為什麼外星生命會是我們的末日——大過濾器：英語精讀講義

Imagine NASA announced today that they found aliens.

想像一下，如果NASA今天宣布他們發現了外星人。

Bacteria on Mars,

火星上的細菌，

weird alien fish in the oceans of Europa,

木衛二海洋裡奇特的外星魚類，

and also ancient alien ruins on Titan.

還有土衛六上古老的外星遺跡。

Wouldn't that be great? 語氣意圖

那不是太棒了嗎？

Well, no.

並不是。

It would be horrible news.

這將是可怕的消息。

Devastating even.

甚至是毀滅性的。

It could mean that the end of humanity is almost certain

這可能意味著人類的終結幾乎是注定的，

and that it might be coming soon.

而且可能很快就會到來。

Why?

為什麼？

Why would the most exciting discovery of our lifetime be bad?

為什麼我們有生之年最激動人心的發現會是壞事？

Let us imagine the development of life from its inception to us today

讓我們把從生命誕生之初到今天我們的發展過程，

as a flight of stairs. 慣用語

想像成一段樓梯。

The first step is dead chemistry that needs to assemble itself into self-replicating patterns,

第一步是沒有生命的化學物質需要將自身組裝成可自我複製的模式，

stable and resilient,

穩定且有韌性，

but also able to change and evolve.

但同時也能夠改變和進化。

The second step is for our early life to become more complex,

第二步是我們早期的生命變得更加複雜，

able to build more complicated structures

能夠構建更複雜的結構，

and use the available energy much more efficiently.

並更高效地利用可用能源。

On the next step,

在下一步，

these cells combine to become multicellular beings,

這些細胞結合成多細胞生物，

enabling unbelievable variety and further complexity. 文法

實現了令人難以置信的多樣性和更深層次的複雜性。

The step above sees the species evolve big brains,

往上一層的階段是物種進化出大容量的大腦，

enabling the use of tools, culture, and shared knowledge,

從而能夠使用工具、發展文化和共享知識，

which creates even higher complexity.

這創造了更高的複雜性。

The species can now become the dominant life form on its planet

此時該物種可以成為其星球上的主導生命形式，

and change it according to its needs.

並根據自己的需要改變它。

First, shy attempts to leave its planet are happening.

最初離開其星球的膽怯嘗試正在發生。

This is where we are now.

這就是我們目前所處的階段。

It's in the nature of life as we know it to reach out, 片語搭配

眾所周知，生命的本性就是向外延伸，

to cover every niche it can.

去佔領每一個它能到達的生存空間。

And since planets have a limited carrying capacity and lifespan, 用詞

而由於行星的承載能力和壽命是有限的，

if a species wants to survive,

如果一個物種想要生存下來，

it will look for more places to spread to.

它就會尋找更多的地方去擴張。

So the steps above the current ones seem logical.

所以在此之上的步驟似乎是符合邏輯的。

Colonize your own solar system.

殖民你自己的太陽系。

Then spread further to reach other stars.

然後進一步擴張以到達其他恆星。

To the possible final step,

直至可能的最終階段，

becoming a galaxy-wide civilization.

成為一個遍布銀河系的文明。

It's very likely that this is a universal principle for civilizations,

很有可能這是文明的一個普遍法則，

no matter where they're from. 文法

不管他們來自哪裡。

If a species is competitive and driven enough to take control over its planet,

如果一個物種具有足夠的競爭力和動力去掌控其星球，

they'll probably not stop there.

他們很可能不會止步於此。

We know that there are up to 500 billion planets in the Milky Way,

我們知道銀河系中多達5000億顆行星，

at least 10 billion Earth-like planets.

至少有100億顆類地行星。

Many have been around billions of years longer than Earth. 片語動詞

許多星球存在的時間比地球長幾十億年。

But we're observing zero galactic civilizations.

但我們沒有觀察到任何銀河文明。

We should be able to see something, 文法

我們應該能看到一些東西，

but there's nothing.

但什麼也沒有。

Space seems to be empty and dead.

太空似乎是空虛且死寂的。

This means something is preventing living things from climbing the staircase

這意味著有什麼東西在阻止生物攀登這座樓梯

beyond the step we're on right now.

越過我們現在所處的階層。

Something that makes becoming a galactic civilization extremely hard,

某些讓成為銀河文明變得極其困難，

maybe impossible.

甚至不可能的東西。

This is the great filter. 文化背景

這就是「大過濾器」。

A challenge or danger so hard to overcome 文法

一個難以克服的挑戰或危險，

that it eliminates almost every species that encounters it.

