与摩根·弗里曼一起穿越虫洞（2010）

一种中微子防护因素
a neutrino protection factor
即使有一万亿也不够用
of 1 trillion or more wouldn't suffice.
在我手上涂上这麽薄薄的一层
Even though just a thin layer of this on my hand
就足以防护光子了，但为了阻止中微子
is good enough for photons, uh, it would have to be vastly,
就需要厚得多得多
vastly thicker for stopping neutrinos.
事实上，这把伞
And, in fact, this umbrella,
用来挡阳光辐射刚刚好
which stops the photons from the sun just fine,
却不能胜任这项工作
wouldn't do the job.
只有一光年厚的铅伞
It would have to be a lead umbrella a light-year thick
才能胜任
to do the job.
约翰认为外星文明
John thinks an alien civilization
或许决定产生一束中微子
might decide to create a beam of neutrinos
把它们以脉冲发射出去
and pulse them,
把消息打造成宇宙摩尔斯电码
manufacturing a message in a kind of cosmic morse code.
但是因为中微子太像幽灵了
But because neutrinos are so ghostly,
它们探测或者测量起来极其困难
they're extremely tough to detect or measure.
地球上最大的探测器
The largest detector on earth,
称作“冰立方”，被埋在南极附近
called icecube, lies buried under nearly three kilometers
三千米深的冰层之下
of ice at the South pole.
86串传感器
86 strands of sensors
等待着中微子之一流经地球
wait for one of the neutrinos streaming through earth
无意中碰到
to bump into one
周围冰块中的电子
of the electrons in the surrounding ice.
冰立方每年只采集到一把
Icecube picks up only a handful of neutrino collisions
中微子碰撞
each year.
中微子的能量各不相同
Neutrinos vary in energy.
能量最高的中微子十分罕见
The highest-energy neutrinos are the most rare.
现在，关于它们的来源
There's a great controversy going on right now about,
存在着广泛的争议
what are the source of these?
是什么机制
What -- what are the mechanisms
产生了这些高能量？
that produce these high energies?
因为它们如此稀少
Because they're so rare,
约翰相信它们可能是外星人最了不起的
John believes they could be great communication tools
通讯工具
for aliens.
如果这些高能中微子之一
If one of these high-energy neutrinos
与冰立方中的一个电子发生了联♥系♥
makes contact with an electron inside icecube,
我们会知道的
we'll know it.
这会产生这个小的爆♥炸♥
It'll make this little explosion,
非常有特点，我们可以唯一地监别出它们
which is so characteristic that we could identify it uniquely.
如果你看到一个
If you saw one,
它一定会引起你的注意
it would certainly get your attention.
物理学家把这种有特点的爆发
Physicists call this characteristic burst
叫做格拉肖共振
the Glashow resonance.
高能中微子作用于电子的方式
The way a high-energy neutrino interacts with an electron
很像音乐与酒杯相遇时发生的事情
is similar to what happens when music meets a wine glass.
- 嘿，伙计们。 - 嘿
- Hey, guys. - Hey.
所有的东西都有一个固有频率
All matter has a natural frequency.
当来自外界源的能量
When energy from an outside source
与固有频率相匹配的时候
matches that natural frequency,
物体会比平常振动得更剧烈
the object will vibrate much more than usual.
这就是共振
That's known as resonance.
那麽我们现在有的是
So what we've got here is a --
一个酒杯，但愿是一个良好共振的酒杯
A glass, hopefully, a nice, resonant glass.
我们还有一个扬声器
And we've got a speaker,
连接到一个扩音器上
which is attached to an amplifier.
我们驱动声学能量
And we're driving acoustic energy, sound,
朝向这个的超高密度的声音
very high-intensity sound toward this.
我们试着达到杯子的共振
And we'll try to hit the resonance in the glass
打碎杯子
and break the glass.
你可以把每一个音高
You can think of each note
想象作不同级别能量的中微子，把酒杯
as a different energy level neutrino and the wine glass
想象作电子
as the electron.
首先，约翰在风琴上试了很多音高
First, John tries various notes on an organ.
然后是歌♥手
Now the singer.
最后，吉他手
Finally, the guitar player.
这是一个
It's a matter of, uh,
找到合适频率的问题
getting the right frequency,
在合适的频率上找到合适的能量
getting enough energy right on the right frequency.
就是这样
Man, that's gone.
格拉肖共振合适的类型的高能中微子
The glashow resonance is the explosion that results
到达时所引起的爆♥炸♥
when just the right type of high-energy neutrino arrives.
