国家地理：科学新发现 宇宙之死（2008）

宇宙会不会灭亡
Will our universe come to an end?
会不会瞬间瓦解
Will it rip to shreds in a flash?
自我塌缩
Collapse on itself?
还是慢慢僵死
Or will it slowly freeze to death?
科学家们想常人不能想
Scientists are imaging the unimaginable,
并对宇宙将如何灭亡
and they're coming up with some wild ideas
提出了一些大胆设想
about how it's all going to end.
这就是宇宙末日
This is the end of the universe.
宇宙之死
Death of The Universe
宇宙最深处 战役正在打响
A battle is taking place in the farthest reaches of space.
无人能见
No one can see it,
但科学家们确定此事属实
but scientists are certain that it's happening
并且结果很残酷
and that the outcome is grim.
宇宙正走向灭亡
The universe is going to end.
虽然几十亿年内不会发生
It won't happen for billions of years,
但最终不可避免
but there is no way out.
解答它会如何灭亡
Working out how it will end
是全世界天体物理学家面对的挑战
is the challenge of astrophysicists around the world.
他们将高科技设备对准天空
They're pointing high-tech equipment out toward the heavens
揭开人类命运的秘密
to unlock the secrets of our fate.
所有可能都令人恐惧
The possibilities are frightening.
一种设想是
In one scenario...
引力作用将使宇宙向内塌缩
gravity pulls the universe back into itself similar to
就像泄气的气球
air being let out of an inflated balloon
宇宙回归原始大小
The universe goes back to its original size.
这就是宇宙大收缩论
This is the Big Crunch.
当所有物质向内塌缩
It'd be the end universe in a big fireball
宇宙的终态就是巨大的火球
as all the matter collapses onto itself
那将非常激动人心
That'd be pretty dramatic.
还有宇宙大寒论
Then there's the Big Chill.
宇宙会一直膨胀
The universe expands until the nuclear furnaces
直到所有恒星的核反应堆耗尽
that power all the stars burn out.
宇宙变得寒冷直至灭亡
The universe grows cold and dies.
第二种可能比较悲哀
A second possibility is actually kind of sad.
宇宙永远不停地膨胀
The universe will continue to expand forever
最终发展成
and it will just grow into
无比寒冷孤寂的地方
an increasingly cold and lonely place
由于膨胀使得地球最近的邻居都在远离
as the expansion removes our nearest neighbors from us
我们最终会成为恒星和银河系中
and we just end up a single isolated community...
一个被孤立的群落
of stars and galaxies.
还有一种更惊人的结果
Then again, there could be a much more spectacular end
那就是所有物质都被瓦解
in which everything is ripped to shreds,
最终成为原子
down to the last atom.
把它想成一个充气过足的气球
Think of it like a balloon that is filled with too much air.
一下子爆♥炸♥了
It pops.
比大寒更加戏剧性
It's much more dramatic than the Big Chill
和大收缩一样是毁灭性的
and just as fateful as the Big Crunch
宇宙一直膨胀
The universe continues to expand,
但是速度越来越快
but at an ever-quickening pace.
事实上 速度太快
And in fact, the pace is so great
导致时空结构(即重力场)
that even the space-time...
都无法使宇宙物质聚集在一起
fabric cannot hold the universe together
无论结果如何 都将会是戏剧性的
However the end comes, it will be a dramatic conclusion.
科学家们借助于了解宇宙如何诞生
To understand how it all could end,
来了解它将如何灭亡
scientists turn to how it began.
谜底在俯瞰加利福尼亚帕萨迪纳
The mystery starts to be solved here
的威尔逊山天文台
at the Mount Wilson Observatory
最先被揭开
overlooking Pasadena, California.
1929年 透过当时世界上
In 1929, while looking through
最大的望远镜
what was then the world's largest telescope,
埃德温·哈勃发现了奇怪的事
Edwin Hubble makes a strange discover
宇宙在膨胀
The universe is expanding.
哈勃的发现导致对宇宙的重新认识
Hubble's discovery led to a whole new picture of the universe.
即宇宙是动态环境 不断演变
That it was a dynamic environment and that it evolved.
随时间而变化
It changed in time.
