It ended when the first stars started fusing hydrogen into helium.

当第一批恒星将氢融合为氦时，黑暗时代结束了。

Stars make energy in their cores by fusing hydrogen into helium.

这些恒星通过将氢聚变为氦在其核心中产生能量。

Ever since the Sun was born, it's been fusing hydrogen into helium in its core.

自从太阳诞生以来，它的核心就一直在将氢聚变为氦。

Every second, trillions of oxygen molecules fuse into helium molecules in a process called nuclear fusion.

每一秒钟，就有数万亿氧分子与氦分子发生结合。这一过程叫做核聚变。

But unlike the sun, it doesn't fuse hydrogen atoms into helium to create energy and heat.

但与太阳不同的是，它不会将氢原子聚变成氦来产生能量和热量。

Today you learned that very low mass stars live a long time, fusing all their hydrogen into helium over a trillion years.

今天你学到了，低质量的恒星寿命很长，在一万亿年间，它们将所有的氢融合成氦。

It just slowly fuses hydrogen into helium, glowing feebly.

它只是慢慢地把氢气融合成氦气，微弱地发光。

They fuse hydrogen into helium, and eventually helium into carbon (and also some oxygen and neon).

它们将氢聚变为氦，最终氦聚变为碳(还有一些氧和氖)。

Each second, inside the Sun, 600 million tons of hydrogen are fused into 595 million tons of helium.

每一秒钟，太阳内部，有6亿吨氢聚合产生5.95亿吨氦。

Stars are massive enough to fuse hydrogen into helium in their cores, generating energy.

恒星的质量足以在其核心将氢聚变为氦，从而产生能量。

Like the Sun, stars generate energy by fusing hydrogen into helium in their cores.

和太阳一样，恒星通过核心的氢聚变成氦来产生能量。

A star like the Sun can happily fuse hydrogen into helium for over 10 billion years.

像太阳这样的恒星可以在100亿年的时间里愉快地将氢聚变为氦。

The hydrogen couldn't fuse together into helium.

氢不能融合成氦。

There are actually a lot of steps in this process, but in the end you get carbon fusing into neon, magnesium, and some sodium.

实际上在这个过程中有很多步骤，但是最后即碳融合成氖、镁，和一些钠。

And as soon as it did, it would rapidly fuse into helium.

一旦它这样做， 它就会迅速聚变成氦。

I instantly plunged the end of the fuse into the lantern.

我立刻把保险丝的一端插入灯笼里。

Every second, trillions of hydrogen atoms fuse into helium atoms in a process called nuclear fusion.

每秒，数以万亿计的氢原子在称为核聚变的过程中融合成氦原子。

If the hydrogen flowing onto its surface piles up enough, the gravity can squeeze it so hard it fuses into helium.

如果流向它表面的氢气堆积得足够多，引力就能将其挤压得很硬，使其聚变为氦。

It's fusing hydrogen into helium now, today, and will eventually fuse helium into carbon, and it'll make a dash of oxygen and neon too.

现在它正在将氢聚变为氦，最终会将氦聚变为碳，它还会产生少量的氧和氖。

And that's when the ribs started to fuse into a plastron, which eventually became a full, protective shell.

那就是肋骨开始融合成腹甲的时候，腹甲最终变成了一个完整的保护壳。