我們能阻止小行星撞擊地球嗎？（比爾·奈客串）：英語精讀講義

We've all witnessed the beauty of a shooting star,

我們都曾見識過流星之美，

but what would happen if an asteroid was on a collision course for Earth? 片語搭配

但如果一顆小行星正沿著撞向地球的軌道飛來，會發生什麼事？

Could we detect it ahead of time? 片語搭配

我們能提早偵測到它嗎？

And more importantly, 表達脈絡

更重要的是，

could we stop it?

我們能阻止它嗎？

I believe I have an answer.

我想我有答案。

Now, you see,

你看，

asteroid impacts are serious business. 慣用語

小行星撞擊可不是鬧著玩的。

When I was in second grade,

我讀小學二年級時，

Ms. McGonigal told us that the dinosaurs,

McGonigal老師告訴我們，恐龍，

the ancient dinosaurs,

那些遠古的恐龍，

died out because they had small brains, 片語動詞

是因為腦袋太小才滅絕的，

maybe like my old boss.

也許就像我的前老闆一樣。

But even she knew that was kind of lame,

但就連她也知道，這種說法有點站不住腳，

with that theory was nothing.

那套理論根本毫無根據。

It turns out in my lifetime people found this crater 表達脈絡

後來，在我有生之年，人們發現了這個隕石坑，

off Chicxulub, Mexico.

位於墨西哥希克蘇魯伯附近。

This crater was so big.

這個隕石坑大得驚人。

How big was it?

到底有多大？

It was so big

它大到這種程度：

that an asteroid hit the Earth or impactors

一顆小行星撞上了地球，或者說多個撞擊體

hit the Earth,

撞上地球後，

threw so much stuff into the Earth's sky.

把大量物質拋進了地球上空。

It was bigger in diameter than the Earth itself.

它的直徑比地球本身還大。

So the Earth was surrounded by red-hot rock for weeks at a time. 片語搭配

於是，地球連續好幾週都被熾熱的岩石包圍。

Cooked everything.

一切都被烤熟了。

And just the animals that lived in burrows and caves,

只有那些住在地洞和洞穴裡的動物活了下來，

our ancestors led to us.

牠們成為我們的祖先，最後演化出了我們。

So,

所以，

serious business.

這絕不是小事。

You may recall Valentine's Day 2013,

你可能還記得2013年的情人節，

Chelyabinsk, Russia air burst. 文化背景

俄羅斯車里雅賓斯克發生了空爆。

See, if you're an asteroid and you're going 10 km a second,

你想，如果你是一顆以每秒10公里飛行的小行星，

20 km a second,

甚至每秒20公里，

and you hit the Earth's atmosphere,

當你撞上地球大氣層時，

the atmosphere is like concrete. 表達脈絡

大氣層就像混凝土一樣堅硬。

Then it can't get out of the way. 慣用語

它根本來不及讓開。

So the asteroid just explodes in air burst. 用詞

於是小行星就在空中爆炸了。

So these asteroids are serious.

所以，這些小行星真的不能小看。

Most of them are very small.

它們大多非常小。

If you're under 10 m in diameter,

如果你的直徑不到10公尺，

you hit the Earth's atmosphere,

撞上地球大氣層後，

you burn up 片語動詞

你會燃燒殆盡，

big blue streak,

劃出一道巨大的藍色光芒，

bl- green streak,

藍——綠色光芒，

white streak,

或白色光芒，

and then humans make wishes upon you. 文化背景

然後人類會對著你許願。

I don't know how efficacious those wishes are, 用詞

我不知道那些願望有多靈驗，

but people do that.

但大家就是會這麼做。

All right.

好吧。

So,

那麼，

if the asteroid starts to get bigger,

如果小行星開始變大，

starts to get into the 25 m and the 45 m in diameter,

直徑達到25公尺乃至45公尺，

then you get Meteor Crater, Arizona.

就會形成像亞利桑那州隕石坑那樣的景象。

Wham, a huge thing.

砰！一個巨大的坑。

That would be like a s- city killer or a county killer.

它足以摧毀一座城市，甚至一個縣。

And then when they get to be 100 m,

等它們的直徑達到100公尺，

140 m,

140公尺時，

now you're into a country killer.

就足以摧毀一個國家了。

And then they get bigger than that,

如果比這還大，

it's a continent killer.

