本集内容

Why aliens probably exist but might not contact us

外星人可能存在却难以联系的原因

文字稿

Aliens probably exist – that's the view of many scientists. But if that's the case, why haven't we heard from them?

外星人可能存在——这是许多科学家的观点。但如果是这样的话，为什么我们还没收到来自外星人的消息？

Even without hard evidence, chances are, somewhere in the billions of galaxies out there, there is life.

即使没有确凿的证据，在宇宙中数十亿个星系里的某个地方也很有可能有生命存在。

But trying to contact them is really difficult.

不过，尝试联系上它们是十分困难的。

We use radio telescopes to listen to signals from space – but if aliens use something else, we might never know they're there.

人类用射电望远镜接收来自太空的信号。如果外星人使用其它方式发出信号，我们就可能永远不会知道它们存在。

And even if we did, the distance between us and them might mean it takes thousands of years to transmit messages.

即使人类联系上了外星人，我们和外星人之间的距离意味着传输消息需要用成千上万年的时间。

Also, while scientists can be fairly sure there's other life out there, what they don't know is whether it's intelligent life.

除此之外，虽然科学家相当确信宇宙中存在其他生命，他们却并不确定这些生命是智慧生命。

For billions of years, life on Earth was simple – mainly bacteria.

在数十亿年的时间里，地球上的生命都十分简单，大多数都是细菌。

It may be that alien life out there currently looks more like this than us.

也许宇宙中的外星生命现在看起来更像细菌，而并不像我们。

If they did develop into something more intelligent, we'd need to be around to see it.

如果它们真的进化成了更智慧的形式，我们也需要和他们同处一个时期才能看到。

Given we've existed for less than 1% of the Earth's history, the chances of this are actually pretty slim.

鉴于我们存在的时间还不到地球历史的1%，我们看到其他智慧生命的机会其实很渺茫。

So, without scientific advances and a whole lot of luck, we probably won't be making contact with any extraterrestrials any time soon.

所以，如果没有科学的进步和十足的运气，我们可能不会在短时间内与外星人取得联系。

重点词汇及表达

galaxy 星系

radio telescope 射电望远镜

transmit 传输

intelligent life 智慧生命

extraterrestrial 外星人，地外生物