Name: 沒有愛因斯坦，廣義相對論仍會被發現嗎？｜薛恩·卡羅 (Why general relativity would’ve been discovered without Einstein | Sean Carroll)
Uploaded: 2025-11-07T18:28:50.000Z
Duration: 16 min 58 s

基礎被動語態

I like to say that Einstein is, if anything, underrated as a physicist, which is hard to imagine given how highly he is rated.

我喜歡說愛因斯坦，如果有的話，他被低估了身為一位物理學家，這點很難想像，因為他已經被評價得很高了。

When we tell the history of physics, we try to keep things straight and we can't remember everything.

當我們講述物理學的歷史時，我們會試著釐清事實，而且我們不可能記住所有事情。

程度副詞

So we kind of give a lot of credit to a relatively small number of individuals, Einstein being one of them.

所以我們傾向於將很多功勞歸於相對少數的幾個人，愛因斯坦就是其中之一。

The messy reality of it is that all of these very smart people, including Isaac Newton, were talking to other people.

實際情況有點混亂，那就是所有這些非常聰明的人，包括牛頓，都在和其他人交流。

So it's always interesting to see the evolution of ideas, which is not exactly lockstep with the evolution of people.

所以觀察想法的演變總是很有趣，這不完全是與人的演變同步的。

They have different ideas at different times.

他們在不同的時間有不同的想法。

他們從不同的來源獲得這些想法。

That's the messy human reality of doing science.

這就是做科學的混亂人性現實。

I am a physicist and philosopher at Johns Hopkins University, host of the Mindscape podcast and also author of a bunch of books, most recently the Biggest Ideas in the Universe series, including Space, time and motion and quanta and fields.

我是約翰霍普金斯大學的物理學家和哲學家，Mindscape 播客的主持人，也是許多書籍的作者，最近的作品是《宇宙中的最大想法》系列，包括 Space, time and motion 和 量子與場。

It's so much fun reading the history of how these ideas developed, because today we're just taught the final result.

閱讀這些想法發展的歷史真的很有趣，因為我們今天學到的只是最終結果。

But, you know, they didn't know what was going on.

但你知道，他們當時並不知道發生了什麼。

Back in the early days, the first really huge revolution in physics was the existence of classical mechanics, handed down by Isaac Newton and others.

在早期，物理學的第一個真正巨大的革命是古典力學的出現，這是由牛頓等人傳下來的。

And Aristotle says that things have natural places they want to be, natural ways, they want to move.

亞里斯多德說，事物有它們想待的自然位置，有它們想移動的自然方式。

And Newton says something completely different.

He says, if something is not acted on by a force, it's going to continue in a straight line at a constant velocity forever.

他說，如果一個物體不受力作用，它將以恆定的速度永遠沿直線運動。

And if it is acted on by a force, I can tell you how it will move.

如果它受到力的作用，我可以告訴你它會如何移動。

我有一個方程式可以做到這一點。

One part of classical mechanics is the idea of space and time both separately existing and being absolute.

古典力學的一部分想法是，空間和時間是獨立存在的，而且是絕對的。

There is no preferred position in the universe.

宇宙中沒有所謂的「偏好位置」。

你可以隨心所欲地待在任何地方。

There's not even a preferred velocity to the universe.

宇宙甚至沒有一個「偏好的速度」。

This was figured out by Galileo, and Newton kind of took it on board.

這部分是伽利略發現的，而牛頓則把它納入考量。

Turns out those assumptions are not quite right.

結果發現，這些假設其實不太對。

And it was a journey to get there, as it often is.

而這是一段漫長的旅程，就像很多事情一樣。

It started in the 1800s with the invention of electromagnetism.

這一切始於 1800 年代，電磁學的發明。

It was James Clerk Maxwell who put the whole story together after work by people like Faraday and Ampere and so forth.

是馬克士威在法拉第、安培等人努力之後，才把整個故事串起來的。

And what he realized is there's two fields pervading the universe.

而他發現的是，宇宙中有兩種場瀰漫其中。

People were very happy at the existence of electromagnetism.

人們對於電磁學的出現感到非常高興。

They started thinking about what it all meant.

他們開始思考這一切到底意味著什麼。

And what they realized is that the sort of way that space and time are treated in Maxwell's theory of electromagnetism is different than the way they are apparently treated in Newton's theory.

