了解宇宙是如何运行的（2010）

How the Universe Works S09E10

Part 5 March 16, 2022, 8:56 a.m.

like the gravitational wave
signal did.
这些碎片减缓了光的速度
The debris gave
the gravitational waves
给了引力波一个先机
a head start by slowing
the light.
所以实际上，引力波
So gravitational waves
and light do,
和光的传播速度是一样的
in fact,
travel at the same speed.
爱因斯坦是对的
Einstein was right.
庞泽:这一事件排除了其他与爱因斯坦理论
PONTZEN: This one event ruled
out the other theories of
相竞争的引力理论
gravity that are competing
with Einstein's theory,
那些人们花了毕生精力研究的理论
things that people have been
working on all their life
一夜之间就消失了
<爱因斯坦真的太厉害了！——译者注>
and overnight, it's gone.
由于引力波的存在
Thanks
to gravitational waves,
暗能量仍然是我们
dark energy remains our best
explanation for why
对宇宙加速膨胀的最佳解释
the universe's expansion
is accelerating.
也许暗能量并不是我们想象的那样
Maybe dark energy isn't what
we think it is, and maybe
也许明天，也许明年
tomorrow, or maybe next year,
也许下个十年或下个世纪
or maybe next decade
or next century,
我们终将会发现它们
——引力波是我们
we will discover that.
- Gravitational waves are a huge
在理解宇宙的努力中向前迈出的一大步
step forward in our effort to
understand the universe,
我指的是关于宇宙的一切
and I mean everything.
空间、时间、物质、暗能量
Space, time, matter,
dark energy.
我们现在有了一个全新的宇宙
We have a completely
new universe to view now.
现在，天文学家想用引力波
Now astronomers want to use
来回答另一个谜题
gravitational waves
to answer another mystery.
超大质量黑洞碰撞时会发生什么？
What happens when supermassive
black holes collide?
我们在2015年首次探测到引力波
We first detected
gravitational waves in 2015.
从那时起，他们就发现了
Since then,
they've revealed colliding
宇宙间黑洞的碰撞
black holes across the universe.
在LIGO上线之前
Prior to LIGO going online,
我们从未直接目睹过黑洞碰撞
we never witnessed black hole
collisions directly,
但现在我们可以通过我们的天文台看到它们
but now that we can witness
them with our observatories,
我们经常发现它们
we're finding them
pretty regularly.
我们看到引力波
We're seeing gravitational
waves come
从左到右
across the LIGO experiment
穿过LIGO实验
left and right.
但LIGO一直以来
But LIGO has only been
listening for gravitational
只侦听到较小宇宙尺度的
waves from black holes
黑洞碰撞所产生的引力波
on the smaller end
of the cosmic scale.
当我们观察宇宙的黑洞动物园
When we look at the cosmic zoo
of black holes out there,
我们发现小质量的，你知道的，10倍至大约30倍
we find small ones weighing,
you know, 10, maybe 30 times as
太阳质量，然后一直到超大质量的
much as the sun, and then large
all the way up to extra-large
从太阳质量
going from, like, a million
一百万倍到十亿倍的
to a billion times
as much as the sun.
这些超大质量黑洞
These supermassive black holes
潜伏在星系的中心
lurk at the hearts of galaxies.
当星系合并时，超大质量的黑洞
When Galaxies merge,
supermassive black holes
也会合并
should merge, too.
但即使我们看到星系
But even though we see
galaxies colliding
在宇宙中碰撞
across the universe,
我们也从未见过两个超大质量黑洞的
we've never seen two
supermassive black holes
碰撞，因为它们的轨道能量
collide, because they have too
太大，无法足够接近并合并
much orbital energy to get
close enough to merge.
奥卢塞伊:轨道能量一定会到某个地方去
OLUSEYI: That orbital energy
has to go somewhere,
超大质量黑洞所做的事情就是
and what supermassive black
holes do is they throw out
把星系核心周围的恒星扔出去
stars that are around
the core of the galaxy.
但当它们足够近的时候，就没有更多的
But when they get sufficiently
close, there are just no more
恒星可以扔出去了
stars to throw out,
所以有个理论认为，它们无法合并
and so the idea is,
they can't merge.
这就有问题了
So there's a problem.
他们是如何设法弥合这个差距
How is it that they managed
to bridge that gap
并最终螺旋进入呢？
and finally spiral in?
了解超大质量黑洞是否合并的
The only way to
understand if supermassive
唯一方法是
black holes merge is by looking
观察它们的引力波信♥号♥♥
at their gravitational
wave signal.
两个超大质量黑洞的合并
Two supermassive black holes
会释放出引力波，其威力
merging should release a burst
of gravitational waves
是恒星质量黑洞
millions of times more powerful
合并时的数百万倍
than a stellar mass
black hole merger.
但是LIGO什么也听不到
But LIGO won't hear a thing.
使用LIGO来探测超大质量黑洞合并的问题
The problem with using LIGO
to detect the merger
实际上是一个时间尺度的问题
of supermassive black holes is
actually a scale of time.
一个波的时间，因为这些物体彼此移♥动♥得非常慢
One wave, as these things move
around each other very slowly,
需要10年以上的时间，才会形成一个波
would take over 10 years
to go by, just one wave.
明加雷利:为了探测一个周期长达
MINGARELLI: In order to detect
a gravitational wave with
几十年的引力波
periods of decades,
你还需要一个在这段时间内
you also need an experiment
that can be extremely stable
非常稳定的实验
over that amount of time.
地震、天气
Vibrations from earthquakes,
甚至附近交通的震动
weather, or even nearby traffic
都会让LIGO在十年里无法听到任何一个这样的波
prevent LIGO from listening for
a decade, just to hear one wave.
但是，可能还有另一种方法
But there may be another way to
来探测来自超大质量黑洞的引力波
detect gravitational waves
from supermassive black holes,
那就是使用一种被称为脉冲星的
using a strange type of dead
star called a pulsar.
奇怪的死亡恒星
A pulsar is a kind of
脉冲星是一种
neutron star
that is rapidly spinning
快速旋转的中子星，它的辐射束
and has a beam of radiation
that makes
在天空中绕着大圈旋转
wide circles across the sky.
当这个圆圈的闪光掠过地球时
And when that flash of circle
washes over the planet Earth,
我们会听到一个小的哔哔、一个小的哔哔
we get a little beep,
a little beep.
我们得到了辐射脉冲，因此知道脉冲星的存在
We get pulses of radiation,
hence pulsar.
脉冲星是宇宙中最好的计时者
Pulsars are the best
timekeepers in the universe,
但传递引力波会让它们错过一个节拍
but passing gravitational
waves make them miss a beat.
泰勒:如果我们注意到脉冲星的频率
THALLER: What if we noticed that
the frequency of a pulsar was
在非常非常缓慢地移♥动♥
shifting very, very slowly,
年复一年，超过10年或更长时间
year to year to year,
over 10 years or more,
只是随着空间本身在我们和脉冲星之间的变化
just slightly getting a little
bit longer as space itself was
而略微变长了一点呢？
changing between us
and the pulsar?
通过对数十颗脉冲星的监测
By monitoring