追溯生命元素：你的身體始於星辰的死亡。，
TED演講
我們全都由原子連接在一起。
We are all atomically connected.
這是放之四海而皆準的基本規律。
Fundamentally,universally.
但這是什麼意思呢？
But what does that mean?
作為一個天體物理學家，我的職責是，
I'm an astrophysicst, and as Such,
追溯構成你的
it is my responsibility to trace the cosmic histrory
每一個原子的宇宙歷史。
Of every single one of your atoms.
事實上，我應該這麼說：
In fact, I would say
現代天文學最偉大的成就之一是
that one of the greatest achievements of modern astronomy
理解我們的原子是怎樣組裝的。
Is the understanding of how our atoms were actually put together.
雖說氫和氮
While hydrogen and helium were made
是在大爆炸的最初兩分鐘誕生的，
during the first two minutes of the big bang,
重金屬的起源，
the origin of heavy elements,
比如說血液中的鐵，呼吸出的氧氣，
such as the iron in your bloody, the oxygen we're breathing,
電腦裡的硅
the silicone in your computers,
都棲身於恆星的整個生命週期之中。
Lies in the life cycle of starts.
核反應將較輕的元素轉換成更重的元素，
Nuclear reactions take lighter elements and transform them into heavier ones,
這使得星辰閃耀，
and that causes stars to shine
最終爆發，
and ultimately explode,
從而讓宇宙充滿了重元素。
Therefore enriching the universe with heavy elements.
如果沒有恆星的死亡，
So without stellar death
也就不會有氧
there would be no oxygen
或者其他比氫和氦更重的元素，
or other elements heavier than hydrogen and helium,
生命也就無從誕生
and therefore, there would be no life.
我們身體中原子的數量
There are more atoms in oure bodies 10^27
比宇宙中星星的數量還多。
Than stars in the universe.
而這些原子及其耐久。
And these atoms are extremely durable.
我們的原子的起源
The origins of our atoms
可以追溯到數十億年前，他們在恆星的內部被製造出來，
can be traceable to stars that manufactured them in their interiors.,
隨後在大爆炸中噴射到
and exploded them all across the Milky Way,
銀河的各個角落。
Billions of years ago.
而我理應對此瞭如指掌，
And I should know this,
因為我是名副其實受認證的星星葬儀師。
Because I am indeed a certified stellar mortician.
今天，我想帶領大家踏上一段旅程，由超新星爆炸開始，
And today ,I want to take you o a journey that starts in a supernova explosion
在我們此刻呼吸的空氣中結束。
And ends with the air that we're breathing right now.
我們的身體是由什麼構成的？
So what is our body made of?
其中96%的組織僅由四種元素構成：N Nitrogen H Hydrogen C Carbon O Oxygen
Ninety-six percent consists of only four elements:
氫、碳、氧、氮
hydrogen, carbon, oxygen and nitrogen.
這個宇宙故事的主角是氧。
Now the main character of this cosmic tale is oxygen.
氧不僅是我們身體的主要部分，
Not only is the vast majority of our bodies made of oxygen,
也是在地球上努力保護生命的那個元素。
But oxygen is the one element fighting to protect life on earth.
宇宙中絕大部分的氧
The vast majority of oxygen in the universe
確實是在整個宇宙的歷史中，在這些超新星爆炸時
was indeed producted over the entire history of the universe
製造出來的。
In these supernova explosions.
這些超新星爆炸宣告著非常巨大的恆星的逝去。
These supernova explosions signal the demise of very massive stars.
在這光輝炫目的一整個月中，
And for a brilliant month,
一次超新星爆炸
one supernova explosion can be brighter than an entire galaxy
可能比包含了數十億星星的整個星系還要明亮
containing billions of stars.
這真的令人歎為觀止。
That is truly remarkable.
那是因為比起其他星星，巨大的恆星燃燒得更加耀眼 10^58
That is because massive stars burn brighter
死亡得也更加輝煌。
And have a spectacular death, compared to other stars.