就足以摧毀一整片大陸。

Much bigger than that and you're taking out whole races of ancient species.

再大得多，就會讓整個遠古物種族群滅絕。

So,

那麼，

what if we found an asteroid that was headed our way? 片語搭配

如果我們發現一顆正朝我們飛來的小行星呢？

How would we find it?

我們要怎麼找到它？

How would we find an asteroid headed our way?

我們要怎麼找到一顆正朝我們飛來的小行星？

That's a good question.

這個問題問得好。

Well,

嗯，

you can use telescopes,

可以使用望遠鏡，

skilled people can point their cameras at the sky and look for fast-moving objects,

讓訓練有素的人把相機對準天空，尋找快速移動的天體，

objects that are crossing the Earth's orbit.

也就是那些正在穿越地球軌道的天體。

But we're missing perhaps a 100,000 of these things, 用詞

但我們可能還漏掉了大約10萬個這類天體，

of these county killers, 用詞

其中有能摧毀一個縣的，

city killers,

能摧毀一座城市的，

country killers.

還有能摧毀一個國家的。

So what we want to do is build a spacecraft called the Sentinel. 文法

所以，我們想打造一艘名為「哨兵號」的太空船。

And as we say,

正如我們常說的，

it's like looking for a charcoal briquette in the dark. 表達脈絡

這就像在黑暗中尋找一塊木炭。

These things are hard to find.

這些東西很難找到。

They're tiny compared to the vastness of space.

和浩瀚的太空相比，它們實在太小了。

But infrared light bounces off of them. 片語動詞

不過，紅外線會從它們表面反射回來。

So what you'll do,

所以，你要做的是——

you're a satellite,

假設你是一顆衛星，

you're a surveying spacecraft,

一艘巡天太空船，

you'll get your back to the Sun

你要背對太陽，

and look out from about the orbit of Venus

從大約金星軌道的位置向外觀測，

and try to find all these asteroids.

設法找出所有這些小行星。

And then you find one, what do you do?

找到一顆之後，該怎麼辦？

Do you run in circles screaming? 慣用語

繞著圈尖叫嗎？

No, no, no.

不，不，不。

We've got to deflect it 文法

我們得讓它偏轉，

just a little, 表達脈絡

只偏一點點，

just a tiny amount.

極其微小的一點。

Asteroid might be going 10 km a second,

小行星的速度可能是每秒10公里，

we want to change its speed about 2 mm a second.

我們只想讓它的速度改變約每秒2公釐。

So 10 km,

那麼，10公里，

that's 10 times a 1,000 m,

就是10乘以1000公尺，

that's 10,000 m.

也就是10000公尺。

A millimeter,

1公釐，

that's a thousandth of a meter.

是1公尺的千分之一。

So that you take the one over the thousandth,

所以，你用這個千分之一來算，

it's a thousand times 10,000,

1000乘以10000，

that's 10 million.

就是1000萬。

You want to change its speed a 10 millionth of its total.

我們只要讓它的速度改變到總速度的千萬分之一。

That's not very much.

這並不算多。

But if you're an asteroid that comes in at 10,000 tons,

但如果你是一顆重達10000噸的小行星，

100,000 tons,

甚至100000噸，

it does take quite a bit of force to change it a 10 millionth of its speed.

要讓速度改變千萬分之一，仍然需要相當大的力。

Okay,

好，

how do we do that?

要怎麼做到呢？

Well, the b- easiest way is to get a rocket,

嗯，最——最簡單的方法是找一枚火箭，

a big rocket.

一枚大火箭。

Just go out there and just smack into it. 用詞

直接飛過去，狠狠撞上它。

Except it's in outer space,

只不過這是在外太空，

so it just goes like that.

所以它只會像這樣動一下。

Okay,

好，

and that would change its speed a little.

這會讓它的速度稍微改變。

Now, notice everybody,

現在，大家注意，

what if it's not just a rock? 文法

如果它不只是一整塊岩石呢？

What if it's what if it's a pile of rocks?

如果它……如果它是一堆岩石呢？

just loosely held together by primordial gravity. 片語動詞

只是靠原始引力鬆散地聚在一起。

And so if you hit them,

那麼，如果你撞上它們，

they'll just spread out and you'll have a shower of rocks.

它們只會四散開來，變成一場岩石雨。

That would be bad.

