to discuss a dream of humanity:

現在，我們在加利福尼亞大學 聖塔芭芭拉分校

the ability to exit our solar system

來討論人類的一個夢想：

and enter another solar system.

發展出足以讓我們從太陽系出發，

And the solution is literally before your eyes.

並進入到另外一個太陽系的能力。

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

而其解決方案其實就近在你的眼前。

and I have a flashlight,

我身上有兩樣你也有的東西—— 我有一支手錶，

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

還有一支手電筒，

So the watch keeps time,

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。

and my flashlight just illuminates my environment.

於是，手錶負責計時，

So like art, to me, science is illuminating.

而我的手電筒就負責 照亮我的環境周遭。

I want to see reality in a different way.

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。

When I turn on the flashlight,

我想要以不同的角度發現真實。

suddenly the dark becomes bright, and I suddenly see.

當我打開手電筒，

The flashlight and its light,

黑暗瞬間變成光明，我突然看得見了。

which you can see coming out --

如你在這邊所見的，

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

手電筒和其發射出的光線——

it's actually pushing on my hand.

這光點不只是照亮了我的手，

Light carries energy and momentum.

其實它也正在施力推我的手。

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

光，是帶有能量與動量的。

by having the exhaust come out this way

所以答案並不是要用手電筒 來製造一艘太空船，

and the spacecraft goes that way --

讓氣體從這一端噴射出來，

that's what we do today with chemistry.

而太空船就朝著另一端前進——

The answer is this:

這是目前我們以化學進行的方法。

Take the flashlight and put it somewhere on the Earth,

真正的解答是這樣子的：

in orbit or on the Moon,

將手電筒放在地球上的某處，

and then shine it on a reflector,

在地球的軌道上或是月球，

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

然後，對著一個反光器照射，

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

手電筒便推進反光器加速， 達到接近光速的速度。

This isn't going to do it,

那你要怎麼製造出 一個夠大的手電筒呢？

my hand doesn't seem to be going anywhere.

這看起來行不通啊，

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

我的手看起來又沒有移動。

So the way that you can solve this problem

那是因為這個推進力非常、非常的弱。

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

所以，解決這問題的方法

and synchronizing them in time,

是將很多、很多個的手電筒 ──其實它們就是雷射光──

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

並及時將它們同步化，

which we call a phased array,

而當你將它們都聚集成 一個巨大的陣列時，

you then have a sufficiently powerful system,

——我們稱作它為「相位陣列」——

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

你便有了一個足夠強大的系統，

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

如果你把它變成大約 相當於一個城市的尺寸，

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

它便能推動一艘大概 相當於手掌大小的太空船，

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

並且它能達到 約光速的四分之一的速度。

which is a little over four light years away,

這艘船可以抵達最近的恆星， 也就是半人馬座的比鄰星，

in less than 20 years.

距離我們四光年多一點，

Initial probes would be roughly the size of your hand,

花不到 20 年的時間就可以抵達。

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

最初使用的探測器 大概相當於你的手掌的大小，

is going to be roughly human size,

而所使用的反光器

so not a whole lot larger than myself,

大概會相當於一個人身體的大小，

but a few meters in size.

所以不會比我大上多少，

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

就只有幾公尺的大小而已。

to propel the spacecraft.

它只利用從這個巨大的雷射陣列 所發出的光的反射

So let's talk about this.

來推動太空船前進。

This is a lot like sailing on the ocean.

所以，我們來談談。

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

這就像是在海上航行一樣。

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

當你在海上航行時，你被風推著前進，

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

而風推動船帆在水中前進。

from this laser array,

就我們的情況而言， 我們正是用這個雷射光陣列

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

在太空中製造那種推進力，

the light from the laser becomes the wind

來自於雷射光的光子 其實就相當於推進帆船的風，

upon which we sail.

雷射發出的光線變成相當於風的作用，

It is a very directed light --

讓我們用以航行。

it's often called directed energy.

