You probably already know everything is made up of little tiny things called atoms or even that each atom is made up of even smaller particles called protons, neutrons and electrons.
你也許已經知道所有的東西都是由微小的原子組成。你可能還知道每一個原子是由更小的叫做質子，中子和電子的微粒組成
And you've probably heard that atoms are small.
也許你聽說過原子很小。
But I bet you haven't ever thought about how small atoms really are.
但我打賭，你從未想過它究竟有多小。
Well, the answer is that they are really, really small.
答案是，它們非常非常非常小。
So you ask, just how small are atoms?
你提出問題了，到底原子有多小呢?
To understand this, let's ask this question: How many atoms are in a grapefruit?
為了去理解它，讓我們先提出一個問題：一個柚子包含多少原子？
Well, let's assume that the grapefruit is made up of only nitrogen atoms, which isn't at all true, but there are nitrogen atoms in a grapefruit.
首先我們假設柚子完全由氮原子構成，雖然不準確，但柚子中確實有氮原子。
To help you visualize this, let's blow up each of the atoms to the size of a blueberry.
為了便於觀察，我們把原子放大到一個藍莓大小。
And then how big would the grapefruit have to be?
那總體柚子又會是多大呢？
It would have to be the same size of -- well, actually, the Earth.
它會跟地球的個頭差不多。
That's crazy! You mean to say that if I filled the Earth with blueberries,
天啊！難道地球裝滿藍莓的數量
I would have the same number of nitrogen atoms as a grapefruit?
會和柚子中的氮原子一樣多？
That's right! So how big is the atom?
的確如此！那麼原子究竟有多小？
Well, it's really, really small! And you know what? It gets even more crazy.
它真的非常非常小，小到超出了你的想像。
Let's now look inside of each atom -- and thus the blueberry, right? What do you see there?
現在讓我們看看原子內部，也就是藍莓。你看到了什麼？
In the center of the atom is something called the nucleus, which contains protons and neutrons, and on the outside, you'd see electrons. So how big is the nucleus?
你會發現原子有一個核心，叫原子核。其中包含著質子和中子，外圍的是電子。那麼原子核有多大？
If atoms are like blueberries in the Earth, how big would the nucleus be?
如果原子是地球中的藍莓，那麼原子核又有多大呢？
You might remember the old pictures of the atom from science class, where you saw this tiny dot on the page with an arrow pointing to the nucleus.
你可能在物理書上看過原子的描繪，原子核是箭頭所指的小點。
Well, those pictures, they're not drawn to scale, so they're kind of wrong.
這些圖不是按比例畫的，所以並不準確。
So how big is the nucleus?
那麼真實的原子核多大呢？
So if you popped open the blueberry and were searching for the nucleus
如果你在藍莓的內部搜索原子核，結果是一無所獲。
You know what? It would be invisible. It's too small to see!
知道為什麼嗎？因為我們看不到它！它太小了，我們看不到！
OK. Let's blow up the atom -- the blueberry -- to the size of a house.
因此我們把原子，也就是藍莓，放大到房子的尺寸。
So imagine a ball that is as tall as a two-story house.
想像一下有兩層房屋那麼高。
Let's look for the nucleus in the center of the atom.
然後在尋找原子中央的原子核，
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。
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.
所以想要直到原子核到底有多大，我們必須把藍莓放大到橄欖球場那樣大。
So imagine a ball the size of a football stadium, and right smack dab in the center of the atom, you would find the nucleus, and you could see it!
然後想像一下橄欖球場大小的球。原子不偏不倚的中央一小點，你就會找到原子核，而且你可以看得到它。
And it would be the size of a small marble.
而它只有玻璃彈珠大小。
And there's more, if I haven't blown your mind by now.
不僅僅如此，如果現在你都沒有被震撼到，
Let's consider the atom some more. It contains protons, neutrons and electrons.
