演講MP3+雙語文稿:月球是怎么形成的？這里有一個新理論

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聽力課堂TED音頻欄目主要包括TED演講的音頻MP3及中英雙語文稿，供各位英語愛好者學(xué)習(xí)使用。本文主要內(nèi)容為演講MP3+雙語文稿:月球是怎么形成的？這里有一個新理論，希望你會喜歡！

【演講者及介紹】Sarah T. Stewart

莎拉·斯圖爾特——行星科學(xué)家，專門研究太陽系中的碰撞。

【演講主題】一個解釋月球起源的新理論

【中英文字幕】

Translation by Cissy Yun. Reviewed by Carol Wang.

00:13

Nobody likes to make a mistake. And I madea whopping one. And figuring out what I did wrong led to a discovery thatcompletely changes the way we think about the Earth and Moon.

沒人喜歡犯錯。而我卻犯了個驚天大錯。但弄清誤點(diǎn)的過程則讓我有了一個發(fā)現(xiàn)，它完全改變了我們對地球和月球的看法。

00:29

I'm a planetary scientist, and my favoritething to do is smash planets together.

我是一個行星科學(xué)家，我最愛做的事是：讓行星相撞。

00:35

（Laughter）

（笑聲）

00:36

In my lab, I can shoot at rocks usingcannons like this one.

在我的實(shí)驗(yàn)室中，我可以用這樣的大炮擊射巖石。

00:43

（Cannon shot）

（大炮射擊）

00:44

（Laughter）

（笑聲）

00:46

In my experiments, I can generate theextreme conditions during planet formation. And with computer models, I cancollide whole planets together to make them grow, or I can destroy them.

在實(shí)驗(yàn)中，我能模擬行星形成時的極端環(huán)境。借助電腦模型，我可以讓所有的行星互相撞擊，讓它們重生，也可讓它們毀滅。

01:00

（Laughter）

（笑聲）

01:02

I want to understand how to make the Earthand the Moon and why the Earth is so different from other planets.

我想弄明白地球和月球是如何形成的，而且地球?yàn)楹闻c其他行星如此不同。

01:11

The leading idea for the origin of theEarth and Moon is called the "giant impact theory." The theory statesthat a Mars-sized body struck the young Earth, and the Moon formed from thedebris disk around the planet. The theory can explain so many things about theMoon, but it has a huge flaw: it predicts that the Moon is mostly made from theMars-sized planet, that the Earth and the Moon are made from differentmaterials. But that's not what we see. The Earth and the Moon are actually likeidentical twins. The genetic code of planets is written in the isotopes of theelements. The Earth and Moon have identical isotopes. That means that the Earthand Moon are made from the same materials.

有關(guān)地球月球起源的主流觀點(diǎn)是“大碰撞理論”。該理論認(rèn)為，一個火星大小的天體撞擊了年輕的地球，而環(huán)繞行星周圍的碎屑盤形成了月球。該理論能解釋有關(guān)月球的許多事，但它有一個巨大的瑕疵：它預(yù)言月球的大部分構(gòu)成來自那個火星大小的行星，即地球和月球是由不同物質(zhì)組成的。但這與我們的發(fā)現(xiàn)大相徑庭。地球與月球其實(shí)像一對孿生子。行星的基因秘鑰寫在它們的元素同位素中，而地球與月球擁有相同的同位素。這說明地球和月球是由相同物質(zhì)構(gòu)成的。

02:03

It's really strange that the Earth and theMoon are twins. All of the planets are made from different materials, so theyall have different isotopes, they all have their own genetic code. No otherplanetary bodies have the same genetic relationship. Only the Earth and Moonare twins.

地球和月球竟然是孿生子？這太怪了。所有行星都由不同的物質(zhì)構(gòu)成，所以它們都有不同的同位素，它們的基因秘鑰也不一樣。沒有任何其他行星天體有同樣的基因關(guān)系。只有地球和月球是孿生子。

02:23

When I started wong on the origin of theMoon, there were scientists that wanted to reject the whole idea of the giantimpact. They didn't see any way for this theory to explain the specialrelationship between the Earth and the Moon. We were all trying to think of newideas. The problem was, there weren't any better ideas. All of the other ideashad even bigger flaws. So we were trying to rescue the giant impact theory.

