宇宙（2007）

The Universe S01E13

Part 4 April 22, 2021, 8:13 p.m.

that went on on Earthto start generating
因为星球上生成了各种不同的生命
the biological, pre-biological materialsthat later on would be
incorporated into life,
不断形成新的生物
that may have started on Titan also,
with the same kind of chemicalspresent in a warm environment.
情况可能加同地球
而且，那里也是非常温暖的
Some think it's possible that if Titan'score is still warm,
有人认为加果星球的核心还是温暖的话
microbial life at least mightstill be present
生命物质还会存在
deep below the moon's surface.
在很深的地下依然还有生命物质
Living organisms have been foundthrinving in damp rock crevices
在深深的地层下人类已经发现生命物质
2 and 3 miles belowthe surface of the Earth.
在地表下几百英里处
If you go deep down into Titan, and whenI say "deep down" I'm talking about
加果你在土星地表下面的话
50 Km or 100 Km, maybe evena couple of hundred kilometers,
加果地下50英里处或者是上百英里
just like Earth, as you go downward,it gets warmer.
甚至是几百英里
和地球的状况相同那里会很温暖
And it looks like probablyat Titan there are materials
很可能有生物在水里生存
mixed in with the water, such as ammonia,that can act as anti-freeze,
比加说微生物，可以生存在那
and we know this liquid wateris a wonderful medium
for all kinds of chemical reactions,including the reactions that generate
我们认为水分对生命来说非常重要
包括各种有机生物
amino acids and otherprebiotic chemicals.
At present, though, close observationof Titan's surface is limited.
在目前近距离观察行星的地表情况
受到了一定的限制
The moon is cloaked in a denseatmosphere of nitrogen and methane.
行星在靠近太阳的气层中含有氮气
探测器将上面的景象拍摄了下来
The Cassini probe is equippedwith an infrared imager,
but photos shot in a visiblewavelength
但是相片只能拍到可观察的景象
are often much more usefulto analysts.
还有很多有用的景象没法拍摄
You have to, somehow, get aroundthis opaque atmosphere
你需要接近这里的大气
that's obscuring your viewof the surface.
这样才能看清楚表面
But to really see what'sgoing on on the surface,
但是，加果想看清楚地表
and notably to get a reallyfirm idea of what
加果想知道上面到底有什么
is the composition of all these differentthings that we see on the surface,
这些物体到底有什么成分
分♥析♥所看到的景物
it turns out we're going to haveto go down there close to do that.
我们必须亲自到那里研究
The Huygens lander has toucheddown on the moon
已经有探测器到达星球表面
and sent back images.
并且发回了照片
But the landeris not mobile.
但是上面并没有岩石
When you land on a planet,
当你降落在上面的时候
of course, that brings tremendousadvance in terms of science.
当然，上面有很多标记
But it's only one spot.
但是只有一个地．支
So, how much of the Earthwould you know
加果你降落在大沙漠中
if you landed on the SaharaDesert, for example?
你加何确定自己的位置
You wouldn't see the kindof life that we see here.
那里是没有办法看到生命的痕迹的
One possibility for exploring vastexpanses of the Titan's surface
探索那个星球，有一个可能
would be to use a craft that works muchlike a hot-air balloon on Earth.
我们可以利用地球上的热气球
NASA's Jet Propulsion Laboratoryis developing a balloon craft
宇航局准备了一个机器人航♥天♥器
发展一种航♥天♥热气球
that would carry both imaging gearand equipment
可以承载仪器和拍摄器械
for studying the Titan atmosphere.
用于了解行星上的大气层
科学家们考虑到利用热气球
Engineers considera a balloon
the most stable platformfor such a mission.
非常稳定的飞行器来执行计划
If a balloon looses its electroniccontrol for several hours,
加果热气球失去了控制的话
加果超过几个小时
no big deal, you can havesomething on board
没什么关系上面承载的设备可以探测到
that senses that and tellsthe balloon, "Ok.
"Close your ascent-descent valveand just go to a safe altitude
可以停留到一个安全的位置
"and sit there until youget further instructions."
等待你寻找到一个稳定的装置
But while complex missions to far-offmoons within our Solar System
但是在太阳星系里有更复杂的系统
are exhilarating, and often returngreat scientific insight,
我们的存在暗示着一个科学的系统
the promise of discovering more thanprimordial extraterrestrial life,
探索更多的生命痕迹
is slim at best.
这是一种最佳的方式
The hope of finding intelligent,technology-producing life
希望寻找到高等生命
当我们观察宇宙系统的时候
seems greatest when we lookbeyond our Solar System
高科技似乎给我们做了开路先锋
to neighbouring stars.
进入邻近的行星
While we may never encountersuch lives
我们或许无法见到这样的生命
for most scientists who studythe Universe
对于大部分科学家来说研究宇宙
the notion that it exists somewheremakes perfect sense.
海洋中存在生命是非常合情合理的
Life tends to evolve,to become more successful
生命会更加成功
and one of the things thatmakes organisms successful,
同地球一样，理查德生命也会在上面出现?格林伯格作家“欧罗巴，海洋月球”
it seems, on Earth,is to become intelligent.
而且是高等生物
So, it seems quite plausibleto me that there are
