they start to spin and throw out a disk of debris  它们开始旋转，甩出的碎屑形成盘状

that will coalesce to form a solar system.  在日后融合形成太阳系

This kind of process is exactly the kind of process  我们的太阳系

that would have formed our solar system.  就是这样形成的

When we look at our solar system,  在我们太阳系中

all of the planets rotate around the sun in the same direction  所有行星都以相同的方向绕着太阳旋转

and they all are in the same plane  而且都位于相同平面

the same flat sheet around our sun,  在相同的平面上绕着太阳旋转

and this is exactly a consequence of the fact  这是因为早期

that the early solar system formed out of a broad disc.  太阳系是在一个广阔的圆盘上形成的

With the solar-system in place  太阳系就定位之后

all that is left is for the young star to light up.  就等年轻的恒星开始发光

When it happens it is sudden and irreversible.  这个现象来得又快又急而且无法逆转

Ultimately the process starts  这个过程终究会发生

and because it liberates so much energy with that first fusion,  因为第一次融合会释放出惊人的能量

then the process takes off.  整个过程便一发不可收拾

Um - it lights up a large area and it starts to shine on its own  它照亮广阔区域

within a matter of minutes.  在短短几分钟内便开始自行发光

It's a very quick process.  这个过程很快

In that first burst of light the star  在第一波猝发的光线中

has begun its lifelong activity as a factory  恒星展开制造

for making other chemical elements.  其他化学元素的生涯

Every atom in everything around us was made in the heart of a star  我们周遭的一切原子都来自恒星的核心

and all were made from the same starting ingredient.  而且起始成分都一模一样

The simplest element that we have is hydrogen  宇宙间最简单的元素是氢

and it's actually the building block  它是所有

for all the other elements that we have.  其他元素的基础材料

In the heart of the sun hydrogen nuclei  氢原子核也就是质子

protons - are stuck together to make heliumlt  在太阳的核心结合形成氦

It sounds straightforward  这听起来很简单

but it can only happen in the most extreme conditions.  但却只能发生在最极端的情况下

In order for these protons to come together,  质子要两两结合的话…

because they're both positively charged  因为它们都带正电

they don't want to come together,  所以会互相排斥

they've actually got to be pushed together.  必须要有外力压迫才行

In order to do this you need very high temperatures  所以需要很高的温度

so they're moving very fast and you also need very,  让它们快速移动

very high pressures.  也需要极高的压力

The only part of the sun that is hot and dense enough is the core.  太阳唯一够热，密度够高的地方

An area that contains over half the star's mass  就是它的核心

in less than 2 percent of its volume.  太阳核心的体积不到太阳的2%

Here at 15 million degrees the protons  但质量却超过太阳的一半

are bashed together so hard that they fuse.  质子在一千五百万度的高温下猛然撞击、融合

A helium nucleus is a tiny bit lighter  氦原子核虽然由四个质子形成

than the combined mass of the 4 protons it is made from.  但重量却比四个质子轻一点

And as Einstein tells us it is  爱因斯坦告诉我们太阳的能量

that tiny bit of lost mass that provides the power.  来自这一点点流失的质量

Energy is equal to mass times the speed of light,  能量等于质量乘以

times the speed of light.  光速的平方