TED-Ed
Jon Bergmann: Just how small is an atom?
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Just how small are atoms? Really, really, really small. This fast-paced animation from TED-Ed uses metaphors (imagine a blueberry the size of a football stadium!) to give a visceral sense of just how small atoms are. Lesson by Jon Bergmann, animation by Cognitive Media.
Jon Bergmann - Educator
Jon Bergmann co-wrote the book on the "flipped classroom" -- using video to help students master new ideas outside the traditional class setting. Full bio
Jon Bergmann co-wrote the book on the "flipped classroom" -- using video to help students master new ideas outside the traditional class setting. Full bio
Double-click the English transcript below to play the video.
(音樂)
你大概已經知道萬物皆是由
00:26
You probably already know
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一種非常微小
稱之為原子的東西所組成
稱之為原子的東西所組成
00:28
everything is made up
of little tiny things called atoms
of little tiny things called atoms
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你甚至可能知道原子還是由
更小的粒子所組成
更小的粒子所組成
00:30
or even that each atom
is made up of even smaller particles
is made up of even smaller particles
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我們稱為質子、中子跟電子
00:33
called protons, neutrons and electrons.
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且你大概都聽說過原子很小
00:35
And you've probably heard
that atoms are small.
that atoms are small.
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但我猜你應該從未想過
原子究竟有多小
原子究竟有多小
00:38
But I bet you haven't ever thought
about how small atoms really are.
about how small atoms really are.
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嗯 答案是 非常 非常 非常小
00:42
Well, the answer is
that they are really, really small.
that they are really, really small.
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因此 你會想知道 究竟原子有多小？
00:46
So you ask, just how small are atoms?
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為了了解 先來研究這個問題
00:49
To understand this,
let's ask this question:
let's ask this question:
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葡萄柚是由多少原子所組成？
00:53
How many atoms are in a grapefruit?
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嗯 假設葡萄柚是只由氮原子所組成
00:55
Well, let's assume that the grapefruit
is made up of only nitrogen atoms,
is made up of only nitrogen atoms,
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當然這不是事實
但確實葡萄柚裡有氮原子
但確實葡萄柚裡有氮原子
00:59
which isn't at all true, but there
are nitrogen atoms in a grapefruit.
are nitrogen atoms in a grapefruit.
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當然 為了幫助你們想像
我們將原子放大
我們將原子放大
01:02
To help you visualize this,
let's blow up each of the atoms
let's blow up each of the atoms
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到像藍莓一般大
01:05
to the size of a blueberry.
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那此時 葡萄柚會變得多大呢?
01:07
And then how big
would the grapefruit have to be?
would the grapefruit have to be?
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葡萄柚會變得...會跟地球一樣大
01:10
It would have to be the same size of
-- well, actually, the Earth.
-- well, actually, the Earth.
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非常不可思議吧...意思是
若把藍莓集合成地球一樣大
若把藍莓集合成地球一樣大
01:14
That's crazy!
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01:16
You mean to say that if I filled
the Earth with blueberries,
the Earth with blueberries,
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就可以得知葡萄柚裡有多少氮原子
01:18
I would have the same number
of nitrogen atoms as a grapefruit?
of nitrogen atoms as a grapefruit?
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沒錯! 所以到底原子有多大?
01:21
That's right!
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01:23
So how big is the atom?
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原子是非常 非常 非常 非常小
01:25
Well, it's really, really small!
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而且你知道嘛?
01:28
And you know what?
It gets even more crazy.
It gets even more crazy.
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更誇張的是
01:31
Let's now look inside of each atom
-- and thus the blueberry, right? --
-- and thus the blueberry, right? --
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讓我們來看看每個原子之中
也就是藍莓
也就是藍莓
你會看到些什麼?
01:34
What do you see there?
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在原子的中央
有個稱為原子核的東西
有個稱為原子核的東西
01:35
In the center of the atom
is something called the nucleus,
is something called the nucleus,
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裡面包含了質子跟中子
01:38
which contains protons and neutrons,
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而在其外你會看到電子
01:40
and on the outside, you'd see electrons.
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原子核多大呢?
01:42
So how big is the nucleus?
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如果原子像藍莓一般大
原子核相對會多大?
原子核相對會多大?
01:44
If atoms are like blueberries
in the Earth,
in the Earth,
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01:46
how big would the nucleus be?
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你可能還記得在理化課上的
舊原子圖片吧
舊原子圖片吧
01:48
You might remember the old pictures
of the atom from science class,
of the atom from science class,
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你看到的頁面上
用箭頭指著的那個小點
用箭頭指著的那個小點
01:51
where you saw this tiny dot on the page
with an arrow pointing to the nucleus.
with an arrow pointing to the nucleus.
