弦理論解析——現實的真正本質是什麼？：英語精讀講義

What is the true nature of the universe?

宇宙的真正本質是什麼？

To answer this question,

為了回答這個問題，

humans come up with stories to describe the world. 片語動詞

人類構思出各種故事來描述世界。

We test our stories and learn what to keep and what to throw away. 文法

我們測試這些故事，搞清楚該保留哪些、捨棄哪些。

But the more we learn, 文法

但是，我們了解得越多，

the more complicated and weird our stories become.

我們的故事就變得越複雜、越離奇。

Some of them so much so that it's really hard to know what they're actually about. 片語搭配

其中一些甚至複雜到讓人很難搞懂它們到底在說什麼。

Like string theory,

比如弦理論，

a famous, controversial,

這是一個著名的、備受爭議的，

and often misunderstood story about the nature of everything.

並且經常被誤解的，關於萬物本質的故事。

Why did we come up with it,

我們為什麼要提出它？

and is it correct or just an idea we should chuck out? 片語動詞

它是正確的，還是一個我們應該拋棄的想法？

To understand the true nature of reality,

為了理解現實的真正本質，

we looked at things up close and were amazed.

我們湊近觀察事物，並感到驚嘆。

Wondrous landscapes in the dust,

灰塵中奇妙的微觀景象，

zoos of bizarre creatures,

千奇百怪的生物樂園，

complex protein robots.

複雜的蛋白質機器人。

All of them made from structures of molecules made up of countless even smaller things, 片語搭配

它們都是由分子結構組成的，而分子又由無數更小的東西組成，

atoms.

即原子。

We thought they were the final layer of reality

我們曾以為原子是現實的最後一層，

until we smashed them together really hard

直到我們用力將它們撞擊在一起，

and discovered things that can't be divided anymore,

並發現了不能再分割的東西，

elementary particles.

基本粒子。

But now we had a problem.

但現在我們遇到了一個問題。

They're so small that we could no longer look at them. 文法

它們太小了，以至於我們無法再觀察它們。

Think about it.

想想看。

What is seeing?

什麼是「看」？

To see something,

要看到某個東西，

we need light,

我們需要光，

an electromagnetic wave.

一種電磁波。

This wave hits the surface of the thing and gets reflected back from it into your eye.

這種波擊中物體的表面，然後反射到你的眼睛裡。

The wave carries information from the object that your brain uses to create an image.

波攜帶著物體的資訊，你的大腦利用這些資訊生成圖像。

So you can't see something without somehow interacting with it.

所以，如果不和物體發生某種相互作用，你就無法看到它。

Seeing is touching, 表達脈絡

看到就是接觸，

an active process,

這是一個主動的過程，

not a passive one.

而非被動的。

This is not a problem with most things.

對於大多數事物來說，這不是問題。

But particles are very, very, very small.

但粒子非常、非常、非常小。

So small that the electromagnetic waves we use to see are too big to touch them. 文法

小到我們用來觀察的電磁波都太大了，無法觸碰到它們。

Visible light just passes over them.

可見光直接從它們上方穿過。

We can try to solve this by creating electromagnetic waves with more and much smaller wavelengths, 文法

我們可以嘗試透過製造波長更短、更小的電磁波來解決這個問題，

but in quantum physics,

但在量子物理學中，

shorter wavelengths means more energy.

更短的波長意味著更多的能量。

So when we touch a particle with a wave that has a lot of energy,

所以，當我們用具有高能量的波去觸碰一個粒子時，

it gets a kick. 用詞

它就會受到衝擊。

By looking at a particle,

只要觀察粒子，

we change it.

我們就會改變它。

In quantum physics,

在量子物理學中，

we cannot know where a particle is and where it's going with absolute precision.

我們無法絕對精確地知道一個粒子在哪裡以及它要去哪裡。

This fact is so important that it has a name,

這個事實非常重要，甚至有它專門的名字，

the Heisenberg uncertainty principle, 文化背景

海森堡不確定性原理，

the basis of all quantum physics.

它是所有量子物理學的基礎。

So what does a particle look like then?

那麼，粒子到底長什麼樣呢？

What is its nature?

它的本質是什麼？

We don't know.