核聚變可以說是所有恆星的命脈，
Nuclear fusion is really the lifeblood of all stars.
包括太陽，
including the sun,
因此也是地球上所有能源的根源。
And as result is the root source of all energy on earth.
你可以把恆星想象成核聚變工廠
You can think of stars as these fusion factories
在它們灼熱而緻密的內部，相互衝撞的原子
which are powered by smashing atoms together
為工廠提供著動力。
In their hot and dense interiors.
比較小的恆星，
Now, stars like our sun,
比如我們的太陽
which are relatively small,
燃燒氫形成氦，
burn hydrogen into helium,
但質量是太陽大約八倍的更重的恆星
but heavier stars of about eight times the mass of the sun
即使在耗盡了內核的氦之後，
continue this burning cycle
依然繼續這個燃燒的循環。
Even after they exhausted their helium in their cores.
那麼這時，
So at this point,
巨大的恆星只剩下一個碳核心，
the massive star is left with a carbon core,
我們都知道，碳也是生命的基石。
Which,as you know, is the building block of life.
這個碳核心繼續塌縮，
This carbon core continues to collapse
造成溫度升高，
and as a result, the temperature increases,
進而導致更多的核反應發生，
which allows further nuclear reactions to take place,
碳進一步燃燒成氧，
and carbon then burns into oxygen,
成為氖、硅、硫，
into neon,silicon,sulphur
最終形成鐵。
And ultimately iron.
鐵是整個過程的重點。
And iron is the end.
為什麼？
Why?
因為鐵是宇宙中結合得最穩定的原子核，
Because iron is the most bound nuclear in the universe,
也就是說我們無法通過燃燒鐵獲取能量。
Whichi means that we cannot extract energy by burning iron.
當大恆星的整個內核充滿了鐵，
So when the entire core of the massive star is made of iron,
它就耗盡了燃料。
It's run out of fuel.
對於一顆恆星來說，那可是相當糟糕的一天。
And that's an incredibly bad day for a star.
沒有燃料，它就我發產生熱量，
Without fuel,it cannot generate heat,
因此引力便在這場戰鬥中勝出。
And therefore gravity has won the battle.
鐵核心除了塌縮，達到異常高的密度之外
The iron core has no other choice but to collapse,
別無選擇。
Reaching incredibly high densities.
想象一下三億噸的質量
Think of 300 million tons
壓縮成一塊方糖大小。
Reduced to a space the size of sugar cube.
在這極高的密度下，核心其實會反抗塌縮，
At these extreme high densities, the core actually resists collapse,
結果就是，
and as a result,
所有這些墜落的物質會從核心反彈。
All of this infalling material bounces off the core.
而這戲劇性的反彈，
And this dramatic bounce,
發生在不到一秒的彈指間，
which happens in a fraction of a second or so,
它導致恆星的其餘部分朝所有方向噴射出去，
is responsible for ejecting the rest of the star in all directions,
最終形成了超新星爆炸。
Ultimately forming a supernova explosion.
從一個天體物理學家的角度來說，遺憾的是，
So,sadly, from the perspective of an astrophysicist,
這些爆炸的星星的內部條件
the conditions in the centers of these exploding stars
無法在實驗室內重現出來。
Cannot be recreated in a laboratory.
不過對於人類來說，這是值得慶幸的事。
Now, thankfully for humanity, we're not able to do that.
但這意味著什麼？
But what does that mean?
這意味著作為天體物理學家，
That means that as astrophysicist,
我們不得不依賴複雜的計算機模擬，
we have to rely on sophisticated computer simulations
以理解這些複雜的現象。
In order to understand these complex phenomena.
我們可以通過這些模擬理解在這種極端條件下
These simulations can be used to really understand how gas behaves
氣體的表現如何。
Under such extreme conditions.
我們也可以通過模擬，回答一些基本的問題，
And can be used to answer fundamental questions
比如說，“歸根結底，大恆星是怎麼被瓦解的？”
like, “What untimately disrupted the massive star?”
