宇宙时空之旅（2014）

Cosmos: A SpaceTime Odyssey S01E04

Part 2 April 25, 2021, 12:39 p.m.

在它的中心是一颗脉冲星
At its heart is a pulsar,
一颗坍缩到一座城市大小的恒星
A collapsed star the size of a city,
并且每秒自转30周
spinning 30 times a second.
这颗脉冲星旋转着的磁场
This pulsar's whirling magnetic field
疯狂地鞭打附近的电子
whips nearby electrons into a frenzy,
将它们加速到接近光速
accelerating them to almost the speed of light.
它们发出炫目的蓝♥光♥
They shine with a blue glow that
照亮了超新星周围的气体
lights up the tendrils of gas
这些气体仍被持续释放出来
still unraveling from the supernova.
蟹状星云
The Crab Nebula
离地球约6500光年
is about 6,500 light-years from Earth.
有些人相信
According to some beliefs,
这就是宇宙的年龄
that's the age of the whole universe.
但是若宇宙只有6500岁
But if the universe were only 6,500 years old,
那我们怎么可能看到蟹状星云
how could we see the light from anything more distant
以外的任何东西呢
than the Crab Nebula?
我们不能
We couldn't.
这个时间不足以让任何方向的光
There wouldn't have been enough time for the light
从任何超过6500光年外的地方
to get to Earth from anywhere farther away
到达地球
than 6,500 light-years in any direction.
这点时间只够光穿过
That's just enough time for light to travel
银河系的很小一部分
through a tiny portion of our Milky Way galaxy.
相信宇宙年轻到
To believe in a universe
只有六千或七千岁
as young as 6,000 or 7,000 years old
就等于隔绝了银河系绝大部分的光
is to extinguish the light from most of the galaxy,
更不用说可观测宇宙中
not to mention the light from all the 100 billion
千亿个星系发出的光了
other galaxies in the observable universe.
银河系的中心
The center of our own galaxy
离地球三万光年
is about 30,000 light-years from Earth.
当我们今天看到的光
The light we see today
从银河系的核心离开时
coming from the core of the Milky Way left there...
我们的祖先正在完善一种征服死亡的方法
When our ancestors were perfecting a way to vanquish death...
那就是通过艺术
by making art
在他们逝去后依旧启发后人
with the power to inspire those who would come long after they were gone,
我们看到的从草帽星系发出的光
the light we see coming from the Sombrero galaxy
已经有三千万年的历史了
is 30 million years old.
当那道光发射出来时
Our ancestors were living in trees
我们的祖先还住在树上
when that light started out.
那时它们也就五千克重还有长尾巴
They weighed about five kilos and had long tails.
但是就算是三千万光年的距离
But even 30 million light-years away
也不过还是在我们宇宙的后院罢了
is still in our own cosmic backyard.
这些星系是后发星系团的一部分
That galaxy is part of the Coma Cluster,
离我们三亿两千万光年
320 million light-years away.
当你所看到的光开始
What was going on back home
飞往地球时地球是什么样的呢
when the light you are seeing began its trip to Earth?
没有熟悉的大♥陆♥ 海洋或河流
No familiar continents, oceans or rivers.
我们的远祖才刚刚
Our distant ancestors were just
离开水登上陆地
leaving the water for the land.
那是很老的光了
That's pretty old light,
但却远不是我们看到的最老的光
but not nearly the oldest light we can see.
最老的光非常微弱
The oldest light is very faint,
是夜空中暗淡的幽灵
a pale ghost in the night.
看见圈中的红点了吗
See that red blob inside the circle?
那是我们见过的最老的星系之一
That's one of the oldest galaxies we've ever seen.
你看到的是被哈勃望远镜捕捉到的
You're looking at 13.4-billion year-old starlight
134亿年前的星光
as captured by the Hubble Space Telescope.
它来自于第一代恒星
It's coming from the very first generation of stars.
那时的地球是什么样子呢
What was happening on Earth back then?
什么也没有
Absolutely nothing.
没有地球没有太阳没有银河系
There was no Earth, no Sun, no Milky Way.
数十亿年后它们才会出现
They would not come to be for billions of years.
当我们想要看到更远的宇宙
When we try to look even farther into the universe,
会发现我们到了空间的尽头
we come to what appears to be the end of space...
但是实际上
But actually...
这是时间的起点
