宇宙（2007）

Right now, our Sun is middle-aged
但是如今 我们的太阳只是中年寿命
and has settled into a quieter, regular schedule.
运行平和 规律而稳定
But it's still generating a lot of energy.
同时仍然释放着能量
The Sun, right now, is about 4 1/2 billion years old.
如今的太阳 已经45亿岁
It's slightly under
几乎达到
half of its total anticipated lifetime.
其既定寿命的一半
So it's kind of like this car
就好像是这辆车
with a little bit more than half of its tank still full.
油箱里的油即将消耗一半
The Sun now is burning fuel...
太阳以稳定然剧烈的速率
that is, fusing hydrogen to helium...
消耗燃料
at a steady but ferocious rate.
即氢氦核聚变
It's like a 90 billion megaton bomb
这就好像是一颗900亿吨♥级的炸♥弹♥
going off every second.
接二连三不间歇地爆♥炸♥
It's just an incredible amount of power.
真是强大得不可思议
On Earth, we're actually only receiving
身居地球 事实上
about one 2-billionth of the energy
我们只接收到了
that's being produced at the Sun.
太阳产生的能量的五亿分之一
Now, on a daily basis, that's enough energy to power
以我们如今的科技水平
about 29 million billion
这足以支持2.9亿亿颗100瓦的灯泡
100-watt light bulbs for one hour.
同时点亮一小时
The amount of energy being generated
从太阳内部产生的能量
in the interior of the Sun is just enormous.
实在是巨大得难以计量
Our Sun will continue
太阳将持续这种活动
to churn out energy over its entire lifetime,
生产能量 并如此穷尽毕生
which is estimated to be around 12 billion years.
据估算 也就是还有120亿年
In the 1990s, scientists confirmed its age
二十世纪九十年代 科学家们通过测算
and when it will die
太阳的亮度和初始质量
by measuring its brightness and original mass
同时对其声波进行分♥析♥
as well as analyzing its sound waves.
得出了它的年龄与确切死期
Light doesn't penetrate the Sun.
光线是无法通过太阳的
It's opaque.
因为它不透明
That sounds strange because light comes from the Sun,
这听上去很奇怪 因为光线正是来自于太阳
but light can't pass through it.
却无法穿过它
So until recently, there was no way
因此直到近些年
to probe the deep interior of the Sun.
我们才找到办法侦测太阳内部的深层地带
There's a science now called helioseismology
是种被称为的太阳地震学的科学
that uses sound waves to actually probe
利用声波
the interior structure of the Sun.
侦测太阳内部结构
And so we have a very good knowledge
我们因而才弄清楚
of what the interior structure of the star looks like,
太阳的内部结构
and that's allowed us to constrain and confirm
并且得以缩小范围和最终确定
the models of the Sun's age and its evolution.
太阳的准确年龄与进化过程
Strangely, our Sun is now 30% brighter than it was at birth.
奇怪的是 太阳比初生时亮度增加了30%
As it ages,
随着年岁的增长
it will gradually grow even brighter and more powerful.
还将变得更加明亮和强大
Our climate is very sensitive to the energy from the Sun.
地球上的气候对太阳能量的波动非常敏感
So if you're worried about global warming,
因此 如果你仍在操心人类的所作所为
you worry about what humans are doing to the atmosphere,
对全球变暖的激烈影响
but you also need to know
同时也要明白
what the Sun is doing to the atmosphere.
太阳也在干扰大气层
The most recent estimate says that maybe 20%
最新的估测结果指出
of all the warming that's happening,
全球变暖20%的热量
the global warming, is due to the Sun.
取决于太阳
In one-billion years, our star's luminosity
十亿年后 地球表面能见度
will be 10% greater
将增强10%
and temperatures on our planet will be 100 degrees hotter.
温度也将上升100度
The moisture in the air
空气中的水分
is very good at trapping infrared radiation or heat.
很好的吸收了红外线与热量
And so it's sort of like putting a blanket on the Earth.
就好像是给地球裹上了一层毛毯
Now, here is the bad part.
由此带来的恶劣影响是这样的
As the Earth warms up,
随着地球变暖
the oceans evaporate even more,
海洋将加剧蒸发
we trap more heat
导致更多的热量被锁定
and so the Earth warms up more.
然后地球会加剧变暖
And when the Earth warms up more, again,
然后当地球变暖加剧 再一次
we trap even more heat and the effect can run away.
