Your body was forged in the spectacular death of stars | Enrico Ramirez-Ruiz

Translator: Ivana Korom Reviewer: Krystian Aparta

翻译人员: Wanting Zhong 校对人员: Jingdan Niu

We are all atomically connected.

我们全都由原子连接在一起。

Fundamentally, universally.

这是放之四海皆准的基本规律。

But what does that mean?

但这是什么意思呢？

I'm an astrophysicist, and as such,

作为一个天体物理学家， 我的职责是，

it is my responsibility to trace the cosmic history

追溯构成你的

of every single one of your atoms.

每一个原子的宇宙历史。

In fact, I would say

事实上，我应该这么说：

that one of the greatest achievements of modern astronomy

现代天文学最伟大的成就之一是

is the understanding of how our atoms were actually put together.

理解我们的原子是怎样组装的。

While hydrogen and helium were made

虽说氢和氦

during the first two minutes of the big bang,

是在大爆炸的最初两分钟诞生的，

the origin of heavy elements,

重元素的起源，

such as the iron in your blood, the oxygen we're breathing,

比如说血液中的铁， 呼吸出的氧，

the silicone in your computers,

电脑里的硅，

lies in the life cycle of stars.

都栖身于恒星的 整个生命周期之中。

Nuclear reactions take lighter elements and transform them into heavier ones,

核反应将较轻的元素 转换成更重的元素，

and that causes stars to shine

这使得星辰闪耀，

and ultimately explode,

最终爆发，

therefore enriching the universe with these heavy elements.

从而让宇宙充满了重元素。

So without stellar death

如果没有恒星的死亡，

there would be no oxygen

也就不会有氧，

or other elements heavier than hydrogen and helium,

或者其他比氢和氦更重的元素，

and therefore, there would be no life.

生命也就无从诞生。

There are more atoms in our bodies

我们身体中原子的数量

than stars in the universe.

比宇宙中星星的数量还多。

And these atoms are extremely durable.

而这些原子极其耐久。

The origins of our atoms

我们的原子的起源

can be traceable to stars that manufactured them in their interiors

可以追溯到数十亿年前， 它们在恒星的内部被制造出来，

and exploded them all across the Milky Way,

随后在爆炸中喷射到

billions of years ago.

银河的各个角落。

And I should know this,

而我理应对此了如指掌，

because I am indeed a certified stellar mortician.

因为我是名副其实 受认证的星星葬仪师。

(Laughter)

（笑声）

And today, I want to take you on a journey that starts in a supernova explosion

今天，我想带领大家踏上一段旅程， 由超新星爆炸开始，

and ends with the air that we're breathing right now.

在我们此刻呼吸的空气中结束。

So what is our body made of?

我们的身体是由什么构成的？

Ninety-six percent consists of only four elements:

其中 96% 的组织仅由四种元素构成：

hydrogen, carbon, oxygen and nitrogen.

氢、碳、氧、氮。

Now the main character of this cosmic tale is oxygen.

这个宇宙故事的主角是氧。

Not only is the vast majority of our bodies made of oxygen,

氧不仅是我们身体的主要成分，

but oxygen is the one element fighting to protect life on earth.

也是在地球上努力保护 生命的那个元素。

The vast majority of oxygen in the universe

宇宙中绝大部分的氧

was indeed produced over the entire history of the universe

确实是在整个宇宙的历史中， 在这些超新星爆炸时

in these supernova explosions.

制造出来的。

These supernova explosions signal the demise of very massive stars.

这些超新星爆炸 宣告着非常巨大的恒星的逝去。

And for a brilliant month,

在这光辉炫目的一整个月中，

one supernova explosion can be brighter than an entire galaxy

一次超新星爆炸

可能比包含了数十亿星星 的整个星系还要明亮。

containing billions of stars.

That is truly remarkable.

这真的令人叹为观止。

That is because massive stars burn brighter

那是因为比起其他星星， 巨大的恒星燃烧得更加耀眼，

and have a spectacular death, compared to other stars.

