But for more than half a century

優雅的宇宙

A dark cloud has been looming over modern science.

有個不為人所知的秘密

Here is the problem

半個多世紀以來

Our understanding of the universe

近代科學一直為烏雲籠罩

Is based on two separate theories.

問題就在於

One is Einstein's general theory of relativity—

我們對宇宙的認知

That's a way of understanding The biggest things in the universe,

是基於兩套不同的理論

Things like stars and galaxies.

一套是愛因斯坦的廣義相對論

But the littlest things in the universe,

描述的是宇宙間最龐大的物質

Atoms and subatomic particles,

像星球跟星系

Play by an entirely different set of rules called,

但宇宙中最微小的物質

"quantum mechanics."

原子跟亞原子粒子

These two sets of rules

則遵循另一種截然不同的定律

Are each incredibly accurate in their own domain

那就是"量子力學"

But whenever we try to combine them,

這兩種定律

To solve some of the deepest mysteries in the universe,

在各自的領域都準確無疑

Disaster strikes.

但一旦嘗試將其合二為一

Take the beginning of the universe, the "big bang."

去探索宇宙的終極奧秘時

At that instant a tiny nugget erupted violently.

災難降臨了

Over the next 14 billion years the universe expanded And cooled

以宇宙誕生之初 也就是"大爆炸"為例

into the stars, Galaxies and planets we see today.

在那一刻 極小的一點猛烈地爆發

But if we run the cosmic film in reverse,

經過140億年 宇宙不斷膨脹 冷卻

Everything that's now rushing apart comes back together

形成了現在所見的恆星 星系和行星

So the universe gets smaller, hotter and denser

但如果我們將宇宙誕生膠片倒轉

as we head back to the beginning of time.

讓所有分裂的物質再度聚合

As we reach the big bang,

宇宙將一直變小 變熱 密度變大

When the universe was both enormously heavy And incredibly tiny

我們將回到時間誕生之初

our projector jams.

抵達大爆炸那一刻時

Our two laws of physics, when combined, break down.

宇宙的質量無窮大而體積無窮小

But what if we could unite quantum mechanics

放映機將停滯於此

And general relativity

一旦這兩套物理定律在此相逢 便會決裂

And see the cosmic film in its entirety?

可要是我們能將量子力學

A new set of ideas called "string theory"

跟廣義相對論成功合併

May be able to do that.

再整體來看宇宙膠片會如何呢

And if it's right,

一種叫做"弦理論"的全新學說

It would be one of the biggest blockbusters In the history of science.

或許能達到目的

Someday, string theory may be able to explain all of nature

如果成功

From the tiniest bits of matter

將是科學史上最轟動事件之一

To the farthest reaches of the cosmos,

日後 弦理論或許能解釋自然界中的一切

Using just one ingredient, tiny vibrating strands of energy

從物質最微小的部分

called strings.

到茫茫宇宙最遙遠的地方

But why do we have to rewrite the laws of physics to accomplish this?

只用一種元素 微小振搗的能量

Why does it matter if the two laws That we have are incompatible?

叫作弦

Well, you can think of it like this.

為何我們要為此改寫物理學定律

Imagine you lived in a city ruled not

兩套定律互不相容有何要緊

By one set of traffic laws,

可以這樣試想

But by two separate sets of laws that conflicted with each other.

假設你住的城市

As you can see it would be pretty confusing.

不是被一種交通規則支配

To understand this place, You'd need to find a way

而是遵循兩套互相矛盾的規則

To put those two conflicting sets of laws together

你就會看到 情形會多混亂

Into one all-encompassing set that makes sense.

為瞭解宇宙 必須找到一種辦法

We work on the assumption that there is a theory out there,

將兩套矛盾的定律

And it's our job,

歸納為一套具有普適性的定律

If we're sufficiently smart and sufficiently industrious,

我們在努力證實存在這樣一套理論

To figure out what it is.

這就是我們的工作

We don't have a guarantee—

如果我們足夠聰明和勤奮

It isn't written in the stars that we're going to succeed

就能找到它

But in the end

我們不能保證

We hope we will have a single theory

成功是板上釘釘的事

That governs everything.