那可就糟了。

So,

所以，

how about this? 語氣意圖

這個辦法怎麼樣？

We'll get a big spacecraft that's massive,

我們打造一艘體積很大的太空船，

a massive spacecraft,

一艘質量巨大的太空船，

and we'll go out there and just get near the asteroid,

然後飛到那裡，只靠近小行星，

just get near it.

就只是靠近它。

And then the mutual gravity of you,

接著，彼此之間的引力——你，

the asteroid,

也就是小行星，

and me, the spacecraft,

和我，也就是太空船——

will tug the asteroid speed just a little bit,

會把小行星的速度稍微拉動一點，

just a tiny bit.

只改變極小的一點。

Or maybe get on the other side and tug this way.

或者飛到另一側，朝這個方向拉它。

That might work, but here's the problem. 表達脈絡

這也許可行，但問題來了。

I need a huge amount of fuel

我需要大量燃料，

for days and weeks and months and years. 表達脈絡

連續維持好幾天、好幾週、好幾個月，甚至好幾年。

And what if it stops working?

要是它停止運作了呢？

You can't go out there and fix it.

你不可能飛過去修理它。

Okay,

好，

how about this?

那這個辦法呢？

The laser bees, 慣用語

「雷射蜜蜂」，

a swarm of sunlight-powered lasers

一群以陽光為能源的雷射器，

that are zapping the surface of the asteroid 用詞

持續照射小行星表面，

for days and weeks and months and years.

一照就是好幾天、好幾週、好幾個月，甚至好幾年。

So some asteroid, some rock is vaporized

這樣，小行星上的一部分岩石就會汽化，

and the ejecta, 用詞

而噴出物，

the stuff ejected,

也就是被噴射出去的物質，

has momentum just like rocket fuel,

會像火箭燃料一樣帶有動量，

just like just like standing on a skateboard and playing catch with a bowling ball, 表達脈絡

就像……就像你站在滑板上和別人互拋保齡球一樣，

the way you do. 語氣意圖

就像你平常會做的那樣。

And so it would then cause the asteroid to change its speed. 文法

這麼一來，小行星的速度就會改變。

And so you send a swarm of these laser spacecraft

因此，可以派出一群這樣的雷射太空船，

so that if one of them stops working, 文法

這樣即使其中一艘停止運作，

you can use the other one.

你也可以使用另一艘。

Or and you can you can have them come in from all different angles.

而且，還可以讓它們從各種不同角度飛來。

And what if the asteroid is irregularly shaped like this?

如果小行星像這樣，形狀很不規則呢？

You could beam it when the thing is smooth 用詞

可以在它表面平滑時發射雷射，

and then when there's a pit or an inefficient place to be beaming,

等轉到凹坑或不適合照射的位置時，

you turn off,

就關掉雷射，

you wait for the asteroid to turn,

等小行星繼續轉動，

then you turn it back on.

然後再把雷射打開。

See, everybody,

大家明白了吧，

just 'cause it's unlikely doesn't mean it's not a big deal. 講解

一件事發生的機率低，並不代表它不嚴重。

You know,

要知道，

if it only happens once every few thousand years.

就算它每幾千年才發生一次。

Well, if it happens during on my watch, 慣用語

可是，如果偏偏在我任內發生，

it would, as the kids say, suck. 語氣意圖

用年輕人的話說，那就「糟透了」。

Okay,

好，

so we don't want that to happen.

所以，我們不希望這種事發生。

We want to avoid that.

我們要避免它。

Asteroids are serious business,

小行星是件嚴肅的事，

but they're exciting.

但也很令人興奮。

Except we're in space,

只不過我們身處太空，

so it's just

所以就只能……

Got a burning question?

有什麼火燒眉毛的問題嗎？

Well, be sure to subscribe to AsapSCIENCE.

那就一定要訂閱AsapSCIENCE。

Follow us on Twitter and Facebook.

還要在Twitter和Facebook上追蹤我們。

That's what all the kids are doing.

年輕人現在都這麼做。

And if it's an asteroid,

如果問題是一顆小行星，

it may not be a burning question, 表達脈絡

它可能就不是一個「火燒眉毛」的問題，

it might be an impacting question

而是一個「撞擊性」的問題，

or even an ablating question.

甚至是一個「燒蝕性」的問題。