如果所有人同時跳起來會怎樣？：英語精讀講義

Hey, Vsauce.

嘿，Vsauce。

Michael here.

Michael 在這裡。

And what if every single person on Earth 文法

要是地球上的每一個人

jumped at the exact same time? 片語搭配

都在完全相同的一刻跳起來，會怎樣？

Could it cause an earthquake

這會引發地震嗎，

or would we not even be able to tell? 文法

還是我們甚至完全感覺不出來？

Well, first things first, 片語搭配

好，首先，

let's talk about the Earth's rotation.

我們來談談地球自轉。

The Earth spins.

地球一直在自轉。

It's why we have night and day,

正因如此，我們才有白天與黑夜，

and it spins quickly.

而且地球轉得很快。

At the equator,

在赤道上，

the Earth is spinning at more than 1,000 mi per hour.

地球自轉的速度超過每小時1,000英里。

Now, a spinning ice skater can speed up 片語動詞

一名正在旋轉的花式滑冰選手可以加快轉速，

by moving mass closer to the center.

方法是讓身體質量更靠近中心。

And the Earth is no different. 片語搭配

地球也不例外。

In fact,

事實上，

if you get down on the ground right now

如果你現在趴到地面上，

and move your mass closer to Earth's center,

讓你的身體質量更靠近地心，

technically, 用詞

嚴格來說，

you will speed up Earth's rotation,

你就會加快地球自轉，

making this day shorter. 文法

讓今天變得更短。

Now, the change that you would make to the Earth's rotation

不過，你對地球自轉造成的改變

is way smaller than we could even measure. 文法

小到我們根本測量不出來。

But it is calculable,

但它是可以計算的，

and the impact can be quite impressive

而它造成的影響可能相當驚人，

when you talk about redistributing more mass than just one person.

前提是重新分配的質量不只來自一個人。

For instance,

舉例來說，

last year the earthquake in Japan redistributed so much of Earth's mass towards the center 文法

去年日本的地震讓地球大量質量重新往地心分布，

that every day since then has been 1.8 microseconds shorter. 文法

使得從那之後，每一天都縮短了1.8微秒。

But that was a giant geological event.

但那是一場規模龐大的地質事件。

What can us humans do to the Earth all on our own? 片語搭配

那麼，人類光靠自己能對地球造成什麼影響？

I mean,

我的意思是，

there are more than 7 billion of us now.

現在我們已經有超過70億人了。

What if we all got together in one place and jumped? 片語動詞

如果我們全都聚在同一個地方一起跳，會怎樣？

Well, what would that even look like? 片語搭配

那個場面究竟會是什麼樣子？

Interestingly,

有趣的是，

if you took the entire human population of Earth

如果把地球上的所有人口

and had them all live in one place

全都安排在同一個地方居住，

with the same density that people live in in New York City, 文法

人口密度和紐約市一樣，

you could fit everyone, all of us, into the state of Texas. 片語搭配

那麼整個德州就容得下我們所有人。

But that's living,

但那指的是居住，

not standing around in a crowd, 片語動詞

不是大家擠在人群裡站著，

which is how we would probably want to do the jump.

而我們大概會用後一種方式來跳。

If every single person alive right now on Earth

如果目前地球上活著的每一個人

stood shoulder-to-shoulder, 片語搭配

全都肩並肩站好，

you could fit all of us into the city of Los Angeles.

整個洛杉磯市就容得下我們所有人。

It would be an incredible sight to behold, 慣用語

那會是一幅令人難以置信的景象：

a mere 500 square miles 用詞

區區500平方英里，

containing every single person on Earth.

就容納了地球上的每一個人。

Okay,

好，

so then we jump.

那我們就跳吧。

What happens?

會發生什麼事？

Unfortunately, not much.

很可惜，沒什麼。

I mean, we're all awesome people here on Earth,

我的意思是，地球上的我們每個人都很了不起，

but our collective mass

但我們的總質量

compared to the mass of the entire Earth,

和整個地球的質量相比，

it's like nothing. 慣用語

幾乎等於沒有。

In fact, dot physics calculated that if all of us were to get together in one location 文法

事實上，Dot Physics計算過，如果我們所有人都聚集在同一個地點，

and all jump 30 cm into the air at the exact same time,

並在完全相同的一刻往上跳30公分，

we would push Earth away from us a tiny amount.

