yet look back 100 years,

但是回顧100年前

and the technologies we take for granted today

許多我們今天視為理所當然的科技

would seem like impossible magic.

似乎像個不可能的魔術

So will there be a point

所以，難道未來真會有一個點

where we reach an actual limit of technological progress?

是我們科技進步真的無法突破之處?

And if so, are we anywhere near that limit now?

如果是這樣，我們現在是否正往這個限制點逐漸接近？

Half a century ago,

半個世紀前

Russian astronomer Nikolai Kardashev was asking similar questions

俄羅斯天文學家尼古拉‧卡達謝夫問了類似的問題

when he came up with a way to measure technological progress,

當時他已想出一個量測科技進步的方法

even when we have no idea exactly what it might look like.

即便我們完全不知道它實際上會是什麼樣貌？

Anything we do in the future will require energy,

由於未來我們所要做的任何事，都需要能源

so Kardashev's scale classifies potential civilizations,

因此，卡達謝夫的量尺已對潛在文明先加以分類，

whether alien civilizations out there in the universe or our own,

無論是宇宙的外來文明或是人類自己的文明

into three levels based on energy consumption.

根據能源的使用，都可分為三個層次

The tiny amount of energy we currently consume

我們目前消耗的微量能源

pales next to what we leave untapped.

我們週圍尚未開發之處

A Type I, or planetary civilization,

屬第一型，或稱行星文明

can access all the energy resources of its home planet.

即可以從行星本身取得各項能源

In our case, this is the 174,000 terawatts Earth receives from the Sun.

以人類本身為例，地球從太陽接收的174,000兆瓦

We currently only harness about 15 terawatts of it,

我們目前只掌握其中約15兆瓦，

mostly by burning solar energy stored in fossil fuels.

大部分都是燃燒儲存在石化燃料中的太陽能。

To approach becoming a Type I civilization,

因此要成為第一型文明

we would need to capture solar energy more directly and efficiently

我們必須要更直接和有效地捕捉太陽能

by covering the planet with solar panels.

藉由鋪設在地球上的太陽能電池板

Based on the most optimistic models,

根據最樂觀的模式估算

we might get there within just four centuries.

我們可能在四個世紀之後，才會到達這個目標。

What would be next?

而接下來呢?

Well, the Earth only gets a sliver of the Sun's energy,

嗯，地球只取得太陽能量的一小部分

while the rest of its 400 yottawatts is wasted in dead space.

而400佑瓦的其他部分，通通浪費在死寂的太空中

But a Type II, or stellar civilization,

但是，第二型或稱恆星文明，

would make the most of its home star's energy.

則是充分利用其母星球的能量

Instead of installing solar panels around a planet,

它不在自己星球表面上安裝太陽能電池板

a Type II civilization would install them directly orbiting its star,

第二型文明則將它們直接安裝在圍繞恆星軌道上

forming a theoretical structure called a Dyson sphere.

形成一種稱為「戴森球面」的理論構造

And the third step?

至於第三步呢?

A Type III civilization would harness all the energy of its home galaxy.

第III型文明則利用其本身星系的所有能量

But we can also think of progress in the opposite way.

然而我們也可以反方向來思考科技進程

How small can we go?

只是我們可以看到多小的東西？

To that end, British cosmologist John Barrow

為此，英國宇宙學家約翰‧巴羅

classified civilizations by the size of objects they control.

則依能控制的物體大小，將文明加以分類

That ranges from mechanical structures at our own scale,

從以我們自己大小規模的機械構造為起點

to the building blocks of our own biology,

到人類本身生物體的基石

down to unlocking atoms themselves.

再下到解鎖原子本身

We've currently touched the atomic level, though our control remains limited.

我們目前已觸及原子的層面，儘管我們能控制的仍屬有限

But we potentially could go much smaller in the future.

而且未來潛在發展可能更小

To get a sense of the extent to which that's true,

如果要體會這真實的程度

the observable universe is 26 orders of magnitude larger than a human body.

可觀測的宇宙約比人體大上26個量級

That means if you zoomed out by a factor of ten 26 times,

這意味著，如果你縮小了10的26次方

you'd be at the scale of the universe.

你就處於宇宙的規模

But to reach the minimum length scale, known as the Planck length,

不過為了達到最小的長度刻度，俗稱普朗克長度，

you would need to zoom in 35 times.

你得再拉近35倍來看

As physicist Richard Feynman once said, "There's plenty of room at the bottom."

物理學家理察·費曼曾說「微觀世界還有很大的發展空間」

Instead of one or the other,

不是非此即彼

it's likely that our civilization will continue to develop

我們的文明可能還會繼續發展

along both Kardashev and Barrow scales.

沿著卡達謝夫和約翰‧巴羅的量尺

Precision on a smaller scale lets us use energy more efficiently

微觀尺度的精確性讓我們能更有效率使用能源

and unlocks new energy sources, like nuclear fusion,

並且解鎖新能源，例如核熔合

or even antimatter.

或者是反物質

And this increased energy lets us expand and build on a larger scale.

這類新增能量能讓我們以更大規模向外擴大和新建

A truly advanced civilization, then,

真正的先進文明，屆時

would harness both stellar energy and subatomic technologies.

就能利用恆星能量和次原子技術

But these predictions weren't made just for us humans.

但這些預言並不只適用於我們人類

They double as a possible means

他們加倍作為一種可能手段

of detecting intelligent life in the universe.

來探測宇宙中的智慧生命

If we find a Dyson sphere around a distant star,

假設我們在一顆遙遠的恆星周圍發現了一個戴森球面

that's a pretty compelling sign of life.

也就是宇宙存有其它生命的強有力跡象

Or, what if, instead of a structure that passively soaked up all the star's energy,

或者，像是，並非被動地吸收星體所有能量的結構

like a plant,

例如，一棵植物

an alien civilization built one that actively sucked the energy out of the star

一個外星文明創建出一個會主動吸取星體的能量構造

like a hummingbird.

例如，一隻蜂鳥

Frighteningly enough, we've observed super dense celestial bodies

可怕的是，我們曾觀察到超級密集的天體

about the size of a planet

大小有如行星一般

that drain energy out of a much bigger star.

會從一個更大的星體吸汲能量

It would be much too premature to conclude that this is evidence of life in the universe.

使得要下宇宙中存有生命的證據定論的時機，仍為時過早

There are also explanations for these observations

這些觀察到的現象仍有其它解釋

that don't involve alien life forms.

即並不牽涉外星生命形式

But that doesn't stop us from asking, "What if?"

但這並不會阻擋我們持續提問「如果呢?」