Why is our universe fine-tuned for life? | Brian Greene

Translator: Jenny Zurawell

翻译人员: Zhixue Su 校对人员: Yuguo Zhang

A few months ago

几个月以前，

the Nobel Prize in physics

诺贝尔物理学奖

was awarded to two teams of astronomers

颁发给两个天文学家团队，

for a discovery that has been hailed

他们的发现被誉为

as one of the most important

史上最重要的

astronomical observations ever.

天文观测之一。

And today, after briefly describing what they found,

今天呢，在简要描述他们的发现之后，

I'm going to tell you about a highly controversial framework

我会告诉你一个颇有争议的理论框架

for explaining their discovery,

用于解释他们的发现，

namely the possibility

这种框架大大超越了

that way beyond the Earth,

我们所认知的地球，

the Milky Way and other distant galaxies,

银河系和其他遥远星系，

we may find that our universe

我们可能会发现我们的宇宙

is not the only universe,

不是唯一的宇宙，

but is instead

相反只是

part of a vast complex of universes

一个庞大复合宇宙的一部分，

that we call the multiverse.

我们称之为多元宇宙。

Now the idea of a multiverse is a strange one.

多元宇宙是个很怪的想法。

I mean, most of us were raised to believe

我是说，大部分人从出生就被教育相信

that the word "universe" means everything.

“宇宙”这个词包含一切。

And I say most of us with forethought,

我是说我们中的绝大多数（都被从小教导有关“一元宇宙”的概念）

as my four-year-old daughter has heard me speak of these ideas since she was born.

就像我四岁大的女儿从一出生就在听我讲这些想法（多元宇宙）一样。

And last year I was holding her

去年，我抱着她，

and I said, "Sophia,

对她说，“索非亚，

I love you more than anything in the universe."

我爱你胜过宇宙的一切。”

And she turned to me and said, "Daddy,

她转过来对我说，“爸爸，

universe or multiverse?"

是宇宙还是多元宇宙？”

(Laughter)

（笑）

But barring such an anomalous upbringing,

但是除了这样一个不同寻常的教育的例子，

it is strange to imagine

我们总是很难让人们（从小接受了一元宇宙观点的人）去想象

other realms separate from ours,

哪些其他与我们的宇宙所分离的国度（宇宙），

most with fundamentally different features,

而其中的大部分又拥有完全不同于我们所处宇宙的特征，

that would rightly be called universes of their own.

而这些宇宙可以被称作他们自己的宇宙。

And yet,

尽管

speculative though the idea surely is,

这个想法是个推理，

I aim to convince you

我想让你相信

that there's reason for taking it seriously,

我们有理由把它当回事，

as it just might be right.

因为它有可能是正确的。

I'm going to tell the story of the multiverse in three parts.

我会分三部分来讲多元宇宙的故事。

In part one,

第一部分，

I'm going to describe those Nobel Prize-winning results

我会描述这些获诺贝尔奖的结果，

and to highlight a profound mystery

并且强调这些成绩

which those results revealed.

揭示的一个意义深远的奥秘。

In part two,

第二部分，

I'll offer a solution to that mystery.

我会解开这个奥秘。

It's based on an approach called string theory,

它基于一种叫“弦理论”的方法，

and that's where the idea of the multiverse

通过它我们把多元宇宙

will come into the story.

引入了这个故事。

Finally, in part three,

最后第三部分，

I'm going to describe a cosmological theory

我将讲述一个宇宙理论

called inflation,

叫暴涨，

which will pull all the pieces of the story together.

通过这个你就能把整个故事完整起来。

Okay, part one starts back in 1929

好吧，故事的第一部分回到1929年，

when the great astronomer Edwin Hubble

当伟大的天文学家爱德温•哈勃

realized that the distant galaxies

意识到，遥远的星系

were all rushing away from us,

都匆匆离我们而去

establishing that space itself is stretching,

建立属于它自身的空间

it's expanding.