更多的热量被锁定 恶性循环 循循不息
It's what we call the Greenhouse Effect.
这就是温室效应
With this surge of heat due to the runaway Greenhouse Effect,
脱缰的温室效应导致的气温飙升
life on Earth will be in peril.
关系地球上生物的生死存亡
Whole societies will need to retreat
届时 所有的生物群
to underground shelters during the day,
将只好退避到地下遮蔽处
then emerge at night when the temperature cools down.
只有在夜晚气温降下的时候 才能走上地面
But as the thermometer continues to climb,
然而随着温度不断攀升
there eventually will be nowhere to run or hide.
终将无处可藏身
We know how that story ends.
最终的结果是已知的
It's called the planet Venus.
那就是 金星
If you think about it,
想想看
Venus is only about 30% closer to the Sun than the Earth is,
金星距离太阳只比地日距离短30%
but it's way, way, way hotter, 800 degrees.
但是却热上很多 温度高达800度
We don't quite have the technology that would allow us
目前我们还没有掌握
to survive on the surface of Venus,
能够在金星表面生存的技术
but we could imagine what would be required,
但是可以推断
insulating yourself from the heat.
隔热是必要前提
So it would be a challenge.
这将是个巨大挑战
In 3 billion years,
30亿年后
our Sun's brightness sill increase 40%.
太阳的亮度会增加40%
By this time, oceans will have boiled off.
至那时 海洋将被烤干
Earth will have become a global desert.
地球变成沙漠之球
The Sun will have used up about three-quarters
太阳会因氢氦核聚变
of the hydrogen in its core fused to helium,
耗尽内部四分之三的氢
like this car is three-quarters empty.
就好像这辆车 已经消耗了四分之三的燃油
By this time, the Sun will be brighter
届时 太阳会比如今明亮
than it is now and bigger.
并且体积也更大
So Earth will be hotter.
因此 地球会变得更热
It won't be a nice place to live at that time.
而不再是生命的乐土
And the solar nightmare is far from over.
然而噩梦还远没有结束
As the Sun nears its ten billionth birthday and beyond,
当太阳寿命超过100亿岁
the most drastic changes will occur.
将发生终极质变
If human-type civilizations are still around,
当太阳覆盖了整个地平线
what will be the options for survival
如若人类文化仍在
when our Sun eventually fills the entire horizon?
将何去何从
It's a foregone conclusion.
结局是注定的
When the Sun is about 10 billion years old,
当太阳达到100亿岁寿命的时候
it will run out of hydrogen fuel in its core.
会耗尽内部所有的氢燃料
It's the beginning of the end for our star,
也就吹响了这颗恒星的死亡号♥角
and it won't die peacefully.
并且 它不会静静地死去
As for Earth, global warming or other cataclysms
对地球来说 全球变暖以及其他的各种灾祸
could snuff out every living thing in a mere 1 billion years.
仅仅10亿年后就将灭绝所有生物
But if human descendants somehow manage to survive until then,
就算那时 人类的后代找到了生存的方法
they could face a living hell.
他们面对的也是人间炼狱
When the Sun burns through all of its hydrogen at its core,
当太阳耗尽内核所有的氢
it will eventually start contracting on itself,
就会开始紧缩
because it's no longer burning through the hydrogen,
因为一旦氢的燃烧停止
fusing it together,
核聚变也将停止
creating this radiation pressure outwards
能够与万有引力抗衡的放射压也会停止生成
to balance the gravitational pull inwards.
内缩的力便胜过了外扩的力
While hydrogen fusion will stop in the core,
当太阳内核的氢聚变停止
it will continue to fuse at a faster rate
地壳的氢聚变将接过接力棒
in the shell surrounding the core.
以更高的速率进行
The extra energy will expand the outer layers of the Sun.
多余的能量扩大太阳的外层
That'll mean that the Sun will grow
这意味着太阳将变得
much more powerful, much more luminous,
更加能量十足 光亮耀眼
Because the hydrogen shell will be fusing
因为太阳的内核收缩速率
while the core is contracting
会比往常快很多
at a greater rate than it normally would.
因此氢壳将被熔化
All the pressure from the energy generated
氢壳熔化产生的能量
in this hydrogen-fusing Shell
会生成压强
will cause the outer parts of the Sun to expand,
而压强将使得太阳外部结构的膨胀
Making it into a red giant.
从而使太阳成为一颗红巨星
A red giant is a star that has exhausted
红巨星指的是一颗恒星已经