如果所有人同时跳起来会怎样？：英语精读讲义

Hey, Vsauce.

嘿，Vsauce。

Michael here.

Michael 在这里。

And what if every single person on Earth 語法

如果地球上的每一个人

jumped at the exact same time? 短語搭配

都在完全相同的一刻跳起来，会怎样？

Could it cause an earthquake

这会引发地震吗，

or would we not even be able to tell? 語法

还是我们甚至根本察觉不到？

Well, first things first, 短語搭配

好，首先要说的是，

let's talk about the Earth's rotation.

我们来聊聊地球自转。

The Earth spins.

地球一直在自转。

It's why we have night and day,

正因如此，才有了昼夜，

and it spins quickly.

而且它转得很快。

At the equator,

在赤道上，

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

地球自转的速度超过每小时1,000英里。

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

一个正在旋转的花样滑冰运动员可以加快转速，

by moving mass closer to the center.

只要把身体质量移得更靠近中心。

And the Earth is no different. 短語搭配

地球也不例外。

In fact,

事实上，

if you get down on the ground right now

如果你现在趴到地面上，

and move your mass closer to Earth's center,

让你的身体质量更靠近地心，

technically, 用詞

严格来说，

you will speed up Earth's rotation,

你就会加快地球自转，

making this day shorter. 語法

让今天变得更短。

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

不过，你对地球自转造成的改变

is way smaller than we could even measure. 語法

小到我们根本测量不出来。

But it is calculable,

但它是可以计算的，

and the impact can be quite impressive

而它造成的影响可能相当惊人，

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

前提是被重新分配的质量不只来自一个人。

For instance,

例如，

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

去年日本的地震让地球大量质量向地心重新分布，

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

使那之后的每一天都缩短了1.8微秒。

But that was a giant geological event.

但那是一场巨大的地质事件。

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

那人类单靠自己能对地球产生什么影响呢？

I mean,

我的意思是，

there are more than 7 billion of us now.

现在我们已经有70多亿人了。

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

如果我们全都聚到一个地方一起跳，会怎样？

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

那场面究竟会是什么样？

Interestingly,

有意思的是，

if you took the entire human population of Earth

如果把地球上的全部人口

and had them all live in one place

都安排在同一个地方居住，

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

人口密度与纽约市相同，

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

那么得克萨斯州就足以容纳我们所有人。

But that's living,

但那说的是居住，

not standing around in a crowd, 短語動詞

而不是大家挤在人群里站着，

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

可我们大概会用后一种方式来跳。

If every single person alive right now on Earth

如果此刻地球上活着的每一个人

stood shoulder-to-shoulder, 短語搭配

都肩并肩站好，

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

整个洛杉矶市就能容纳我们所有人。

It would be an incredible sight to behold, 習語

那会是无比壮观的景象：

a mere 500 square miles 用詞

区区500平方英里，

containing every single person on Earth.

就容纳了地球上的每一个人。

Okay,

好，

so then we jump.

那我们就跳吧。

What happens?

会发生什么？

Unfortunately, not much.

很遗憾，没什么。

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

我的意思是，地球上的我们每个人都很了不起，

but our collective mass

可我们的总质量

compared to the mass of the entire Earth,

与整个地球的质量相比，

it's like nothing. 習語

几乎等于没有。

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

事实上，Dot Physics计算过，如果我们所有人都聚集在同一个地点，

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

并在完全相同的一刻向上跳30厘米，

we would push Earth away from us a tiny amount.

我们会把地球从身边推开一点点。

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

地球远离我们的距离只相当于

of a single hydrogen atom.

一个氢原子直径的约百分之一。

And here's another thing.

还有一点。

Because we are all jumping

因为我们全都跳起来后，

and then going back to where we started,

又会回到原来所在的位置，

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

地球也只会移回它原来的位置。

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

所以，我们这次集体大跳跃无法改变

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

可话说回来，70亿人一起跳，

that's got to be able to cause 語氣意圖

总该能引起

some sort of seismic activity, right?

某种地震活动吧？

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

假设有一大群人聚在一个地方，

and you have them all jump on 1 2 3.

然后让所有人听到“一、二、三”就起跳。

Did you feel that?

你感觉到了吗？

Well, the BBC did this with 50,000 people

BBC曾让5万人这样做，

and discovered that a kilometer and a half away,

结果发现，在1.5公里外，

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

仪器记录到的震级只有里氏0.6级。

You would need 7 million times more people 語法

你需要让比

than even live on Earth right now to jump at once

当今地球总人口多700万倍的人同时起跳，

to recreate the earthquake that recently happened in Japan.

才能重现最近发生在日本的那场地震。

So, even though we're all awesome, 語法

所以，尽管我们都很了不起，

compared to the size of the Earth,

可与地球的大小相比，

we're not much.

我们实在微不足道。

But don't get too discouraged. 語氣意圖

不过，别太灰心。

Our collective jump would contain a lot of energy.