我們不知道。

If we look really hard,

如果我們非常仔細地觀察，

we can see a blurry sphere of influence,

我們可以看到一個模糊的勢場，

but not the particles themselves.

但看不到粒子本身。

We just know they exist.

我們只知道它們存在。

But if that's the case, 片語搭配

但如果是這樣的話，

how can we do any science with them?

我們怎麼能對它們進行任何科學研究呢？

We did what humans do and invented a new story,

我們做了人類慣常做的事，編造了一個新故事，

a mathematical fiction. 慣用語

一個數學小說。

The story of the point particle.

點粒子的故事。

We decided that we would pretend that a particle is a point in space.

我們決定假裝粒子是空間中的一個點。

Any electron is a point with a certain electric charge and a certain mass, 用詞

任何電子都是具有特定電荷和特定質量的一個點，

all indistinguishable from each other. 片語搭配

它們之間完全無法區分。

This way, 表達脈絡

這樣一來，

physicists could define them and calculate all of their interactions.

物理學家就可以定義它們，並計算它們所有的相互作用。

This can be made precise in quantum field theory,

這在量子場論中可以被精確化，

and this solved a lot of problems.

並且解決了很多問題。

All of the standard model of particle physics is built on it, 片語動詞

粒子物理學的整個標準模型都是建立在它的基礎上的，

and it predicts lots of things very well.

並且它非常準確地預測了許多事情。

Some quantum properties of the electron,

例如，電子的某些量子性質，

for example,

已經經過測試，

have been tested and are accurate up to 0.000000000002%. 片語搭配

其精確度達到了 0.000000000002%。

So while particles are not really points,

所以，雖然粒子並不是真正的點，

by treating them as if they were, 文法

但透過把它們當成點來對待，

we get a pretty good picture of the universe.

我們得到了關於宇宙的相當不錯的圖景。

Not only did this idea advance science, 文法

這個想法不僅推動了科學的發展，

it also led to a lot of real-world technology we use every day.

它還促成了我們每天使用的許多現實世界中的技術。

But there's a huge problem,

但這裡有一個巨大的問題，

gravity.

重力。

In quantum mechanics,

在量子力學中，

all physical forces are carried by certain particles. 用詞

所有物理力都是由特定的粒子傳遞的。

But according to Einstein's general relativity, 片語搭配

但根據愛因斯坦的廣義相對論，

gravity is not a force like the others in the universe.

重力與宇宙中的其他力不同。

If the universe is a play, 慣用語

如果宇宙是一出戲，

particles are the actors,

粒子是演員，

but gravity is the stage.

那麼重力就是舞台。

To put it simply, 表達脈絡

簡單來說，

gravity is a theory of geometry,

重力是一個關於幾何的理論，

the geometry of space-time itself,

是時空本身的幾何，

of distances which we need to describe with absolute precision.

那些我們需要用絕對精度來描述的距離的幾何。

But since there is no way to precisely measure things in the quantum world,

但由於在量子世界中沒有辦法精確測量事物，

our story of gravity doesn't work with our story of quantum physics.

我們的重力故事與我們的量子物理學故事不相容。

When physicists tried to add gravity to the story by inventing a new particle,

當物理學家試圖透過發明一種新粒子將重力加入這個故事時，

their mathematics broke down. 片語動詞

他們的數學崩潰了。

And this is a big problem.

這是一個大問題。

If we could marry gravity to quantum physics and the standard model, 慣用語

如果我們能把重力與量子物理學和標準模型結合起來，

we would have the theory of everything.

我們就能得到萬物理論。

So very smart people came up with a new story.

於是非常聰明的人想出了一個新故事。

They asked,

他們問，

what is more complex than a point?

什麼比點更複雜？

A line,

一條線，

or a string.

或者一根弦。

String theory was born.

弦理論由此誕生。

What makes string theory so elegant is that it describes many different elementary particles as different modes of vibration of the string. 文法

弦理論之所以如此優雅，是因為它將許多不同的基本粒子描述為弦的不同振動模式。

Just like a violin string vibrating differently can give you a lot of different notes, 表達脈絡

就像小提琴琴弦的不同振動可以產生許多不同的音符一樣，

a string can give you different particles.

一根弦可以給你不同的粒子。

Most importantly,

最重要的是，

this includes gravity.

