The questions I would like to talk about are:

我想討論的問題是，

one, where did we come from?

第一、我們從哪裡來？

How did the universe come into being?

這個宇宙如何產生？

Are we alone in the universe?

我們在宇宙中是孤單的嗎？

Is there alien life out there?

宇宙有沒有任何的外星生物？

What is the future of the human race?

人類的未來是什麼？

Up until the 1920s,

直到一九二零年代，

everyone thought the universe was essentially static

人們認為宇宙本質上是固定的，

and unchanging in time.

不會隨著時間改變。

Then it was discovered that the universe was expanding.

之後，人們發現宇宙是一直在膨脹的。

Distant galaxies were moving away from us.

遠方的銀河正在漸漸地遠離我們。

This meant they must have been closer together in the past.

這個行星比宇宙剛形成時更靠近，

If we extrapolate back,

如果我們更近

we find we must have all been on top of each other

從以宇宙的起源來看，

about 15 billion years ago.

在一百五十億年前，

This was the Big Bang, the beginning of the universe.

大爆炸是宇宙的開始，

But was there anything before the Big Bang?

但在大爆炸之前，是否有宇宙呢？

If not, what created the universe?

如果沒有，那到底是什麼創造了宇宙？

Why did the universe emerge from the Big Bang the way it did?

為什麼宇宙是經由大爆炸而形成呢？

We used to think that the theory of the universe

我們以前認為相關理論

could be divided into two parts.

有兩部分，

First, there were the laws

第一是

like Maxwell's equations and general relativity

麥斯威爾的理論到相對論決定宇宙的演化

that determined the evolution of the universe,

在太空中一個特定時間點內

given its state over all of space at one time.

決定宇宙的狀態。

And second, there was no question

第二是沒有任何

of the initial state of the universe.

關於宇宙起源的疑問。

We have made good progress on the first part,

我們在第一部份有一些進展，

and now have the knowledge of the laws of evolution

在宇宙演化的部分

in all but the most extreme conditions.

多了一些知識，

But until recently, we have had little idea

但是，近來在第二個宇宙起源的發現

about the initial conditions for the universe.

沒有很多進展。

However, this division into laws of evolution and initial conditions

然而，這些關於宇宙演化的理論

depends on time and space being separate and distinct.

是依據時間與空間是分開並獨立的假設。

Under extreme conditions, general relativity and quantum theory

但在極端的條件下，相對論的變化以及量子理論時，

allow time to behave like another dimension of space.

已經讓時間變成另一個影響太空的變量。

This removes the distinction between time and space,

這個想法解除了原先時間與空間

and means the laws of evolution can also determine the initial state.

是分開獨立的假設，這也使得宇宙演化的研究直接會影響到宇宙起源的探索。

The universe can spontaneously create itself out of nothing.

宇宙可能會從完全沒有的狀態自發地產生。

Moreover, we can calculate a probability that the universe

此外，我們可以計算宇宙創造的的

was created in different states.

不同狀態的或然率。

These predictions are in excellent agreement

這些預測可以由

with observations by the WMAP satellite

Wmap衛星佐證，

of the cosmic microwave background,

這些觀察數據可以取得

which is an imprint of the very early universe.

宇宙早期形成的微波。

We think we have solved the mystery of creation.

我們認為我們已經解決的宇宙發生的秘密。

Maybe we should patent the universe

或許我們應該開始去尋找太空

and charge everyone royalties for their existence.

是否有多樣的生物存在。

I now turn to the second big question:

現在轉到第二個問題，

are we alone, or is there other life in the universe?

我們是唯一在宇宙中的唯一生物嗎？

We believe that life arose spontaneously on the Earth,

我們相信地球是自然地產生生物。

so it must be possible for life to appear on other suitable planets,

所以，也有可能在其他適合生存的行星上也會有生物，

of which there seem to be a large number in the galaxy.

而且這種星球在銀河裡應該很多。

But we don't know how life first appeared.

但我們還不知道生命剛剛形成的形式。

We have two pieces of observational evidence

我們有兩個可觀察的證據

on the probability of life appearing.

可以參考。

The first is that we have fossils of algae

第一是地球在

from 3.5 billion years ago.

三十五億年前的化石。

The Earth was formed 4.6 billion years ago

在四十六億年前的地球，

and was probably too hot for about the first half billion years.

前五億年或許還因為太熱不適合生物生存。

So life appeared on Earth

所以在地球剛開始的

within half a billion years of it being possible,

五億年沒有生物生存的可能，

which is short compared to the 10-billion-year lifetime

但到了地球產生的十億年時

of a planet of Earth type.

可能有基本形式的生命開始，

This suggests that a probability of life appearing is reasonably high.

當時生物存在的機率相對地高。

If it was very low, one would have expected it

如果存在機率非常低，那也大概會在

to take most of the ten billion years available.

