Just How Small is an Atom?

原子究竟有多小?

譯者: Cheng An Yang 審譯者: Yuen-Lam Tsang

(音樂)

You probably already know

你大概已經知道萬物皆是由

everything is made up of little tiny things called atoms

一種非常微小 稱之為原子的東西所組成

or even that each atom is made up of even smaller particles

你甚至可能知道原子還是由 更小的粒子所組成

called protons, neutrons and electrons.

我們稱為質子、中子跟電子

And you've probably heard that atoms are small.

且你大概都聽說過原子很小

But I bet you haven't ever thought about how small atoms really are.

但我猜你應該從未想過 原子究竟有多小

嗯 答案是 非常 非常 非常小

Well, the answer is that they are really, really small.

So you ask, just how small are atoms?

因此 你會想知道 究竟原子有多小？

To understand this, let's ask this question:

為了了解 先來研究這個問題

葡萄柚是由多少原子所組成？

How many atoms are in a grapefruit?

Well, let's assume that the grapefruit is made up of only nitrogen atoms,

嗯 假設葡萄柚是只由氮原子所組成

當然這不是事實 但確實葡萄柚裡有氮原子

which isn't at all true, but there are nitrogen atoms in a grapefruit.

To help you visualize this, let's blow up each of the atoms

當然 為了幫助你們想像 我們將原子放大

to the size of a blueberry.

到像藍莓一般大

And then how big would the grapefruit have to be?

那此時 葡萄柚會變得多大呢?

It would have to be the same size of -- well, actually, the Earth.

葡萄柚會變得...會跟地球一樣大

That's crazy!

非常不可思議吧...意思是 若把藍莓集合成地球一樣大

You mean to say that if I filled the Earth with blueberries,

I would have the same number of nitrogen atoms as a grapefruit?

就可以得知葡萄柚裡有多少氮原子

That's right!

沒錯! 所以到底原子有多大?

So how big is the atom?

原子是非常 非常 非常 非常小

Well, it's really, really small!

而且你知道嘛?

And you know what? It gets even more crazy.

更誇張的是

Let's now look inside of each atom -- and thus the blueberry, right? --

讓我們來看看每個原子之中 也就是藍莓

What do you see there?

你會看到些什麼?

In the center of the atom is something called the nucleus,

在原子的中央 有個稱為原子核的東西

which contains protons and neutrons,

裡面包含了質子跟中子

and on the outside, you'd see electrons.

而在其外你會看到電子

So how big is the nucleus?

原子核多大呢?

If atoms are like blueberries in the Earth,

如果原子像藍莓一般大 原子核相對會多大?

how big would the nucleus be?

你可能還記得在理化課上的 舊原子圖片吧

You might remember the old pictures of the atom from science class,

你看到的頁面上 用箭頭指著的那個小點

where you saw this tiny dot on the page with an arrow pointing to the nucleus.

嗯 那些圖片 其實並非照比例而畫

Well, those pictures, they're not drawn to scale,

so they're kind of wrong.

因此是錯誤的

所以 原子核究竟多大呢?

So how big is the nucleus?

如果你切開那個和原子一樣大的藍莓

So if you popped open the blueberry and were searching for the nucleus ...

然後尋找原子核

你知道 原子會是隱形的

You know what? It would be invisible.

It's too small to see!

因為它太小以至於你無法看到

OK. Let's blow up the atom -- the blueberry --

因此 我們在將原子 也就是藍莓

to the size of a house.

放大到像房子一樣大

So imagine a ball that is as tall as a two-story house.

想像一下這個球跟 兩層樓的房子一樣高

Let's look for the nucleus in the center of the atom.

然後再來尋找在原子中央的原子核

And do you know what? It would just barely be visible.

你知道嗎? 原子核還是幾乎不可見

所以 為了知道到底原子核有多大

So to get our minds wrapped around how big the nucleus is,

we need to blow up the blueberry, up to the size of a football stadium.

我們必須把原子從藍莓的大小 放大到美式足球場一樣

So imagine a ball the size of a football stadium,

然後想像一顆美式足球場般大的球

and right smack dab in the center of the atom,

原子不偏不倚的中央一小點

you would find the nucleus, and you could see it!

你就會找到原子核 而且你可以看得到它

它就和一個彈珠的大小一樣

And it would be the size of a small marble.

不僅僅如此 如果我還沒讓你驚訝的話

And there's more, if I haven't blown your mind by now.

Let's consider the atom some more.