我們來更詳盡地了解原子。原子中包含了質子，中子，電子。
The protons and neutrons live inside of the nucleus, and contain almost all of the mass of the atom.
質子和中子是在原子核之內，且佔了原子大部分的重量。
Way on the edge are the electrons.
在原子邊緣的是電子。
So if an atom is like a ball the size of a football stadium, with the nucleus in the center, and the electrons on the edge, what is in between the nucleus and the electrons?
如果原子像一個橄欖球場那樣大的話，原子核在中央，而電子在邊緣，那麼兩者之間的東西又是什麼呢？
Surprisingly, the answer is empty space. That's right. Empty!
相當令人驚訝，答案是什麼都沒有。沒錯，空無一物！
Between the nucleus and the electrons, there are vast regions of empty space.
在原子核和電子之間，存在著大片的空洞區域。
Now, technically there are some electromagnetic fields, but in terms of stuff, matter, it is empty.
嚴格的說來那裡存在著電磁場，但就本質而言，那裡是空的。
Remember this vast region of empty space is inside the blueberry, which is inside the Earth, which really are the atoms in the grapefruit.
記得這一大片空間，是位於和組成地球的藍莓一樣大的原子之中組成地球的藍莓就好比是葡萄柚裡的原子。
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 now, there is some amount of mass in the electrons, but most of it is in the nucleus how dense is the nucleus? Well, the answer is crazy.
既然事實是原子的全部質量集中在原子核，當然電子也有一定質量，但是可以忽略。那麼原子核的密度是多少？你會覺得不可思議。
The density of a typical nucleus is four times 10 to the 17th kilograms per meter cubed.
一般而言，原子核的密度是4乘以10的17次方千克/立方米。
But that's hard to visualize. OK, I'll put it in English units.
但數字是難以想像的，那麼換作英制單位是
2.5 times 10 to the 16th pounds per cubic feet.
2.5乘以10的16次方磅/立方英尺。
OK, that's still kind of hard to figure. OK, here's what I want you to do.
當然這還是難以理解的，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英尺長的盒子，
Now let's go and grab all of the nuclei from a typical car.
然後集合一堆重量相當於一輛汽車的原子
Now, cars on average weigh two tons.
車子一般而言重約兩噸。
How many cars' nuclei would you have to put into the box to have your one-foot-box have the same density of the nucleus?
要在盒子裡放多少輛車子的原子才能讓這個每邊1英尺盒子的密度等同於原子核呢？
Is it one car? Two? How about 100? Nope, nope and nope.
一輛，兩輛，還是一百輛？都不是。
The answer is much bigger. It is 6.2 billion.
答案是不止如此。需要62億輛。
That is almost equal to the number of people in the Earth.
這差不多是世界人口總數。
So if everyone in the Earth owned their own car and they don't and we put all of those cars into your box.
所以假設地球上每個人都擁有一輛車，當然並非如此，我們把這些車都裝進你的盒子裡，
That would be about the density of a nucleus.
就差不多相當於一個原子核的密度。
So I'm saying that if you took every car in the world and put it into your one-foot box, you would have the density of one nucleus. OK, let's review.
我的意思是你把世界上每一輛車都裝進一個每邊1英尺長的盒子中，你才得到原子核的密度。我們回顧一下。
The atom is really, really, really small.
原子極其渺小的。
Think atoms in a grapefruit like blueberries in the Earth. The nucleus is crazy small.
柚子中的一粒原子就相當於地球上的一顆藍莓。原子核更是出奇的小。
Now look inside the blueberry, and blow it up to the size of a football stadium, and now the nucleus is a marble in the middle.
把藍莓放大到足球場一邊大，原子核就是其中央的一顆彈珠。
The atom is made up of vast regions of empty space. That's weird.
原子的組成是一大片空間。這是很不尋常的。
The nucleus has a crazy-high density. Think of putting all those cars in your one-foot box.
原子核有極高的密度。這好比把所有的車放進每邊為1英尺的盒子中。