They wouldn 8217;t tell you anything about humans directly, but if you watched the Earth for long enough, you could figure out a lot about our atmosphere from the reflectivity. You could probably figure out what our water cycle looked like, and our oxygen-rich atmosphere would give you a hint that something weird was going on.
这些信号并不能直接透露出关于人类的任何信息，但如果你花足够长的时间观测地球，你就可以通过反射率来了解地球的大气层，你可以推断出我们的水循环是什么样的，而我们富含氧气的大气层也会让你想到地球上一定正在发生什么不寻常的事情。
So in the end, the clearest signal from Earth might not be from us at all. It might be from the algae that have been terraforming the planet-and altering the signals we send into space-for billions of years.
所以到头来，来自地球的最为明显的信号恐怕并不是由我们发出的，它可能来自数十亿年以来使我们的星球地球化的藻类，而且它们还在影响着我们发向太空的信号。
Heeeey, look at the time. Gotta run.
嘿，不早了，我们得走了。
Of course, if we wanted to send a clearer signal, we could. A radio transmission has the problem that they have to be paying attention when it arrives.
当然了，如果我们想发送一个更加明显的信号，我们是可以做到的，但不是靠无线电通信，因为当无线电信号到外星人那儿的时候，需要外星人去接收。
Instead, we could make them pay attention. With ion drives, nuclear propulsion, or just clever use of the Sun 8217;s gravity well, we could probably send a probe out of the solar system fast enough to reach a given nearby star in a few dozen millennia. If we can figure out how to make a guidance system that survives the trip (which would be tough), we could use it to steer toward any inhabited planet.
相反，我们可以让外星人注意到我们。在离子驱动、核脉冲推进或仅是巧妙利用引力弹弓效应的帮助下，我们也许可以发射一颗速度足够快的探测器，能够在几万年的时间里飞出太阳系并到达邻近的星球。如果我们能够研发出一套能够全程使用的导航系统（这可不容易），那么我们就可以把探测器送到任何一颗宜居星球上。
To land safely, we 8217;d have to slow down. But slowing down takes even more fuel. And, hey, the whole point of this was for them to notice us, right?
如果想要安全着陆的话，我们得减速，但减速需要消耗更多的燃料。喂，我们这么做的目的只是为了让外星人注意到我们对吧？
So maybe if those aliens looked toward our solar system, this is what they would see:
所以当某一天外星人仰望太阳系的时候，他们也许会看到这个……
1 I mean, if you want.
1．如果你真的想这么尝试的话。
2 Contrary to the claims made by certain unreliable webcomics.
2．和某不靠谱网络漫画的声称相反。
3 I wasn 8217;t alive during most of this period, but from what I hear, the mood was tense.
3．我只经历过那段时期中很短的一个阶段，但就我听到的来说，当时的风声有点紧。
4 Which is exactly what we saw once, in 1977. The source of this blip (dubbed the “Wow Signal”) has never been identified.
4．我们在1977年就收到过这样一个信号，它被人们称为“哇”（Wow）信号，但信号源头一直不得而知。