了解宇宙是如何运行的（2010）

How the Universe Works S08E03

Part 3 Jan. 30, 2022, 2:58 p.m.

45亿年
for over 4.5 billion years,
这段时间足以让人类进化成
time enough for humankind
to evolve into an intelligent
一个智慧的、技术先进的物种
and technologically advanced
species.
但与宇宙的年龄相比
But compared to the age
of the universe,
地球还只是个孩子
planet earth is just a kid.
普莱特:地球已经有45亿年的历史了
Plait: The earth is over
4 1/2 billion years old,
我们认为它花了这么长时间
and we think it's taken
this long
才创造出第一个科技文明——
to create the first
technological civilization --
我们人类
us.
有一些恒星系统比我们的年龄大得多
There are star systems out there
much older than we are.
宇宙有138亿年的历史
The universe is
13.8 billion years old.
卡罗尔:我们总觉得自己很了不起，对吧？
Carroll: We tend to think
we're hot stuff, right?
我们有技术能力，我们可以建造火箭
We're technologically capable,
we can build rockets,
我们可以收听无线电波
and we can listen to
radio waves.
但一个典型的其他智慧先进文明
But a typical other intelligent
advanced civilization
在技术上确实比我们领先
would be literally
millions of years ahead of us
数百万年
in technology.
如果一个外星社会比我们存在的时间更长
Narrator: So if an alien society
has been around longer than us,
那么他们的技术会先进多少？
how much more technologically
advanced could they be?
卡尔达肖夫指数
One method of measuring
just how much
提供了一种测量的方法
is provided by
the kardashev scale.
特朗布莱:卡尔达肖夫指数
Tremblay:
The kardashev scale classifies
将潜在的外星文明分为三种类型
potential alien civilizations
into three types
就是基于他们能够从当地环境中
based on the amount of energy
that they're able to harness
利用的能量
from their local environment.
第一类文明只能利用
A type-one civilization
can harness the energy
其母星的能量
of only its home planet.
第二类假设可以利用
Type-two could hypothetically
harness the energy
母恒星的能量
of its own solar system.
第三类可以利用整个星系的
And a type-three could harness
the energy
潜在能量
potentially of an entire galaxy.
如果你想知道我们在这个范围内处于什么位置
Narrator: If you're wondering
where we fit on that scale,
请准备好听到一些坏消息
prepare for some bad news.
我们在0和1之间
We are somewhere between
zero and a one.
我们不能利用地球上所有的资源
We can't use
all of earth's resources.
大概是0.7
So we're at about a 0.7.
一个先进的物种达到卡尔达谢夫2级
Narrator: An advanced species
reaching kardashev level two
甚至3级
or even three
就可以创造出高度先进的结构
could create
highly advanced structures
来利用恒星的能量
that can harness
the power of a star.
普莱特:如果你成为一个足够先进的文明
Plait: If you get to be
an advanced enough civilization,
而你的能源需求又非常巨大
eventually if your
energy demands are so huge,
最终你可能会建造太阳能电池板
you might build solar panels
把你的恒星包裹起来
that you have enveloped
your star.
这是由弗里曼·戴森首先想到的
This was first thought of
by freeman dyson,
所以我们称这之为戴森球
and so we call these
dyson spheres.
如果这种史诗般的工程
Narrator: If such epic
engineering occurs
发生在其他恒星系统甚至其他星系
in other star systems
or even other galaxies,
我们能否找到一些证据
could we pick up some evidence
然后进行第一次接触？
and then make first contact?
普莱特:戴森球的特点是
Plait: The thing about
a dyson sphere is that
你已经完全阻挡了
you've completely blocked
恒星发出的所有光线
all the light
coming out from a star,
除了红外线
except for the infrared
因为这些面板吸收了阳光
because these panels are
absorbing that sunlight
并且正在升温
and warming up.
当你加热一个物体时
When you warm up an object,
它会发出所谓的热红外光
it gives off what's called
thermal infrared light.
你可以扫描天空寻找这个信♥号♥♥
You can scan the skies looking
for that signature
看看那里是否有任何的戴森球
to see if there are
any dyson spheres out there.
2015年——
Narrator: 2015 --
美国航♥空♥航♥天♥局的广域红外探测探测器
nasa's wide field
infrared survey explorer
扫描了10万个附近的星系
scanned 100,000 nearby galaxies
通过观察从戴森球泄漏出来的红外光线
to locate advanced
kardashev civilizations
来定位先进的卡尔达肖夫文明
by observing infrared light
leaking away from dyson spheres.
他们的搜寻结果……
They detected...
什么都没有
Nothing.
菲利平科:没有发现这样的星系
Filippenko:
No such galaxy was found,
所以他们没有找到任何红外线确凿证据
so they didn't find
any infrared smoking gun.
考虑到我们的宇宙如此古老
Narrator:
Given our universe is so old,
其他文明当然应该有时间进化
surely other civilizations
should have had time to evolve.
如果是这样，也许我们只是错过了它们
If so,
maybe we've simply missed them.
普莱特:完全有可能出现了文明
Plait: It's entirely possible
that civilizations arose,
试图与他们周围的星系交流
tried to communicate
with the galaxy around them,
问题是他们对我们的请求太早了
and the problem was they were
asking too early for us.
他们想敲我们的门
They're trying to
knock on our door,
但我们的房♥子还没建好
but our house wasn't built yet.
地球已经存在了宇宙138亿年寿命的
Narrator: Earth has been around
for under one-third
三分之一不到的时间
of the universe's
13.8-billion-year lifespan,
人类只有30万年
the human race
just 300,000 years,
对于第一次接触而言这是一个
a relatively tiny window
of opportunity
相对较小的机会窗口
to make first contact.
我们观测天空已经有几十年了
We've been looking at the sky
for tens of years,
大概是这样
something like that.
在这些时间内
What is the likelihood
that at that exact moment
有人向我们发出信♥号♥♥的可能性有多大？
someone is gonna be beaming
a signal toward us?
也许宇宙
Narrator:
Perhaps the universe prevents
阻止了智慧文明存活太久的时间
intelligent civilizations
from surviving for very long,
使得我们第一次接触的机会
making our chances
for first contact
更加渺小
even more unlikely.
普莱特:也许外面有什么东西
Plait: Maybe there is
something out there
在过滤我们，让我们看不到它们
that is filtering us
from seeing them.
我们把它叫做伟大的过滤器
We actually call this
the great filter.
也许有一些东西在说
Maybe there is something
that says,
“是的，你不能通过这里”
"yeah, you're not getting
past here."
像我们这样的岩石行星是孕育生命的理想场所