這包含了重力。

String theory promised to unify all fundamental forces of the universe.

弦理論承諾統一宇宙的所有基本力。

This caused enormous excitement and hype.

這引起了巨大的興奮和炒作。

String theory quickly graduated to a possible theory of everything. 慣用語

弦理論很快晉升為可能的萬物理論。

Unfortunately,

不幸的是，

string theory comes with a lot of strings attached. 慣用語

弦理論附帶了很多限制條件。

Much of the maths involving a consistent string theory does not work in our universe

涉及一致的弦理論的許多數學在我們的宇宙中行不通，

with its three spatial and one temporal dimensions. 用詞

因為我們的宇宙有三個空間維度和一個時間維度。

String theory requires 10 dimensions to work out.

弦理論需要 10 個維度才能成立。

So string theorists did calculations in model universes

所以弦理論家在模型宇宙中進行計算，

and then try to get rid of the six additional dimensions and describe our own universe. 片語動詞

然後試圖去掉那六個多餘的維度，並描述我們自己的宇宙。

But so far, 片語搭配

但到目前為止，

nobody has succeeded,

還沒有人成功，

and no prediction of string theory has been proven in an experiment. 文法

而且弦理論的任何預測都沒有在實驗中被證明。

So string theory did not reveal the nature of our universe.

所以弦理論並沒有揭示我們宇宙的本質。

One could argue that in this case, 表達脈絡

有人可能會爭辯說，在這種情況下，

string theory really isn't useful at all.

弦理論真的毫無用處。

Science is all about experiments and predictions.

科學全在於實驗和預測。

If we can't do those,

如果我們不能做這些，

why should we bother with strings? 語氣意圖

我們為什麼還要在弦上費心思呢？

It really is all about how we use it.

實際上，一切都取決於我們如何使用它。

Physics is based on maths.

物理學基於數學。

2 + 2 makes 4.

2 + 2 等於 4。

This is true no matter how you feel about it. 文法

無論你對此有什麼感覺，這都是真的。

And the maths in string theory does work out. 文法

而且弦理論中的數學確實是成立的。

That's why string theory is still useful.

這就是為什麼弦理論仍然有用。

Imagine that you want to build a cruise ship,

想像一下，你想建造一艘遊輪，

but you only have blueprints for a small rowing boat.

但你只有一艘小划艇的藍圖。

There are plenty of differences,

它們有很多不同之處，

the engine,

引擎、

the materials,

材料、

the scale.

規模。

But both things are fundamentally the same,

但這兩者在根本上是一樣的，

things that float.

都是漂浮在水上的東西。

So by studying the rowing boat blueprints, 文法

所以，透過研究划艇的藍圖，

you might still learn something about how to build a cruise ship eventually.

你可能仍然能學到一些最終如何建造遊輪的知識。

With string theory,

藉助弦理論，

we can try to answer some questions about quantum gravity

我們可以嘗試回答一些關於量子重力的問題，

that have been puzzling physicists for decades, 文法

這些問題幾十年來一直困擾著物理學家，

such as how black holes work or the information paradox.

比如黑洞是如何運作的，或者資訊悖論。

String theory may point us in the right direction. 慣用語

弦理論可能會為我們指明正確的方向。

When used in this spirit, 文法

當本著這種精神使用時，

string theory becomes a precious tool for theoretical physicists

弦理論成為了理論物理學家的寶貴工具，

and help them discover new aspects of the quantum world

並幫助他們發現了量子世界的新面向

and some beautiful mathematics.

以及一些優美的數學。

So maybe the story of string theory is not the theory of everything, 文法

所以也許弦理論的故事並不是萬物理論，

but just like the story of the point particle,

但就像點粒子的故事一樣，

it may be an extremely useful story.

它可能是一個極其有用的故事。

We don't yet know what the true nature of reality is,

我們還不知道現實的真正本質是什麼，

but we'll keep coming up with stories to try and find out

但我們會繼續想出新的故事去嘗試弄清楚，

until one day,

直到有一天，

hopefully,

希望

we do know.

我們真的能知道。

This video was supported by the Swiss National Science Foundation

本影片由瑞士國家科學基金會贊助支持，

and realized with the scientific advice of Alessandro Sfondrini.

並由 Alessandro Sfondrini 提供科學建議。