The universe being as vast as it is, it seems unlikely that we would be the only civilization in existence. Becoming an intelligent species in the universe is much like waking up in a desert oasis with no memory of who you are, where you came from, or if there is anyone else out there. In more recent times, we’ve started shouting; “Hello? Is anybody there?” For nearly a century, we have been broadcasting our existence at the speed of light, with the invention of radio. Any extraterrestrials within a hundred light-years of us that have invented radio astronomy may know of us.
Since 1984*, the SETI institute (Search for Extraterrestrial Intelligence) has been listening to the galaxy with radio telescopes, trying to see if anybody is, indeed, out there and broadcasting their existence. So far, we’ve turned up empty. But there is a lot of sky, and only so many people listening to it. In the search, we remain not discouraged. Should humanity continue its technological progress (as well as saving itself from hazards), then the day when we encounter intelligent life from elsewhere in the galaxy could be inevitable. There is no certainty in the existence of alien life; life arising at all could be so rare that we are alone in the whole galaxy. But scientific consensus seems to be leaning the other direction. We have to face the very real possibility that there are others out there, and we may one day meet them.
Still, questions and problems remain, not the least of which is how we would communicate with another intelligent species, should we encounter them. Thankfully, there are people who have been pondering just this question. NASA recently released the book Archeology, Anthropology, and Interstellar Communication for free immediate download in PDF format, and I would recommend that each and every one of you go and download it. The book deals with the problem of communicating with extraterrestrials by looking at humanity’s past. Looking into past human civilizations and the languages and symbols they used could help us in such an event. I have myself downloaded the book and plan on reviewing it here once I finish reading it. In the meantime, it’s assigned reading for the rest of you.
*Author’s note: though SETI activities were ongoing since before 1984, that is the year when the institute was officially founded.