“這樣的相信爆炸是怎麼被逆轉變成向外爆炸的？”
“How is it that this implosion can be reversed in to an explosion?”
這個領域有大量爭論，
There's a huge amount of debate in the field,
但我們達成的共識是，
but we all agree that neutrinos,
中微子，也就是某種難以捕捉的基本例子，
which are these elusive elementary particles,
在其中扮演了至關重要的角色。
Play a crucial role.
聽上去如何？
Yeah?
下面我要給大家演示其中一個模擬。
I'm about to show you one of those simulations.
中微子在恆星內核塌縮時大量產生的。
So neutrinos are produced in huge numbers once the core collapses.
事實上，
And in fact,
它們擔負著內核中傳遞能量的職責。
They are responsible for transferring the energy in this core.
就像暖氣機中的熱輻射一樣，
Like thermal radiation in a heater,
中微子將能量超內核中泵送，
neutrinos pump energy into the core,
增加了恆星被破壞的可能。
Increasing the possibility of disrupting the star.
事實上，在幾分之一秒的時間內，
In fact , for about a fraction of a second,
中微子輸送的能量如此龐大，
neutrinos pump so much energy
使得壓力升高到足以產生衝擊波，
that the pressure increase high enough that a shock wave is produced
而衝擊波進一步將整顆恆星破壞。
And the shock wave goes and disruptes the entire star.
正是在這個衝擊波之中，各種元素誕生了。
And it is in that shock wave where elements are produced.
中微子，謝謝你們
So thank you, neutrinos.
超新星非常耀眼
Supernovas shine bright,
在一段短暫的時間裡，
and for brief period of time,
它們輻射出的能量比太陽生命週期內釋放的還多。
They radiate more energy that the sun will in its entire lifetime.
你們在那裡看到的光點
That point of light that your see there,
之前絕對不存在，
which was certainly not there before,
它現在像燈塔一樣熊熊燃燒，
burns like a beacon,
清楚地標識著巨大恆星死去的位置。
Clearly indicating the position where the massive star has died.
在一個像銀河系一樣的星系裡，
In a galaxy like our own Milky Way,
我們估計大約每50年
we estimate that about once every 50 years,
就有一顆大恆星死亡。
A massive star dieds.
這意味著大約每一秒鐘，
This implies that somewhere in the universe,
宇宙中的某處就有一次超新星爆發。
There's a supernova explosion every second or so.
對於天文學家來說，謝天謝地的是，
And thankfully for astronomers,
其中一些的發生未知離地球相對比較近。
Some of them are actually found relatively close to earth.
早在天文望遠鏡被發現之前，許多文明已經
Various civilazations recorded these supernova explosions
對這些超新星爆炸有所記載。
Long before the telescope was invented.
其中最著名的當屬
The most famous of all of them
誕生了蟹狀星雲的那場超新星爆炸。
Is probably the supernova explosion that gave rise to the Crabe Nebula.
韓國和中國的天文學家在1054年記錄了這顆超新星，
Korean and Chinese astronomers recorded this supernova in 1054,
基本可以肯定美國原住民也對此進行了記錄。
As did, almost certainly , Native Americans.
這次超新星爆發發生在距離地球約5600光年的地方。
This supernova happened about 5600 light-years away from earth.
它如此明亮，
And it was so incredibly bright
天文學家們在白晝都能看到它。
That astronomers could see it during the day.
在大約兩年的時間裡，它在夜空中裸眼可見。
And it was visible to the naked eye for about two years in the night sky.
向前快進約1000年，我們看到了什麼？
Fast forward 1000 years or so later, and what do we see?
我們看到了因爆炸而迸發的光絲，
We see these filaments that were blasterd by the explosion,
以每秒300英里的速度移動。
Moving at 300 miles per second.
這些光絲對於我們理解大恆星如何死亡
These filaments are essential for us to understand
至關重要
how massive stars die.
大家看到的這副圖像，
The image that you see there
是由哈勃天文望遠鏡
was assembled by the Hubble Space Telescope
耗時三個月收集的。
Over a span of three months.