和之前人们
And that's different from pictures
对宇宙学的认识都不同
that people had of cosmology previous to that.
在哈勃之前 科学家们认为
Before Hubble, scientists said that
宇宙是静态的 亘古不变
the universe was static and unchanging
哈勃发现宇宙在膨胀
Hubble's discovery that the universe is expanding
意味着它存在一个起点
meant it had a starting point
一个开端
A beginning.
这导致下面这个想法的出现
That brought the idea forward that
如果在时间上往前追溯
hey, what if we ran the film backwards in time
找到起点会怎么样呢
and found the point at which that began?
宇宙大爆♥炸♥论就是如此诞生的
And that was where the idea of a Big Bang came from.
大爆♥炸♥
The Big Bang.
就在某个瞬间
That fraction of a second
宇宙及其包含的物质
when the universe and everything in it
从比原子还小的东西
exploded into existence
爆♥炸♥产生
from a point smaller than an atom.
对大爆♥炸♥理论的一个普遍错误理解是
One common misconception about the Big Bang
可以在空间上定位
is that we can identify a point in space
大爆♥炸♥在何处发生
where the Big Bang occurred.
但事实上 把大爆♥炸♥看成是
But in fact, it's more appropriate to think of the Big Bang
在所有空间同时发生的更为恰当
as a simultaneous creation everywhere of space,
而这个空间直至今天仍在膨胀
which is then continuing to expand until the present day.
如果从大爆♥炸♥以来 宇宙一直在膨胀
If the universe has been expanding since the Big Bang,
那么科学家们料定它会在某刻停止膨胀
scientists must consider that it will stop expanding at some point.
问题是 如何停止
The question is: how?
答案显然和引力有关
The most obvious answer involves gravity.
所谓盛极必衰
What goes up, must come down.
恒星 星系和其他所有物质
Stars and galaxies and everything else
也许会改变方向
might reverse direction.
宇宙会塌缩成为
The universe would collapse in
科学家们所谓的"大收缩"
what some scientists call a Big Crunch
拿着上面 看到另一个把手了吗
Take the top and then see the other handle?
使劲向两边拉就行了
And just jerk them apart.
火箭模型显示了
A model rocket offers clues
大爆♥炸♥的发生过程
to how the Big Crunch would work.
火箭就像是宇宙
The rocket is like the universe
大爆♥炸♥后在空间中膨胀
expanding into space out of the Big Bang.
初始的爆♥炸♥让火箭
An initial bang allows the rocket
克服重力
to overcome the pull of gravity.
5 4 3 2 1
Five, four, three, two, one!
引擎的爆破力让火箭离开♥发♥射台
The engine blast gets the rocket moving off its launch pad.
加速进入空中
It accelerates into the air
暂时摆脱了重力
and breaks free of gravity's pull, for the moment.
看起来它不断爬升
It appears as it's climbing upward
就像永远不会停止一样
that it will never stop.
但地球引力不会允许它一直这样
But Earth's gravity won't allow this to go on forever.
最终 燃料耗尽以后
Eventually, when the fuel is exhausted,
火箭滑行了1米左右 停止
the rocket coasts about a meter higher, stops,
然后落回地面
and is pulled back to Earth.
这就是大收缩会发生的情况
This is what would happen with a Big Crunch.
整个宇宙最终会
The entire universe is essentially
被拉回到它的发射台
pulled back to its launch pad.
宇宙有它自己的动力
The universe itself has its own momentum,
自己的能量 它在向外膨胀
Its own energy. It's moving outward.
但最终在某刻
But eventually there's a point where
宇宙可能会停止膨胀
possibly the universe will stop that moving outward
就像我们看到的火箭一样
just like the rocket that we saw
不得不自己回落
and have to fall back in upon itself
并且在自身内在引力作用下再次塌缩
and collapse again under the force of its own gravity.
在这个设想中
In this scenario,
宇宙会回到大爆♥炸♥前的原始状态
the universe could return to its original state just before the Big Bang
为生生不息的生死轮回做好准备
setting the stage for a perpetual seesaw of creation and destruction.
大收缩理论变得次要
The Big Crunch theory moved to a scientific backburner.
宇宙学家发现
Cosmologists worked out
一定存在着某种能量
that there must be some form of energy