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The composition of the sun lies in this bar code.
這個條碼說明了太陽的組成
All the thin lines are caused by tiny amounts of complex elements
這些細(xì)細(xì)的線條，都是微量復(fù)雜元素造成的
metals like iron and magnesium.
好比說像鐵或鎂等金屬
But there are 3 very deep,broad lines,
但是這里有三條很暗、很粗的線條
and they are all caused by
它們都是
an enormous amount of a single element.
由大量單一元素形成的
There's some helium and traces of heavier elements.
太陽中含有氦和少量較重的元素
But over 90% of the sun is Hydrogen.
但有90%是氫
It is the simplest and most common element in the universe.
氫是宇宙中最簡單也最常見的元素
The secrets of the sun's power must lie in this gas.
太陽能量的秘密，想必和這種氣體有關(guān)
Look carefully into the night sky
仔細(xì)觀察夜空
and you'll see huge clouds of
你會發(fā)現(xiàn)大片由氫組成的云
hydrogen floating in interstellar space.
在星際間飄移
These are nebulae.
這些是星云
And they can be hundreds of light years across.
它們直徑可能高達(dá)數(shù)百光年
They are some of the brightest areas in the sky
星云被新近形成的巨大恒星強光照亮
lit up by the intense light of newly formed massive stars.
是空中最明亮的區(qū)域
In them we can see stars being born.
我們可以在星云中看到誕生中的恒星
It is to areas like this that astronomers turn
天文學(xué)家用望遠(yuǎn)鏡觀察這些區(qū)域
their telescopes when they want to study how our sun was formed.
以研究太陽的形成過程
There she is,
在那里
okay,so now let's recentre on her.
把焦距移到這里
By studying different nebulae it's possible to
科學(xué)家藉由研究不同的星云
piece together the stages in which stars are made.
拼湊出恒星的形成階段
And it all starts in a cold dark cloud,
這一切的起點，是一片冰冷、黝黑的云
floating around waiting for something to happen.
飄浮在虛無中等待大事發(fā)生
Cold clouds like this are actually quite stable.
像這樣的冰冷云朵其實很穩(wěn)定
They will sit there for a very very long time,
有時它們會靜止很長很長時間
for thousands and in some cases millions of years
幾千，甚至幾百萬年
before they'll actually do anything.
才會發(fā)生變化
What you need to do to get the star formation process going
它們要受到刺激
is you need to kick it with something.
才會展開恒星形成的過程
That can be the impact on the cloud
刺激可能來自
from one side by a supernova blast wave;
超新星的爆炸波
a massive star nearby has gone boom at the end of its life
鄰近的巨大恒星在生命盡頭爆炸
and that sends out in all directions very energetic
并朝四面八方發(fā)出能量十足的壓縮波
compression waves that hit the gas and compress it.
壓縮波撞擊氣體并將之壓縮
The shock waves knock the cloud out of balance.
云朵因震波而失去平衡
Causing localised clumps of hydrogen to form.
并導(dǎo)致某些區(qū)域出現(xiàn)氫氣團塊
These are the seeds from which stars grow.
這就是萌生恒星的種子
The increased gravity of the seeds sucks in more
種子與日俱增的引力吸引越來越多氫氣
and more hydrogen in a runaway process
這樣的出走過程
that lasts for a million years.
會持續(xù)一百萬年
As more hydrogen is squeezed into the clumps the temperature rises.
團塊聚集的氫氣越多，溫度就越高
They are not yet producing light
它們還不會發(fā)光
but they are well on the way to becoming stars.
但已踏上成為恒星的道路