當(dāng)我開始研究月球起源時，已經(jīng)有科學(xué)家嘗試擯棄“大碰撞理論”。他們認(rèn)為，該理論完全無法解釋地球與月球之間的特殊關(guān)系。我們都在嘗試找到新的想法。但問題是，沒有什么更好的想法，所有其他的想法漏洞更大。因此，我們試圖去拯救“大碰撞理論”。

02:53

A young scientist in my group suggestedthat we try changing the spin of the giant impact. Maybe making the Earth spinfaster could mix more material and explain the Moon. The Mars-sized impactorhad been chosen because it could make the Moon and make the length of Earth'sday. People really liked that part of the model. But what if something elsedetermined the length of Earth's day? Then there would be many more possiblegiant impacts that could make the Moon. I was curious about what could happen,so I tried simulating faster-spinning giant impacts, and I found that it ispossible to make a disk out of the same mixture of materials as the planet. Wewere pretty excited. Maybe this was the way to explain the Moon.

團(tuán)隊中的一位年輕科學(xué)家建議我們嘗試改變大碰撞中的自轉(zhuǎn)：也許將地球自轉(zhuǎn)的速度提高后，巖屑盤可以混入更多物質(zhì)，并解釋月球的成因。選中火星大小的撞擊物是因?yàn)樗軌蛐纬稍虑?，并形成地球上一天的時長。人們非常喜歡模型的這一部分。但是，倘若地球一天的時長是由其他因素導(dǎo)致的呢？那么，很多其他可能的大碰撞都有可能生成月球。我很好奇會發(fā)生什么情況，所以，我模擬了行星轉(zhuǎn)速加快后的大碰撞實(shí)驗(yàn)，發(fā)現(xiàn)的確有可能產(chǎn)生與行星物質(zhì)相同的巖屑盤。我們都非常興奮，也許，這可以解釋月球起源。

03:48

The problem is, we also found that that'sjust not very likely. Most of the time, the disk is different from the planet,and it looked like making our Moon this way would be an astronomicalcoincidence, and it was just hard for everyone to accept the idea that theMoon's special connection to Earth was an accident. The giant impact theory wasstill in trouble, and we were still trying to figure out how to make the Moon.

問題是，我們也發(fā)現(xiàn)這種可能性極小，因?yàn)槎鄶?shù)情況下，巖屑盤與行星的物質(zhì)是不一樣的，若如此形成了月球，看起來像是天文巧合。大家很難接受月球和地球的特殊關(guān)系僅僅是一個巧合?！按笈鲎怖碚摗币廊粺o法解釋，我們?nèi)栽趪L試搞清月球的成因，

04:21

Then came the day when I realized mymistake. My student and I were looking at the data from these fast-spinninggiant impacts. On that day, we weren't actually thinking about the Moon, wewere looking at the planet. The planet gets super-hot and partially vaporizedfrom the energy of the impact. But the data didn't look like a planet. Itlooked really strange. The planet was weirdly connected to the disk. I got thatsuper-excited feeling when something really wrong might be something reallyinteresting.

直到有一天，我發(fā)現(xiàn)自己弄錯了。我和學(xué)生在研究行星高速自轉(zhuǎn)時大碰撞所產(chǎn)生的數(shù)據(jù)。那一天，我們其實(shí)沒思考有關(guān)月球的事，我們在觀察那個行星。因?yàn)榕鲎菜a(chǎn)生的能量，那個星球會變得超級熱，并會部分蒸發(fā)。但數(shù)據(jù)顯示，不像是行星，它看起來十分奇怪。行星以一種奇怪的方式與巖屑盤聯(lián)結(jié)著。我忽然有了那種超級興奮的感覺：當(dāng)某件事看起來很不對勁時，極有可能是個有趣的發(fā)現(xiàn)。

05:00

In all of my calculations, I had assumedthere was a planet with a separate disk around it. Calculating what was in thedisk as how we tested whether an impact could make the Moon. But it didn't lookthat simple anymore. We were making the mistake of thinking that a planet wasalways going to look like a planet. On that day, I knew that a giant impact wasmaking something completely new.

