如何移动太阳：恒星引擎：英语精读讲义

Nothing in the universe is static.

宇宙中没有什么是静止的。

In the Milky Way, billions of stars orbit the galactic center.

在银河系中，数十亿颗恒星围绕着银河系中心运转。

Some, like our sun, are pretty consistent,

有些恒星，比如我们的太阳，非常稳定，

keeping a distance of around 30,000 light years from the galactic center,

与银心保持着大约3万光年的距离，

completing an orbit every 230 million years.

每2.3亿年完成一次公转。

This dance is not an orderly ballet, 習語

这场舞蹈并非井然有序的芭蕾，

more like a skating rink filled with drunk toddlers.

而更像是一个挤满醉酒幼儿的溜冰场。

This chaos makes the galaxy dangerous.

这种混乱让银河系充满了危险。

Our solar neighborhood is constantly changing,

我们的太阳系邻居在不断变化，

with stars moving hundreds of kilometers every second.

恒星以每秒数百公里的速度移动。

Only the vast distances between objects

只有天体之间广阔的距离

protect us from the dangers out there.

才能保护我们免受外面的危险。

But we might get unlucky in the future.

但在未来，我们可能会倒霉。

At some point, we could encounter a star going supernova, 用詞

在某个时候，我们可能会遇到一颗爆发超新星的恒星，

or a massive object passing by

或者一个巨大的天体路过

and showering Earth with asteroids. 用詞

让地球下起小行星雨。

If something like this were to happen, 語法

如果真的发生这样的事，

we would likely know thousands, 表達脈絡

我们可能会提前几千年

if not millions of years in advance.

甚至几百万年知道。

But we still couldn't do much about it,

但我们仍然无能为力，

unless we move our whole solar system out of the way. 短語搭配

除非我们把整个太阳系移开。

To move the solar system,

要移动太阳系，

we need a Stellar Engine, 文化背景

我们需要一台恒星引擎，

a megastructure used to steer a star through the galaxy. 語法

这是一个用来驾驶恒星穿越星系的巨型结构。

It's the kind of thing that might be built by an advanced civilization

这大概是先进文明才会建造的东西，

with Dyson sphere level technology 文化背景

他们拥有戴森球级别的技术，

that's thinking about their future millions of years ahead of time. 短語搭配

并且在提前数百万年思考他们的未来。

But how do we possibly move the hundreds of thousands of objects in the solar system? 表達脈絡

但是，我们该如何移动太阳系中的数十万个天体呢？

The good news is, 表達脈絡

好消息是，

we can ignore all of that.

我们可以忽略所有那些东西。

We only need to move the sun.

我们只需要移动太阳。

All the other stuff is glued to it by gravity 習語

其他所有物质都被引力“粘”在太阳上，

and will follow it wherever it decides to go.

并且会跟随它去任何它决定去的地方。

There are lots of ideas about what a Stellar Engine might look like 語法

关于恒星引擎是什么样子，

and how it would work.

以及它如何运作，有很多想法。

We've picked two grounded in our current understanding of physics 短語搭配

我们基于当前的物理学认识挑选了两个，

that could be built in theory. 短語搭配

理论上可以建造。

The simplest kind of Stellar Engine is the Shkadov thruster, 文化背景

最简单的一种恒星引擎是什卡多夫推进器，

a giant mirror.

是一面巨大的镜子。

It works on the same principle as a rocket. 短語搭配

它的工作原理和火箭一样。

Like rocket fuel,

就像火箭燃料一样，

the photons released as solar radiation

作为太阳辐射释放的极少量光子

carry momentum.

带有动量。

Not a lot,

动量不大，

but a bit.

但有一点。

For example,

例如，

if an astronaut turned on a flashlight in space, 語法

如果宇航员在太空中打开手电筒，

it would push them backwards very very slowly.

它会非常、非常缓慢地把他们向后推。

A Stellar Engine will work a little better than a flashlight

恒星引擎的工作效果会比手电筒好一点，

because the sun produces a lot of photons.

因为太阳能产生大量光子。

The basic idea of the Shkadov thruster

什卡多夫推进器的基本理念

is to reflect up to half of the solar radiation 用詞

是反射多达一半的太阳辐射，

to create thrust and slowly push the sun where we want it to go.

从而产生推力，慢慢将太阳推向我们想去的地方。

In order for the Shkadov thruster to work, 語法

为了让什卡多夫推进器起作用，

it must be kept in the same place,

它必须保持在同一个地方，

not orbiting the sun.