我們會把地球從身邊推開一點點。

Earth would only move away from us about 1/100 of the width 片語搭配

地球遠離我們的距離只相當於

of a single hydrogen atom.

一個氫原子直徑的大約百分之一。

And here's another thing.

還有一點。

Because we are all jumping

因為我們全都跳起來後，

and then going back to where we started,

又會回到原本的位置，

Earth is just going to move back to where it started.

地球也只會移回原本的位置。

So, our big jump won't be able to change

所以，我們這次集體大跳躍無法改變

Earth's position in space.

地球在太空中的位置。

But come on, 7 billion people all jumping together, 語氣意圖

可是拜託，70億人一起跳，

that's got to be able to cause 語氣意圖

總該能引起

some sort of seismic activity, right?

某種地震活動吧？

So, let's say you have a lot of people all together in one place, 表達脈絡

假設有一大群人聚在同一個地方，

and you have them all jump on 1 2 3.

然後讓大家數到「一、二、三」就起跳。

Did you feel that?

你感覺到了嗎？

Well, the BBC did this with 50,000 people

BBC曾讓5萬人這樣做，

and discovered that a kilometer and a half away,

結果發現，在1.5公里外，

it only registered as a 0.6 on the Richter scale. 文化背景

儀器記錄到的芮氏規模只有0.6。

You would need 7 million times more people 文法

你需要讓人數達到

than even live on Earth right now to jump at once

現今地球總人口的700萬倍，並同時起跳，

to recreate the earthquake that recently happened in Japan.

才能重現最近發生在日本的那場地震。

So, even though we're all awesome, 文法

所以，儘管我們都很了不起，

compared to the size of the Earth,

但和地球的大小相比，

we're not much.

我們實在微不足道。

But don't get too discouraged. 語氣意圖

不過，別太灰心。

Our collective jump would contain a lot of energy.

我們集體跳躍時會蘊含大量能量。

The Straight Dope calculated that even if only the people who lived in China

The Straight Dope計算過，即使只有住在中國的人

got together and jumped,

聚在一起跳，

their jump would be the equivalent of 500 tons of TNT. 片語搭配

這次跳躍也相當於500噸TNT的威力。

Of course, 500 tons of TNT doesn't do much to an Earth

當然，對地球來說，500噸TNT算不了什麼，

that weighs 6 sextillion 588 quintillion tons. 用詞

畢竟地球重達6.588×10²¹噸。

To make yourself feel more powerful,

想讓自己覺得更有力量，

pick a card.

就選一張牌吧。

I've got 10 of them here.

我這裡有10張。

Let's say mm you choose this one.

假設，嗯……你選了這張。

Boom. Congratulations.

砰！恭喜。

We have just decimated this deck of cards. 用詞

我們剛剛把這副牌「decimate」了。

Why?

為什麼？

Well, because technically,

因為嚴格來說，

decimate

「decimate」

does not mean obliterate completely.

並不表示徹底摧毀。

Deci=10.

「Deci」=10。

It means to take away 1/10 of something.

它的意思是拿走某樣東西的十分之一。

So, the next time you take a quiz 文法

所以下次你參加測驗，

and don't do so well on it, 片語搭配

考得不太好，

you only get 10%, well, sure, that's an F. 文化背景

只拿到10%，好吧，那當然是不及格。

But by getting 10% of them right, 文法

但只要答對其中10%的題目，

you decimated that quiz.

也可以說你「decimated」了這場測驗。

And since we've been talking about crowds, 表達脈絡

既然我們一直在談人群，

let's talk about YouTube crowds, YouTube audiences,

那就來談談YouTube上的人群，也就是YouTube的觀眾，

that view count that you see at the bottom of every video,

以及每部影片下方顯示的觀看次數，

and get some perspective on it. 片語搭配

看看這些數字究竟代表什麼。

We'll begin with Dunbar's number. 文化背景

我們先從鄧巴數說起。

It's an estimation of the maximum number of people

它是對人數上限的一種估算：

we can have stable social relationships

在某個特定時刻，我們能和多少人

with at a given moment.

