How humanity can reach the stars | Philip Lubin

翻译人员: Justin Li 校对人员: Yolanda Zhang

We're here at the University of California, Santa Barbara

这里是利福尼亚大学 圣巴巴拉分校,

to discuss a dream of humanity:

接下来，我们会共同讨论 一个全人类的梦想：

the ability to exit our solar system

离开我们的太阳系,

and enter another solar system.

进入另一个太阳系。

And the solution is literally before your eyes.

解决方案实际上就在我们的眼前。

So I have two things on me that you have -- I have a watch,

我身上有两件东西，你们也有：

and I have a flashlight,

一块手表，和一个手电筒,

which, if it's not on you, it's on your phone.

至少在你们的手机上 都可以找到。

So the watch keeps time,

手表用来查看时间，

and my flashlight just illuminates my environment.

手电筒则可以照亮 我周围的环境。

So like art, to me, science is illuminating.

就像艺术一样，对我而言， 科学就是一盏明灯。

I want to see reality in a different way.

我想以不同的方式看待现实。

When I turn on the flashlight,

当我打开手电筒时,

suddenly the dark becomes bright, and I suddenly see.

周围立刻就变得明亮起来， 视野也开阔了。

The flashlight and its light,

你可以看到,

which you can see coming out --

手电筒发出的光——

the light on my hand is not only illuminating my hand,

我手上的光不仅照亮了我的手，

it's actually pushing on my hand.

它实际上也推动着我的手。

Light carries energy and momentum.

光伴随着能量和动量。

So the answer is not to make a spacecraft out of a flashlight,

所以答案并不是 要用手电筒制作宇宙飞船，

by having the exhaust come out this way

而是要让光 以这种方式产生推力，

而航天器以这种方式移动——

and the spacecraft goes that way --

that's what we do today with chemistry.

就是我们今天 用化学燃料所实现的。

The answer is this:

答案是这样的：

Take the flashlight and put it somewhere on the Earth,

将手电筒放在地球上的某个地方,

in orbit or on the Moon,

在轨道或月球上，

and then shine it on a reflector,

然后将其照射在反射器上，

which propels the reflector to speeds which can approach the speed of light.

从而推动反射器， 让其能够以接近光速移动。

Well, how do you make a flashlight that's big enough?

那么问题来了, 如何做出足够大的手电筒?

很明显，我手里的手电筒 起不到什么效果，

This isn't going to do it,

my hand doesn't seem to be going anywhere.

我的手也没有感受到任何推力。

那是因为这股力量非常非常小,

And that's because the force is very, very low.

那么解决此问题的方法就是,

So the way that you can solve this problem

采用许多激光手电筒，

is taking many, many flashlights, which are actually lasers,

and synchronizing them in time,

并及时进行同步。

and when you gang them all together into a gigantic array,

当将它们组合成 一个巨大的阵列，

which we call a phased array,

我们称之为“相控阵”,

you then have a sufficiently powerful system,

于是就有了一个足够强大的系统。

which, if you make it roughly the size of a city,

如果把它做成一个城市的大小，

it can push a spacecraft, which is roughly the size of your hand,

它就可以将一个 手掌大小的航天器

to speeds which are roughly 25 percent the speed of light.

以大约 25% 的光速推向天空。

That would enable us to get to the nearest star, Proxima Centauri,

这将使我们能够 在不到 20 年的时间内

which is a little over four light years away,

到达离我们只有 4 光年多一点的

in less than 20 years.

最近的恒星， 比邻星（Proxima Centauri）。

Initial probes would be roughly the size of your hand,

最初的探针大约是手掌的大小,

and the size of the reflector that you're going to use

而所使用的反射器

is going to be roughly human size,

大约是一个人的大小，

so not a whole lot larger than myself,

所以不会比我大很多,

but a few meters in size.

大概几米。

It only uses the reflection of light from this very large laser array

它仅使用来自这个非常大的 激光器阵列所反射的光

to propel the spacecraft.

来推动航天器。

So let's talk about this.

打个比方，

This is a lot like sailing on the ocean.

这就像在海上航行。

When you sail on the ocean, you're pushed by the wind.

当我们在海上航行时，

And the wind then drives the sail forward through the water.

会被风推动着前进,

In our case, we're creating an artificial wind in space

在我们的例子中， 我们是在通过激光器阵列,

from this laser array,

在空间中创建人造风,

except the wind is actually the photons from the laser itself,

只不过这里的“风” 实际上是激光器本身的光子，

the light from the laser becomes the wind

来自激光器的光变成了

upon which we sail.