死亡得也更加辉煌。

Nuclear fusion is really the lifeblood of all stars,

核聚变可以说是 所有恒星的命脉，

including the sun,

包括太阳，

and as a result is the root source of all the energy on earth.

因此也是地球上所有能源的根源。

You can think of stars as these fusion factories

你可以把恒星想象成核聚变工厂，

which are powered by smashing atoms together

在它们灼热而致密的内部， 互相冲撞的原子

为工厂提供着动力。

in their hot and dense interiors.

Now, stars like our sun,

比较小的恒星，

比如我们的太阳，

which are relatively small,

burn hydrogen into helium,

燃烧氢形成氦，

but heavier stars of about eight times the mass of the sun

但质量是太阳大约八倍 的更重的恒星

continue this burning cycle

即使在耗尽了内核的氦之后，

even after they exhausted their helium in their cores.

依然继续这个燃烧的循环。

So at this point,

那么这时，

the massive star is left with a carbon core,

巨大的恒星 只剩下一个碳核心，

which, as you know, is the building block of life.

我们都知道，碳也是生命的基石。

This carbon core continues to collapse

这个碳核心继续坍缩，

and as a result, the temperature increases,

造成温度升高，

which allows further nuclear reactions to take place,

进而导致更多核反应发生，

and carbon then burns into oxygen,

碳进一步燃烧成为氧，

into neon, silicon, sulphur

成为氖、硅、硫，

and ultimately iron.

最终形成铁。

And iron is the end.

铁是整个过程的终点。

Why?

为什么？

Because iron is the most bound nuclei in the universe,

因为铁是宇宙中 结合得最稳定的原子核，

which means that we cannot extract energy by burning iron.

也就是说我们无法 通过燃烧铁获取能量。

So when the entire core of the massive star is made of iron,

当大恒星的整个内核充满了铁，

it's run out of fuel.

它就耗尽了燃料。

And that's an incredibly bad day for a star.

对于一颗恒星来说， 那可是相当糟糕的一天。

(Laughter)

（笑声）

Without fuel, it cannot generate heat,

没有燃料，它就无法产生热量，

and therefore gravity has won the battle.

因此引力便在这场战斗中胜出。

The iron core has no other choice but to collapse,

铁核心除了坍缩， 达到异常高的密度之外

reaching incredibly high densities.

别无选择。

Think of 300 million tons

想象一下三亿吨的质量

reduced to a space the size of a sugar cube.

压缩成一块方糖的大小。

At these extreme high densities, the core actually resists collapse,

在这极高的密度下， 核心其实会反抗坍缩，

and as a result,

结果就是，

all of this infalling material bounces off the core.

所有这些坠落的物质 会从核心反弹。

And this dramatic bounce,

而这戏剧性的反弹，

which happens in a fraction of a second or so,

发生在不到一秒的弹指间，

is responsible for ejecting the rest of the star in all directions,

它导致恒星的其余部分 朝所有方向喷射出去，

ultimately forming a supernova explosion.

最终形成了超新星爆炸。

So, sadly, from the perspective of an astrophysicist,

从一个天体物理学家 的角度来说，遗憾的是，

the conditions in the centers of these exploding stars

这些爆炸的星星的内部条件

cannot be recreated in a laboratory.

无法在实验室内重现出来。

(Laughter)

（笑声）

Now, thankfully for humanity, we're not able to do that.

不过对于人类来说， 这是值得庆幸的事。

(Laughter)

（笑声）

But what does that mean?

但这意味着什么？

That means that as astrophysicists,

这意味着作为天体物理学家，

we have to rely on sophisticated computer simulations

我们不得不依赖复杂的计算机模拟，

in order to understand these complex phenomena.

以理解这些复杂的现象。

These simulations can be used to really understand how gas behaves

我们可以通过这些模拟理解 在这种极端条件下

under such extreme conditions.