在所有的計算中，我都假設(shè)行星被一個分離的巖屑盤所環(huán)繞。把計算巖屑盤的成分作為測試大碰撞是否生成月球的方法。但它看起來卻不再那么簡單，我們犯的錯在于認(rèn)為行星總是其終極狀態(tài)的樣子，直到那天，我才意識到大碰撞創(chuàng)造出一種全新的天體。

05:33

I've had eureka moments. This was not oneof them.

我有過很多次“恍然大悟”的時刻，但這次卻不是。

05:37

（Laughter）

（笑聲）

05:38

I really didn't know what was going on. Ihad this strange, new object in front of me and the challenge to try and figureit out. What do you do when faced with the unknown? How do you even start?

我完全不知道到底發(fā)生了什么。在我面前的是這個奇怪的新型天體, 我的挑戰(zhàn)則是弄清它是什么。當(dāng)你面對未知物時，你會怎么做？你該如何著手？

05:55

We questioned everything: What is a planet?When is a planet no longer a planet anymore? We played with new ideas. We hadto get rid of our old way of thinking, and by playing, I could throw away allof the data, all of the rules of the real world, and free my mind to explore.And by making a mental space where I could try out outrageous ideas and thenbring them back into the real world to test them, I could learn. And byplaying, we learned so much. I combined my lab experiments with computer modelsand discovered that after most giant impacts, the Earth is so hot, there's nosurface. There's just a deep layer of gas that gets denser and denser withdepth. The Earth would have been like Jupiter. There's nothing to stand on. Andthat was just part of the problem. I wanted to understand the whole problem. Icouldn't let go of the challenge to figure out what was really going on ingiant impacts. It took almost two years of throwing away old ideas and buildingnew ones that we understood the data and knew what it meant for the Moon.

我們質(zhì)疑所有事情：什么才是行星？什么情況下，行星就不再是行星了？我們玩索各種腦洞大開的新想法。我們得摒棄舊的思考方式，因?yàn)椤巴妗钡男再|(zhì)，我可以忘卻所有數(shù)據(jù)、扔掉所有現(xiàn)實(shí)中的條條框框、讓我的思想去自由地探索。我先在大腦中創(chuàng)建一個讓自己任意遐想的空間，然后再在現(xiàn)實(shí)世界中去測試這些想法，并從中學(xué)習(xí)。通過玩索，我們受益匪淺。我把實(shí)驗(yàn)與電腦模型結(jié)合起來，發(fā)現(xiàn)在多數(shù)大碰撞之后，地球會變得滾燙，沒有地表。地球只有一層厚厚的氣體，愈深密度愈高，這時的地球其實(shí)像木星一樣，表面沒有任何固體。但這只是問題的一部分，而我想搞清整個問題。我放手不了這個弄清大碰撞到底 發(fā)生了什么的挑戰(zhàn)，為此，我花了大約兩年的時間 去摒棄老思維，并筑建新理論，這些理論基于理解實(shí)驗(yàn)數(shù)據(jù)、 和弄清它對月球的影響。

07:17

I discovered a new type of astronomicalobject. It's not a planet. It's made from planets. A planet is a body whoseself-gravity is strong enough to give it its rounded shape. It spins around alltogether. Make it hotter and spin it faster, the equator gets bigger and biggeruntil it reaches a tipping point. Push past the tipping point, and the materialat the equator spreads into a disk. It's now broken all the rules of being aplanet. It can't spin around together anymore, its shape keeps changing as itgets bigger and bigger; the planet has become something new.

我發(fā)現(xiàn)了一種新型天文物體，它不是行星，但它來自于行星。行星，是受強(qiáng)大自引力作用而呈球狀的星體。它作為一個整體進(jìn)行自轉(zhuǎn)。溫度越高，自轉(zhuǎn)速度就越快，赤道會越變越大，直至到達(dá)臨界點(diǎn)。一旦過了臨界點(diǎn)，在赤道附近的物質(zhì)會向外擴(kuò)散形成巖屑盤，此時，它也不再遵循行星的所有規(guī)律。它再也無法自轉(zhuǎn)，隨著不斷變大，其形狀也會不斷變化，行星變成了一種全新的天體。

08:00

We gave our discovery its name: synestia.We named it after the goddess Hestia, the Greek goddess of the hearth and home,because we think the Earth became one. The prefix means "alltogether," to emphasize the connection between all of the material. Asynestia is what a planet becomes when heat and spin push it over the limit ofa spheroidal shape.