吹动船帆的风。

It is a very directed light --

它是定向性非常好的光——

it's often called directed energy.

通常被称为“定向能量”。

So why is this possible today,

那么，为什么今天 这一切成为了可能呢?

why can we talk about going to the stars today,

为什么我们在今天 可以讨论太空旅行了呢?

when 60 years ago,

然而 60 年前,

when the space program began in earnest,

当太空计划刚启动时，

people would have said, "That's not possible"?

人们会说：“那不可能。”

Well, the reason it's possible today has a lot to do with the consumer,

然而今天，这一切之所以成为了可能， 与消费者有着很大的关系，

and the very fact that you're watching me.

具体来说， 就是你们观看视频的行为。

You're watching me over a high-speed internet,

你们正通过高速互联网 收看这段视频，

which is dominated by the photonics of sending data over fiber optics.

这项技术是由通过光纤 传输数据的光子学主导的。

Photonics essentially allow the internet to exist

从本质上说，有了光子学,

in the way it does today.

今天的互联网才得以存在。

The ability to send vast amounts of data very quickly

快速发送大量数据的能力,

is the same technology that we're going to use

与我们将要用来

to send spacecraft very quickly to the stars.

将航天器快速发射到 恒星的技术大同小异。

You effectively have an infinite supply of propellent,

你们实际上已经拥有了 无限量的推进剂，

you can turn it on and off as needed.

可以根据需要开启和关闭。

You do not leave the laser array that produces the light on

我们不会在整个行程中

都让激光阵列保持开启的状态。

for the entire journey.

For small spacecraft, it's only on for a few minutes,

对于小型航天器， 只需要开启几分钟，

and then it's like shooting a gun.

就能如同开枪一般 把航天器发射出去。

You have a projectile which just moves ballistically.

航天器会按照预定轨道飞行。

Even if we, as humans, are not on the spacecraft,

即使人类不在太空飞船上，

at least we have the ability to send out such spacecraft.

至少我们也有能力 发射这种太空飞船。

You want to remotely view,

我们可以对一个对象

or have remote imaging and remote sensing,

进行远程监控，

或远程成像和遥感。

of an object.

So when we go to Jupiter, for example,

那么，假如当我们带着飞行任务

with a flyby mission,

前往木星时，

we are taking pictures of Jupiter,

我们可以为木星拍照，

we're measuring the magnetic field,

测量磁场

the particle density,

和粒子密度，

and we're basically exploring remotely.

基本上都是在进行远程探索。

The same way that you are looking at me.

这就跟你们 在线观看这个视频一样。

And all of the current missions that are beyond the Moon

目前，除月球以外的所有任务

are remote-sensing missions.

都是遥感任务。

What would we hope to find if we visited an exoplanet?

如果我们拜访了系外行星， 我们希望找到什么？

Perhaps there's life on an exoplanet,

也许系外行星上会有生命，

and we would be able to see evidence of life,

我们将能够通过大气生物特征

either through atmospheric biosignatures

或动态的画面

or through, you know, a dramatic picture,

观察到生命存在的证据，

we would be able to see something actually on the surface.

我们将能够看到 星球表面的情况。

We don't know if there's life elsewhere in the universe.

我们不知道宇宙中 是否还有其他生命。

Perhaps on the missions that we send out, we will find evidence for life,

也许在我们执行的任务中， 我们会找到生命的证据，

perhaps we will not.

也许不会。

And while economics may seem like an inappropriate thing

尽管把经济学理论应用在 星际探索能力方面

to bring into a talk on interstellar capability,

有些不妥，

it is in fact one of the driving issues in achieving interstellar capability.

但实际上，这是实现 星际探索能力的驱动因素之一。

You have to get things to the point where they're economically affordable

我们必须在经济 可以承受的范围内

to do what we want to do.

去做我们想做的事。

So currently,

现在,

we have systems in the lab

我们实验室中的系统

which have achieved the ability to synchronize over very large scales,

已经实现了 大空间内的同步能力，

out to about 10 kilometers or roughly six miles.

能够达到大约 10 公里 或 6 英里的空间范围。

We've been able to achieve synchronization of laser systems,

我们已经能够实现激光系统的同步，

and it's worked beautifully.