它是一種固定導向的光——

So why is this possible today,

它常常被稱作為「導能」。

why can we talk about going to the stars today,

所以，為什麼這答案 在今天是可行的呢？

when 60 years ago,

為什麼今日我們可以談論航向星際，

when the space program began in earnest,

而在 60 年前，

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

也是太空計畫發軔的年代，

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

大家會說「這是不可能的」呢？

and the very fact that you're watching me.

今日這得以實現的理由， 與消費者有很大的關係，

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

以及你現在正在看著我演講也有關。

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

你正在透過高速的網路看我演講，

Photonics essentially allow the internet to exist

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。

in the way it does today.

光子學技術在本質上讓網路

The ability to send vast amounts of data very quickly

得以今日的形式存在。

is the same technology that we're going to use

這個能夠快速地傳送 大量的資料的能力，

to send spacecraft very quickly to the stars.

和我們今日打算用來 將太空船快速地航向星際

You effectively have an infinite supply of propellent,

採用的是同樣的技術。

you can turn it on and off as needed.

你其實可以擁有無限的推進燃料供給，

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

你可以視需要打開或關閉，

for the entire journey.

在航程中，你不需要將 產生出光線的雷射陣列

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

一直保持在打開的狀態。

and then it's like shooting a gun.

對於一個小型太空船而言， 你只要將光線打開幾分鐘，

You have a projectile which just moves ballistically.

然後，就像是用槍 發射出一顆子彈一樣，

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

它就會飛快地沿著彈道飛行。

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

即便我們人類不坐在太空船上，

You want to remotely view,

至少我們有能力 將這種太空船送到宇宙中。

or have remote imaging and remote sensing,

你會需要在遠端觀看，

of an object.

或使用遠端遙控成像與感測技術，

So when we go to Jupiter, for example,

來觀察物體。

with a flyby mission,

所以，舉個例子，當我們前往木星，

we are taking pictures of Jupiter,

進行飛掠任務，

we're measuring the magnetic field,

我們拍木星的照片，

the particle density,

測量它的磁場、

and we're basically exploring remotely.

粒子的密度、

The same way that you are looking at me.

而我們基本上是在遠端遙控探索。

And all of the current missions that are beyond the Moon

就跟你正在看著我是同一回事。

are remote-sensing missions.

而且目前比月球還遙遠的所有任務，

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

都是遠端遙控感測的任務。

Perhaps there's life on 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？

and we would be able to see evidence of life,

或許在那顆系外行星上 會有生命的存在，

either through atmospheric biosignatures

而我們就會找到生命存在的證據，

or through, you know, a dramatic picture,

無論是透過大氣中的生物標記

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

或者是透過一張意想不到的照片，

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

讓我們會真正在地表上看到一些什麼。

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

我們並不知道與宇宙中 是否還有其他生命。

perhaps we will not.

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，

And while economics may seem like an inappropriate thing

或許我們不會找到。

to bring into a talk on interstellar capability,

而當我們討論星際任務的可能性時，

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

經濟狀況的話題 似乎不適合拿出來一起討論，

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

但它其實正是實現星際任務的 其中一個驅動因素。

to do what we want to do.

你必須要讓這些技術夠經濟實惠，

So currently,

我們才能應用。

we have systems in the lab

所以現在，

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

我們在實驗室裡建造了一個系統，

out to about 10 kilometers or roughly six miles.

它已經能夠在巨大的規模上 進行同步化，

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

規模大約是十公里，或是六英里左右。

and it's worked beautifully.

我們已經達成雷射光系統的同步化，

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

而且運作得好極了。

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

我們知道如何建造雷射裝置 已經好幾十年了，

and become mature enough

現在只需要等待這個技術 變得不那麼昂貴，

that we can imagine having huge arrays, literally,

而且變得更加成熟，

kilometer-scale arrays, much like solar farms,

屆時我們才有可能使用巨大的陣列，

but instead of receiving light, they transmit light.

