宇宙（2007）

The Universe S05E08

Part 6 April 22, 2021, 1:50 p.m.

By the time the Sun becomes a white dwarf,
到太阳成为白矮星的时候
we can imagine that temperatures on Earth,
我们可以想象那时地球的温度
depending on where it is in its orbit,
根据它所处于不同的轨道位置
would drop significantly fairly rapidly
会以一个惊人的速度显著下降
because the white dwarf is no longer producing energy through fusion
因为白矮星不再通过聚变产能
so it's not producing this energy to heat the Earth.
因此它不再产能供给地球所需的热量
We'll be fried to a crisp
如果地球在太阳红巨星阶段
if we remain where we are during the red giant stage,
保持它的轨道不变我们就会被热焦
but in a similar vein,
同样的
we will go into a deep freeze
如果在白矮星时地球仍处于这个轨道
if we remain where we are when the Sun becomes a white dwarf.
我们就会被冻僵
Nevertheless, there will be some pockets
不过生命在某些区域
where life could continue to survive.
仍可以延续下去
For example, in the liquid parts deep in the oceans,
比如在海洋深处的液态区域
it could survive.
生命能幸免于难
At the outset,
理论上来说
humans could theoretically live in submarines,
一开始人类可以住进潜艇
near hot hydrothermal vents,
在靠近热液火山口的区域生活
while they dredge up the geothermal energy
它们能从深处的地核
from deep within the Earth's core.
提取地热能
But after a million years,
但是一百万年后
the oceans would completely freeze
海洋彻冻结底
and life would inevitably perish.
生命不可避免地走向灭亡
After the Sun becomes a white dwarf,
太阳变成白矮星后
it's just gonna cool and cool.
会越来越冷
It's very much like a pot on the stove.
这很像炉子上的锅
Once you turn off the burner, there's no more source of energy,
当你关闭了燃嘴它就失去了能量来源
and so it just gradually gets cooler and cooler and cooler.
温度逐渐降低降低再降低
If the Earth manages to survive
如果当太阳仅仅是一颗白矮星的时
until the Sun is only a white dwarf star,
地球还幸免于难
it will hardly be getting any energy at all.
那时将很难获取任何能量
I can say with absolute certainty
我可以十分确信地说
that if you stick around long enough,
如果你活得够长
you could experience both death by fire
便能经历火的炼狱
and also death by ice.
与冰的洗礼
Without energy from our Sun,
失去了太阳释放的能量
all remaining life in our solar system will disappear.
太阳系幸存的生命都将灰飞烟灭
However, this disaster could be preempted
然而我们可以通过目前无法实现的技术
by accomplishing what so far has been impossible to do...
预先阻止这场灾难
actually duplicating the Sun's hydrogen fusion right here on Earth.
那就是在地球上复♥制♥太阳的氢聚变反应
Science has already been able to manufacture nuclear fission,
控制核聚变的产生与进行已在科学能力所及
which involves the splitting of atoms into lighter, smaller nuclei.
它能使重原子核分♥裂♥成更轻更小的轻原子
This is the power that drives our nuclear power plants
正是这股力量驱动了我们的核电站
and ignites nuclear weapons.
并由此激生了核武器
But nuclear fusion,
然而在太阳核心
which occurs in the core of the Sun,
进行的核裂变
requires putting nuclei together to form a larger, heavier nucleus.
需要将轻原子聚合生成更大更重的原子核
And so far, this process has not been achieved here on Earth.
到目前为止这项技术还没在地球上实现
The problem with recreating the Sun's conditions
重造一个太阳环境最根本的难点是
is essentially getting materials to the densities
让物质拥有太阳核心处的
and temperatures that you have in the center of the Sun.
物质密度和温度
The Sun has its gravity to drive the pressures and densities up,
太阳自身的引力使压力与密度达到很高的水准
so it can get these high reactions.
所以它可以进行这些高级反应
On Earth, we don't have the luxury of using the Sun's gravity,
在地球上人类不能奢望利用太阳的引力
so we have to find other ways to try and compress the material