并且效果很好。

We've known how to build lasers for many decades,

我们几十年前就已经 知道如何制造激光器了,

but it's only now that the technology has gotten inexpensive enough,

但是现在这项技术 已经变得足够便宜，

and become mature enough

并且足够成熟，

that we can imagine having huge arrays, literally,

让我们得以想象 如何构建巨大的、

kilometer-scale arrays, much like solar farms,

可以达到公里规模的阵列， 就像太阳能电站一样，

but instead of receiving light, they transmit light.

但是不会接收光，只会透射光。

The beauty of this type of technology is it enables many applications,

这种技术的优点在于 它可以实现许多应用，

not just relativistic flight for small spacecraft,

不仅适用于 小型航天器的相对论飞行,

but enables high-speed spacecraft,

还可以支持高速航天器

high-speed flight in our solar system,

在太阳系中的高速飞行,

it enables planetary defense,

实现行星防御、

it enables space debris removal,

空间碎片清除，

it enables powering of distant assets that we may want to send power to,

还可以为我们的 远距离资产提供电力，

such as spacecraft or bases on the Moon or other places.

例如月球或其他地方的 航天器和基地。

It's an extremely versatile technology,

这是一项极为灵活的技术，

it's something that humanity would want to develop

也是人类想要研发的东西，

even if they didn't want to send spacecraft to the stars,

即使人类并不想 将航天器送入星际空间，

because that technology allows so many applications

因为该技术能够许多

that are currently not feasible.

目前不可行的应用变成现实。

And therefore, I feel it's an inevitable technology,

因此，我认为这是 一种不可避免的技术，

because we have the ability,

因为我们有能力，

we just need to fine-tune the technology

只需要对技术进行微调，

and in a sense, wait for economics to catch up with us

并且在某种意义上， 等经济变得更发达，

so that it becomes cheap enough to build the large systems.

成本降低到足以构建大型系统。

The smaller systems are affordable now.

目前，小型系统的造价 还是可以承受的，

And we've already started building prototype systems in our lab.

而且我们已经开始 在实验室中构建原型系统。

So while it's not going to happen tomorrow,

因此，尽管现在还不能做到 一觉醒来，美梦成真，

we've already begun the process,

但我们已经迈出了第一步，

and so far, it's looking good.

到目前为止，进展还算顺利。

This is both a revolutionary program,

就变革性技术而言，

in terms of being a transformative technology,

这既是一个革命性的项目，

but it's also an evolutionary program.

也是一个有进化意义的项目。

So personally, I do not expect to be around

就我个人而言， 我不认为此生能有幸看到

when the first relativistic flight happens.

第一次相对论飞行实现的那一天。

I think that's probably 30-plus years off before we get to that point,

我认为距达到这一目标 可能还要 30 多年的时间,

and perhaps more.

甚至更久。

But what inspires me

但让我备受鼓舞的是

is to look at the ability to achieve the final goal.

可以预见能够达到 最终目标的能力。

Even if it does not happen in my lifetime,

就算我这代人赶不上那一天，

it can happen in the lifetime of the next generation

下一代人也会见证那一刻，

or the generation beyond that.

或者再往后的一代人。

The consequences are so transformative

这种成果具有 极其深远的变革意义，

that we literally, in my opinion, must go down this path,

在我看来， 我们必须沿着这条路走下去，

and must explore what the limitations are,

必须探索局限性是什么，

and then how do we overcome the limitations.

然后如何克服这些局限性。

The search for life on other planets

在其他星球上寻找生命

would be one of humanity's foremost explorations,

将是人类最重要的探索之一,

and if we're able to do so,

如果我们能够做到，

and actually find life on another planet,

并且的确 在另一个星球上找到了生命，

it would change humanity forever.

就将永远改变人类。

Everything is profound in life.

生命中的每一件事 都有其深刻的意义。

If you look deep enough,

如果你观察得足够深入，

you'll find something incredibly complex and interesting and beautiful in life.

就会发现生活中令人难以置信的 复杂、有趣和美丽的事物。

And the same is true with the lowly photon

我们每天接触到的微小的光子

that we use to see every day.

也是如此。

But when we look outside and we imagine something vastly greater,

但是当我们把目光投向外太空， 同时想象一番更广阔的天地，

an array of lasers that are synchronized,

一个同步的激光阵列，

we could imagine things which are just extraordinary in life.

我们就可以想象到 生活中那些非同寻常的事物。

And the ability to go to another star

而去往另一颗星球的能力,

is one of those extraordinary capabilities.

就是这种非凡的能力之一。

(Birds chirping)

（鸟鸣）