it's the beginning of time.
地球拉着我们
Earth pulls on us.
我们无时不刻不在与引力做斗争
Our lives are a relentless struggle with gravity.
那个小女孩正尽全力摆脱
That little girl is trying her best to climb out
引力的束缚
of a gravitational well.
从我们最初想站起来到我们最终屈服
From our first efforts to stand to our final surrender,
我们都在挣扎着克服地球的引力
we are struggling to overcome the Earth's pull.
一个几乎和宇宙同样古老的力场
We are born, live and die in a force field--
我们在其中出生生活死亡
one that is almost as old as the universe itself.
宇宙有多老呢
And how old is that?
为了看清138亿年历史的宇宙
To visualize the 13.8 billion year age of the universe,
我们将所有的宇宙时间
we've compressed all of cosmic time
压缩到一年的年历中
into a single year-at-a-glance calendar.
12月31日的午夜就是现在
Midnight on December 31 is this very moment right now.
而1月1日就是时间的开始
And January 1 is the beginning of time.
看见那团炽热的雾了吗
See that glowing fog out there?
那时大爆♥炸♥留下的辐射
It's radiation left over from the Big Bang,
也就是138亿年创造了宇宙的
The explosion that made the universe
宇宙大爆♥炸♥
13.8 billion years ago.
现在我们就在已知空间和时间的边缘
Right now, we're at the very edge of known space and time.
那么宇宙大爆♥炸♥之前是什么样子呢
So what happened before the big bang?
没人知道
Nobody knows.
没有任何大爆♥炸♥之前的证据留下来
No evidence survives from before that moment.
关于宇宙从何而来
We've got some pretty crazy ideas
我们有一些非常疯狂的想法
about where the universe came from,
我们后面会讲到
which we'll get to, in time.
我们在宇宙中的什么位置
Where are we in the universe?
就在宇宙中心
At the very center.
在可观测的宇宙人人都可以与众不同
In the observed universe, everyone gets to feel special.
无论你生活在哪个星系
No matter which galaxy you happen to live in,
当你抬头望向宇宙时你都会发现
when you look out to the universe, you'll find yourself
自己身处宇宙的中♥央♥
at the center of the cosmic horizon.
但这只是个幻觉
But this is just an illusion.
实际上宇宙没有中心
In reality, there is no center,
宇宙的地平线和海上的地平线一样
and the cosmic horizon is no more real
都并不存在
than the horizon at sea.
在一个光速有限时间也有起点的宇宙
It's what you get when you have a finite speed of light
你只能得到这样的结果
in a universe that had a beginning in time.
在宇宙大爆♥炸♥的数亿年后
A few hundred million years after the big bang,
巨大的氢气和氦气云收缩成
vast clouds of hydrogen and helium condensed
最初的恒星和星系
into the first stars and galaxies.
出现了这些新光源
With these new sources of light,
宇宙漫长的黑暗时代结束了
the long dark ages of the universe ended.
随着空间继续膨胀
As space continued to expand,
宇宙在更大尺度上演化
cosmic evolution unfolded on grander scales.
当第一代恒星死去后
As the first generation of stars died,
它们向宇宙播撒了更重元素的种子
they seeded space with heavier elements,
为行星的形成创造了可能
making possible the formation of planets,
最后是生命
and ultimately, life.
大爆♥炸♥创造了物质和能量
Matter and energy were formed in the big bang.
但还不仅于此
But that's not all.
空间和时间也被创造了
Space and time were created, too,
以及所有将物质约束到一起的力
and all the forces that bind matter together,
其中就有引力
including gravity.
艾萨克·牛顿发现了一条数学法则
Isaac Newton discovered a mathematical law
用于描述引力的作用方式
that describes how gravity works.
有那条法则就可以解释行星的运动了
With that law, he could explain the motions of the planets.
100多年后
More than 100 years later,
威廉·赫歇尔发现引力能做的远不止这些
William Herschel realized gravity could do much more.
约翰你能保守一个秘密吗
John, can you keep a secret?
可以父亲
Yes, father.
我有一个发现但是从没告诉过别人
I've made a discovery and have yet to tell another soul.
将我们束缚在地球上的引力
The gravity that holds us to the Earth--
也就是牛顿发现的
the same gravity that Newton showed
将行星约束在轨道上的引力
keeps the planets in their orbits--
我发现
I've discovered