他們發現，在馬克士威的電磁學理論中，空間和時間的處理方式，跟牛頓理論中明顯的處理方式不一樣。

In particular, Maxwell's equations predicted a special velocity.

特別是，馬克士威的方程式預測了一個特殊的「速度」。

There's no special velocity in Newtonian mechanics.

在牛頓力學裡，並沒有什麼特殊的「速度」。

Maxwell says there is something called the speed of light.

馬克士威說，有一個東西叫做光速。

It is the speed at which waves in the electromagnetic fields move.

那是電磁場中波浪前進的速度。

And naively, you look at the equations and everyone measures the same value for the speed of light.

直觀來看，你看看這些方程式，大家測量到的光速值都一樣。

How can it possibly be the case that everyone measures the same speed for light, even if they're moving with respect to each other?

為什麼大家測量到的光速都一樣，即使他們彼此之間有相對運動？

So for a long time, for decades, people, physicists, bashed their heads against this problem.

所以很長一段時間，幾十年來，人們，物理學家，都在苦思這個問題。

They came with very elaborate schemes to get rid of it.

他們想出了非常複雜的方案來擺脫它。

And it was Einstein, Albert Einstein, in his great paper in 1905, who first said, you should get rid of the idea of these waves traveling through a medium.

而愛因斯坦，阿爾伯特·愛因斯坦，在他 1905 年的偉大論文中，首先說，你們應該拋棄這些波浪透過某種介質傳播的想法。

You should think of the electromagnetic waves as really being the thing that exists.

你們應該把電磁波本身看作是真正存在的東西。

And when the equations tell you everyone measures the speed of light the same, that's because they do take that seriously.

當方程式告訴你，大家測量到的光速都一樣時，那是因為他們真的認真看待這件事。

All you have to do is entirely rejigger your thoughts about what space and time are.

你們只需要徹底重新調整對空間和時間的看法。

And in fact, it wasn't until two years later when Herman Minkowski, who was a mathematician, who had been one of Einstein's professors, said, you know, the right way to think about Einstein's theory is to say that space and time aren't separate anymore.

而且事實上，要到兩年後，一位數學家，也是愛因斯坦的教授赫曼·閔可夫斯基提出，你們知道，看待愛因斯坦理論的正確方式就是說，空間和時間不再是分開的。

To imagine there's one thing called space time, and

different people, different observers moving in different ways through the universe will divide it up into space and time differently.

而不同的人，在宇宙中以不同方式移動的不同觀察者，會以不同的方式將其劃分為空間和時間。

There's no objective, true fact about when I snap my fingers now, what's happening light years away.

關於我現在彈手指，距離光年遠的地方發生了什麼事，並沒有客觀的真相。

That's going to depend on who is doing the observing and who's doing the measuring.

這將取決於誰在觀察，誰在測量。

It can all be explained very beautifully by imagining a single four dimensional space time instead of separate space and time.

這一切都可以透過想像一個單一的四維時空，而不是獨立的空間和時間來美麗地解釋。

Einstein himself was not impressed by this move.

愛因斯坦本人對這個轉變並不以為意。

Einstein was a hilarious character because he was a physicist's physicist.

愛因斯坦是個很有趣的人物，因為他是一位物理學家中的物理學家。

You know, don't believe the stories that Einstein wasn't good at math in school.

你們知道，別相信那些說愛因斯坦小時候數學不好的故事。

he wasn't in it for the math, he was in it for the physics.

他不是為了數學而做，他是為了物理學。

And when Bikovsky says, I have some new math that unifies space and time based on Einstein's theories, Einstein himself is like, I don't need that.

當 Bikovsky 說，我有一些基於愛因斯坦理論的數學，可以統一時空，愛因斯坦本人卻說，我不需要那個。

那根本是額外的數學胡說八道。

He soon changed his mind because it Turns out that that move from space and time being separate to being combined is super useful going forward.

他很快就改變了主意，因為事實證明，從空間和時間是分離到結合的這一步，對未來非常有用。

When Einstein put together what we now call the special theory of relativity, the idea that there's no preferred standard of rest in the universe, but

當愛因斯坦提出了我們現在稱為狹義相對論的理論，也就是宇宙中沒有首選的靜止標準，但

also everyone thinks the speed of light is the same.

