I chose the "They are too far away to ever get here" option. It's not exactly what I believe, but was the closest fit.
I am of the "the universe is too big for there to not be others" school of thought. It seems obvious IMO, and new discoveries about how common other planetary systems are in the galaxy only makes extraterrestrial life that much likelier.
Even if light speed truly is the absolute, and it takes hundreds or thousands of years to cross interstellar space, some race or their machines should have covered the galaxy by now. By "living off the land" so to speak, it should be possible for self-constructing robotic probes to move from star system to star system, building copies to send off on new missions from local resources like asteroids, moons, comets, etc. Such a system should create a geometrical explosion that would cover the galaxy in, say half a million years or so. The probes left behind could act as relay stations for the ones further on and watch life bearing planets to see if they develop inteligence. Slow as compared to "Star Trek" but it would get the job done and map the galaxy.
Assuming a hundred races existed at some point in the galaxy's history that didn't "blow themselves up", and didn't come up with more exotic technology that allowed them to explore "at will", one ought to have kicked off such a mission by now. I foresee ourselves having the capability to build such self-replicating probes within a century or two ourselves.
Maybe such a probe did enter our solar system millennia ago, and we've simply not yet found where it mined the materials to create and send off it's "children" to other nearby stars. The probe, waiting in the outer solar system turns on every thousand years to check out the area, and see if anything interesting has come back from it's child probes to pass along to it's own parent probe one star over. Maybe, the next time it activates for a check on the promising planets around our sun like Earth, it's in for a surprise.. If so, we should have an answer soon. But it demonstrates why if there is advanced extraterrestrial intelligence, we should be hearing from them. Even a little more advanced than us, it becomes too easy to do things we should notice.
The other possibility, which makes some sense explaining "the silent skies", is "The Singularity". This hypothesis coined by the recent wave of "cyberpunk" SF authors, states that after a certain point, technological progress becomes exponential, as advances begin to reinforce one another. Just like the singularity at the center of a black hole, from which the theory gets it's name. A black hole's singularity is where conditions are unknowable, and the only way to find out is "go there" (you never come back either), the same is true for the technological singularity.
Technological progress starts to reinforce itself, Ex: Computers and " most everything" these days, robotic manufacture, CAD design vs. paper, new features, rapid evolutionary prototyping, etc. DNA/Genetics, materials science etc. These advances, improving everything and each other, over and over, faster and faster, reaches a runaway point where our society is unrecognizable, possibly as even being human anymore. Or we destroy ourselves in one giant "oops". Example: Near future replicating nanotech robots designed to eat cancer, misfires, grows out of control, and eats everyone instead, etc. One SF author has joked: "Supernovae are really just very, very, very, bad 'industrial accidents'."
So instead of a measured progression from stone age, iron age, industrial age, information/space age, to a "Star Trek" age, then onward, progress just explodes at some point, and the "Star Trek" age just gets leap-frogged entirely. In a scant few decades, we, or other races might go from "Hey! I just got my DNA mapped!" and, "Look at my cool iPod!" to something like the "space spirits" that made the monoliths in 2001, wondering what happened to them.
And then, after The Singularity, the gulf between us and "them" is just too great for visitation or "missionary work", so to speak. Communicating between us would be like trying to train monkeys to hunt at night by giving them the plans to a SureFire factory so they could build their own Digital U2 Ultras from scratch. We may just have to wait for our own Singularity to meet them.
) believing i was an alien. i was from the planet quadroupolous, and for the life of me i can't remember why on earth i came to earth... :thinking:
