宇宙时空之旅（2014）

Cosmos: A SpaceTime Odyssey S01E04

Part 1 April 25, 2021, 12:39 p.m.

眼见不一定为实
Seeing is not believing.
我们的感觉也会欺骗我们
Our senses can deceive us.
即使是恒星也并非它们看起来的样子
Even the stars are not what they appear to be.
被科学展现出来的宇宙
The cosmos, as revealed by science,
可比我们所能想象的要奇怪得多
is stranger than we ever could have imagined.
光时间空间引力
Light and time and space and gravity
共同创造出一个
conspire to create realities
超越人类经验的现实世界
which lie beyond human experience.
那就是我们要去的地方
That's where we're headed.
跟我来
Come with me.
1802年一个这样的夜晚
Back in 1802, on a night like this,
天文学家威廉·赫歇尔与他的儿子约翰
The astronomer William Herschel strolled the beach
漫步在英国的海滩上
on the English coast, with his son John.
赫歇尔是第一个
Herschel was the first person ever
看到了宇宙之海深处的人
to see into the deeper waters of the cosmic ocean.
在那里他瞥见了
There he glimpsed the magic trick
光用时间施下的魔法
that light does with time.
父亲
Father...
您相信灵魂吗
do you believe in ghosts?
为什么这么问我相信孩子
Why, yes, my son!
您真的相信吗
You, you do?
我还以为您不信呢
I would not have thought so.
不我信的并非人类的灵魂
Oh, no, not in the human kind of ghost.
不完全不是
No... not at all.
但是抬头看我的孩子
But look up, my boy,
你可以看见灵魂充满了天空
And see a sky full of them.
您是说恒星吗父亲
The stars, father?
我不明白
I do not follow.
每一颗恒星都和我们的太阳一样大而明亮
Every star is a sun as big, as bright as our own.
想像一下要把太阳移多远
Just imagine how far away from us you'd have to move the sun
才能让它像恒星一样小而黯淡呢
to make it appear as small and faint as a star.
恒星发出的光速度很快
The light from the stars travels very fast,
比一切东西都要快
faster than anything,
但却不是无穷快
but not infinitely fast.
它们的光到达我们也是需要时间的
It takes time for their light to reach us.
对于最近的一颗也要花好几年时间
For the nearest ones, it takes years.
对别的则要几个世纪
For others, centuries.
有些恒星离得太远了
Some stars are so far away,
它们的光到达地球甚至需要数十亿年
it takes eons for their light to get to Earth.
有些恒星的光到达这里时
By the time the light from some stars gets here,
它们都已经死了
they are already dead.
对这些恒星我们看到的是它们的灵魂
For those stars, we see only their ghosts.
我们看到了它们的光
We see their light,
但它们本身在很久以前就已经逝去了
but their bodies perished long, long ago.
约翰与我之前的人相比
John, I have seen further back in time
我能看到更久之前
than any man before me--
我能看到数百万年前
millions of years into the past.
威廉·赫歇尔第一个理解了
William Herschel was the first person to understand
望远镜其实是一台时间机器
that a telescope is a time machine.
我们只要望向太空
We cannot look out into space
那么看到的一定是过去
without seeing back in time.
光一秒钟能传播三十万千米
In one second, light travels 300,000 kilometers,
或是十八万六千英里
or 186,000 miles.
这几乎是地球到月球的距离
That's nearly the distance from the Earth to the Moon.
所以月球离我们一光秒远
So, the Moon is about one light-second away.
下一次你抬头看月亮
The next time you look at the Moon,
你看到的是一秒前的历史
you'll be seeing one second into the past.
宇宙
时空之旅
太阳
That Sun...
其实并不在那里
it's not really there.
两分钟后它才真正从地平线升起
It won't actually be above the horizon for another two minutes.
日出其实是幻象
The sunrise is an illusion.
地球的大气像是一个透镜或是一杯水一样
Earth's atmosphere bends the incoming rays of sunlight
弯曲了阳光
like a lens or a glass of water.
所以我们看到的太阳
So we see the image of the Sun
只是在太阳到达那里前
projected above me is a mirage
投射出的幻象
before the physical Sun is actually there.
我身后的太阳就是个幻象
That Sun behind me is a mirage.
和在一个大热天荒芜的道路上
No more real than the shimmering image
远处出现的蜃楼没有什么不同
that hovers in the distance over a desert road on a hot day.
阳光到达地球需要八分钟时间
Sunlight takes about eight minutes to reach Earth,
所以太阳距离我们八光分
so the sun is eight light-minutes away.
从地球上我们只能看见
From Earth, we can only ever see the Sun
八分钟前的太阳
as it was eight minutes ago.
还有一件事
And another thing,
太阳其实根本不会"升"起来
the Sun doesn't really "rise" at all.
地球在旋转而我们也跟着一起转
The Earth turns and we turn with it.
也许看起来并不像但是现在
It may not look like it, but right at this moment,
我比一架喷气机的速度还快
I'm moving faster than a jet plane
所有在地球上的人都一样
and so are you and everyone on Earth.
当我向那边去时
While I'm at it,
那条地平线
that horizon...
其实并不存在
it's not really there at all.
那边没有边界
There's no edge.
地平线也是另一种幻象
The horizon is just another illusion.
地球和最外侧行星海王星之间的距离
The distance between Earth and the outermost planet Neptune
随着行星绕太阳公转改变
varies as the planets orbit the Sun.
平均而言需要光走四个小时
On average, the light makes that trip in four hours.
对地球上的我们而言
So for us on Earth,
我们看到的海王星永远是四小时前的
the Neptune we see is always four hours in the past,
距离四光时远
four light-hours away.
但是行星间的距离
But the distances to the planets,
就算最远的一个
even the farthest one...
从恒星和星系的大尺度上看
are mere baby steps on a much grander scale
其实离得很近
of the stars and galaxies.
一旦我们离开太阳附近
As soon as we leave the Sun's immediate neighborhood,
我们就得把距离单位
we need to change the unitive distance
从光时变成光年
from light-hours to light-years.
光年才是宇宙的尺度
A light-year is the yardstick of the cosmos.
一光年就有近百万亿千米
A single one is nearly ten trillion kilometers,
或是60万亿英里
or about six trillion miles.
这是一个距离单位和米或英里一样
It's a unitive distance, just like a meter or a mile.
光年就是光传播一年的距离
It's the distance light travels in a year.
离太阳最近的恒星即比邻星
The nearest star to the Sun, Proxima Centauri,
离地球有超过四光年的距离
is a little more than four light-years away from Earth.
四光年有多远呢
How far away is four light-years?
美国宇航局的旅行者号♥飞船
NASA's Voyager spacecraft moves
速度超过每小时5.6万千米
at more than 56,000 kilometers an hour.
就算在这样惊人的速度下旅行者号♥
Even at that astonishing speed, it would take Voyager
也要花八万多年才能到达最近的恒星
more than 80,000 years to reach the nearest star.
而昴宿星团的恒星
And the stars of the Pleiades Cluster,
则有400光年远
400 light-years away.
想象号♥飞船
The ship of the imagination
拥有极不寻常的能力
is equipped with a highly unusual capability--
实际上是独一无二的
one-of-a-kind, actually.
它让我们可以看到
It makes it possible for us to see what was happening
光从遥远的恒星或是星系
when the light from a distant star or galaxy
踏上去往地球的漫长之旅时发生的事情
first set out on its long journey to Earth.
当那束光大约400年前离开昴星团时
When that light left the Pleiades, about 400 years ago,
伽利略正第一次通过望远镜观测
Galileo was taking his first look through a telescope.
几年以后他尝试着测量光的速度
A few years later, he tried to measure the speed of light,
但是他失败了
but he couldn't do it.
他的计划非常精妙但是那时的技术
He had a very clever plan, but the technology of that era
没有办法测量
just wasn't good enough to measure
像光一样快的运动
the motion of anything that moves as fast as light.
当我们从地球上看蟹状星云
When we look at the Crab Nebula from Earth,
我们看到的是更久之前的样子
we're seeing much farther back in time.
蟹状星云曾是一颗巨星
The Crab Nebula was once a giant star,
质量是太阳的十倍
ten times the mass of the Sun,
直到它发生了超星新爆♥炸♥
until it exploded in a supernova.