我們來更詳盡的了解原子 它包含了質子 中子 跟電子

It contains protons, neutrons and electrons.

The protons and neutrons live inside of the nucleus,

質子跟中子是在原子核之內

且佔了原子大部分的重量

and contain almost all of the mass of the atom.

而其邊緣上則為電子

Way on the edge are the electrons.

So if an atom is like a ball the size of a football stadium,

如果原子是一顆 跟美式足球場般大的球

with the nucleus in the center, and the electrons on the edge,

原子在中央 電子在邊緣

what is in between the nucleus and the electrons?

那在原子核跟電子之間是什麼呢?

相當令人驚訝地 答案是什麼都沒有

Surprisingly, the answer is empty space.

(風聲)

(Wind noise)

沒錯 什麼都沒有 空的

That's right. Empty!

Between the nucleus and the electrons, there are vast regions of empty space.

在原子核跟電子之間 有著相當廣大的空間

嚴格來說 那裡存在著電磁場

Now, technically there are some electromagnetic fields,

but in terms of stuff, matter, it is empty.

但就本質而言 那裡是空的

Remember this vast region of empty space is inside the blueberry,

記得這個一大片的空間

是位於跟和組成地球的 藍莓一樣大的原子之中

which is inside the Earth,

組成地球的藍莓 就好比是葡萄柚裡的原子

which really are the atoms in the grapefruit.

OK, one more thing, if I can even get more bizarre.

另外還有一件事 是更難以想像的

Since virtually all the mass of an atom is in the nucleus --

既然事實是原子的全部重量 是集中於原子核中

嗯 當然電子當然還是 佔有一部分的重量

now, there is some amount of mass in the electrons,

但是大部分是集中於原子核上

but most of it is in the nucleus --

那麼原子核的密度有多大呢?

how dense is the nucleus?

Well, the answer is crazy.

答案是相當驚人的

The density of a typical nucleus

一般而言原子核的密度是

is four times 10 to the 17th kilograms per meter cubed.

每立方公尺重達4乘10的17次方公斤

But that's hard to visualize. OK, I'll put it in English units.

但數字是難以想像的 讓我來用英制表示

2.5 times 10 to the 16th pounds per cubic feet.

每立方英吋重達

2.5乘10的16次方磅

OK, that's still kind of hard to figure.

當然 這仍然是難以理解的

OK, here's what I want you to do.

不如我告訴你怎麼做

Make a box that is one foot by one foot by one foot.

做一個各邊都是1英呎的盒子

然後集合相當於 一台普通車子的所有原子

Now let's go and grab all of the nuclei from a typical car.

車子一般而言重約兩噸

Now, cars on average weigh two tons.

How many cars' nuclei would you have to put into the box

要在盒子裡放入多少輛車子的原子

才能讓這每邊為1英呎盒子的 密度等同於原子核呢?

to have your one-foot-box have the same density of the nucleus?

一輛 兩輛 還是100輛

Is it one car? Two?

How about 100?

以上皆非

Nope, nope and nope.

The answer is much bigger.

答案是不只如此

It is 6.2 billion.

是62億

那是相當於地球上的所有人口

That is almost equal to the number of people in the Earth.

假設地球上每個人都擁有一部車

So if everyone in the Earth owned their own car --

and they don't --

當然並非如此

(Cars honking)

我們將所有的車子放到你的箱子裡

and we put all of those cars into your box ...

那就是原子核的密度

That would be about the density of a nucleus.

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

So I'm saying that if you took every car in the world

and put it into your one-foot box,

那就是一個原子核的密度

you would have the density of one nucleus.

好了 讓我們來複習一下

OK, let's review.

The atom is really,

原子是非常 非常 非常小

really, really small.

葡萄柚裡的一粒原子 就好比地球上的一顆藍莓

Think atoms in a grapefruit like blueberries in the Earth.

原子核是超級小

The nucleus is crazy small.

把藍莓放大到足球場一般大

Now look inside the blueberry,

and blow it up to the size of a football stadium,

原子核就是在藍莓中央的一顆彈珠

and now the nucleus is a marble in the middle.

原子的組成是一大片的空間

The atom is made up of vast regions of empty space.

這是非常詭異的

That's weird.

The nucleus has a crazy-high density.

原子核的密度是極度大

Think of putting all those cars in your one-foot box.

就好比將地球上所有的車放進 每邊為1英呎的盒子中

我想我累了

I think I'm tired.

(打呵欠)