这个空间在不断地扩展。

Now this was revolutionary.

现在我们要讨论的问题开始富有革命性了。

The prevailing wisdom was that on the largest of scales

普遍的观点是在最大的尺度下

the universe was static.

宇宙是静态的。

But even so,

但即便如此，

there was one thing that everyone was certain of:

有一件事大家都是确定的，

The expansion must be slowing down.

就是扩张必须放缓。

That, much as the gravitational pull of the Earth

就像万有引力

slows the ascent of an apple tossed upward,

减慢了抛向空中的苹果上升的速度，

the gravitational pull

每个星系

of each galaxy on every other

对其他星系的万有引力

must be slowing

必须减缓

the expansion of space.

空间的扩展。

Now let's fast-forward to the 1990s

现在让我们快进到二十世纪90年代，

when those two teams of astronomers

我开始提到的

I mentioned at the outset

那两个天文学家小组

were inspired by this reasoning

受到这个推理的启发

to measure the rate

来测量

at which the expansion has been slowing.

这种扩张放缓的速率。

And they did this

他们辛勤地

by painstaking observations

观察了

of numerous distant galaxies,

为数众多的遥远星系，

allowing them to chart

并据此画出了

how the expansion rate has changed over time.

膨胀率随时间变化的图表。

Here's the surprise:

令人惊讶的是，

They found that the expansion is not slowing down.

他们发现扩张并没有减速。

Instead they found that it's speeding up,

相反速度在加快，

going faster and faster.

越来越快。

That's like tossing an apple upward

就像抛一个苹果，

and it goes up faster and faster.

它快速地上升。

Now if you saw an apple do that,

如果你看到一个苹果这样的话，

you'd want to know why.

你一定想知道为什么。

What's pushing on it?

是一种什么力量推动它呢？

Similarly, the astronomers' results

同样，天文学家的结果

are surely well-deserving of the Nobel Prize,

肯定配得诺贝尔奖，

but they raised an analogous question.

但他们提了一个类似的问题。

What force is driving all galaxies

是什么力量驱动所有的星系

to rush away from every other

不断加速地

at an ever-quickening speed?

远离其它的呢？

Well the most promising answer

最有希望的答案

comes from an old idea of Einstein's.

还是来自爱因斯坦的老观点。

You see, we are all used to gravity

你看，我们都习惯于认为，

being a force that does one thing,

地心引力这种力量就做一件事，

pulls objects together.

就是把东西拉在一起。

But in Einstein's theory of gravity,

但在爱因斯坦的引力理论中，

his general theory of relativity,

他的广义相对论，

gravity can also push things apart.

引力也可以把东西推开的。

How? Well according to Einstein's math,

怎么说呢？根据爱因斯坦的数学，

if space is uniformly filled

如果空间是

with an invisible energy,

被无形的能量均匀地充满，

sort of like a uniform, invisible mist,

就像一种统一，无形的雾，

then the gravity generated by that mist

这种雾所产生的重力

would be repulsive,

会是

repulsive gravity,

排斥重力，

which is just what we need to explain the observations.

这正是我们需要解释的观测。

Because the repulsive gravity

因为空间中的

of an invisible energy in space --

这种无形能量的排斥重力--

we now call it dark energy,

我们把它叫做暗能量，

but I've made it smokey white here so you can see it --

但这里我把它用白色烟雾表示是为了便于看到--

its repulsive gravity

它的排斥重力

would cause each galaxy to push against every other,

会导致每个星系互相推斥，

driving expansion to speed up,

驱使扩张加快

not slow down.

而不是减缓。

And this explanation

这个解释

represents great progress.

代表着很大的进步。

But I promised you a mystery

我答应过你这是

here in part one.

第一部分的一个谜。

Here it is.

这个就是。

When the astronomers worked out

在天文学家计算出

how much of this dark energy

必须注入多少暗能量

must be infusing space

到空间

to account for the cosmic speed up,

去证明宇宙的加速时，

look at what they found.