後來的十億年發展出生物，

On the other hand, we don't seem to have been visited by aliens.

另一方面，我們似乎沒有資訊顯示外星人來訪，

I am discounting the reports of UFOs.

我手上沒有什麼飛碟資料，

Why would they appear only to cranks and weirdoes?

為什麼他們只出現在特定人士面前？

If there is a government conspiracy to suppress the reports

如果政府為保密而壓制這些外星人資訊，

and keep for itself the scientific knowledge the aliens bring,

使得科學家沒有機會研究外星人相關知識，

it seems to have been a singularly ineffective policy so far.

目前對我似乎也不會是個有效的政策。

Furthermore, despite an extensive search by the SETI project,

再者，雖然有很多廣泛或相關的專案或研究，

we haven't heard any alien television quiz shows.

我們也沒有在電視的秀中看到任何訊息。

This probably indicates that there are no alien civilizations

在我們現有的研究發展下，我們在宇宙用無線電波

at our stage of development

在光年距離做宇宙測試的現象，

within a radius of a few hundred light years.

這似乎顯示我們並沒有任何外星人的文明，

Issuing an insurance policy

我想對於要確認是否有外星人存在，

against abduction by aliens seems a pretty safe bet.

我們的研究將是一個安全的背書。

This brings me to the last of the big questions:

這帶我們進入最後一個大問題，

the future of the human race.

人類的未來，

If we are the only intelligent beings in the galaxy,

如果我們是銀河裡唯一高智慧生物，

we should make sure we survive and continue.

我們應該確認是否能永續生存，

But we are entering an increasingly dangerous period of our history.

但我們正進入一個正在逐漸危險的人類歷史時期，

Our population and our use of the finite resources of planet Earth

我們的人口與我們使用這個地球行星的資源，

are growing exponentially, along with our technical ability

是快速的成長以及我們高速的科技發展

to change the environment for good or ill.

已經大量改變這個地球的生態，

But our genetic code

但我們的基因解碼研究

still carries the selfish and aggressive instincts

已經使我們有積極的進展，

that were of survival advantage in the past.

使我們未來可以比過去生存的更好

It will be difficult enough to avoid disaster

我們在未來一百年，

in the next hundred years,

或未來幾百萬年，

let alone the next thousand or million.

都將很難避免未來的災難。

Our only chance of long-term survival

我們的唯一長期生存的機會，

is not to remain lurking on planet Earth,

並不是去在地球重建另一個行星，

but to spread out into space.

而是去擴散到太空去。

The answers to these big questions

回答這些問題的答案是，

show that we have made remarkable progress in the last hundred years.

顯現我們過去幾百年的努力的輝煌成就。

But if we want to continue beyond the next hundred years,

我們要再用未來幾百年把力氣

our future is in space.

用在太空研究上，

That is why I am in favor of manned --

這是為什麼我會傾向

or should I say, personed -- space flight.

研究人類的太空飛行。

All of my life I have sought to understand the universe

我用我的一生去研究瞭解這個宇宙

and find answers to these questions.

與替這些問題找答案，

I have been very lucky

很幸運，

that my disability has not been a serious handicap.

我的缺陷並沒會成為一個嚴重的殘障。

Indeed, it has probably given me more time than most people

事實上，或許使我可以有更多時間與找到更多人

to pursue the quest for knowledge.

來去追求我想要的知識

The ultimate goal is a complete theory of the universe,

這個最終目標在宇宙的理論

and we are making good progress.

正在進行好的發展。

Thank you for listening.

謝謝您的聆聽！

Chris Anderson: Professor, if you had to guess either way,

Chris Anderson: 教授如果你願意做個猜測的話，

do you now believe that it is more likely than not

我想請問你相信在銀河裡面

that we are alone in the Milky Way,

我們是否是唯一

as a civilization of our level of intelligence or higher?

最高而有文明的高智商動物？

This answer took seven minutes, and really gave me an insight

這個答案需要七分鐘，這整個TED的演講

into the incredible act of generosity this whole talk was for TED.

真的讓我大開眼界。

Stephen Hawking: I think it quite likely that we are the only civilization

Stephen Hawking: 我認為很可能我們是在幾百光年內

within several hundred light years;

我們是唯一的文明，

otherwise we would have heard radio waves.

否則我們應該會聽到無線電波，

The alternative is that civilizations don't last very long,

其他的文明沒有維持很久

but destroy themselves.

但可能自我毀滅過。

CA: Professor Hawking, thank you for that answer.

Chris Anderson:教授，謝謝您的答案，

We will take it as a salutary warning, I think,

我們會把你的意見

for the rest of our conference this week.

當作我們在地球的的警訊。

Professor, we really thank you for the extraordinary effort you made

也謝謝您把你思考的問題

to share your questions with us today.

分享給我們。

Thank you very much indeed.

真的非常感謝您。

(Applause)

(掌聲)