而不是绕着太阳转。

Although the sun's gravity will try to pull it in,

尽管太阳的引力会试图将它拉过去，

it would be supported by radiation pressure, 用詞

但它会受到辐射压的支撑，

which props the mirror up. 短語動詞

辐射压支撑着这面镜子。

This means the mirror would have to be very light,

这意味着镜子必须非常轻，

made of micron thin

由微米级厚度的

reflecting foil

反射箔制成，

from materials like aluminum alloys.

材料可以是铝合金之类。

The mirror's shape is important, too.

镜子的形状也很重要。

Enveloping the sun in a giant spherical shell

用一个巨大的球壳包裹太阳

wouldn't work

是行不通的，

because that would refocus light back to the sun,

因为那会把光重新聚焦回太阳，

heating it up

让它升温，

and creating all sorts of unpleasant problems.

并造成各种令人不快的问题。

Instead,

相反，

we use a parabola,

我们使用抛物面，

which sends most of the photons around the sun

将大部分光子绕过太阳

and in the same direction,

射向同一个方向，

which maximizes thrust.

从而使推力最大化。

To prevent accidentally burning or freezing Earth

为了防止过强或过弱的阳光

with too much or too little sunlight, 語法

意外烤焦或冻结地球，

the only safe place to build a Shkadov thruster is over the sun's poles.

建造什卡多夫推进器唯一安全的地方是太阳两极上方。

This means we can only move the sun vertically

这意味着我们只能垂直移动太阳

in the plane of the solar system

在太阳系的平面内，

and one direction in the Milky Way,

以及在银河系中的一个方向，

which limits our travel options a bit.

这有点限制了我们的出行选择。

But that is basically it.

但基本上就是这样。

For a civilization capable of building a Dyson sphere,

对于有能力建造戴森球的文明来说，

this is a relatively simple endeavor.

这相对是一个简单的尝试。

Not complicated, 表達脈絡

并不复杂，

just very hard to build.

只是极难建造。

At full throttle, 用詞

在全功率运行下，

the solar system could probably be moved by about a 100 light years

太阳系大概可以移动100光年左右

over 230 million years.

在2.3亿年内。

Over a few billion years,

经过几十亿年，

it gives us near complete control over the sun's orbit in the galaxy.

它让我们几乎完全控制太阳在银河系中的轨道。

But in the short term,

但在短期内，

this might not be fast enough to dodge a deadly supernova.

这个速度可能不足以躲避致命的超新星。

That's why we thought we could do better.

这就是为什么我们认为我们可以做得更好。

So we asked our astrophysicist friend

于是我们问了我们的天体物理学家朋友，

if he could design a faster Stellar Engine for this video.

他是否能为这个视频设计一种更快的恒星引擎。

He did

他设计了，

and wrote a paper about it

并写了一篇论文，

that's been published in a peer-reviewed journal. 文化背景

发表在了一本同行评审的期刊上。

You can find it in our sources document.

你可以在我们的资料文档里找到它。

We're going to call at our new Stellar Engine the Caplan thruster.

我们要把这种新型恒星引擎叫做卡普兰推进器。

It works a lot like a traditional rocket.

它的工作方式非常像传统火箭。

Shoot exhaust one way 語法

往一个方向喷出废气

to push yourself the other.

就能向另一个方向推动自己。

It's a large space station platform

它是一个巨大的空间站平台，

powered by a Dyson sphere

由一个戴森球提供动力，

that gathers matter from the sun

该戴森球从太阳收集物质，

to power nuclear fusion.

为核聚变提供动力。

It shoots out a very fast jet of particles

它喷射出非常快的粒子流，

at nearly 1% the speed of light

以接近光速1%的速度，

out of the solar system.

飞出太阳系。

A second jet pushes the sun along like a tugboat. 習語

第二股射流像拖船一样推动太阳前进。

The Caplan thruster requires a lot of fuel,

卡普兰推进器需要大量燃料，

millions of tons per second.

每秒数百万吨。

To gather this fuel,

为了收集这些燃料，

our thruster uses very large electromagnetic fields

我们的推进器利用巨大的电磁场，

to funnel hydrogen and helium from the solar wind into the engine. 用詞

将太阳风中的氢和氦汇集到引擎中。

The solar wind alone doesn't provide enough fuel, though,

然而，仅靠太阳风无法提供足够的燃料，

and that's where the Dyson sphere comes in. 表達脈絡

于是戴森球派上了用场。

Using its power,

利用它的能量，

sunlight can be refocused to the surface of the sun.

阳光可以被重新聚焦到太阳表面。

This heats small regions to extreme temperatures,

这会将局部区域加热到极高温度，

lifting billions of tons of mass off the sun. 語法

使数十亿吨物质脱离太阳。

This mass can be collected and separated into hydrogen and helium.

