
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因為我想讓你的大腦也來思考一下。
05:23
because I want to engage
your brains in this.
your brains in this.
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這就是齒輪的樣子。它有一大堆的凹槽
05:25
So this is a toothed wheel.
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05:27
It's got a bunch of notches
and it's got a bunch of teeth.
and it's got a bunch of teeth.
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還有一堆的凸齒。
這是斐索用來發送離散脈衝光的作法。
05:30
This was Fizeau's solution
to sending discrete pulses of light.
to sending discrete pulses of light.
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他讓一束光穿過這些凹口之一。
05:33
He put a beam behind one of these notches.
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射到另一個實驗站的鏡子反射
05:35
If I point a beam
through this notch at a mirror,
through this notch at a mirror,
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來回各五英里, 這束光回來後
05:39
five miles away, that beam
is bouncing off the mirror
is bouncing off the mirror
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會通過這個凹口被看到。
05:41
and coming back to me through this notch.
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但當他把齒輪轉得更快時, 有趣的事情發生了。
05:44
But something interesting happens
as he spins the wheel faster.
as he spins the wheel faster.
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他觀察到如同反射的光被關上的門擋住了
05:47
He notices that it seems
like a door is starting to close
like a door is starting to close
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眼睛看不到反射回來的光了。
05:50
on the light beam
that's coming back to his eye.
that's coming back to his eye.
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這是為什麼？
05:53
Why is that?
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這是因為反射的光並沒有
05:55
It's because the pulse
of light is not coming back
of light is not coming back
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通過發射時相同的凹口。
實際上是擊中一顆凸齒。
實際上是擊中一顆凸齒。
05:57
through the same notch.
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05:59
It's actually hitting a tooth.
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他把齒輪轉得夠快
06:00
And he spins the wheel fast enough
and he fully occludes the light.
and he fully occludes the light.
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對光的現象充分的觀察
再依據兩個地點之間的距離
06:05
And then, based on the distance
between the two stations
between the two stations
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06:08
and the speed of his wheel
and the number of notches in the wheel,
and the number of notches in the wheel,
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還有他的齒輪的轉速與齒數
他計算出與實際光速誤差不到 2% 的數值。
06:11
he calculates the speed of light
to within two percent of its actual value.
to within two percent of its actual value.
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他在 1849 年作出了這樣的實驗。
06:16
And he does this in 1849.
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這也是為什麼讓我對科學一直有興趣的緣故。
06:21
This is what really gets me
going about science.
going about science.
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每當我在理解一個概念時遇到了問題,
我會回去研究發現了這個概念的研究者。
我會回去研究發現了這個概念的研究者。
06:23
Whenever I'm having trouble
understanding a concept,
understanding a concept,
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06:26
I go back and I research
the people that discovered that concept.
the people that discovered that concept.
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我觀察他們如何逐漸搞懂整件事情。
06:29
I look at the story of how
they came to understand it.
they came to understand it.
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當你看到了研究者如何思考,
06:31
What happens when you look
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06:33
at what the discoverers
were thinking about
were thinking about
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看到他們如何發現事物, 你就會知道
06:35
when they made their discoveries,
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06:37
is you understand that
they are not so different from us.
they are not so different from us.
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其時他們跟我們沒有什麼不同。
我們都是血肉之軀。我們都能使用相同的工具。
06:42
We are all bags of meat and water.
We all start with the same tools.
We all start with the same tools.
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我很喜歡把科學的不同分支稱做研究領域的說法。
06:46
I love the idea that different branches
of science are called fields of study.
of science are called fields of study.
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大多數人認為科學是封閉的黑箱,
06:50
Most people think of science
as a closed, black box,
as a closed, black box,
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當事實上它是一個開放的領域。
06:53
when in fact it is an open field.
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而且我們大家都是探險家。
06:56
And we are all explorers.
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貢獻出這些發現的人只是想得比我們努力些
06:58
The people that made these discoveries
just thought a little bit harder
just thought a little bit harder
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對於他們所研究的事情, 有著更多的好奇心
07:01
about what they were looking at,
and they were a little bit more curious.
and they were a little bit more curious.
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他們的好奇心改變了人們對這個世界的觀點,
07:05
And their curiosity changed the way
people thought about the world,
people thought about the world,
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也因此而改變了世界。
07:08
and thus it changed the world.
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他們能改變這個世界, 當然你也可以。
07:10
They changed the world, and so can you.
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謝謝。
07:14
Thank you.
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07:15
(Applause)
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（掌聲）
ABOUT THE SPEAKER
Adam Savage - Maker, critical thinkerAdam Savage is an internationally renowned television producer, host and public speaker.
Why you should listen
Adam Savage's mother is a psychologist; his father was a celebrated artist, painter and filmmaker. From the youngest age they encouraged his flights of fancy. Savage has been a paperboy, a projectionist, juggler, unicycle rider, sculptor, graphic designer, scenic painter, robot builder, welder, carpenter, machinist, prop maker, toy designer, actor, writer, executive producer and director. He spent six years in theater and 10 years in commercial and film special effects working for clients such as Nike, Corning, Hershey's, and Coca-Cola, and films like Star Wars, The Matrix films, A.I., Space Cowboys, Terminator 3 and Galaxy Quest.
Savage has built everything from theater sets to miniature particle accelerators. From spaceships to animatronic arms. He's made Rube Goldberg machines, hand props and spacesuits. His online videos have generated over 230 million page views. He's written for Popular Mechanics, the Wall Street Journal and Wired Magazine, among others. His program "Mythbusters" produced 270 episodes that aired in over 100 countries for 14 years. Adam shares his builds, his love for movie props and costumes, and passion for the transformative power of making on his award winning website Tested.com. He lives in San Francisco with his wife Julia, his twin boys Thing1 and Thing2, and two amazing dogs.
(Photo: Michael Shindler)
Adam Savage | Speaker | TED.com