看看他们发现了什么。

This number is small.

这是个小数目。

Expressed in the relevant unit,

用相关的单位来表现，

it is spectacularly small.

它非常小。

And the mystery is to explain this peculiar number.

谜团是去解释这个奇特的数字。

We want this number

我们希望这一数字

to emerge from the laws of physics,

可能摆脱物理定律，

but so far no one has found a way to do that.

但到目前为止还没有人找到一个方法。

Now you might wonder,

你现在可能想知道，

should you care?

你应该担忧吗？

Maybe explaining this number

也许解释这个数字

is just a technical issue,

只是个技术问题，

a technical detail of interest to experts,

一个专家感兴趣的技术细节，

but of no relevance to anybody else.

根别人没什么关系。

Well it surely is a technical detail,

这的确是一个技术上的细节，

but some details really matter.

但有些细节至关重大。

Some details provide

一些细节

windows into uncharted realms of reality,

给未知的现实领域提供窗口，

and this peculiar number may be doing just that,

这个奇特的数字可能只有这个用途，

as the only approach that's so far made headway to explain it

至今为止作为唯一方法取得了进展，

invokes the possibility of other universes --

去解释它调用奇特宇宙的可能性--

an idea that naturally emerges from string theory,

这个想法自然地脱离弦理论，

which takes me to part two: string theory.

带我进入第二部分：弦理论。

So hold the mystery of the dark energy

先把暗能量的谜团

in the back of your mind

放在脑后，

as I now go on to tell you

我继续讲

three key things about string theory.

有关弦理论的三个关键的事情。

First off, what is it?

第一个，是什么呢？

Well it's an approach to realize Einstein's dream

那是实践爱因斯坦的物理统一理论的

of a unified theory of physics,

梦想的一种途径，

a single overarching framework

一个总体框架

that would be able to describe

能够描述

all the forces at work in the universe.

宇宙所有的力量在起作用。

And the central idea of string theory

而弦理论的中心思想

is quite straightforward.

非常简单。

It says that if you examine

它说，如果你非常细致地检查

any piece of matter ever more finely,

任何一样物质。

at first you'll find molecules

起初你会发现分子，

and then you'll find atoms and subatomic particles.

然后你会发现原子和亚原子粒子。

But the theory says that if you could probe smaller,

但这个理论说，如果你能够探测到更小的，

much smaller than we can with existing technology,

比我们现有技术能做到的更小的，

you'd find something else inside these particles --

你会在这些粒子里找到别的东西--

a little tiny vibrating filament of energy,

一个小小的能量震动纤维，

a little tiny vibrating string.

一个小小的震动弦。

And just like the strings on a violin,

就像小提琴上的弦一样，

they can vibrate in different patterns

它们通过不同的震动

producing different musical notes.

来产生不同的音符。

These little fundamental strings,

这些小小的基本的弦，

when they vibrate in different patterns,

当他们以不同的模式震动时，

they produce different kinds of particles --

它们产生不同种类的粒子--

so electrons, quarks, neutrinos, photons,

所以，电子，夸克，中微子，光子，

all other particles

所有的粒子

would be united into a single framework,

会合并成一个单一的框架，

as they would all arise from vibrating strings.

它们会通过震动的弦而出现。

It's a compelling picture,

那是个令人信服的场面，

a kind of cosmic symphony,

一种宇宙交响乐，

where all the richness

我们看到的

that we see in the world around us

从周围世界的音乐

emerges from the music

而展现的丰富，

that these little, tiny strings can play.

这些小小的弦也能演奏出。

But there's a cost

但这种优雅的统一

to this elegant unification,

是有代价的，

because years of research

因为多年的研究

have shown that the math of string theory doesn't quite work.