因此我们必须找到其它方法试着压缩物质
and generate the kinds of densities that you see.
从而产生足够大的密度
At the Lawrence Livmore national laboratory in northern California,
在加州北部的劳伦斯利弗莫尔国家实验室中
scientists are taking on the challenge
科学家们正进行一次挑战
by attempting to create a miniature man-made star.
他们试图创造一颗微缩人造恒星
The experiment involves aiming the world's largest laser...
这项实验包括将有三个足球场大小的
the size of three football fields...
世界上规模最大的激光器
at a BB-sized target filled with hydrogen fuel.
瞄准一个满载氢燃料的BB子弹大小的目标
In an inertial confinement experiment
在一个惯性约束实验中
like the one at Lawrence Livermore,
就像劳伦斯利弗莫尔的这次实验
you start with a small pellet,
你需要一颗小圆球
maybe a half an inch across,
它的直径大概有半英寸
the core of which is made of a solid material
中心填充着固体材料
containing lots of hydrogen to undergo fusion.
由聚变所需的氢组成
The outside of which has layers of different material
外层包裹着几层不同的材料
that are engineered to produce a shock wave
这种设计使它们能产生冲击波
that will drive in and compress that core as much as possible.
尽可能地进入并挤压内核
The colossal laser will split into 192 separate beams
强激光束将散射成192小束
that will strike the pellet housed inside a capsule.
轰击舱内的小球
When the fuel pellet's shell is struck by these high energy x-rays,
当燃料丸的外壳接触到高能X射线
it should implode
便会发生爆♥炸♥
and then ultimately produce nuclear fusion in its core.
最终在核内产生核聚变反应
If we had controlled, affordable nuclear fusion,
如果我们掌握了可控廉价的核聚变技术
it would change everything.
它将改变一切
Many things about our lives would change.
我们生活的方方面面都将变得不同
But most importantly, we wouldn't need the Sun anymore.
最重要的是我们将不再需要太阳
We could produce energy, heat, light on demand.
我们能随心所欲地生产能量热量和光
We could live anywhere in the cosmos
有了氢的供给便能生产我们所需的能量
with a supply of hydrogen and make our own energy.
人类便能立足于宇宙的任何一个角落
We could fly to other planets very quickly,
我们可以迅速飞往其它行星
in days instead of years.
只用几天时间而不再是几年
You can extract all the water you need from practically any material
你几乎可以从任何含有氢氧元素的物质中
that contains hydrogen and oxygen.
提取所需的水
If there isn't enough oxygen around, you could make some.
如果周围没有充足的氧气你可以自己生产
Generating reliable nuclear fusion could
产生稳定的核聚变
ultimately save Earth and all forms of life
将消除我们对太阳的依赖
by eliminating our dependence on the Sun.
并最终拯救地球和所有的生命
Yet the Sun's own fate is forever sealed.
然而太阳自身的命运却已注定
As a white dwarf, it will become dimmer and cooler.
那就是成为一颗日益黯淡阴冷的白矮星
The star that once provided energy to an entire solar system
这颗曾经为整个太阳系提供能量的恒星
will eventually fade from sight.
终将从人们的视野中淡去
When the Sun eventually cools off so much,
当太阳最终冷却到一定程度
you won't even be able to see it with your eyes.
它甚至无法被你的肉眼观测到
And so that's why some people call it a black dwarf
这也是为什么有些人称它为黑矮星
or a dark star.
或暗恒星
It'll just be invisible, sitting there in space nearly forever.
它无影于无形静止于太空流传于永恒
Our solar system cannot dodge its date with doom in 5 billion years.
在五十亿年里太阳系将注定迎来它的末日
But the death of one planetary system
但一个星系的终结
can spark the birth of another.
能唤起另一个星系的新生
Our Sun's nebula will eventually blend together
太阳的星云最终将和
with other stellar material
其它星际物质交融
and spawn the next generation of stars.
孕育出下一代恒星
And one might even nurture
也许在它的呵护下
another vibrant planet like Earth.
另一个生机勃勃的地球终将出现