它對於天文學家非常重要
And it is incredibly important to astronomers
因為歸根結底，它承載的是發生爆炸的星體
because it untimately carries the chemical legacy
的化學遺產
of the star that exploded.
這些橘色的光絲是那顆恆星殘破的遺骸
The orange filaments that you see there are the tattered remains of the star,
主要由氫構成，
and are made primarily hydrogen,
而藍色和紅色的光絲，
while the blue and red filaments that you see
是新鮮生成的氧
are the freshly synthesized oxygen.
因此，研究像蟹狀星雲那樣的超新星的殘留物，
So studying supernova remnasnts, like the Crab Nebula,
能讓天文學家得出鑑定的結論：
alllowed astronomers to firmly conclude
地球上絕大多數氧元素都是在宇宙的歷史長河中
that the vast majority of oxygen on earth was produced by supernova explosions
由超新星爆炸產生的。
Over the history of the universe.
我們可以估算，
And we can estimate
為了組裝我們身體裡所有的氧原子，
that in order to assemble all atoms of oxygen in our body,
需要上億的超新星。
It took on the order of a 100 million supernova.
因此大家的全身上下，至少是其中的絕大部分，
So every bit of you , or at lease the majority of it,
都來自這些超新星爆炸中的一個。
Came from one of these supernova explosions.
那麼現在各位可能會納悶，
So now you may be wondering,
這些在如此極端條件下
how is it that these atoms
原子的產生，最終會怎樣
that were generated in such extreme conditions
在我們的身體裡定居？
Ultimately took residence in our body?
我想讓各位進行一個思想實驗。
So I want you to follow the thought experiment.
想象一下我們在銀河系，一場超新星爆炸開始了。
Imagine that we're in the Milky Way, and a supernova happens.
它將無數氧原子
It blasted tons and tons of oxygen atoms
轟進了空空如也的太空。
Almost into empty space.
其中少數被聚集成為星雲
A few of them were able to be assembled in a cloud.
45億年前，
Now , 4.5 billion years ago,
某種東西擾亂了那篇星雲，使其土崩瓦解，
something unsettled that cloud and caused it to collapse,
在它的中心形成了太陽和太陽系。
Forming the sun in its center and the solar system.
因此太陽，行星和地球上的生命
So the sun, the planets and life on earth
都仰賴這個美麗的循環：
depend on this beautiful cycle
恆星誕生，恆星死亡，恆星誕生。
Of stellar birth, stellar death and stellar rebirth.
在這個過程循環往復，將宇宙中的原子回收再利用。
And this continues the recycling of atomes in the universe.
因此，天文學家和化學是緊密聯繫的。
And as a result, astronomy and chemistry are intimately connected.
我們這種生命形態，演化到要依靠植物廢棄產物來呼吸。
We are life forms that have evolved to inhale the waste products of plants.
不過現在大家也瞭解了，
But now you know
我們同時也呼吸著超新星爆炸的廢棄產物。
That we also inhale the waste products of supernova explosions.
所以花點時間，深吸一口氣吧。
So take a moment, inhale.
一個氧原子剛剛進入了你的身體。
An oxygen atom has just gone into your body.
可以肯定的是，
It is certain that that oxygen [atom]
那個氧原子記得它曾經身處某顆恆星的內部，
remembers that it was in the interior of a star
也記得它很可能是在一場超新星爆炸中被製造出來的。
And it was probably manufactured by a supernova explosion.
這個原子或許經歷了跨越整個太陽系的跋涉，
This atome may have tranveled the entire solar system
才濺落到地球上，
until it splashed on earth,
有過了很久很久才和你相遇。
Long before reaching you.
我們呼吸時，
When we breathe,
每天都消耗掉數百升氧氣。
We use hundred of liters of oxygen every day.
所以我今天非常幸運的站在這群美妙的觀眾面前，
So I'm incredibly lucky to be standing in front of this beautiful audience,
但我其實是在偷你們的氧原子。
But I'm actually sealing your oxygen atoms.
….
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