约翰认为一连串的
John thinks a string
这种罕见的爆♥炸♥不会是个巧合
of these rare explosions wouldn't be a coincidence
一定是地外智慧的迹象
but rather a sign of an extra terrestrial intelligence.
倘若我们看到那些中微子来自于同一个方向
And if we see those neutrinos coming from the same direction,
我们就可以肯定地
then we certainly
知道那不是一个自然现象
know that that is not a natural phenomenal.
这将是有史以来最伟大的发现
Would be the greatest discovery ever.
我想不到任何事情
I can't think of anything
会是比找到第一个地外生命的迹象
that would be a more amazing discovery
更加伟大的发现
than to find the first signs of extraterrestrial life.
这会改变我们的世界
It would change our world.
尽管发现外星消息很激动人心
As exciting as it would be to find an alien message,
阅读它却可能威胁到我们的存在
the simple act of reading it could threaten our existence.
外星通讯所携带的可以远不止是问候
Alien communication could carry a lot more than a greeting.
与外星文明第一次接触的时刻
The moment of first contact with an alien civilization
势必永久载入史册
will be the most important event in human history.
但也许我们已经错过了呢？
But if we already missed it?
如果外星消息已经来过了，但我们没有注意到呢？
What if an alien message has arrived and we didn't notice?
也许它现在就在这里
Maybe it's here right now,
藏身于我们的技术中
hiding inside our technology.
安德鲁·谢米昂
Andrew Siemion
在加州大学伯克利分校的搜寻外星智能项目研究中心
specializes in the search for extraterrestrial intelligence
专门研究搜寻地外文明
at U.C. Berkeley's SETI research center.
他和他的同事们
He and his colleagues
正在寻找外太空中的不寻常的信♥号♥♥
are looking for unusual signals in outer space,
希望找到一个可能来自于外星文明的信♥号♥♥
hoping to find one that might come from an alien civilization.
我认为我们与高度先进生命的初次邂逅
I think that our first encounter with very advanced life
很可能不会是一座太空船
probably will not come in a spaceship landing
降落在金门公园
in golden gate park.
更有可能是它会通过一个
It's quite likely that it will come via a signal
我们碰巧窃听到的信♥号♥♥
that we just happen to eavesdrop on.
但或许外星人已经在监听
But it may be that aliens are already listening
我们的无线电♥信♥♥号♥♥了
to our radio signals.
如果地球附近有非常先进的生命
If there were very advanced life nearby to earth,
他们监视着我们已经
they've monitored our radio signals
离开了这座行星的信♥号♥♥
that have left this planet.
他们几乎一定对我们有了很多的了解
And so they almost certainly know quite a lot about us.
自从1960年开始，通讯卫星
Since the 1960s, communications satellites
一直都在计算机之间转播信息
have been relaying information from one computer to another.
这些信息已经泄露到了太空中
And that information has been leaking out into space.
如果外星人懂得我们的计算机网络
If aliens understand how our computer networks
是如何动作的，而且知道我们在积极地监听他们
operate and know that we're actively listening for them,
安德鲁相信他们会利用这一情况
Andrew believes they could take advantage of the situation.
他们可以投递数字病毒
They could deliver a digital virus
并知道我们很快就会感染它
and know that we'd scoop it right up.
每年在对智能通讯的搜寻中
We gather millions of radio signals from space
我们都从太空中收集数百万个无线电♥信♥♥号♥♥
each year in our search for intelligent communication.
那些信♥号♥♥直接走向我们的计算机
Those signals go straight to our computers
于是研究员们可以分♥析♥它们
so researchers can analyze them.
捕捉先进科技的证据
Hunting for evidence of advanced technology,
这些无线电♥信♥♥号♥♥
these radio signals,
有点像捕捉复活节彩蛋
is kind of like hunting for easter eggs.
有点像捕捉一个小金块
We're looking for that one small nugget
从风景中脱颖而出
that stands out from the landscape.
我们寻找的这些信♥号♥♥非常非常微弱
The signals that we look for are very, very weak,
所以我们需要过滤掉各种噪声
so we have to sift through all of the noise,
这些噪声产生自其他天体物理学的来源
noise produced from other astrophysical sources,
诸如类星体和脉冲星
quasars and pulsars.
一旦搜寻外星智能项目研究员收集到了潜在的外星信♥号♥♥
Once SETI researchers gather potential alien signals,