or because there's a quarantine on emerging civilizations.
Isn't that the Star Trek philosophy?
On a rational level, I'd find it supremely arrogant (or a cosmic comedy) to have humanity as the first species at least pondering on interstellar travel...
Yet on interstellar travel, I always get stuck in the quandary of transportation and time. Rumsfeldian "we don't know what we don't know" may offer a pinch of hope, but for a while now I've been leaning to the idea that intelligent life, even if has flowered copiously through the galaxy, is hopelessly stuck, each on their own gyrating piece of rock, each and every one feeling miserably alone. And in space, as the saying goes, no one hears you scream.
And that's what I'd call tragedy.
you are the media you consume.
The former are obviously unlikely, in any form we would recognize.
The latter assume they still use radio as a means of communication, using inefficient, simple codes. Again, if they are using radio at all, the search for information efficiency has already lead them to formats that sound to outsiders like noise. Guess what: The universe is full of radio noise.
Assuming they use radio at all. But would they? Not if they had something better. What would THAT be? Well, perforce we would have no clue--as should be obvious.
The biggest problem, though, is that we imagine them to be like us. But if they are, they have already crashed and burned, leaving no interstellar trace but a century of rapidly fading radio modulations--which no one (being either too primitive or having already crashed) has the sensitivity to catch.