表明弦理论的数学也不是行得通的。

It has internal inconsistencies,

它内部不一致，

unless we allow

除非我们考虑

for something wholly unfamiliar --

完全陌生的事--

extra dimensions of space.

即额外纬度空间。

That is, we all know about the usual three dimensions of space.

我们都知道通常的三维空间。

And you can think about those

你可以用

as height, width and depth.

高度，宽度和深度来考虑。

But string theory says that, on fantastically small scales,

但弦理论认为，在极其小的尺度下，

there are additional dimensions

在这么小的尺寸下

crumpled to a tiny size so small

还有附加的维度，因为太小

that we have not detected them.

我们还探测不出。

But even though the dimensions are hidden,

但即使这些维度是隐藏的，

they would have an impact on things that we can observe

它们对一些东西的影响我们能够观察到，

because the shape of the extra dimensions

因为额外维度的形状

constrains how the strings can vibrate.

限制着弦的震动。

And in string theory,

在弦理论中，

vibration determines everything.

振动决定一切。

So particle masses, the strengths of forces,

所以呢，粒子的质量，力量的强度，

and most importantly, the amount of dark energy

最重要的，暗能量的总量

would be determined

会取决于

by the shape of the extra dimensions.

额外维度的形状。

So if we knew the shape of the extra dimensions,

如果我们了解额外维度的形状，

we should be able to calculate these features,

我们就能计算出这些特征，

calculate the amount of dark energy.

计算出暗能量的总量。

The challenge

目前的挑战是

is we don't know

我们不知道

the shape of the extra dimensions.

额外维度的形状。

All we have

我们有的

is a list of candidate shapes

是通过数学算出的

allowed by the math.

一些候选形状。

Now when these ideas were first developed,

当这些想法首次推出的时候，

there were only about five different candidate shapes,

只有5个候补形状，

so you can imagine

你可以想象到

analyzing them one-by-one

一个一个分析它们

to determine if any yield

来决定哪一个符合

the physical features we observe.

我们观察的物理特征。

But over time the list grew

可是随着时间的迁移，

as researchers found other candidate shapes.

研究人员发现了更多的候选形状。

From five, the number grew into the hundreds and then the thousands --

从起初的5个到几百个，最后几千个--

A large, but still manageable, collection to analyze,

数目很多但还管得过来，

since after all,

去分析这些的工作

graduate students need something to do.

就交给刚毕业的学生了。

But then the list continued to grow

但是这个数目单继续增加到了

into the millions and the billions, until today.

几百万，到今天有数十亿了。

The list of candidate shapes

候选形状的清单

has soared to about 10 to the 500.

也飙升到10至500个。

So, what to do?

那，怎么办呢？

Well some researchers lost heart,

有些研究人员失去信心，

concluding that was so many candidate shapes for the extra dimensions,

结论是额外维度有这么多的候选形状，

each giving rise to different physical features,

每一个都有不同的物理特征，

string theory would never make

弦理论永远不会做出

definitive, testable predictions.

确定的，可检验的预测。

But others turned this issue on its head,

但是另一些从另一个角度考虑，

taking us to the possibility of a multiverse.

把我们带到多元宇宙的可能性。

Here's the idea.

想法是这样的。

Maybe each of these shapes is on an equal footing with every other.

也许这些性状之间是互相平等的。

Each is as real as every other,

每一个都很真实，

in the sense

就是说

that there are many universes,

有很多的宇宙，

each with a different shape, for the extra dimensions.

每个对额外维度都有不同的形状。

And this radical proposal

这种激进的建议

has a profound impact on this mystery:

对这个谜团有着深刻的影响：

the amount of dark energy revealed by the Nobel Prize-winning results.

诺贝尔得奖结果揭示了暗能量的总量。

Because you see,

因为你看，

if there are other universes,

如果有很多的其他宇宙，

and if those universes

而这些宇宙

each have, say, a different shape for the extra dimensions,

每个都有不同的额外维度形状，

then the physical features of each universe will be different,

那么每个宇宙的物理特征将会不同，

and in particular,

特别是，

the amount of dark energy in each universe

每个宇宙的暗能量

will be different.