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嗯 那些圖片 其實並非照比例而畫
01:55
Well, those pictures,
they're not drawn to scale,
they're not drawn to scale,
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因此是錯誤的
01:57
so they're kind of wrong.
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所以 原子核究竟多大呢?
01:59
So how big is the nucleus?
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如果你切開那個和原子一樣大的藍莓
02:01
So if you popped open the blueberry
and were searching for the nucleus ...
and were searching for the nucleus ...
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然後尋找原子核
你知道 原子會是隱形的
02:06
You know what? It would be invisible.
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因為它太小以至於你無法看到
02:08
It's too small to see!
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因此 我們在將原子 也就是藍莓
02:10
OK. Let's blow up the atom --
the blueberry --
the blueberry --
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放大到像房子一樣大
02:13
to the size of a house.
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02:15
So imagine a ball that is as tall
as a two-story house.
as a two-story house.
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想像一下這個球跟
兩層樓的房子一樣高
兩層樓的房子一樣高
然後再來尋找在原子中央的原子核
02:18
Let's look for the nucleus
in the center of the atom.
in the center of the atom.
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你知道嗎? 原子核還是幾乎不可見
02:21
And do you know what?
It would just barely be visible.
It would just barely be visible.
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所以 為了知道到底原子核有多大
02:25
So to get our minds wrapped
around how big the nucleus is,
around how big the nucleus is,
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我們必須把原子從藍莓的大小
放大到美式足球場一樣
放大到美式足球場一樣
02:27
we need to blow up the blueberry,
up to the size of a football stadium.
up to the size of a football stadium.
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02:32
So imagine a ball the size
of a football stadium,
of a football stadium,
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然後想像一顆美式足球場般大的球
02:35
and right smack dab
in the center of the atom,
in the center of the atom,
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原子不偏不倚的中央一小點
02:38
you would find the nucleus,
and you could see it!
and you could see it!
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你就會找到原子核
而且你可以看得到它
而且你可以看得到它
它就和一個彈珠的大小一樣
02:41
And it would be the size
of a small marble.
of a small marble.
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不僅僅如此 如果我還沒讓你驚訝的話
02:45
And there's more, if I haven't
blown your mind by now.
blown your mind by now.
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我們來更詳盡的了解原子
它包含了質子 中子 跟電子
它包含了質子 中子 跟電子
02:47
Let's consider the atom some more.
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02:49
It contains protons,
neutrons and electrons.
neutrons and electrons.
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質子跟中子是在原子核之內
02:51
The protons and neutrons
live inside of the nucleus,
live inside of the nucleus,
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且佔了原子大部分的重量
02:54
and contain almost
all of the mass of the atom.
all of the mass of the atom.
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而其邊緣上則為電子
02:56
Way on the edge are the electrons.
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02:58
So if an atom is like a ball
the size of a football stadium,
the size of a football stadium,
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如果原子是一顆
跟美式足球場般大的球
跟美式足球場般大的球
03:01
with the nucleus in the center,
and the electrons on the edge,
and the electrons on the edge,
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原子在中央 電子在邊緣
那在原子核跟電子之間是什麼呢?
03:03
what is in between the nucleus
and the electrons?
and the electrons?
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相當令人驚訝地 答案是什麼都沒有
03:07
Surprisingly, the answer is empty space.
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(風聲)
03:10
(Wind noise)
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沒錯 什麼都沒有 空的
03:13
That's right. Empty!
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03:15
Between the nucleus and the electrons,
there are vast regions of empty space.
there are vast regions of empty space.
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在原子核跟電子之間
有著相當廣大的空間
有著相當廣大的空間
嚴格來說 那裡存在著電磁場
03:19
Now, technically there are
some electromagnetic fields,
some electromagnetic fields,
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但就本質而言 那裡是空的
03:21
but in terms of stuff,
matter, it is empty.
matter, it is empty.
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記得這個一大片的空間
03:24
Remember this vast region of empty space
is inside the blueberry,
is inside the blueberry,
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是位於跟和組成地球的
藍莓一樣大的原子之中
藍莓一樣大的原子之中
03:28
which is inside the Earth,
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組成地球的藍莓
就好比是葡萄柚裡的原子
就好比是葡萄柚裡的原子
03:30
which really are the atoms
in the grapefruit.
in the grapefruit.
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另外還有一件事 是更難以想像的
03:32
OK, one more thing,
if I can even get more bizarre.
if I can even get more bizarre.
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既然事實是原子的全部重量
是集中於原子核中
是集中於原子核中
03:36
Since virtually all the mass
of an atom is in the nucleus --
of an atom is in the nucleus --
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嗯 當然電子當然還是
佔有一部分的重量
佔有一部分的重量
03:40
now, there is some amount
of mass in the electrons,
of mass in the electrons,
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但是大部分是集中於原子核上
03:43
but most of it is in the nucleus --
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那麼原子核的密度有多大呢?