同時每個人都認為光速是相同的。

All you have to do is imagine ultimately that space and time are together.

你所要做的就是最終想像空間和時間是結合在一起的。

That was a radical reworking of the framework of physics.

那是對物理學框架的一次徹底重塑。

You know, Newton's idea of separate space and separate time, absolute and agreed upon by everyone, had been there for hundreds of years.

你知道嗎，牛頓認為空間和時間是分離的，是絕對的，而且是大家公認的，這已經存在好幾百年了。

And when you do that, when you say, okay, I'm going to completely invent space and time, in part because I want to match this wonderful theory we have, Maxwell's theory of electricity and magnetism, you have to go back to everything that was a success in your previous way of doing things and say, does it still work?

當你這麼做的時候，當你說，好吧，我要徹底重新發明空間和時間，部分原因是我想要匹配我們現有的這個很棒的理論，馬克士威的電磁學理論，你必須回顧你過去所有成功的做法，然後問，它還有效嗎？

The biggest success of Newtonian classical mechanics was gravity, the famous inverse square law of gravity.

牛頓古典力學最大的成功就是重力，就是那個著名的平方反比定律。

Newton posited that you have two objects with two different masses.

牛頓提出，你有兩個不同質量的物體。

They have a gravitational force that will pull them together that diminishes as one over the square of the distance between them.

它們之間會有一種引力將它們拉在一起，這種引力會隨著它們之間距離的平方而減弱。

And that simple rule plus the framework of Newtonian mechanics is enough to match exactly what you see in the sky in terms of the planets moving around.

這個簡單的規則加上牛頓力學的框架，就足以精確地匹配你在天空中看到的行星運動。

It's enough to launch a rocket and get it to the moon.

這足以發射火箭並將其送往月球。

So Einstein comes along and says, well, okay, can I make a version of Newton's theory of gravity that is compatible with my new theory of special relativity?

所以愛因斯坦來了，他說，好吧，我可以建立一個與我的狹義相對論新理論相容的牛頓萬有引力理論版本嗎？

在嘗試之後，他說，不行，我做不到。

You have to do something much more dramatic.

你必須做一些更戲劇性的事情。

And what he realized is that gravity is not a force on top of spacetime.

而他意識到的是，引力並非是疊加在時空上的力。

Well, my ex, Professor Minkowski, says that spacetime has a geometry.

嗯，我的前任，明可夫斯基教授，他說，時空具有一種幾何結構。

And there are equations telling me how particles move in it.

並且有方程式告訴我粒子在其中如何移動。

Maybe it's not like a flat tabletop like Euclidean geometry, but

或許它不像歐幾裡得幾何那樣是個平坦的桌面，而是

maybe it's warped and bent and dynamical and changes in response to the existence of mass and energy and things like that.

或許它是扭曲、彎曲且動態的，會隨著質量、能量等事物的存在而改變。

It takes you a lot of effort and a lot of mathematical work to figure it out.

這需要你花費很多心力跟很多數學上的努力才能弄懂。

So 10 years later, in 1915, Einstein finally completes what we call the general theory of relativity.

所以十年後，也就是1915年，愛因斯坦終於完成了我們稱之為廣義相對論的理論。

And the general theory of relativity says space time is a four dimensional thing.

而廣義相對論說，時空是一個四維的物體。

That four dimensional thing has a geometry.

這個四維的物體有它的幾何結構。

It's pushed around by matter and energy, and

we experience the curvature of space time as the force of gravity.

我們將時空的彎曲體驗為重力。

I would Put Einstein and Galileo in my pantheon of people who just felt what the universe should be like very, very deeply.

我會把愛因斯坦和伽利略放進我的萬神殿，他們都是非常、非常深刻地感受到宇宙應該是什麼樣子的人。

And this let Einstein make enormous amounts of progress.

這讓愛因斯坦取得了巨大的進展。

the thing is, once you use that intuition, Einstein used his ideas about gravity disappearing in small regions of space time to invent general relativity.

關鍵是，一旦你運用這種直覺，愛因斯坦就利用他關於重力在時空小區域內消失的想法，發明瞭廣義相對論。

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沒有愛因斯坦，廣義相對論仍會被發現嗎？｜薛恩·卡羅 (Why general relativity would’ve been discovered without Einstein | Sean Carroll)

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