forge cities on planets thousands of light-years away,

在數千光年外的星球上鑄造城市。

and maintain a galactic web of trade and transport.

並維持銀河系的貿易和運輸網。

What would it take for our civilization to make that leap?

我們的文明要怎樣才能實現這一飛躍？

There are many things to consider— how would we communicate?

要考慮的事情很多--我們會如何溝通？

What might a galactic government look like?

銀河系政府會是什麼樣子？

And one of the most fundamental of all:

也是最基本的一個。

where would we get enough energy to power that civilization—

我們從哪裡得到足夠的能源來推動這個文明呢？

its industry, its terraforming operations, and its starships?

它的工業、它的地球改造作業和它的星艦？

An astronomer named Nikolai Kardashev proposed a scale

一位名叫尼古拉-卡達舍夫的天文學家提出了一個比例尺。

to quantify an evolving civilization's increasing energy needs.

以量化不斷髮展的文明對能源需求的增加。

In the first evolutionary stage, which we're currently in,

在第一個進化階段，也就是我們目前所處的階段。

planet-based fuel sources like fossil fuels,

化石燃料等基於地球的燃料來源。

solar panels and nuclear power plants

太陽能電池板和核電站

are probably enough to settle other planets inside our own solar system,

可能足以讓其他行星在我們的太陽系內定居。

but not much beyond that.

但除此之外就沒有什麼了。

For a civilization on the third and final stage,

對於處於第三階段也是最後階段的文明。

expansion on a galactic scale would require about 100 billion times

銀河系級的膨脹需要大約1000億倍的時間。

more energy than the full 385 yotta joules our sun releases every second.

比太陽每秒釋放的385億焦耳的能量還要多。

Barring a breakthrough in exotic physics,

除非異國物理學有突破性進展。

there's only one energy source that could suffice:

只有一種能源可以滿足。

a supermassive black hole.

一個超大品質黑洞。

It's counterintuitive to think of black holes as energy sources,

把黑洞當作能源是違反直覺的。

but that's exactly what they are, thanks to their accretion disks:

但這正是它們的特點，這要歸功於它們的吸積盤。

circular, flat structures formed by matter falling into the event horizon.

物質落入事件地平線形成的圓形、扁平結構。

Because of conservation of angular momentum,

因為角動量守恆。

particles there don't just plummet straight into the black hole.

那裡的粒子不會直接墜入黑洞。

Instead, they slowly spiral.

而是慢慢的螺旋式上升。

Due to the intense gravitational field of the black hole,

由於黑洞的強烈引力場。

these particles convert their potential energy to kinetic energy

這些粒子將其勢能轉化為動能。

as they inch closer to the event horizon.

當他們逐漸接近事件的地平線時。

Particle interactions allow for this kinetic energy

粒子間的相互作用使這種動能得以實現。

to be radiated out into space

輻射到太空

at an astonishing matter-to-energy efficiency:

以驚人的物質-能量效率。

6% for non-rotating black holes, and up to 32% for rotating ones.

非旋轉黑洞為6%，旋轉黑洞則高達32%。

This drastically outshines nuclear fission,

這大大超過了核裂變。

currently the most efficient widely available mechanism

目前最有效的、廣泛存在的機制

to extract energy from mass.

從品質中提取能量。

Fission converts just 0.08% of a Uranium atom into energy.

裂變只將0.08%的鈾原子轉化為能量。

The key to harnessing this power may lie in a structure

駕馭這種力量的關鍵可能在於一個結構。

devised by physicist Freeman Dyson, known as the Dyson sphere.

由物理學家弗里曼-戴森設計的，被稱為戴森球。

In the 1960s, Dyson proposed that an advanced planetary civilization

20世紀60年代，戴森提出，一個先進的行星文明

could engineer an artificial sphere around their main star,

可以在他們的主星周圍設計一個人造球體。

capturing all of its radiated energy to satisfy their needs.

捕捉其所有的輻射能量來滿足他們的需求。

A similar, though vastly more complicated design

類似的設計，但要複雜得多

could theoretically be applied to black holes.

理論上可以應用於黑洞。

In order to produce energy, black holes need to be continuously fed—

為了產生能量，黑洞需要不斷地被餵養----------。

so we wouldn't want to fully cover it with a sphere.

所以我們不會想用一個球體完全覆蓋它。

Even if we did, the plasma jets that shoot from the poles

即使如此，從兩極射出的等離子體噴射器也是如此

of many supermassive black holes

眾多超大品質黑洞的

would blow any structure in their way to smithereens.

會把任何擋路的建築炸得粉碎。

So instead, we might design a sort of Dyson ring,

所以，我們可能會設計一種戴森環。

made of massive, remotely controlled collectors.

由大量的、遙控的收集器組成。

They'd swarm in an orbit around a black hole,

它們會在黑洞周圍的軌道上聚集。

perhaps on the plane of its accretion disk, but farther out.

也許在它的吸積盤平面上，但在更遠的地方。

These devices could use mirror-like panels

這些設備可以使用類似鏡子的面板

to transmit the collected energy to a powerplant,

將收集到的能量傳輸到發電廠。

or a battery for storage.

或電池進行存儲。

We'd need to ensure that these collectors are built at just the right radius:

我們需要確保這些收集器的建造半徑恰到好處。

too close and they'd melt from the radiated energy.

太近了，它們會被輻射的能量融化。

Too far, and they'd only collect a tiny fraction of the available energy

太遠了，他們只能收集一小部分可用的能量。

and might be disrupted by stars orbiting the black hole.

並可能被圍繞黑洞運行的恆星破壞。

We would likely need several Earths worth of highly reflective material

我們可能需要好幾個地球的高反射材料。

like hematite to construct the full system—

像赤鐵礦一樣構築完整的體系-。

plus a few more dismantled planets to make a legion of construction robots.

再加上幾顆拆解的星球，組成一個建築機器人軍團。

Once built, the Dyson ring would be a technological masterpiece,

一旦建成，戴森戒指將是一個科技傑作。

powering a civilization spread across every arm of a galaxy.

為遍佈銀河系各個角落的文明提供動力。

This all may seem like wild speculation.

這一切看似是胡亂猜測。

But even now, in our current energy crisis,

但即使是現在，在我們當前的能源危機中。

we're confronted by the limited resources of our planet.

我們面對的是地球上有限的資源。

New ways of sustainable energy production will always be needed,

總是需要新的可持續能源生產方式。

especially as humanity works towards the survival

特別是在人類為生存而努力的時候

and technological progress of our species.

和我們人類的技術進步。

Perhaps there's already a civilization out there

也許外面已經有一個文明瞭

that has conquered these astronomical giants.

征服了這些天文巨頭。

We may even be able to tell

我們甚至可以看出

by seeing the light from their black hole periodically dim

看到黑洞的光線週期性地變暗。

as pieces of the Dyson ring pass between us and them.

當戴森戒指的碎片在我們和他們之間傳遞時。

Or maybe these superstructures are fated to remain in the realm of theory.

或者說，這些上層建築註定只能停留在理論的範疇。

Only time— and our scientific ingenuity— will tell.

只有時間和我們的科學智慧才能證明。