以至於幾乎每一個遇到它的物種都會被淘汰。

There are two scenarios.

有兩種假設。

One means we are incredibly special and lucky,

一種意味著我們無比特殊且幸運，

the other one means we are doomed and practically already dead.

另一種意味著我們在劫難逃，基本上已經死了。

It depends on where the filter is on our staircase, 文法

這取決於過濾器在我們階梯上的哪個位置，

behind or ahead of us. 慣用語

是在我們身後還是前方。

Scenario one.

假設一。

The filter is behind us.

過濾器在我們身後。

We are the first.

我們是第一批。

If the filter is behind us,

如果過濾器在我們身後，

that means that one of the steps we passed

這意味著我們走過的其中一個台階

is almost impossible to take.

是幾乎不可能跨越的。

Which step could it be?

會是哪一步呢？

Is life itself extremely rare?

是生命本身就極其罕見嗎？

It's very hard to make predictions 片語搭配

很難預測

about how likely it is for life to emerge from dead things. 文法

生命從無生命物質中出現的可能性有多大。

There is no consensus. 片語搭配

目前尚未達成共識。

Some scientists think it develops everywhere where the conditions are right, 片語搭配

一些科學家認為，只要條件合適，生命就會隨處誕生，

others think that Earth might be the only living place in the universe.

而另一些人則認為地球可能是宇宙中唯一有生命的地方。

Another candidate is the step of complex animal cells.

另一個可能則是複雜動物細胞這一步。

A very specific thing happened on this step,

在這一步發生了一件非常特殊的事情，

and as far as we know, 片語搭配

據我們所知，

it happened exactly once.

僅僅發生過一次。

A primitive hunter cell swallowed another cell,

一個原始的捕獵細胞吞噬了另一個細胞，

but instead of devouring it, 文法

但非但沒有消化它，

the two cells formed a union.

這兩個細胞形成了一個聯盟。

The bigger cell provided shelter,

更大的細胞提供了住所，

took care of interacting with the environment and providing resources, 文法

負責與環境互動並提供資源，

while the smaller one used its new home and free stuff

而較小的細胞則利用新家和免費的東西，

to focus on providing a lot of extra energy for its host. 片語搭配

專注於為其宿主提供大量額外能量。

With the abundant energy,

有了充足的能量，

the host cell could grow more than before

宿主細胞可以長得比以前更大，

and build new and expensive things to improve itself,

並建造新且昂貴的東西來完善自己，

while the guest became the powerhouse of the cell. 慣用語

而客細胞則成了細胞的能量核心。

These cells make up every animal on the planet. 片語動詞

地球上的每種動物都是由這些細胞構成的。

Maybe there are billions of bacteria-covered planets in the Milky Way,

也許銀河系中有數十億顆布滿細菌的行星，

but not a single one apart from us

但除了我們之外，沒有一顆星球

has achieved our level of complexity.

達到了我們的複雜程度。

Or intelligence.

或者智能。

We humans feel very smart and sophisticated with our crossword puzzles and romantic novels,

我們人類透過填字遊戲和言情小說，覺得自己非常聰明複雜，

but a big brain is first and foremost 片語搭配

但大容量大腦首先

a very expensive evolutionary investment.

是一項極其昂貴的進化投資。

They are fragile.

它們很脆弱。

They don't help in a fistfight with a bear,

在和熊赤手空拳搏鬥時幫不上忙，

they cost enormous amounts of energy,

它們消耗巨大的能量，

and despite them,

而且儘管有大腦，

it took modern humans 200,000 years to get from sharp sticks to civilization. 文法

現代人類也花了一二十萬年才從用削尖的木棍進化到文明社會。

Being smart does not mean you get to win automatically.

變聰明並不意味著你能自動獲勝。

Maybe intelligence is just not so great

也許智慧本身並沒有那麼偉大，

and we're lucky that it worked out for us. 片語動詞

我們只是幸運地從中受益了。

Scenario two.

假設二。

The filter is ahead of us.

過濾器在我們前方。

Plenty of others died already.

已經有無數文明滅亡了。

A great filter before us

橫亙在我們前方的大過濾器

is orders of magnitude more dangerous 用詞

比我們迄今遇到的任何事物

than anything we encountered so far.

都要危險好幾個數量級。

Even if a major disaster killed most of us or threw us back thousands of years, 文法

即使一場重大災難殺死了我們絕大多數人，或把我們打回幾千年前，

we would survive and recover.