公里級規模的陣列， 就像是太陽能發電廠一樣，

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

但並不是接收光線，而是發射光線。

not just relativistic flight for small spacecraft,

這種技術的美妙之處 就是它可以發展出眾多其他的應用，

but enables high-speed spacecraft,

不只是用來做 小型太空船的相對論飛行，

high-speed flight in our solar system,

也可以使高速太空船得以

it enables planetary defense,

在我們的太陽系中進行高速飛行，

it enables space debris removal,

這技術讓行星防禦得以可能，

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

能夠進行太空垃圾的清除，

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

它能夠讓我們為需要充電的 遠端資產傳送能量，

It's an extremely versatile technology,

像是太空船，或位於月球上 或其他地方上的基地。

it's something that humanity would want to develop

它是一個用途非常廣泛的科技。

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

即使人類並不打算送太空船航向星空，

because that technology allows so many applications

還是會希望發展這樣的科技，

that are currently not feasible.

因為這項科技能夠讓我們發展出

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

現在做不到的許多用途

because we have the ability,

因此，我認為這是一項 必然會發展的科技，

we just need to fine-tune the technology

因為我們有這項能力，

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

我們只需要對這技術進行微調，

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

並且等到經濟發展足以跟上來。

The smaller systems are affordable now.

到那時候，技術變得足夠便宜， 以建造出大型的系統。

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

我們已經負擔得起小型系統了，

So while it's not going to happen tomorrow,

而我們也已經開始在實驗室裡 建造雛形的系統了。

we've already begun the process,

儘管不是明天就可以實現，

and so far, it's looking good.

但我們已經開始一段時間，

This is both a revolutionary program,

而且，到目前為止， 看起來發展得不錯。

in terms of being a transformative technology,

在變革性的技術方面，

but it's also an evolutionary program.

這是個革命性的計畫，

So personally, I do not expect to be around

但它又是一個漸進性的計畫。

when the first relativistic flight happens.

因此，我個人可能活不到目睹

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

第一次相對論飛行實現的時刻。

and perhaps more.

我想，在我們發展到那個地步之前 還需要花 30 年的時間，

But what inspires me

可能甚至還要更久。

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

但是真正啟發我的是

Even if it does not happen in my lifetime,

能夠看見這項科技達成終極的目標，

it can happen in the lifetime of the next generation

即便在我這輩子並不會實現，

or the generation beyond that.

它可能在下一代的有生之年中成真，

The consequences are so transformative

或是要等到再下一代。

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

它的結果是如此地具有變革性，

and must explore what the limitations are,

所以我認為我們必須往這條路上走，

and then how do we overcome the limitations.

並且必須去探索其限制為何，

The search for life on other planets

以及接下來我們該如何克服那些限制。

would be one of humanity's foremost explorations,

在其他行星上尋找生命

and if we're able to do so,

會是人類最意義深遠的探索之一，

and actually find life on another planet,

而如果我們有能力去做到，

it would change humanity forever.

並且真的在另外一顆行星上找到生命，

Everything is profound in life.

那將會徹底改變人類的命運。

If you look deep enough,

生命中的每一件事物都是深奧的，

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

如果你看得足夠深入，

And the same is true with the lowly photon

你就會在生命中找到 極其複雜、有趣且美麗的事物。

that we use to see every day.

而同樣的道理也適用在

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

我們每天隨處可見、 微不足道的光子上。

an array of lasers that are synchronized,

但是當我們向外看， 並想像更廣、更大的東西，

we could imagine things which are just extraordinary in life.

像是同步化的雷射陣列，

And the ability to go to another star

我們能夠發想出令人意想不到的事物，

is one of those extraordinary capabilities.

而能夠航向另外一顆星球的能力

(Birds chirping)

就是其中一個非凡的潛能。