《那些古怪又讓人憂心的問題》第47期:外星天文學家(3)
They wouldn'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.
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.
所以到頭來，來自地球的最爲明顯的信號恐怕並不是由我們發出的，它可能來自數十億年以來使我們的星球地球化的藻類，而且它們還在影響着我們發向太空的信號。Heeeey, look at the time. Gotta run.
嘿，不早了，我們得走了。
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.
當然了，如果我們想發送一個更加明顯的信號，我們是可以做到的，但不是靠無線電通信，因爲當無線電信號到外星人那兒的時候，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'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，我們可以讓外星人注意到我們。在離子驅動、核脈衝推進或僅是巧妙利用引力彈弓效應的幫助下，我們也許可以發射一顆速度足夠快的探測器，能夠在幾萬年的時間裏飛出太陽系併到達鄰近的星球。如果我們能夠研發出一套能夠全程使用的導航系統（這可不容易），那麼我們就可以把探測器送到任何一顆宜居星球上。To land safely, we'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?
如果想要安全着陸的話，我們得減速，但減速需要消耗更多的燃料。喂，我們這麼做的目的只是爲了讓外星人注意到我們對吧？So maybe if those aliens looked toward our solar system, this is what they would see:
所以當某一天外星人仰望太陽系的時候，他們也許會看到這個……1 I mean, if you want.
1．如果你真的想這麼嘗試的話。2 Contrary to the claims made by certain unreliable webcomics.
2．和某不靠譜網絡漫畫的聲稱相反。3 I wasn't alive during most of this period, but from what I hear, the mood was tense.
3．我只經歷過那段時期中很短的一個階段，但就我聽到的來說，當時的風聲有點緊。4 Which is exactly what we saw once, in 1977. The source of this blip (dubbed the “Wow Signal”) has never been identified.
4．我們在1977年就收到過這樣一個信號，它被人們稱爲“哇”（Wow）信號，但信號源頭一直不得而知。
