How humanity can reach the stars | Philip Lubin

譯者: Yunchi Hsu 審譯者: Amanda Zhu

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

現在，我們在加利福尼亞大學 聖塔芭芭拉分校

to discuss a dream of humanity:

來討論人類的一個夢想：

the ability to exit our solar system

發展出足以讓我們從太陽系出發，

and enter another solar system.

並進入到另外一個太陽系的能力。

And the solution is literally before your eyes.

而其解決方案其實就近在你的眼前。

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

我身上有兩樣你也有的東西—— 我有一支手錶，

and I have a flashlight,

還有一支手電筒，

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

如果這些都不在你身上的話， 你的手機裡也能找到這些功能。

So the watch keeps time,

於是，手錶負責計時，

and my flashlight just illuminates my environment.

而我的手電筒就負責 照亮我的環境周遭。

So like art, to me, science is illuminating.

所以，就像藝術，對我來說， 科學就像是一支照亮黑暗的手電筒。

I want to see reality in a different way.

我想要以不同的角度發現真實。

When I turn on the flashlight,

當我打開手電筒，

suddenly the dark becomes bright, and I suddenly see.

黑暗瞬間變成光明，我突然看得見了。

The flashlight and its light,

如你在這邊所見的，

which you can see coming out --

手電筒和其發射出的光線——

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

這光點不只是照亮了我的手，

it's actually pushing on my hand.

其實它也正在施力推我的手。

Light carries energy and momentum.

光，是帶有能量與動量的。

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

所以答案並不是要用手電筒 來製造一艘太空船，

by having the exhaust come out this way

讓氣體從這一端噴射出來，

而太空船就朝著另一端前進——

and the spacecraft goes that way --

that's what we do today with chemistry.

這是目前我們以化學進行的方法。

The answer is this:

真正的解答是這樣子的：

Take the flashlight and put it somewhere on the Earth,

將手電筒放在地球上的某處，

在地球的軌道上或是月球，

in orbit or on the Moon,

and then shine it on a reflector,

然後，對著一個反光器照射，

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

手電筒便推進反光器加速， 達到接近光速的速度。

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

那你要怎麼製造出 一個夠大的手電筒呢？

這看起來行不通啊，

This isn't going to do it,

我的手看起來又沒有移動。

my hand doesn't seem to be going anywhere.

那是因為這個推進力非常、非常的弱。

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

所以，解決這問題的方法

So the way that you can solve this problem

是將很多、很多個的手電筒 ──其實它們就是雷射光──

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

and synchronizing them in time,

並及時將它們同步化，

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

而當你將它們都聚集成 一個巨大的陣列時，

which we call a phased array,

——我們稱作它為「相位陣列」——

you then have a sufficiently powerful system,

你便有了一個足夠強大的系統，

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

如果你把它變成大約 相當於一個城市的尺寸，

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

它便能推動一艘大概 相當於手掌大小的太空船，

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

並且它能達到 約光速的四分之一的速度。

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

這艘船可以抵達最近的恆星， 也就是半人馬座的比鄰星，

which is a little over four light years away,

距離我們四光年多一點，

in less than 20 years.

花不到 20 年的時間就可以抵達。

Initial probes would be roughly the size of your hand,

最初使用的探測器 大概相當於你的手掌的大小，

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

而所使用的反光器

is going to be roughly human size,

大概會相當於一個人身體的大小，

so not a whole lot larger than myself,

所以不會比我大上多少，

but a few meters in size.

就只有幾公尺的大小而已。

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

它只利用從這個巨大的雷射陣列 所發出的光的反射

to propel the spacecraft.

來推動太空船前進。

So let's talk about this.

所以，我們來談談。

This is a lot like sailing on the ocean.

這就像是在海上航行一樣。

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

當你在海上航行時，你被風推著前進，

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

而風推動船帆在水中前進。

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

就我們的情況而言， 我們正是用這個雷射光陣列

from this laser array,

在太空中製造那種推進力，

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

來自於雷射光的光子 其實就相當於推進帆船的風，

the light from the laser becomes the wind

雷射發出的光線變成相當於風的作用，

upon which we sail.