将会不同。

Which means that the mystery

也就意味着，

of explaining the amount of dark energy we've now measured

我们现在测量到的暗能量总量的解释谜呢，

would take on a wholly different character.

将会是 一个完全不同的角色。

In this context,

在这种背景下，

the laws of physics can't explain one number for the dark energy

物理定律不能解释暗能量的一个数，

because there isn't just one number,

因为不知一个数，

there are many numbers.

有很多数。

Which means

也意味着，

we have been asking the wrong question.

我们一直问错了问题。

It's that the right question to ask is,

应该问的正确问题是，

why do we humans find ourselves in a universe

为什么我们人类在一个宇宙中测量

with a particular amount of dark energy we've measured

一种特定量的暗能量，

instead of any of the other possibilities

而不是在另外的

that are out there?

其他外围宇宙呢？

And that's a question on which we can make headway.

我们在这个问题上能取得进展。

Because those universes

因为那些宇宙

that have much more dark energy than ours,

有着比我们的更多的暗能量，

whenever matter tries to clump into galaxies,

当物质要聚成星系时，

the repulsive push of the dark energy is so strong

暗能量的排斥力太强，

that it blows the clump apart

把物质快吹散，

and galaxies don't form.

星系就无法形成。

And in those universes that have much less dark energy,

这些宇宙中的暗能量较少，

well they collapse back on themselves so quickly

它们非常快地崩溃后回来，

that, again, galaxies don't form.

也形成不了星系。

And without galaxies, there are no stars, no planets

没有星系，就没有星星，没有行星，

and no chance

所以在别的宇宙中

for our form of life

没法有

to exist in those other universes.

像我们这样的生命存在。

So we find ourselves in a universe

我们发现我们自己存在于

with the particular amount of dark energy we've measured

一个我们简单测量的有一个特别数量的暗能量的宇宙中，

simply because our universe has conditions

只因为我们的宇宙有合适的条件

hospitable to our form of life.

供我们生命的存在。

And that would be that.

就是那个。

Mystery solved,

谜团破解了，

multiverse found.

多元宇宙被发现。

Now some find this explanation unsatisfying.

有些人对这个解释不满意。

We're used to physics

我们习惯于物理学

giving us definitive explanations for the features we observe.

给我们观察的特征的明确解释。

But the point is,

但问题是，

if the feature you're observing

如果你观察的特征

can and does take on

能够并且确实承担

a wide variety of different values

现实中的

across the wider landscape of reality,

不同价值，

then thinking one explanation

那么对一种

for a particular value

特定值用一种解释

is simply misguided.

就会简单地误导人。

An early example

一个早期的例子

comes from the great astronomer Johannes Kepler

来自于伟大的天文学家约翰 开普勒，

who was obsessed with understanding

他很着迷于研究

a different number --

不同的数字--

why the Sun is 93 million miles away from the Earth.

为什么太阳离地球9千3百万英里。

And he worked for decades trying to explain this number,

他花了几十年的时间试图解释这个数字，

but he never succeeded, and we know why.

但从未成功，我们知道为什么。

Kepler was asking

开普勒

the wrong question.

问错了问题。

We now know that there are many planets

现在我们知道有许多行星

at a wide variety of different distances from their host stars.

距离它们的宿主恒星有不同的距离。

So hoping that the laws of physics

单单希望物理定律

will explain one particular number, 93 million miles,

能解释一个特殊的数据，9千3百万，

well that is simply wrongheaded.

是执迷不悟。

Instead the right question to ask is,

正确的问题应该是，

why do we humans find ourselves on a planet

为什么我们人类发现我们在一个行星上的

at this particular distance,

距离是特定的，

instead of any of the other possibilities?

而不是别的可能呢？

And again, that's a question we can answer.

