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As they grow bigger and bigger,
隨著體積越來越大
they start to spin and throw out a disk of debris
它們開始旋轉(zhuǎn)，甩出的碎屑形成盤狀
that will coalesce to form a solar system.
在日后融合形成太陽系
This kind of process is exactly the kind of process
我們的太陽系
that would have formed our solar system.
就是這樣形成的
When we look at our solar system,
在我們太陽系中
all of the planets rotate around the sun in the same direction
所有行星都以相同的方向繞著太陽旋轉(zhuǎn)
and they all are in the same plane
而且都位于相同平面
the same flat sheet around our sun,
在相同的平面上繞著太陽旋轉(zhuǎn)
and this is exactly a consequence of the fact
這是因為早期
that the early solar system formed out of a broad disc.
太陽系是在一個廣闊的圓盤上形成的
With the solar-system in place
太陽系就定位之后
all that is left is for the young star to light up.
就等年輕的恒星開始發(fā)光
When it happens it is sudden and irreversible.
這個現(xiàn)象來得又快又急而且無法逆轉(zhuǎn)
Ultimately the process starts
這個過程終究會發(fā)生
and because it liberates so much energy with that first fusion,
因為第一次融合會釋放出驚人的能量
then the process takes off.
整個過程便一發(fā)不可收拾
Um - it lights up a large area and it starts to shine on its own
它照亮廣闊區(qū)域
within a matter of minutes.
在短短幾分鐘內(nèi)便開始自行發(fā)光
It's a very quick process.
這個過程很快
In that first burst of light the star
在第一波猝發(fā)的光線中
has begun its lifelong activity as a factory
恒星展開制造
for making other chemical elements.
其他化學(xué)元素的生涯
Every atom in everything around us was made in the heart of a star
我們周遭的一切原子都來自恒星的核心
and all were made from the same starting ingredient.
而且起始成分都一模一樣
The simplest element that we have is hydrogen
宇宙間最簡單的元素是氫
and it's actually the building block
它是所有
for all the other elements that we have.
其他元素的基礎(chǔ)材料
In the heart of the sun hydrogen nuclei
氫原子核也就是質(zhì)子
protons - are stuck together to make heliumlt
在太陽的核心結(jié)合形成氦
It sounds straightforward
這聽起來很簡單
but it can only happen in the most extreme conditions.
但卻只能發(fā)生在最極端的情況下
In order for these protons to come together,
質(zhì)子要兩兩結(jié)合的話…
because they're both positively charged
因為它們都帶正電
they don't want to come together,
所以會互相排斥
they've actually got to be pushed together.
必須要有外力壓迫才行
In order to do this you need very high temperatures
所以需要很高的溫度
so they're moving very fast and you also need very,
讓它們快速移動
very high pressures.
也需要極高的壓力
The only part of the sun that is hot and dense enough is the core.
太陽唯一夠熱，密度夠高的地方
An area that contains over half the star's mass
就是它的核心
in less than 2 percent of its volume.
太陽核心的體積不到太陽的2%
Here at 15 million degrees the protons
但質(zhì)量卻超過太陽的一半
are bashed together so hard that they fuse.
質(zhì)子在一千五百萬度的高溫下猛然撞擊、融合
A helium nucleus is a tiny bit lighter
氦原子核雖然由四個質(zhì)子形成
than the combined mass of the 4 protons it is made from.
但重量卻比四個質(zhì)子輕一點
And as Einstein tells us it is
愛因斯坦告訴我們太陽的能量
that tiny bit of lost mass that provides the power.
來自這一點點流失的質(zhì)量
Energy is equal to mass times the speed of light,
能量等于質(zhì)量乘以
times the speed of light.
光速的平方