讓我們用以航行。

It is a very directed light --

它是一種固定導向的光——

it's often called directed energy.

它常常被稱作為「導能」。

So why is this possible today,

所以，為什麼這答案 在今天是可行的呢？

why can we talk about going to the stars today,

為什麼今日我們可以談論航向星際，

when 60 years ago,

而在 60 年前，

when the space program began in earnest,

也是太空計畫發軔的年代，

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

大家會說「這是不可能的」呢？

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

今日這得以實現的理由， 與消費者有很大的關係，

and the very fact that you're watching me.

以及你現在正在看著我演講也有關。

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

你正在透過高速的網路看我演講，

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

而高速網路是由透過光纖傳送資料的 光子學技術來主導的。

Photonics essentially allow the internet to exist

光子學技術在本質上讓網路

in the way it does today.

得以今日的形式存在。

The ability to send vast amounts of data very quickly

這個能夠快速地傳送 大量的資料的能力，

is the same technology that we're going to use

和我們今日打算用來 將太空船快速地航向星際

to send spacecraft very quickly to the stars.

採用的是同樣的技術。

You effectively have an infinite supply of propellent,

你其實可以擁有無限的推進燃料供給，

you can turn it on and off as needed.

你可以視需要打開或關閉，

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

在航程中，你不需要將 產生出光線的雷射陣列

for the entire journey.

一直保持在打開的狀態。

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

對於一個小型太空船而言， 你只要將光線打開幾分鐘，

and then it's like shooting a gun.

然後，就像是用槍 發射出一顆子彈一樣，

You have a projectile which just moves ballistically.

它就會飛快地沿著彈道飛行。

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

即便我們人類不坐在太空船上，

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

至少我們有能力 將這種太空船送到宇宙中。

You want to remotely view,

你會需要在遠端觀看，

or have remote imaging and remote sensing,

或使用遠端遙控成像與感測技術，

of an object.

來觀察物體。

So when we go to Jupiter, for example,

所以，舉個例子，當我們前往木星，

with a flyby mission,

進行飛掠任務，

we are taking pictures of Jupiter,

我們拍木星的照片，

we're measuring the magnetic field,

測量它的磁場、

the particle density,

粒子的密度、

and we're basically exploring remotely.

而我們基本上是在遠端遙控探索。

The same way that you are looking at me.

就跟你正在看著我是同一回事。

And all of the current missions that are beyond the Moon

而且目前比月球還遙遠的所有任務，

are remote-sensing missions.

都是遠端遙控感測的任務。

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

那如果我們造訪一顆系外行星， 我們希望能找到什麼呢？

Perhaps there's life on an exoplanet,

或許在那顆系外行星上 會有生命的存在，

and we would be able to see evidence of life,

而我們就會找到生命存在的證據，

either through atmospheric biosignatures

無論是透過大氣中的生物標記

or through, you know, a dramatic picture,

或者是透過一張意想不到的照片，

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

讓我們會真正在地表上看到一些什麼。

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

我們並不知道與宇宙中 是否還有其他生命。

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

或許在我們所分派的任務過程中， 我們能找到生命存在的證據，

perhaps we will not.

或許我們不會找到。

And while economics may seem like an inappropriate thing

而當我們討論星際任務的可能性時，

to bring into a talk on interstellar capability,

經濟狀況的話題 似乎不適合拿出來一起討論，

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

但它其實正是實現星際任務的 其中一個驅動因素。

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

你必須要讓這些技術夠經濟實惠，

to do what we want to do.

我們才能應用。

So currently,

所以現在，

we have systems in the lab

我們在實驗室裡建造了一個系統，

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

它已經能夠在巨大的規模上 進行同步化，

out to about 10 kilometers or roughly six miles.

規模大約是十公里，或是六英里左右。

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

我們已經達成雷射光系統的同步化，

and it's worked beautifully.