同样，这个问题我们能回答。

Those planets which are much closer to a star like the Sun

那些行星更接近于一颗星就像太阳

would be so hot

一样热，

that our form of life wouldn't exist.

以至像我们这样的生命无法存在。

And those planets that are much farther away from the star,

而那些离这个星太远的行星，

well they're so cold

因为太冷，

that, again, our form of life would not take hold.

同样也没法有我们这样的生命。

So we find ourselves

所以，我们发现我们

on a planet at this particular distance

在这颗行星的特定距离

simply because it yields conditions

只是因为它的条件

vital to our form of life.

符合我们生命的存在。

And when it comes to planets and their distances,

讲到行星和它们的距离时，

this clearly is the right kind of reasoning.

这显然是合理的推理。

The point is,

关键是，

when it comes to universes and the dark energy that they contain,

讲到宇宙和他们所含的暗能量时，

it may also be the right kind of reasoning.

它也可能是合适的推理。

One key difference, of course,

一个重要的区别是，

is we know that there are other planets out there,

我们知道外边还有很多别的行星，

but so far I've only speculated on the possibility

但到目前为止，我只是推测可能

that there might be other universes.

会有其他的宇宙。

So to pull it all together,

把这些合起来，

we need a mechanism

我们需要一个机制，

that can actually generate other universes.

实际上可以生成其它宇宙。

And that takes me to my final part, part three.

这样我就来到最后一部分，第三部分。

Because such a mechanism has been found

因为宇宙学家们在试图了解

by cosmologists trying to understand the Big Bang.

大爆炸时发现了这个机制。

You see, when we speak of the Big Bang,

你看，但我们说起大爆炸时，

we often have an image

我们常常有一个

of a kind of cosmic explosion

宇宙爆炸的图画，

that created our universe

这个爆炸创造了我们的宇宙，

and set space rushing outward.

且把空间向外扩。

But there's a little secret.

但有一个小秘密。

The Big Bang leaves out something pretty important,

大爆炸留下了很重要的就是，

the Bang.

爆炸。

It tells us how the universe evolved after the Bang,

它告诉我们宇宙在爆炸后时如何进化，

but gives us no insight

但没有给我们

into what would have powered the Bang itself.

提供爆炸本身的力量。

And this gap was finally filled

最终，这个差距

by an enhanced version of the Big Bang theory.

被一个增强版的大爆炸理论填补上了

It's called inflationary cosmology,

它被称为暴胀宇宙学，

which identified a particular kind of fuel

找到了一种特殊的燃料，

that would naturally generate

会自然产生

an outward rush of space.

向往冲的空间。

The fuel is based on something called a quantum field,

燃料基于一种叫做量子场的东西，

but the only detail that matters for us

但对我们有关的唯一细节是

is that this fuel proves to be so efficient

这种燃料被证明是如此高效，

that it's virtually impossible

它几乎不可能

to use it all up,

完全用尽，

which means in the inflationary theory,

这就意味着在暴胀理论中，

the Big Bang giving rise to our universe

大爆炸出现在我们宇宙

is likely not a one-time event.

不是一次性的事件。

Instead the fuel not only generated our Big Bang,

相反，燃料不仅产生了我们的大爆炸，

but it would also generate countless other Big Bangs,

它也产生了无数的别的爆炸，

each giving rise to its own separate universe

每个形成它自己的宇宙，

with our universe becoming but one bubble

我们的宇宙变成

in a grand cosmic bubble bath of universes.

大宇宙泡泡浴里的一个泡泡。

And now, when we meld this with string theory,

现在，当我们把这融合到弦理论，

here's the picture we're led to.

我们就看到了这张图片。

Each of these universes has extra dimensions.

这些宇宙中的每一个都有额外维度。

The extra dimensions take on a wide variety of different shapes.

额外维度有不同的形状。

The different shapes yield different physical features.