但說到底

But before we can find that theory,

我們希望能找到唯一的一套理論

We need to take a fantastic journey

適用於萬事萬物

To see why the two sets of laws We have

在找到那種理論之前

conflict with each other.

我們要先來一次奇幻旅程

And the first stop on this strange trip

看看為何現有的兩套定律

Is the realm of very large objects.

會互相衝突

To describe the universe on large scales

奇妙旅程的第一站

We use one set of laws，Einstein's general theory of relativity,

是龐然大物的國度

And that's a theory of how gravity works.

從宏觀角度描述宇宙時

General relativity pictures space as sort of like a trampoline

我們會用愛因斯坦的廣義相對論

A smooth fabric

它描述了引力是如何運作的

that heavy objects like stars and planets can warp and stretch.

廣義相對論描繪的宇宙像一張蹦床

Now, according to the theory,

一片光滑的結構

These warps and curves create what we feel as gravity.

重物如恆星和行星可以扭曲和擴張

That is，The gravitational pull that keeps the earth In orbit around the sun

根據這套理論

Is really nothing more than our planet Following the curves and contours

這些空間的扭曲讓我們感覺到了所謂的引力

that the sun creates in the spatial fabric.

就是說 保持地球在繞日軌道運行的引力

But the smooth, Gently curving image of space

只是地球在太陽製造的扭曲和波紋

predicted By the laws of general relativity

形成的特殊空間結構上的運動而已

is not the whole story.

但廣義相對論裡預言的

To understand the universe on extremely small scales,

平滑而起伏有致的空間

We have to use our other set of laws, quantum mechanics.

並不是宇宙的全部

And as we'll see,

要以極微觀的角度理解宇宙

Quantum mechanics paints a picture of space

我們得用上另一套定律 量子力學

So drastically different from general relativity

如我們即將所見

That you'd think they were describing

量子力學描繪的宇宙畫卷

two completely separate universes.

與廣義相對論的大不相同

To see the conflict between general relativity

甚至被認為二者描繪的是

And quantum mechanics

兩個完全不同的宇宙

We need to shrink way, way, way down in size.

要瞭解廣義相對論

And as we leave the world of large objects behind

與量子力學之間的矛盾

And approach the microscopic realm,

我們要變得 很小很小

The familiar picture of space In which everything behaves predictably

在我們離開龐然大物的世界

Begins to be replaced by a world

來到微觀粒子領域時

With a structure that is far less certain.

那幅萬物皆可預知的熟悉宇宙圖畫

And if we keep shrinking,

將逐漸被一個

Getting billions and billion of times

結構極不確定的世界取代

Smaller than even the tiniest bits of matter—

如果我們繼續縮小

Atoms and the tiny particles inside of them—

變得比最小的物質

The laws of the very small, quantum mechanics,

原子和原子中的微觀粒子

Say that the fabric of space becomes bumpy and chaotic.

還小上幾十億倍

Eventually we reach a world

描述微觀世界的量子力學表示

So turbulent that it defies common sense.

這時空間結構將變得波動而混亂

Down here,

最終我們來到了這個

Space and time are so twisted and distorted

喧囂而又違背常理的世界

That the conventional ideas of left and right, up and down,

在這裡

Even before and after, break down.

時間跟空間被扭曲變形

There's no way to tell for certain that I'm here,

傳統概念中的 左右 上下

Or here or both places at once.

甚至是時間的前後 都不復存在

Or maybe I arrived here before I arrived here.

這個世界裡 無法確定我是在這裡

In the quantum world you just can't pin everything down.

在這裡 還是同時處於兩個地方

It's an inherently wild and frenetic place.

又或者我來這裡之前 已經到了這裡

The laws in the quantum world

在量子的世界裡 沒什麼是確知無疑的

Are very different from the laws that we are used to.

這是個放蕩不羈 難以捉摸的地方

And is that surprising?

量子世界的定律

Why should the world of the very small, at an atomic level,

與我們習慣的定律截然不同

Why should that world obey the same kind of rules and laws

是不是非常令人驚訝

that we are used to in our world, With apples and oranges

為何原子層面的超微觀世界

And walking around on the street?

