Alien life – but not as we know it
Don’t be fooled by Hollywood aliens: any extra-terrestrial intelligence we encounter is likely to be artificial, not biological
Oh, sure, they might be short, big-eyed and hairless – decked out in skin smoother than gourmet prosciutto. But really, these creatures from afar are usually so anthropomorphic (aside from their grey complexions), they could pass for hominid relatives, freshly flushed from some cryptic, jungle habitat.
You should expect that from movie-makers. After all, the alien characters in films should be “readable”. The audience needs to look at their faces (note that they have faces) and instantly judge whether these beings are happy, hungry or homicidal.
Subconsciously, the researchers who look for sentience beyond Earth in the effort known as Seti (the Search for Extraterrestrial Intelligence), make a similar mental picture of their quarry. The idea of Seti is to use large antennas to possibly eavesdrop on radio transmissions from technically competent aliens. Its practitioners don’t really insist that the guys behind the microphone be either gray or glabrous, but they do – implicitly – assume that they’ve evolved on a world that, like Earth, is wrapped in oceans and an atmosphere. In other words, that the aliens are biological.
So Seti experiments often train their radio ears on star systems that seem most likely to host earth-like worlds.
That sounds both plausible and responsible. Sure, you could protest that alien life doesn’t have to be life as we know it, a pleasant observation that’s hard to refute. But it’s also silly to throw out the one bit of information we have in the matter; namely, that intelligence has successfully emerged on an ocean-covered planet with a thick atmosphere.
Still, there’s something to be learned by considering not just the evolutionary history of our planet, but its short-term future. We are now building digital devices that can process information at blistering speeds. Our computers double in capability on timescales of only a few years. It’s hardly outrageous to believe that we will successfully develop thinking machines within a handful of decades, or at most a century or two.
If that happens, these artificial sentients will quickly leave us behind. Unburdened from the slow and aimless process of Darwinian evolution, the machines will self-improve, and will do so in short order.
They might leave us behind in a literal sense, as well. While human space travel is daunting, machines – with their indefinitely long lifetimes – could travel the galaxy. It might make little difference to them that bridging the distance from one star to the next could take hundreds of thousands of years or more.
But where would they go? That’s like asking a trilobite to speculate on the lifestyles of humans. Obviously, we can say little, except this: heavy-duty computing takes plenty of power. The most attractive habitats for synthetic sentience might be the vicinities of exceptional sources of energy – for example black holes, or even the neighbourhoods of large stars, which routinely boil off the energy of ten thousand suns. These are the destinations they may seek.
It comes down to this: if any species reaches the point of inventing radio, it is only a handful of centuries from inventing its intellectual successors. Biological intelligence is merely a short stepping stone on the path to the prodigious talents of machines. Consequently, the majority of the intelligence in the universe could well be artificial intelligence.
So while it’s certainly reasonable to continue to train our telescopes on cosmic locales where biology might thrive, it seems prudent to spend at least some time examining places that only a machine could love.