不同的形状产生不同的物理特征。

And we find ourselves in one universe instead of another

我们发现我们自己在一个而不是

simply because it's only in our universe

另一个宇宙中单单因为我们的宇宙的

that the physical features, like the amount of dark energy,

物理特征，譬如暗能量的总量

are right for our form of life to take hold.

正好适合我们生命的存在。

And this is the compelling but highly controversial picture

这是具有吸引力但对更广阔宇宙的

of the wider cosmos

又极有争议的图片，

that cutting-edge observation and theory

尖端的观察与理论

have now led us to seriously consider.

让我们去更严肃地思考。

One big remaining question, of course, is,

一个悬而未决的问题，当然是，

could we ever confirm

我们能否确认

the existence of other universes?

其他宇宙的存在？

Well let me describe

让我来描述一种

one way that might one day happen.

可能有一天会发生的方法。

The inflationary theory

通胀理论

already has strong observational support.

已经有强大的观测支持。

Because the theory predicts

因为这个理论预言

that the Big Bang would have been so intense

大爆炸将是如此强烈

that as space rapidly expanded,

以至于空间快速扩张，

tiny quantum jitters from the micro world

微小的量子从微观世界

would have been stretched out to the macro world,

延伸到宏观世界，

yielding a distinctive fingerprint,

产生一种独特的指纹，

a pattern of slightly hotter spots and slightly colder spots,

一种既有微热和微冷的

across space,

斑点模式

which powerful telescopes have now observed.

已经被功能强大的望远镜观察到了。

Going further, if there are other universes,

讲的远点，如果有其他的宇宙，

the theory predicts that every so often

这个理论预测这些宇宙

those universes can collide.

可能互相碰撞。

And if our universe got hit by another,

如果我们的宇宙被别的宇宙撞上了，

that collision

碰撞

would generate an additional subtle pattern

会在空间里产生额外的

of temperature variations across space

微妙的温度变化，

that we might one day

我们可能有一天

be able to detect.

能探测到。

And so exotic as this picture is,

正像这张奇特的照片，

it may one day be grounded

有一天也许会基于

in observations,

观测，

establishing the existence of other universes.

建立其它宇宙的存在。

I'll conclude

最后，

with a striking implication

我将用一个有关遥远未来的

of all these ideas

所有想法

for the very far future.

的令人瞩目的暗示来结束。

You see, we learned

你看，我们得知

that our universe is not static,

我们的宇宙不是静态的，

that space is expanding,

空间是在扩张的，

that that expansion is speeding up

这个扩张是在加速的，

and that there might be other universes

可能会有别的宇宙，

all by carefully examining

我们可以通过仔细检查

faint pinpoints of starlight

微弱的星光

coming to us from distant galaxies.

来确定那些遥远的星系。

But because the expansion is speeding up,

但是因为这种扩张太快，

in the very far future,

在遥远的未来，

those galaxies will rush away so far and so fast

这些星系会离我们很远很远

that we won't be able to see them --

以至我们再也看不到它们--

not because of technological limitations,

不是因为技术的限制，

but because of the laws of physics.

而是因为物理定律。

The light those galaxies emit,

这些星系发出的光，。

even traveling at the fastest speed, the speed of light,

即使以很快的速度行走，以光速行走，

will not be able to overcome

也克服不了

the ever-widening gulf between us.

我们之间已经扩展的鸿沟

So astronomers in the far future

所以在将来天文学家

looking out into deep space

遥望远空

will see nothing but an endless stretch

除了静静的漆黑的沉寂

of static, inky, black stillness.

什么也看不到。

And they will conclude

他们就会下结论

that the universe is static and unchanging

说宇宙是安静的不变的，

and populated by a single central oasis of matter

由一个中央绿洲的居民

that they inhabit --

占据着--

a picture of the cosmos

这幅宇宙的图画

that we definitively know to be wrong.