維持穩定的社會關係。

And it's based on the size of our neocortex.

這個數字取決於我們大腦新皮質的大小。

These aren't just acquaintances. 表達脈絡

這些人可不只是點頭之交。

These are people you have social contact with,

他們是和你有社交往來的人，

a network where you know

形成一個你清楚知道

how everyone relates to everyone else.

每個人彼此關係如何的社交網路。

And the number is usually given to be somewhere between 100 and 230, 用詞

這個數字通常被認為介於100到230之間，

which means that when a YouTube video

這表示，當一部YouTube影片

receives more than 230 views from different people,

獲得來自不同觀眾的230次以上觀看時，

more people have seen that video 文法

看過這部影片的人數

than you could ever realistically hope

就已經超過你在現實中

to know well at a given moment.

某一時刻可能熟識的人數。

If a video has more than 100,000 views

如果一部影片獲得超過10萬次

from different people,

來自不同觀眾的觀看，

more people have seen that video

那麼看過這部影片的人數

than you will ever meet in your life.

就比你一輩子會遇見的人還多。

And by meet, I mean shake hands with, 表達脈絡

這裡說的「遇見」，是指和他們握手、

learn their name, talk to them for a bit.

知道他們的名字，再聊上一會兒。

I mean, think of it this way. 表達脈絡

換個角度想想。

You and me, we are only statistically expected 片語搭配

從統計上來看，你我預計只能

to live around 28,470 days.

活大約28,470天。

So, even if you were to meet someone, 文法

所以，就算你一輩子每天都認識

two, three people every day of your life,

兩、三個人，

including when you were a baby,

連嬰兒時期也算進去，

you still wouldn't meet as many people

你遇見的人仍然不會多過

as have seen that YouTube video

看過那部YouTube影片的人，

with 100,000 views.

而它有10萬次觀看。

But keep this in mind.

但請記住這一點。

Even though you or even a large group of us 表達脈絡

雖然你，甚至我們一大群人，

can't do much to

都無法在多大程度上

change Earth's location or rotation,

改變地球的位置或自轉，

we can affect it a little bit. 用詞

但我們還是能帶來一點點影響。

Newton's third law guarantees this. 文化背景

牛頓第三運動定律保證了這一點。

If you weigh 150 lb,

如果你重150磅，

the Earth is pulling you down

地球會把你往下拉，

with a force of 150 lb,

力量為150磅力；

but you are also pulling up on the Earth

但你也在往上拉地球，

with a force of 150 lb.

同樣施加150磅力。

If you fall 3 m,

如果你下落3公尺，

the Earth has pulled you down

地球就把你往下拉了

3 m,

3公尺，

but you have also

但同時，你也

exerted a equal and opposite force 片語搭配

施加了一個大小相等、方向相反的力，

on the Earth.

而這個力作用在地球上。

Of course, it's a lot bigger.

當然，地球比你大得多。

So, if you fall 3 m,

所以，如果你下落3公尺，

you pull the Earth up

你會把地球往上拉動

about a billionth

大約十億分之一個

of the width of a proton,

質子直徑的距離，

which ain't bad. 語氣意圖

這已經不錯了。

So, the next time you move your body, 表達脈絡

所以下次你移動身體時，

the next time you jump,

下次你跳起來時，

Felicia, think about this.

Felicia，想想這一點。

You just affected the Earth

你剛剛對地球造成的影響，

as much as it affected you. 文法

和地球對你造成的影響一樣大。

You've got that kind of power.

你就是擁有這樣的力量。

Speaking of power, 表達脈絡

說到力量，

you all should go check out Geek and Sundry, 片語動詞

大家都該去看看Geek and Sundry，

Felicia's new channel.

Felicia的新頻道。

It's one of my new favorite things.

這是我最近最喜歡的頻道之一。

And as always, thanks for watching.

一如往常，謝謝收看。