我們給這個發(fā)現(xiàn)起了個名字：索內(nèi)斯蒂亞（synestia），用女神赫斯提亞來命名它，她是古希臘神話中的家爐之神，因?yàn)槲覀冋J(rèn)為地球就變成了這樣的角色。詞首“syn”意味著“一起”，強(qiáng)調(diào)了所有物質(zhì)之間的聯(lián)結(jié)。當(dāng)熱量和轉(zhuǎn)速將行星推越了球型天體的極限后，行星就變成了索內(nèi)斯蒂亞。

08:27

Would you like to see a synestia?

你們想看看索內(nèi)斯蒂亞嗎？

08:30

（Cheers）

（歡呼）

08:33

In this visualization of one of mysimulations, the young Earth is already spinning quickly from a previous giantimpact. Its shape is deformed, but our planet would be recognizable by thewater on its surface. The energy from the impact vaporizes the surface, thewater, the atmosphere, and mixes all of the gases together in just a few hours.We discovered that many giant impacts make synestias, but these burning, brightobjects don't live very long. They cool down, shrink and turn back intoplanets. While rocky planets like Earth were growing, they probably turned intosynestias one or more times.

這是其中的一個模擬視頻，因?yàn)橹暗囊淮闻鲎?，年輕的地球在快速自轉(zhuǎn)。地球有些變形，但根據(jù)地表的水，我們還認(rèn)得出它是地球。大碰撞帶來的能量讓地球表層、水、大氣層完全蒸發(fā)，在短短幾小時中，所有的氣體混合起來。我們發(fā)現(xiàn)許多大碰撞會產(chǎn)生索內(nèi)斯蒂亞，但這些燃燒著的熾熱天體壽命不長。它們會降溫，縮小，并再次變回行星。在類似地球這樣的巖石行星在成長過程中，可能會一次或數(shù)次變成索內(nèi)斯蒂亞。

09:19

A synestia gives us a new way to solve theproblem of the origin of the Moon. We propose that the Moon formed inside ahuge, vaporous synestia. The Moon grew from magma rain that condensed out ofthe rock vapor. The Moon's special connection to Earth is because the Moonformed inside the Earth when Earth was a synestia. The Moon could have orbitedinside the synestia for years, hidden from view. The Moon is revealed by thesynestia cooling and shrinking inside of its orbit. The synestia turns intoplanet Earth only after cooling for hundreds of years longer. In our newtheory, the giant impact makes a synestia, and the synestia divides into twonew bodies, creating our isotopically identical Earth and Moon. Synestias havebeen created throughout the universe. And we only just realized that by findingthem in our imagination: What else am I missing in the world around me? What ishidden from my view by my own assumptions?

索內(nèi)斯蒂亞為我們解決月球起源提供了新途徑，我們提出，月球形成于一個巨型、氣化的索內(nèi)斯蒂亞內(nèi)部。月球形成于巖石蒸汽凝結(jié)而產(chǎn)生的巖漿雨。月球與地球間的特殊聯(lián)系是因?yàn)樵虑蛐纬捎诘厍騼?nèi)部，那時，地球還是一個索內(nèi)斯蒂亞。月球在索內(nèi)斯蒂亞內(nèi)部可能已公轉(zhuǎn)了許久，但我們無法觀察到它。而當(dāng)索內(nèi)斯蒂亞冷卻縮小到月球公轉(zhuǎn)軌道以內(nèi)時，月球才出現(xiàn)在我們的視線中，只有經(jīng)歷了幾百年的冷卻后，索內(nèi)斯蒂亞才會變成地球。在我們的新理論中，大碰撞形成了索內(nèi)斯蒂亞，而索內(nèi)斯蒂亞分成兩個新天體，就是同位素相同的地球與月球。索內(nèi)斯蒂亞在宇宙各處都在發(fā)生，通過想象他們的存在，我們才剛剛意識到這個現(xiàn)象：在我周圍的世界中，我還遺漏了什么？我自己的臆測 還妨礙我看到什么其他信息？

10:51

The next time you look at the Moon,remember: the things you think you know may be the opportunity to discoversomething truly amazing.

下一次你賞月時，請記住: 你認(rèn)為自己知道的事，也許正是讓你發(fā)現(xiàn)真正令人驚訝事情的好機(jī)會。

11:05

（Applause）

（掌聲）