而且運作得好極了。

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

我們知道如何建造雷射裝置 已經好幾十年了，

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

現在只需要等待這個技術 變得不那麼昂貴，

and become mature enough

而且變得更加成熟，

that we can imagine having huge arrays, literally,

屆時我們才有可能使用巨大的陣列，

kilometer-scale arrays, much like solar farms,

公里級規模的陣列， 就像是太陽能發電廠一樣，

but instead of receiving light, they transmit light.

但並不是接收光線，而是發射光線。

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

這種技術的美妙之處 就是它可以發展出眾多其他的應用，

not just relativistic flight for small spacecraft,

不只是用來做 小型太空船的相對論飛行，

but enables high-speed spacecraft,

也可以使高速太空船得以

high-speed flight in our solar system,

在我們的太陽系中進行高速飛行，

it enables planetary defense,

這技術讓行星防禦得以可能，

it enables space debris removal,

能夠進行太空垃圾的清除，

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

它能夠讓我們為需要充電的 遠端資產傳送能量，

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

像是太空船，或位於月球上 或其他地方上的基地。

It's an extremely versatile technology,

它是一個用途非常廣泛的科技。

it's something that humanity would want to develop

即使人類並不打算送太空船航向星空，

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

還是會希望發展這樣的科技，

because that technology allows so many applications

因為這項科技能夠讓我們發展出

that are currently not feasible.

現在做不到的許多用途

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

因此，我認為這是一項 必然會發展的科技，

because we have the ability,

因為我們有這項能力，

we just need to fine-tune the technology

我們只需要對這技術進行微調，

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

並且等到經濟發展足以跟上來。

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

到那時候，技術變得足夠便宜， 以建造出大型的系統。

The smaller systems are affordable now.

我們已經負擔得起小型系統了，

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

而我們也已經開始在實驗室裡 建造雛形的系統了。

So while it's not going to happen tomorrow,

儘管不是明天就可以實現，

we've already begun the process,

但我們已經開始一段時間，

and so far, it's looking good.

而且，到目前為止， 看起來發展得不錯。

This is both a revolutionary program,

在變革性的技術方面，

in terms of being a transformative technology,

這是個革命性的計畫，

but it's also an evolutionary program.

但它又是一個漸進性的計畫。

So personally, I do not expect to be around

因此，我個人可能活不到目睹

when the first relativistic flight happens.

第一次相對論飛行實現的時刻。

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

我想，在我們發展到那個地步之前 還需要花 30 年的時間，

and perhaps more.

可能甚至還要更久。

But what inspires me

但是真正啟發我的是

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

能夠看見這項科技達成終極的目標，

Even if it does not happen in my lifetime,

即便在我這輩子並不會實現，

it can happen in the lifetime of the next generation

它可能在下一代的有生之年中成真，

or the generation beyond that.

或是要等到再下一代。

The consequences are so transformative

它的結果是如此地具有變革性，

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

所以我認為我們必須往這條路上走，

and must explore what the limitations are,

並且必須去探索其限制為何，

and then how do we overcome the limitations.

以及接下來我們該如何克服那些限制。

The search for life on other planets

在其他行星上尋找生命

would be one of humanity's foremost explorations,

會是人類最意義深遠的探索之一，

and if we're able to do so,

而如果我們有能力去做到，

and actually find life on another planet,

並且真的在另外一顆行星上找到生命，

it would change humanity forever.

那將會徹底改變人類的命運。

Everything is profound in life.

生命中的每一件事物都是深奧的，

If you look deep enough,

如果你看得足夠深入，

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

你就會在生命中找到 極其複雜、有趣且美麗的事物。

And the same is true with the lowly photon

而同樣的道理也適用在

that we use to see every day.

我們每天隨處可見、 微不足道的光子上。

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

但是當我們向外看， 並想像更廣、更大的東西，

an array of lasers that are synchronized,

像是同步化的雷射陣列，

we could imagine things which are just extraordinary in life.

我們能夠發想出令人意想不到的事物，

And the ability to go to another star

而能夠航向另外一顆星球的能力

is one of those extraordinary capabilities.

就是其中一個非凡的潛能。

(Birds chirping)

(鳥叫聲)