03:45
how dense is the nucleus?
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答案是相當驚人的
03:46
Well, the answer is crazy.
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一般而言原子核的密度是
03:48
The density of a typical nucleus
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每立方公尺重達4乘10的17次方公斤
03:50
is four times 10 to the 17th
kilograms per meter cubed.
kilograms per meter cubed.
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但數字是難以想像的
讓我來用英制表示
讓我來用英制表示
03:54
But that's hard to visualize.
OK, I'll put it in English units.
OK, I'll put it in English units.
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每立方英吋重達
03:57
2.5 times 10 to the 16th pounds
per cubic feet.
per cubic feet.
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2.5乘10的16次方磅
當然 這仍然是難以理解的
04:02
OK, that's still kind of hard to figure.
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不如我告訴你怎麼做
04:04
OK, here's what I want you to do.
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做一個各邊都是1英呎的盒子
04:06
Make a box that is one foot
by one foot by one foot.
by one foot by one foot.
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然後集合相當於
一台普通車子的所有原子
一台普通車子的所有原子
04:10
Now let's go and grab
all of the nuclei from a typical car.
all of the nuclei from a typical car.
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車子一般而言重約兩噸
04:14
Now, cars on average weigh two tons.
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要在盒子裡放入多少輛車子的原子
04:16
How many cars' nuclei would you
have to put into the box
have to put into the box
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才能讓這每邊為1英呎盒子的
密度等同於原子核呢?
密度等同於原子核呢?
04:20
to have your one-foot-box have
the same density of the nucleus?
the same density of the nucleus?
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一輛 兩輛 還是100輛
04:23
Is it one car? Two?
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04:24
How about 100?
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以上皆非
04:26
Nope, nope and nope.
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答案是不只如此
04:28
The answer is much bigger.
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是62億
04:30
It is 6.2 billion.
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那是相當於地球上的所有人口
04:34
That is almost equal to the number
of people in the Earth.
of people in the Earth.
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假設地球上每個人都擁有一部車
04:37
So if everyone in the Earth
owned their own car --
owned their own car --
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當然並非如此
04:39
and they don't --
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04:40
(Cars honking)
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我們將所有的車子放到你的箱子裡
04:42
and we put all of those
cars into your box ...
cars into your box ...
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那就是原子核的密度
04:46
That would be about
the density of a nucleus.
the density of a nucleus.
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我的意思是 如果你將地球上
所有的車子放進每邊一英呎的盒子裡
所有的車子放進每邊一英呎的盒子裡
04:49
So I'm saying that if you took
every car in the world
every car in the world
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04:52
and put it into your one-foot box,
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那就是一個原子核的密度
04:54
you would have the density of one nucleus.
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好了 讓我們來複習一下
04:57
OK, let's review.
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原子是非常 非常 非常小
04:58
The atom is really,
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04:59
really, really small.
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葡萄柚裡的一粒原子
就好比地球上的一顆藍莓
就好比地球上的一顆藍莓
05:02
Think atoms in a grapefruit
like blueberries in the Earth.
like blueberries in the Earth.
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原子核是超級小
05:06
The nucleus is crazy small.
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把藍莓放大到足球場一般大
05:09
Now look inside the blueberry,
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05:10
and blow it up to the size
of a football stadium,
of a football stadium,
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原子核就是在藍莓中央的一顆彈珠
05:13
and now the nucleus
is a marble in the middle.
is a marble in the middle.
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原子的組成是一大片的空間
05:16
The atom is made up
of vast regions of empty space.
of vast regions of empty space.
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這是非常詭異的
05:20
That's weird.
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原子核的密度是極度大
05:21
The nucleus has a crazy-high density.
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就好比將地球上所有的車放進
每邊為1英呎的盒子中
每邊為1英呎的盒子中
05:23
Think of putting all those cars
in your one-foot box.
in your one-foot box.
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我想我累了
05:27
I think I'm tired.
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(打呵欠)
ABOUT THE SPEAKER
Jon Bergmann - EducatorJon Bergmann co-wrote the book on the "flipped classroom" -- using video to help students master new ideas outside the traditional class setting.
Why you should listen
Jon Bergmann is considered one of the pioneers in the Flipped Class Movement -- in fact, he co-wrote the book on the Flipped Classroom, available from ISTE Press in June 2012. Bergmann believes educators should ask one guiding question: What is best for my students in my classroom? To the best of his abilities he has done this in his two-plus decades as a high school science teacher. He received the Presidential Award for Excellence for Math and Science Teaching in 2002 and was named Semi-Finalist for Colorado Teacher of the Year in 2010. He blogs at flipped-learning.com.
He is the Lead Technology Facilitator for the Joseph Sears School in Kenilworth, Illinois.
Read about the making of "How Small Is an Atom?" >>
Jon Bergmann | Speaker | TED.com