我们知道是完全错的。

Now maybe those future astronomers will have records

或许这些未来的天文学家

handed down from an earlier era,

会有早期时代传下来的纪录，

like ours,

就像我们的，

attesting to an expanding cosmos

证明有一个充满星系的

teeming with galaxies.

膨胀的宇宙。

But would those future astronomers

但这些未来的天文学家

believe such ancient knowledge?

会相信这里古老的知识吗？

Or would they believe

或者他们会相信

in the black, static empty universe

他们自己最先进的观测

that their own state-of-the-art observations reveal?

显示的这个黑色的静态的空旷的宇宙吗？

I suspect the latter.

我怀疑后者。

Which means that we are living

这意味着，我们正经历

through a remarkably privileged era

一个非常特权的时代，

when certain deep truths about the cosmos

宇宙某些深层的真理

are still within reach

还在人类探索

of the human spirit of exploration.

能及的范畴。

It appears that it may not always be that way.

看来也许并不总是这样。

Because today's astronomers,

因为当今的天文学家们，

by turning powerful telescopes to the sky,

透过强大的望远镜，

have captured a handful of starkly informative photons --

已经捕捉到少数可提供信息的光子--

a kind of cosmic telegram

宇宙电报要走

billions of years in transit.

10亿年的路程。

and the message echoing across the ages is clear.

这个经历了不同的年代信息是清晰的。

Sometimes nature guards her secrets

有时，自然通过

with the unbreakable grip

牢不可破的物理定律

of physical law.

来守护着她的秘密。

Sometimes the true nature of reality beckons

有时现实的真实

from just beyond the horizon.

在地平线那边呼唤。

Thank you very much.

多谢！

(Applause)

（鼓掌）

Chris Anderson: Brian, thank you.

Chris Anderson：布赖恩，谢谢你。

The range of ideas you've just spoken about

你刚刚谈到的这些想法的范围

are dizzying, exhilarating, incredible.

真是令人眼花缭乱，兴奋不已，和难以置信。

How do you think

从历史的角度来看，

of where cosmology is now,

你认为现在的宇宙学

in a sort of historical side?

走到了哪一步？

Are we in the middle of something unusual historically in your opinion?

从你的观点来说，我们是在历史中的不寻常的一个时期吗？

BG: Well it's hard to say.

BG：这个很难说。

When we learn that astronomers of the far future

当我们知道将来的天文学家

may not have enough information to figure things out,

没有足够的信息去把事情弄明白，

the natural question is, maybe we're already in that position

很自然的问题是，也许我们已经

and certain deep, critical features of the universe

在一个位置和深度，

already have escaped our ability to understand

因为宇宙学的演化，

because of how cosmology evolves.

宇宙的一些重要特性已经超出我们的理解能力。

So from that perspective,

所以从这个角度来看，

maybe we will always be asking questions

也许我们永远是问问题，

and never be able to fully answer them.

永远无法完全解答它们。

On the other hand, we now can understand

另一方面，现在我们能理解

how old the universe is.

宇宙有多老。

We can understand

我们知道

how to understand the data from the microwave background radiation

如何理解137.2亿年前的

that was set down 13.72 billion years ago --

微波背景辐射的数据--

and yet, we can do calculations today to predict how it will look

我们今天可以计算并预测它将来会是什么样子，

and it matches.

并如何与它匹配。

Holy cow! That's just amazing.

不会吧！这太惊人了！

So on the one hand, it's just incredible where we've gotten,

所以，一方面，我们得到的太不可思议了，

but who knows what sort of blocks we may find in the future.

但谁知道我们将来会发现什么障碍呢？

CA: You're going to be around for the next few days.

CA：你还要在这呆几天。

Maybe some of these conversations can continue.

或许我们会继续讨论。

Thank you. Thank you, Brian. (BG: My pleasure.)

谢谢！谢谢你，布莱恩。（BG：很荣幸。）

(Applause)

（鼓掌）