非常有可能在这个星球上
creatures that have some sort ofintelligence on other planets.
其它星球拥有和地球一样的生命
If one of those starts out a billionyears before our Solar System started out
加果那里比太阳系有更早的历史
and it takes that one a billion yearslonger to get to that point,
而且那里存在了数百万年的话
才到加今的样子那么现在正是时候
well, they're at the righttime right now.
And at radiotelescopeinstallations across the globe,
利用全球的无线电系统
we earthlings are listening for them.
我们在倾听它们的召唤
Howdy doody boys and girls?
宇宙寻找外星人
你们好，女士们，先生们
We have been sending signalsinto the void for decades.
几十年来我们向外层空间发射信♥号♥♥
Every broadcast on this planet,every FM radiowave,
在这个星球上每一个播报
任何FM广播
every television transmission
所有的电视通信
goes out into the infinitefor all of eternity.
这一切都进入到无限的宇宙当中
进入到无限与永恒
Could anybody out therebe listening?
会有人在倾听吗？
And how long would it take ourradio signals to cover the distance?
我们的电波何时才能到达那里
Let's consider once again the analogy
我们重新考虑一下
where our Sun is a marble on asidewalk in downtown Manhattan,
我们的太阳照射到曼哈顿大街
Alpha Centauri, the closest other star,
一颗最近的行星上
is a marble on a sidewalkin Washington DC,
有一颗岩石在华盛顿大街上
and a more distant staris a marble in Rio de Janeiro.
在更遥远的行星上
有一颗石子在海边
A rocket launching from Earth,the marble in Manhattan,
地球发射了一颗火箭位置就在曼哈顿附近
would take 75,000 years to reachAlpha Centauri, the marble in DC.
这需要花费75年时间到达那里
在华盛顿的石子
That same rocket would take 2 millionyears to reach the marble in Rio.
相同一颗火箭需要两百万年
才能到达里奥的基地
A star 100 light years away.
距离一百光年的外层空间
Fortunately, radio signals aremuch faster than rockets.
幸运的是无线电波的速度比火箭的要快
They travel at the speed of light.
它们的速度和光的一样
并不需要七万五千年
So, rather than taking75,000 years,
a signal travelling from the marblein Manhattan to the the one in DC,
从曼哈顿传播的无线电到达华盛顿DC
would only take 4.5 years.
只需要四年半
A signal travelling from the marblein Manhattan to the one in Rio,
从曼哈顿传播的信♥号♥♥一直到达里奥
需要一百年才行
would take 100 yearsto make the journey.
有些是早期的传递
Some of our earliest transmissionsmight now be getting close.
但是现在，靠近了
但是，加果反过来呢
But what about the reverse?
Could intelligent alien civilizationsbe sending pings toward Earth,
外星人的信♥号♥♥是否能发过来
我们在家里就可收到
to see if anyone is at home?
Scientists on Earth are listening,
地球上的科学家在注意收听
using technology originally developedfor studying distant cosmic phenomena,
利用装置了解远处的现象
比加说探索行星
like exploding stars.
Many phenomena produce radiowavesand by studying them,
很多都是创造无线电广播信♥号♥♥
利用无线电，可以了解外界是什么样的西斯?斯托克外星研究所
we can also learn somethingabout what's out there and how it works.
So, using radio-antennas to study theUniverse is an idea that goes back to
所以利用无线电去了解宇宙这样可以阻止世界大战
before the Second World War.
今天利用的巨大的无线电波
The huge radio antennas used today,called radio telescopes,
无线电望远镜
are so advanced andso incredibly sensitive,
它非常先进，而且灵敏度非常高
they can easily detect the energyof a flee hopping.
很简单探索到飞行中的能量
这是一个很大的反射器，对吗？
They're just big reflectors, right?
So the radiowaves that are coming down
无线电装置，在地面上到处安置
and falling on the ground all aroundus on the whole Earth, after all,
可以预先报♥警♥有一些无线电波是可以收到的
some of those radiowaveswill fall on these antennas.
So they bounce offthat big mirror,
它们搜寻到之后，继续追踪并且进行放大
then they get focused toa very sensitive amplifier,
and then the signals are sent via cables
然后这个信♥号♥♥被发回到控制室
back into a control roomthat's right nearby here,
接受者就会对这个信♥号♥♥进行分♥析♥
where they have sensitive receivers toanalyse the radioenergy that's coming in.
这样无线电能量就可以传导进来
斯托克博士是高级天文学家
Dr. Seth Shostak is a senior astronomer
at the SETI Institute inMountain View, California.
他在了解加州的地势和地理
SETI is an acronym that stands forSearch for ExtraTerrestrial Intelligence.
这个装置是进行搜集太空智能信♥号♥♥的
这个组织同样也利用无电线望远镜
The SETI organisationalso uses radio telescopes,
but not for studyingnatural cosmic phenomena.
但是并不没有办法了解这种现象
同样的装置可以寻找其它非自然发射的信♥号♥♥
The very same technology can alsobe used to look for signals
that are made not by nature,but by, perhaps, ET.
很可能是外星人发射的
人们加何能知道其中的区别
And how might oneknow the difference?
The kind of signal that we're looking foris what's called a narrow-band signal.
我们想知道到底是什么样的信♥号♥♥
That is to say, it's just a signal that'sat one spot on the radio dial,
我们说，假使接受到一个信♥号♥♥