It lights our homes,

能量可以點亮我們的家、

grows our food,

生長食物、

powers our computers.

讓我們的電腦運作。

We can get it lots of ways:

有很多有很多方式可以獲得能量：

burning fossil fuels,

燃燒化石燃料、

splitting atoms

分裂原子

or sunlight striking photovoltaics.

或是太陽能發電。

But there's a downside to everything.

但每種方法都有缺點。

Fossil fuels are extremely toxic,

化石燃料會極度汙染

nuclear waste is... well, nuclear waste,

核廢料…嗯，就是核廢料

and there are not enough batteries to store sunlight for cloudy days yet.

而且，現在還沒有足夠的電池可以儲存足夠的陽光給陰天的時候用呢。

And yet, the Sun seems to have virtually limitless, free energy.

然而，太陽似乎有幾乎無限的免費能量

Is there a way we could build a sun on Earth?

有沒有辦法在地球上製造一顆太陽呢？

Can we bottle a star?

我們能否把星星裝進瓶子裡？

The Sun shines beacuse of nuclear fusion.

太陽的光來自核融合。

In a nutshell - fusion is a thermonuclear process,

簡而言之，核融合是一種熱核融合反應

meaning that the ingredients have to be incredibly hot, so hot,

這意味著材料一定要熱得不得了

that the atoms are stripped of their electrons,

熱到讓原子上的電子離家出走

making a plasma where nuclei and electrons

他們就變成電漿了，在電漿裡原子核和電子

bounce around freely.

會自由地彈跳。

Since nuclei are all positively charged, they repell each other.

由於原子核都帶正電，它們之間會相互排斥。

In order to overcome this repulsion

要克服這個斥力

the particles have to be going very, very fast.

該粒子必須動的非常非常快。

In this context, very fast means very hot:

在這種情況下，非常快的意思是「非常熱」：

millions of degrees.

好幾百萬度。

Stars cheat to reach these temperatures.

星星會作弊來達到這些溫度。

They are so massive, that the pressure in their cores

他們是如此龐大，在他們核心裡的壓力

generates the heat to squeeze the nuclei together

產生的熱會把原子核擠成一團

until they merge and fuse,

然後他們就融合在一起了

creating heavier nuclei and releasing energy in the process.

這樣會創造出較重的原子核，並在過程中釋放能量。

It is this energy release

正是這種能量的釋放

that scientists hope to harness

科學家想要採集的

in a new generation of power plant:

就在新型的發電廠

the fusion reactor.

也就是核融合反應爐裡。

On Earth, it's not feasible to use this brute-force method

在地球上，像太陽一樣使用暴力來產生融合

to create fusion.

是不可行的。

So if we want to build a reactor that generates energy from fusion,

因此，如果我們想建立從核融合產生能量的反應爐，

we have to get clever.

我們就要略施小計。

To date, scientists have invented two ways of making plasmas

迄今為止，科學家已經發明了兩種使電漿

hot enough to fuse:

熱到足以產生融合的方式：

The first type of reactor uses a magnetic field

第一類型的反應爐的使用磁場來

to squeeze a plasma in a donut-shaped chamber

把電漿擠壓在甜甜圈形狀的空間裡

where the reactions take place.

這裡面就會發生核反應。

These magnetic confinement reactors, such as the ITER reactor in France,

這些磁力可以約束反應爐，如法國的 I.T.E.R 反應爐

use superconducting electromagnets cooled with liquid helium

透過液態氦冷卻的超導體電磁鐵

to within a few degrees of absolute zero.

使其溫度被降到離絕對零度不到幾度。

Meaning they host some of the biggest temperature gradients in the known Universe.

這意味著裡面有已知的宇宙裡最大的溫差。

The second type, called inertial confinement,

第二類被稱為「慣性約束」，

uses pulses from superpowered lasers

使用超高能的雷射的脈衝

to heat the surface of a pellet of fuel,

來加熱燃料丸的表面

imploding it,

使其內爆，

briefly making the fuel hot and dense enough to fuse.

短暫使燃料夠熱、夠密到足以產生融合。

In fact,

事實上，

one of the most powerful lasers in the world

世界上最強大的雷射之一

is used for fusion experiments

正是用於核融合實驗，

at the National Ignition Facility in the US.

它位在美國的國家點火設施。

These experiments and others like them around the world

這些實驗以及其他世界各地的類似設施

are today just experiments.

到目前為止都還只是實驗。

Scientists are still developing the technology.

科學家們仍在開發這項科技。

And although they can achieve fusion,

雖然他們可以實現融合，

right now, it costs more energy to do the experiment

目前，做這實驗要花的電

than they produce in fusion.

比核融合產生的電還多。

The technology has a long way to go

這項科技還有很長的路要走

before it's commercially viable.