我们集体跳跃时会蕴含大量能量。

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

The Straight Dope计算过，即使只有居住在中国的人

got together and jumped,

聚在一起跳，

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

这次跳跃也相当于500吨TNT的威力。

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

当然，对于地球来说，500吨TNT算不了什么，

that weighs 6 sextillion 588 quintillion tons. 用詞

因为地球重达6.588×10²¹吨。

To make yourself feel more powerful,

想让自己觉得更有力量，

pick a card.

就选一张牌吧。

I've got 10 of them here.

我这里有10张。

Let's say mm you choose this one.

假设，嗯……你选了这张。

Boom. Congratulations.

砰！恭喜。

We have just decimated this deck of cards. 用詞

我们刚刚把这副牌“decimate”了。

Why?

为什么？

Well, because technically,

因为严格来说，

decimate

“decimate”

does not mean obliterate completely.

并不表示彻底毁灭。

Deci=10.

“Deci”=10。

It means to take away 1/10 of something.

它的意思是拿走某样东西的十分之一。

So, the next time you take a quiz 語法

所以下次你参加测验，

and don't do so well on it, 短語搭配

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，这当然是不及格。

But by getting 10% of them right, 語法

但答对其中10%的题，

you decimated that quiz.

也可以说你“decimated”了这场测验。

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

既然我们一直在谈人群，

let's talk about YouTube crowds, YouTube audiences,

那就来聊聊YouTube上的人群，也就是YouTube的观众，

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

以及每段视频底部显示的观看次数，

and get some perspective on it. 短語搭配

看看这些数字究竟意味着什么。

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

我们先从邓巴数说起。

It's an estimation of the maximum number of people

它是对人数上限的一种估算：

we can have stable social relationships

在某个特定时刻，我们能够与多少人

with at a given moment.

维持稳定的社会关系。

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

这个数字取决于我们大脑新皮层的大小。

These aren't just acquaintances. 表達脈絡

这些人可不只是点头之交。

These are people you have social contact with,

他们是与你有社交往来的人，

a network where you know

形成一个你清楚知道

how everyone relates to everyone else.

每个人彼此关系如何的社交网络。

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

这个数字通常被认为介于100到230之间，

which means that when a YouTube video

这意味着，当一段YouTube视频

receives more than 230 views from different people,

获得来自不同观众的230次以上观看时，

more people have seen that video 語法

看过这段视频的人数

than you could ever realistically hope

就已经超过你在现实中

to know well at a given moment.

某一时刻可能熟悉的人数。

If a video has more than 100,000 views

如果一段视频获得超过10万次

from different people,

来自不同观众的观看，

more people have seen that video

那么看过这段视频的人数

than you will ever meet in your life.

就比你一生中会遇见的人还多。

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

这里说的“遇见”，是指与他们握手、

learn their name, talk to them for a bit.

知道他们的名字，再聊上一会儿。

I mean, think of it this way. 表達脈絡

换个角度想想。

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

从统计上说，你我预计只能

to live around 28,470 days.

活大约28,470天。

So, even if you were to meet someone, 語法

所以，即使你一生中每天都认识

two, three people every day of your life,

两三个人，

including when you were a baby,

连婴儿时期也算上，

you still wouldn't meet as many people

你遇见的人仍然不会多过

as have seen that YouTube video

看过那段YouTube视频的人，

with 100,000 views.

而它有10万次观看。

But keep this in mind.

但请记住这一点。

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

虽然你，甚至我们一大群人，

can't do much to

都无法在多大程度上

change Earth's location or rotation,

改变地球的位置或自转，

we can affect it a little bit. 用詞

但我们还是能带来一点点影响。

Newton's third law guarantees this. 文化背景

牛顿第三定律保证了这一点。

If you weigh 150 lb,

如果你重150磅，

the Earth is pulling you down

地球会把你向下拉，

with a force of 150 lb,

力量为150磅力；

but you are also pulling up on the Earth

但你也在向上拉地球，

with a force of 150 lb.

同样施加150磅力。

If you fall 3 m,

如果你下落3米，

the Earth has pulled you down

地球就把你向下拉了

3 m,

3米，

but you have also

但与此同时，你也

exerted a equal and opposite force 短語搭配

施加了一个大小相等、方向相反的力，

on the Earth.

而这个力作用在地球上。

Of course, it's a lot bigger.

当然，地球比你大得多。

So, if you fall 3 m,

所以，如果你下落3米，

you pull the Earth up

你会把地球向上拉动

about a billionth

大约十亿分之一个

of the width of a proton,

质子直径的距离，

which ain't bad. 語氣意圖

这已经不赖了。

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

所以下次你移动身体时，

the next time you jump,

下次你跳起来时，

Felicia, think about this.

Felicia，想想这一点。

You just affected the Earth

你刚刚对地球产生的影响，

as much as it affected you. 語法

和地球对你产生的影响一样大。

You've got that kind of power.

你就是拥有这样的力量。

Speaking of power, 表達脈絡

说到力量，

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

大家都该去看看Geek and Sundry，

Felicia's new channel.

Felicia的新频道。

It's one of my new favorite things.

它是我最近最喜欢的频道之一。

And as always, thanks for watching.

一如既往，感谢观看。