这些物质可以被收集起来，分离成氢和氦。

The helium is burned explosively in thermonuclear fusion reactors. 用詞

氦在热核聚变反应堆里被爆炸性燃烧。

A jet of radioactive oxygen

一束放射性氧射流

at a temperature of nearly a billion degrees

带着近十亿度的高温

is expelled and becomes our primary source of propulsion

被排出，并成为我们主要推进力来源，

from our Stellar Engine.

来自我们的恒星引擎。

To prevent the engine from just crashing into the sun, 語法

为了防止引擎直接坠入太阳，

it needs to balance itself.

它需要保持平衡。

To do this,

为了做到这一点，

we accelerate the collected hydrogen with electromagnetic fields

我们用电磁场加速收集到的氢，

using particle accelerators

使用粒子加速器，

and shoot a jet back at the sun.

然后向太阳发射回一股射流。

This balances the thruster

这能平衡推进器，

and transfers the thrust of our engine

并把我们引擎的推力

back to the sun.

传递回太阳。

In as little as a million years, 短語搭配

仅仅只需一百万年，

this engine can move the sun by 50 light years,

这种引擎就可以把太阳移动50光年，

more than enough to dodge a supernova. 語法

这完全足够躲避超新星了。

At full throttle,

在全功率下，

the solar system can be completely redirected

太阳系可以被完全重定向

in its galactic orbit

在其银河轨道上，

in 10 million years.

用时一千万年。

But wait, 表達脈絡

但等等，

will we use up the sun this way?

这样会消耗完太阳吗？

Fortunately,

幸运的是，

the sun is so massive 語法

太阳质量如此之大，

that even billions of tons of material

以至于即便是几十亿吨的物质，

will barely scratch the surface. 習語

也只不过是九牛一毛。

In fact,

事实上，

this megastructure will actually extend our sun's life

这个巨型结构实际上会延长太阳的寿命，

since lower mass stars burn slower,

因为质量较小的恒星燃烧得更慢，

keeping the solar system inhabitable

让太阳系保持适宜居住的状态

for many more billions of years.

再延续几十亿年。

With a Caplan thruster,

有了卡普兰推进器，

we could turn the entire solar system

我们就可以把整个太阳系

into our spaceship.

变成我们的宇宙飞船。

For example,

例如，

by orbiting backwards in the galaxy

通过在银河系中逆向运行，

and colonizing hundreds or thousands of stars

并在经过数以千计的恒星时

as we pass by them.

殖民它们。

It may even be possible to escape the galaxy entirely

甚至有可能完全逃离星系，

and expand beyond the Milky Way.

并向银河系外扩张。

Stellar engines are the kind of machines built by civilizations

恒星引擎是那种高级文明才会建造的机器，

thinking not in terms of years or decades, 語法

他们的考量不以年或十年为单位，

but eons.

而是以万古为单位。

Since we know that our sun will die one day,

既然我们知道太阳终有一天会死亡，

a Stellar Engine could allow the far future descendants of humans

一台恒星引擎或许能让人类遥远未来的后代

to travel to other stars

去往其他恒星，

without ever having to venture into the terrifying dark abyss 語法

而永远不必冒险进入可怕的黑暗深渊

of interstellar space.

在那星际空间之中。

Until we build a Stellar Engine,

在我们建造出恒星引擎之前，

we're adrift and subject to the whims of the galactic sea. 習語

我们只能随波逐流，受制于银河之海的变幻莫测。

We may not like where it leads us.

我们可能不喜欢它带我们去的地方。

Maybe our descendants will set sail

也许我们的后代会扬帆起航，

and become an interstellar species

成为一个星际物种

for millions of years to come.

在未来的几百万年里。

This was our last video for the year 12,019 of the human era. 文化背景

这是我们在人类纪元12019年的最后一个视频。

And what a year it was. 語法

真是令人难忘的一年。

So much stuff happened everywhere,

到处都发生了好多事情，

to so many different people.

发生在那么多不同的人身上。

Calendars and holidays are just imaginary,

日历和假期都只是想象出来的，

but they help us to cut our lives into pieces 習語

但它们帮助我们把生活切成小块，

that our brains can handle.

让我们的脑袋更容易处理。

We're leaving 12,019 behind with a weird mixture of disillusion

我们正在把12019年抛在脑后，带着一种奇怪的、混合着幻灭

and hope.

与希望的心情。

The world is screwed up, 用詞

这个世界搞砸了，

but we can fix it.

但我们可以修复它。

In a few days,

几天之后，

this year will be over

这一年就结束了，

and we'll get to try again. 語法

我们又有了重新尝试的机会。

Thank you for watching our videos

感谢您观看我们的视频，

and for sticking around for so many years. 短語動詞

感谢您这么多年来的陪伴。

See you all in 12,020.

我们12020年再见。