Have you ever wondered why alien visitors to this planet never contact anyone even remotely sensible? And have you noticed that this same ranking of mental acuity can be applied to those who believe the notion that when President Bush (the not quite so stupid one) proclaimed ‘a new world order’ after the end of the Cold War, this was code, for those in the know, for the takeover of the world by a race of reptilian aliens? This is not to suggest that there aren’t aliens out there. The problem is the lack of evidence.
Which is where scientists come into the picture. Some of them have been looking for that evidence. SETI (Search for Extra-Terrestrial Intelligence) is the collective name for the various attempts to identify intelligent signals from space that have been conducted over the past fifty years, so far unsuccessfully. In the meantime, we’ve sent out maps (Pioneer 10 and Pioneer 11 in 1972 and 1973, respectively) telling any passing spaceship that happens to retrieve one how to get here. And the Voyager probes carried the same maps, together with sufficient information to give the finders a very good idea of conditions on Earth.
There is clearly a presumption that a race with the intelligence to intercept and decipher this information will be benign, but this is mere guesswork based on our own experiences here on Earth and an optimism about the future of the human race that may be misplaced. What if the information were to be intercepted by a military civilization that already rules half the galaxy with a level of ruthless efficiency and routine cruelty that the police states of the twentieth century couldn’t even begin to dream about? An empire that is driven by moral imperatives that would not have been considered out of place in Nazi Germany, led by beings compared to whom Pol Pot would have been diagnosed as someone with a mild personality disorder? An empire that has the technology to cross the intervening distance in a matter of days? The military mismatch would be beyond imagining. The best that we could hope for would be perpetual enslavement. At worst, we might be considered a substandard species, to be exterminated to make room for incoming colonists.
However, as with the invention of the atomic bomb, our actions cannot now be rescinded or reversed. We live with the daily threat of sudden invasion, although it has to be said in mitigation that the probability of this occurring is vanishingly small. The moral of this story is that it is pointless worrying about something that you are utterly powerless to influence or prevent. Have a nice day.