我們也能生存下來並恢復元氣。

And if we can recover,

而如果我們能恢復，

even if it takes a million years,

哪怕需要一百萬年，

then it's not a great filter, 表達脈絡

那它就不是大過濾器，

but just a roadblock to an eventual galactic civilization.

而僅僅是通往最終銀河文明的絆腳石。

On universal timescales,

在宇宙的時間尺度上，

even millions of years are just the blink of an eye. 慣用語

哪怕數百萬年也只是眨眼之間。

If a great filter really lies before us,

如果我們面前真的存在一個大過濾器，

it has to be so dangerous,

那麼它必須極其危險，

so purely devastating and powerful

極具純粹的破壞力和威力，

that it has destroyed most, 表達脈絡

導致它摧毀了絕大多數，

if not all advanced civilizations in our galaxy,

如果不是全部的話，銀河系中的高級文明，

over billions of years.

在幾十億年的時間裡。

A really daunting and depressing hypothesis

一個真正令人氣餒且沮喪的假設是，

is that once a species takes control over its planet, 文法

一旦一個物種控制了其星球，

it's already on the path to self-destruction. 慣用語

它就已經踏上了自我毀滅之路。

Technology is a good way to achieve that.

科技就是實現這一目標的好方法。

It needs to be something that's so obvious that virtually everybody discovers it

它需要是極其顯而易見的東西，以至於幾乎所有人都會發現它，

and so dangerous that its discovery leads almost universally to an existential disaster. 片語搭配

且極其危險，它的發現幾乎無一例外地會導致生存災難。

A large-scale nuclear war.

比如一場大規模核戰爭。

Nanotechnology that gets out of control. 片語動詞

失控的奈米技術。

Genetic engineering of the perfect superbug.

基因工程製造出的完美超級細菌。

An experiment that lights the whole atmosphere on fire.

點燃整個大氣層的實驗。

It might be a superintelligent AI

可能是超級智能AI

that accidentally or purposely destroys its creators.

意外或故意地摧毀了它的創造者。

Or things that we can't even see coming right now. 片語動詞

或者是我們現在甚至無法預見的事情。

Or it's way simpler. 用詞

或者可能簡單得多。

Species competitive enough to take over their planet 片語動詞

具有足夠競爭力去佔領其星球的物種，

necessarily destroy it while competing with each other for resources.

必然會在相互爭奪資源時毀滅它。

Maybe there are runaway chain reactions in every ecosystem

也許每個生態系統中都存在失控的連鎖反應，

that once set in motion are not fixable. 片語搭配

一旦啟動便無法修復。

And so once a civilization is powerful enough to change the composition of its atmosphere, 文法

因此，一旦一個文明強大到足以改變其大氣層的成分，

they make their planet uninhabitable 100% of the time.

它們100%會讓自己的星球變得無法居住。

Let's hope that that's not the case. 語氣意圖

希望情況並非如此。

If the filter is ahead of us,

如果過濾器在我們前方，

our odds are really bad.

我們的處境就會非常糟糕。

What we can hope for.

我們能抱有什麼希望呢。

This is why finding life beyond Earth

這就是為什麼在地球之外發現生命

would be horrible.

是一件可怕的事。

The more common life is in the universe 文法

宇宙中的生命越普遍，

and the more advanced and complex it is,

越是高級和複雜，

the more likely it becomes that a filter is in front of us.

過濾器在我們前方的可能性就越大。

Bacteria would be bad,

發現細菌很糟糕，

small animals would be worse,

發現小動物會更糟，

intelligent life would be alarming.

發現智能生命將令人不寒而慄。

Ruins of ancient alien civilizations

古代外星文明的遺跡

would be horrible.

將會是一場噩夢。

The best case scenario for us right now

對我們現在來說，最好的情況

is that Mars is sterile,

是火星上毫無生命，

that Europa's oceans are devoid of life, 用詞

木衛二的海洋裡沒有生命，

and the vast arms of the Milky Way

銀河系廣闊的旋臂中

harbor only empty oceans hugging dead continents. 用詞

只懷抱著環繞著死亡大陸的空蕩海洋。

That there are billions of empty planets waiting to be discovered 文法

有數十億顆空蕩蕩的星球等待著被發現，

and to be filled up with life. 片語動詞

等待著被生命填滿。

Billions of new homes

數十億個新家園

waiting for us to finally arrive.

終於等到我們的到來。