在有商業價值之前。

And maybe it never will be.

也許這永遠不會成功。

It might just be impossible to make a viable fusion reactor on Earth.

也許在地球上建造一個可行的核融合反應爐是不可能的。

But, if it gets there it will be so efficient,

但如果我們做到了，它的效能會非常高

that a single glass of sea water

比起一杯海水

could be used to produce as much energy as burning a barrel of oil,

就可以產生跟一桶油一樣多的能量，

with no waste to speak of.

而且不會產生廢氣。

This is because fusion reactors would use hydrogen or helium as fuel,

這是因為核融合反應爐會使用氫或氦作為燃料，

and sea water is loaded with hydrogen.

而海水有滿滿的氫。

But not just any hydrogen will do:

但不是任何的氫都可以用：

specific isotopes with extra neutrons, called deuterium and tritium,

必須使用具備額外中子的氫同位素，就是所謂的氘和氚

are needed to make the right reactions.

才能產生正確的反應。

Deuterium is stable and can be found in abundance in sea water,

氘是穩定的，在海水裡就可以找到很多，

though, tritium is a bit trickier.

不過氚有點難對付。

It's radioactive and there may only be twenty kilograms

它有放射性並且可能只有20公斤的氚

of it in the world, mostly in nuclear warheads

在世界各地，大多在核彈頭裡

which makes it incredibly expensive.

所以它非常昂貴。

So, we may need another fusion body for deuterium instead of tritium.

因此，我們需要氘的核融合好友，而不用氚。

Helium-3, an isotope of helium, might be a great substitute.

而是用氦的同位素，氦-3 它可能是一個很棒的替代品。

Unfortunately,

不幸的是，

it's also incedibly rare on Earth.

它在地球上極其稀少。

But here the Moon might have the answer.

但在月球這裡可能有答案。

Over billions of years,

幾十億年間，

the solar wind may have built up huge deposits

太陽風可能已經堆滿了

of helium-3 on the moon.

大量的氦-3 在月球上。

Instead of making helium-3, we can mine it.

我們不用親自生產氦-3，我們可以去挖掘它。

If we can sift the lunar dust for helium,

如果我們可以把月球塵埃過篩尋找氦，

we'd have enough fuel to power the entire world

那我們就會有足夠的燃料讓全世界

for thousands of years.

使用幾千年。

One more argument for establishing a moon base,

這是建立月球基地的又一個理由，

if you weren't convinced already.

如果你不支持月球基地的話。

Okay, maybe you think building a mini sun

好吧，也許你認為製造一個小型太陽

still sounds kind of dangerous.

聽起來有點危險。

But they'd actually be much safer than most other types of power plant.

但他們實際上比大多數其他類型的發電廠更安全。

A fusion reactor is not like a nuclear plant

核融合反應爐並不像普通的核電廠，

which can melt down catastrophically.

它不會災難性的融解。

If the confinement failed,

如果約束失敗了，

then the plasma would expand and cool and the reaction would stop.

那麼裡面的電漿將擴大並冷卻導致核反應停止。

Put simply, it's not a bomb.

簡單地說，它不會變成炸彈。

The release of radioactive fuel like tritium

放射性燃料的釋放，比如說氚

could pose a threat to the environment.

可能對環境造成威脅。

Tritium could bond with oxygen, making radioactive water

氚可以與和氧結合，產生有放射性的水

which could be dangerous as it seeps into the environment.

這可能是危險的，因為它會滲透到環境裡。

Fortunately, there's no more than a few grams of tritium

幸運的是，我們不會超過幾公克

in use at a given time,

每次使用的量，

so a leak would be quickly diluted.

所以洩漏物很快會被稀釋掉。

So we've just told you

所以，我們剛告訴你

that there's nearly unlimited energy to be had,

世界上有幾乎無限的能量

at no expense to the environment

又不必犧牲環境

in something as simple as water.

就存在在水裡。

So, what's the catch?

那麼，我們為什麼不用？

Cost.

答案是成本。

We simply don't know if fusion power will ever be commercially viable.

我們根本不知道核融合有沒有商業價值。

Even if they work, they might be too expensive to ever build.

即使有可能建造，它們可能貴到蓋不出來。

The main drawback is that it's unproven technology.

它的主要缺點是，它是未經驗證的技術。

It's a ten billion dollar gamble.

它是百億美元的豪賭。

And that money might be better spent on other clean energy

而這些錢用在其他已經證實可行的乾淨能源上

that's already proven itself.

可能會更好。

Maybe we should cut our losses.

也許我們應該現在收手不幹。

Or maybe,

又或許，

when the payoff is unlimited, clean energy for everyone,

當成果可以讓每個人 享有無限乾淨能源時，

it might be worth a risk?

這可能是值得冒險的？