气体的表现如何。

And can be used to answer fundamental questions

我们也可以通过模拟， 回答一些基本的问题，

like, "What ultimately disrupted the massive star?"

比如说，“归根结底， 大恒星是怎么被瓦解的？”

"How is it that this implosion can be reversed into an explosion?"

“这样的向心爆炸是怎样被逆转 变成向外爆炸的？”

There's a huge amount of debate in the field,

这个领域中有大量争论，

but we all agree that neutrinos,

但我们达成的共识是，

中微子，也就是某种 难以捉摸的基本粒子，

which are these elusive elementary particles,

play a crucial role.

在其中扮演了至关重要的角色。

Yeah?

听上去如何？

I'm about to show you one of those simulations.

下面我要给大家演示 其中一个模拟。

So neutrinos are produced in huge numbers once the core collapses.

中微子是在恒星内核坍缩时 大量产生的。

And in fact,

事实上，

they are responsible for transferring the energy in this core.

它们担负着在内核中 传递能量的职责。

Like thermal radiation in a heater,

就像暖气机中的热辐射一样，

neutrinos pump energy into the core,

中微子将能量朝内核中泵送，

increasing the possibility of disrupting the star.

增加了恒星被破坏的可能。

In fact, for about a fraction of a second,

事实上，在几分之一秒的时间内，

neutrinos pump so much energy

中微子输送的能量如此庞大，

that the pressure increases high enough that a shock wave is produced

使得压力升高到 足以产生冲击波，

and the shock wave goes and disrupts the entire star.

而冲击波进一步将整颗恒星破坏。

And it is in that shock wave where elements are produced.

正是在这个冲击波之中， 各种元素诞生了。

So thank you, neutrinos.

中微子，谢谢你们。

(Laughter)

（笑声）

Supernovas shine bright,

超新星非常耀眼，

and for a brief period of time,

在一段短暂的时间里，

they radiate more energy than the sun will in its entire lifetime.

它们辐射出的能量 比太阳在生命周期内释放的还多。

That point of light that you see there,

你们在那里看到的光点，

which was certainly not there before,

之前绝对不存在，

burns like a beacon,

它现在像灯塔一样熊熊燃烧，

clearly indicating the position where the massive star has died.

清楚地标示着 巨大恒星死去的位置。

In a galaxy like our own Milky Way,

在一个像我们的银河系 一样的星系里，

we estimate that about once every 50 years,

我们估计大约每 50 年

a massive star dies.

就有一颗大恒星死亡。

This implies that somewhere in the universe,

这意味着大约每一秒钟，

there's a supernova explosion every second or so.

宇宙中的某处就有一次超新星爆发。

And thankfully for astronomers,

对于天文学家来说，谢天谢地的是，

some of them are actually found relatively close to earth.

其中一些的发生位置 离地球相对比较近。

Various civilizations recorded these supernova explosions

早在天文望远镜被发明之前， 许多文明已经

对这些超新星爆炸有所记载。

long before the telescope was invented.

The most famous of all of them

其中最著名的当属

is probably the supernova explosion that gave rise to the Crab Nebula.

诞生了蟹状星云的 那场超新星爆炸。

Yeah?

对吧？

Korean and Chinese astronomers recorded this supernova in 1054,

韩国和中国的天文学家 在 1054 年记录了这颗超新星，

as did, almost certainly, Native Americans.

基本可以肯定美国原住民 也对此进行了记录。

This supernova happened about 5,600 light-years away from earth.

这次超新星爆炸发生在距离地球 约 5600 光年的地方。

And it was so incredibly bright

它如此明亮，

that astronomers could see it during the day.

天文学家们在白昼也能看到它。

And it was visible to the naked eye for about two years in the night sky.

在大约两年的时间里， 它在夜空中裸眼可见。

Fast forward 1,000 years or so later, and what do we see?

向前快进约 1000 年， 我们看到了什么？

We see these filaments that were blasted by the explosion,

我们看到这些因爆炸 迸发的光丝，

moving at 300 miles per second.