卻同樣遵守著

Why would that world behave the same way?

這個我們習慣的 有蘋果橙子

The fluctuating jittery picture of space and time predicted

還有人在街上走的世界的規則呢

By quantum mechanics

為何那個世界與我們的世界表現相同

is in direct conflict With the smooth, orderly,

這個時間跟空間劇烈動盪

Geometric model of space and time

由量子力學預言的世界

described by general relativity.

與那個平穩的 有條理的

But we think that everything,

廣義相對論描繪的幾何時空模型

From the frantic dance of subatomic particles

格格不入

To the majestic swirl of galaxies,

但我們認為 宇宙萬物

Should be explained by just one grand physical principle,

從亞原子粒子的瘋狂躍動

One master equation.

到星系的瑰麗漩渦

If we can find that equation,

應該由一套普適的物理學定律解釋

How the universe really works at every time and place

由一個主方程描述

Will at last be revealed.

若我們能找出這個方程

You see,

宇宙在何時何地如何運行的奧秘

What we need is a theory

終將揭曉

That can cope with the very tiny and the very massive,

你知道了

One that embraces both quantum mechanics and general relativity,

我們需要的是一套

And never breaks down, ever.

能在微觀和宏觀通用的理論

For physicists,

一套包含了量子力學和廣義相對論

Finding a theory that unites general relativity

永不崩潰的理論

And quantum mechanics is the holy grail,

對物理學家來說

Because that framework would give us a single mathematical theory

這套合併廣義相對論

That describes all the forces that rule our universe.

和量子力學的理論就像聖盃

General relativity describes

因為這套體系能帶來一套數學理論

The most familiar of those gravity.

可以描述所有規範宇宙的作用力

The quantum mechanics describes three other forces.

廣義相對論描述的是

The strong nuclear force

最為熟悉的作用力 重力

That's responsible for gluing protons and neutrons together inside of atoms;

量子力學則描述另外三種作用力

Electromagnetism,

強核力

which produces light, Electricity and magnetic attraction;

能使質子和中子在原子內結合

And the nuclear forces.

電磁力

That's the force responsible for radioactive decay.

能產生光 電 和磁吸引

Every event in the universe

還有核力

From the splitting of a atom, to the birth of a star

能導致輻射衰變

Is nothing more than these four forces into acting with manner

宇宙中的所有現象

Albert Einstein spent the last 30 years Of his life

從原子的分裂 到恆星的誕生

searching For a way to describe the forces Of nature

都不外乎是這幾種力的相互作用

in a single theory,

阿爾伯特·愛因斯坦 用他最後30年

And now string theory may fulfill

尋找能將自然界的所有作用力

His dream of unification.

用單一理論描述的方法

For centuries,

現在 弦理論也許能夠實現

Scientists have pictured the fundamental ingredients of nature

他理論大統一的夢想

atoms and the smaller particles inside of them

幾個世紀以來

As tiny balls or points.

科學家們把自然界的最基本元素

But string theory proclaims

原子和原子內的微觀粒子

That at the heart of every bit of matter

描繪為是小球體 或小點

is a tiny, Vibrating strand of energy called a string.

但弦理論宣告

And a new breed of scientist believes

一切物質的核心

These miniscule strings

都是微小振動的能量物質 叫做弦

Are the key to uniting the world of the large

新一代的科學家相信

And the world of the small in a single theory.

這些微小弦就是

The idea that a scientific theory That we already have in our hands

將宏觀跟微觀世界用一種理論

could answer the most basic questions

統一起來的關鍵

Is extremely seductive.

這種我們已掌握的科學理論

For about 2,000 years,

可以解決大部分基本問題

All of our physics essentially has been based on...

這十分誘人

Essentially we were talking about billiard balls.

差不多2000年來

The very idea of the string is such a paradigm shift,

所有物理學精髓都基於

Because instead of billiard balls,

我們所謂的桌球理論

You have to use little strands of spaghetti.

弦這個想法 是一次概念的轉換

But not everyone is enamored of this new theory.