以每秒 300 英里的速度移动。

These filaments are essential for us to understand

这些光丝对于我们理解 大恒星如何死亡

how massive stars die.

至关重要。

The image that you see there

大家看见的这幅图像，

was assembled by the Hubble Space Telescope

是由哈勃天文望远镜

over a span of three months.

耗时三个月收集的。

And it is incredibly important to astronomers

它对于天文学家非常重要，

because it ultimately carries the chemical legacy

因为归根结底， 它承载的是发生爆炸的星体

of the star that exploded.

的化学遗产。

The orange filaments that you see there are the tattered remains of the star,

这些橘色的光丝 是那颗恒星残破的遗骸，

and are made primarily of hydrogen,

主要由氢构成，

while the blue and red filaments that you see

而蓝色和红色的光丝，

are the freshly synthesized oxygen.

是新鲜生成的氧。

So studying supernova remnants, like the Crab Nebula,

因此，研究像蟹状星云那样的 超新星的残留物，

allowed astronomers to firmly conclude

能让天文学家得出坚定的结论：

that the vast majority of oxygen on earth was produced by supernova explosions

地球上绝大部分氧元素 都是在宇宙的历史长河中

over the history of the universe.

由超新星爆炸产生的。

And we can estimate

我们可以估算，

that in order to assemble all the atoms of oxygen in our body,

为了组装我们身体里 所有的氧原子，

it took on the order of a 100 million supernova.

需要上亿的超新星。

So every bit of you, or at least the majority of it,

因此大家的全身上下， 至少是其中的绝大部分，

came from one of these supernova explosions.

都来自这些超新星爆炸中的一个。

So now you may be wondering,

那么现在各位可能会纳闷，

how is it that these atoms

这些在如此极端条件下

that were generated in such extreme conditions

产生的原子，最终是怎样

ultimately took residence in our body?

在我们的身体里定居的？

So I want you to follow the thought experiment.

我想让各位进行一个思想实验。

Imagine that we're in the Milky Way, and a supernova happens.

想象一下我们在银河里， 一场超新星爆炸开始了。

It blasted tons and tons of oxygen atoms

它将无数氧原子

almost into empty space.

轰进了空空如也的太空。

A few of them were able to be assembled in a cloud.

其中少数被聚集成为星云。

Now, 4.5 billion years ago,

45 亿年前，

something unsettled that cloud and caused it to collapse,

某种东西扰乱了那片星云， 使其土崩瓦解，

forming the sun in its center and the solar system.

在它的中心形成了太阳和太阳系。

So the sun, the planets and life on earth

因此太阳、行星，和地球上的生命

depend on this beautiful cycle

都仰赖这个美丽的循环：

of stellar birth, stellar death and stellar rebirth.

恒星诞生、恒星死亡、恒星重生。

And this continues the recycling of atoms in the universe.

这个过程循环往复， 将宇宙中的原子回收再利用。

And as a result, astronomy and chemistry are intimately connected.

因此，天文学和化学是紧密联系的。

We are life forms that have evolved to inhale the waste products of plants.

我们这种生命形态，演化到 要依靠植物的废弃产物来呼吸。

But now you know

不过现在大家也了解了，

that we also inhale the waste products of supernova explosions.

我们同时也呼吸着 超新星爆炸的废弃产物。

(Laughter)

（笑声）

So take a moment, inhale.

所以花点时间，深吸一口气吧。

An oxygen atom has just gone into your body.

一个氧原子刚刚进入了你的身体。

It is certain that that oxygen [atom]

可以肯定的是，

remembers that it was in the interior of a star

那个氧原子记得 它曾身处某颗恒星的内部，

and it was probably manufactured by a supernova explosion.

也记得它很可能是在一场 超新星爆炸中被制造出来的。

This atom may have traveled the entire solar system

这个原子或许历经了 跨过整个太阳系的跋涉，

until it splashed on earth,

才溅落在地球上，

long before reaching you.

又过了很久很久 才和你相遇。

When we breathe,

我们呼吸时，

we use hundreds of liters of oxygen every day.

每天都消耗掉数百升氧。

So I'm incredibly lucky to be standing in front of this beautiful audience,

所以我今天非常幸运 能站在这群美妙的观众面前，

but I'm actually stealing your oxygen atoms.

但我其实是在偷你们的氧原子。

(Laughter)

（笑声）

And because I'm speaking to you,

而因为我在和你们交谈，

I'm giving you some of them back, that once resided in me.

我会归还给你们一些 曾经住在我体内的氧原子。

So breathing, yeah,

所以没错，通过呼吸，

participates in this beautiful exchange of atoms.

参与到这场美丽的原子交换之中。

And you can then ask,

接下来你就可以发问，

"Well, how many atoms in our body once belonged to Frida Kahlo?"

“那么，我们体内有多少原子曾经属于 弗里达·卡罗【注：墨西哥女画家】？”

(Laughter)

（笑声）

About 100,000 of them.

大约有 10 万个。

100,000 more probably belonged to Marie Curie,

还有 10 万个或许曾属于居里夫人，

100,000 more to Sally Ride,

另外 10 万个曾属于萨莉·莱德， 【注：第一位进入太空的美国女性】

or whoever you want to think of.

或者任何一位你想起的人。

So breathing is not only filling our lungs with cosmic history,

所以呼吸为我们的肺部充满的 不仅是宇宙的历史，

but with human history.

也是人类的历史。

I would like to end my talk by sharing a myth

我想分享一个 藏在我内心的传说，

that is very close to my heart.

以此结束这次演讲。

A myth from the Chichimeca culture,

一个来自奇奇梅克文化的传说， 【注：墨西哥北部的游牧民族】

which is a very powerful Mesoamerican culture.

这是一种非常强大的中美洲文化。

And the Chichimecas believe

奇奇梅克人相信

that our essence was assembled in the heavens.

我们的本质是在天上组装的。

And on its journey towards us,

而在朝我们前进的路途上，

it actually fragmented into tons of different pieces.

它破裂成了无数不同的碎片。

So my abuelo used to say,

我的祖父曾经说过，

"One of the reasons you feel incomplete

“你感到自己不完整的原因之一

is because you are missing your pieces."

是因为你确实确实了一些东西。”

(Laughter)

（笑声）

"But don't be fooled by that.

“但不要为此所欺骗。

You've been given an incredible opportunity of growth.

你获得了难以置信的成长机会。

Why?

为什么？

Because it's not like those pieces were scattered on earth

因为那些碎片并不是 散落在地球各处，

你要去把它们捡起来。

and you have to go and pick them up.

No, those pieces fell into other people.

不，那些碎片落在了别人身上。

And only by sharing them you will become more complete.

只有通过分享碎片， 你才会变得更加完整。

Yes, during your life,

没错，在一生之中，

there's going to be individuals that have these huge pieces

你会遇见拥有巨大碎片的人，

他们会让你感到完整。

that make you feel whole.

But in your quest of being complete,

但在你追寻完整的旅途中，

you have to treasure and share every single one of those pieces."

你必须珍视并分享每一片碎片。”

Sounds a lot like the story of oxygen to me.

我觉得这听起来很像 氧原子的故事。

(Laughter)

（笑声）

Which started in the heavens in a supernova explosion,

氧原子的故事在天空中 伴随着超新星爆炸开始，

and continues today,

并持续至今，

within the confines of our humanity.

在人类的界限之内继续书写。

Our atoms in our body have embarked on an epic odyssey,

我们身体里的原子 踏上了一场史诗般的长途冒险，

with time spans from billions of years to mere centuries,

历时横跨数十亿年 到仅仅几个世纪，

all leading to you,

全都指引向你的身边，

all of you,

你们所有人身边，

witnesses of the universe.

你们是宇宙的见证人。

Thank you.

谢谢大家。

(Applause)

（掌声）