不再是桌球

So far no experiment has been devised that

而是一條條意面

Can prove these tiny strings exist.

但並不是所有人都傾心於這個理論

And let me put it bluntly.

目前為止

There are physicists and there are string theorists.

沒有實驗能證明這些微小弦的存在

It is a new discipline,

恕我直言

A new—you may call it a tumor

現在有物理學家 還有弦理論家

——you can call it what you will,

這是一種新的學說

But they have focused on questions

你可以稱之為"腫瘤"

Which experiment cannot address.

隨你怎麼叫

They will deny that, These string theorists,

但他們關注的問題

But it's a kind of physics which is not yet testable,

無法用實驗證明

It does not make predictions that have anything

弦理論家可能會否認

To do with experiments that can be done in the laboratory or

但這一尚未驗證的物理學分支

With observations that could be made in space or from telescopes.

其所做出的預測

And I was brought up to believe, and I still believe,

與實驗室裡的實驗

That physics is an experimental science.

和望遠鏡的太空觀測 無任何關係

It deals with the results to experiments,

我的所學讓我直到現在仍相信

Or in the case of astronomy, observations.

物理學是一門實驗科學

From the start, many scientists thought

實驗出結論

String theory was simply too far out.

在天文領域 就靠觀察星體

And frankly,

一開始 很多科學家認為

The strange way the theory evolved—in a series of twists,

弦理論太脫離現實了

Turns and accidents—only made it seem more unlikely.

坦白說

In fact, even it's birth has turned something . which goes like this

這套理論的演化過程

In the late 1960s

異乎尋常 充滿巧合 令人更加難以置信

a young Italian physicist,

就連它的誕生 也成了傳奇

Named Gabriele venetian,

十九世紀六十年代晚期

Was searching for a set of equations

一位年輕的意大利物理學家

That would explain the strong nuclear force,

伽布利耶·威尼采亞諾

The extremely powerful glue that

在尋找一個方程組

Holds the nucleus of every atom together

用來描述強核力

Binding protons to neutrons.

也就是在原子核內

As the story goes,

使每個原子內的質子和中子

He happened on a dusty book on the history of mathematics,

緊密結合的強力膠水

And in it he found a 200-year old equation,

據說某天

First written down by a Swiss mathematician, Leonhard Euler.

他無意間在一本滿是灰塵的數學史書中

Veneziano was amazed to discover

找到一組200年前的舊方程式

that Euler』s equations, Long thought to be nothing More than a mathematical curiosity,

最先由瑞士數學家萊昂哈德·歐拉寫下

Seemed to describe the strong force.

威尼采亞諾驚訝地發現

He quickly published a paper and was famous

這組被視為數學遊戲的歐拉方程

Ever after for this "accidental" discovery.

竟然似乎能用來描述強核力

I see occasionally, written in books,

他很快發表了一篇論文

That, uh, that this model was invented by chance or was, ,

並因這次意外發現 一舉成名

Found in the math book

我偶然在書裡看到

,,this makes me feel pretty bad.

這模型是機緣巧合地

What is true

在數學書裡被發現的

Is that the function was the outcome of a long year of work,

這讓我很不高興

And we accidentally discovered string theory.

實際情況是

However it was discovered, Euler』s equation,

伽瑪函數真的是一整年科學研究的成果嗎

Which miraculously explained the strong force,

我們就偶然地發現了弦理論

Took on a life of its own.

不管歐拉方程是怎樣被發現的

This was the birth of string theory.

它奇跡般地解釋了強核力

Passed from colleague to colleague,

展現了其理論價值

Euler's equation ended up on the chalkboard

弦理論就此誕生

In front of a young American physicist, Leonard Susskind.

通過學者間的不斷流傳

To this day I remember the formula.

歐拉方程最終來到一位年輕

The formula was...

美國物理學家面前 李奧納特·蘇士侃

And I looked at it, and I said,

至今我仍記得這個方程

"this is so simple even I can figure out what this is."

它是這樣的

Susskind retreated to his attic to investigate.

我剛看著它時說到

He understood that this ancient formula described