That said, we’re basing all of this on the idea that their world is like ours – and that evolution took a very similar set of paths that resulted in similar biodiversity. But they don’t have to be the same size we are. For example, for all we know, there could be sapient extraterrestrials the size of a small building or the size of a freight train. They don’t have to have a head or limbs resembling what we’ve seen on this planet. They don’t even need to have a skin instead of, say, a cellulose wall or something made of an exotic compound. Even more exciting to contemplate are extraterrestrial life forms that don’t share our biochemistry at all. It is theorised, for example, that silicon-based beings would be of a crystalline structure and thrive in high-temperature places, though silicon biochemistry is not as flexible and apt for life as carbon’s is.
Another interesting but less meaningful energy-related question is, of course, how they power their infrastructure and technology. Presumably, whatever they do to keep their ships afloat or their lights on is something we could apply to our own technology, if it is more efficient than our own energy-extraction processes and as long as it isn’t based on a resource that their planet has and ours doesn’t.
What's Their Story
Again, the way they would approach us would be, in more than one way, defined by their history. A society unaccustomed to violence might be benevolent to a fault, almost naive, in their first interactions with another intelligent society. Then again, it could also be exceedingly cautious, aware that not all civilizations regard the concept of harmony with such devotion. A society that has become used to conflict, on the other hand, is likely to have developed both a more sophisticated diplomacy apparatus and a military – and the extent to which they rely on either is something we can only speculate about. Some, including Jared Diamond and Stephen Hawking, have speculated that, if we ever come into contact with a civilization that is superior to us and behaves more or less like us, then, judging by the outcome of the most significant encounters between two societies that’s occurred throughout human history, it is likely that the superior civilization would come to dominate us, perhaps through a combination of hard power (force or coercion) and soft power (non-intimidating persuasion).
Expectations of Us
Again, going back to the Neanderthal analogy, just imagine that we come into contact with a race that’s just as intellectually capable as the Neanderthal: they would understand their encounter with us very differently from the way we would understand it. They are limited by their brain and would not comprehend our efforts to communicate with them; meanwhile, we would be frustrated and disappointed, as our interaction with them would prove fruitless. Now imagine that we come into contact with a race that’s much, much smarter than us, such that their advantage over us is the same as ours is over the Neanderthal. Would they be frustrated by our inability to do and comprehend what they can do and comprehend? Or is there a minimum level of intelligence that we’ve already achieved, past which all forms of communication are possible? (The same way there is a minimum level of intelligence that dogs have achieved, past which they are as capable as we are of identifying their “loved ones.”)
The concept of cosmicism, developed by fiction writer H. P. Lovecraft, is more or less related to this issue, as it describes the inability of humanity to comprehend much greater forces that rule the universe, and proposed that the magnitude of these forces renders us insignificant in the grand scheme of things.
Unfortunately, we do not have control over what civilizations that haven’t had contact with us do, and so there is a probability that someone somewhere, unbeknownst to us, is developing a form of artificial intelligence, if they haven’t already. The probability of this scenario is fairly low, and it’s even less probable that a species of such intelligence would not have a sense of precaution. Even then, it’s very, very unlikely that this could pose a threat to our existence. But it’s a question worth asking, and one that has produced some quality works of fiction.
Cognition and Emotion
Equally intriguing is the idea that they may feel very different emotions from us. Many of our emotions are hypothesized to be the byproducts of evolution, and so the way we feel emotions has been shaped by our own, unique evolutionary history. It is quite possible, then, that whatever alien civilization we make first contact with does not understand the purpose of laughter, doesn’t feel spite, or isn’t scared or awed by the things that scare and awe us. Conversely, it is also possible that they feel emotions that we cannot even begin to comprehend. This would make interplanetary diplomacy less easy than we wish it were.
Knowledge of the Universe
However, as stated above, it is possible that we are simply too limited in intelligence to comprehend the work and the understanding that the other civilization is capable of. However, it is obvious that humans have not stopped evolving, and there exists the possibility that from us will emerge a more intelligent species, or at least more intelligent humans, twenty thousand years from now or a million years from now.
Not too long ago, when the Big Crunch seemed like the most plausible end-of-the-universe scenario, a physicist named Frank Tipler proposed that the solution would be to create an infinitely powerful computer, which would harness all the energy created by the Big Crunch. With this energy, he argued, the computer could “bring back to life… all life that ever existed”. In the very last second of objective time (i.e., “physical” time), the computer could create an infinite amount of “subjective” time in which it could emulate all possible quantum states of the universe – including every life form that ever existed. The takeaway from this is that, as self-preserving life forms, we meet our awareness of the finitude of the universe with ideas to overcome it and make the existence of life infinite (if only subjectively so – but does that matter?).
Why are they here?
But supposing we are one day able to distort space-time to travel to faraway places, where should we look? It’s not just planets at a certain distance from their stars that we should look for. The size of the star, its luminosity, its dark spots, the way the planet revolves around the star (e.g., tidal lock), the atmospheric components of the planet, the planet’s rotation and tilt, the size and distance of other planets orbiting around the same star (which could stabilize the habitable planet’s orbit and shield it from asteroids and comets), and even the shape and activity of the galaxy are all important factors to consider.
Regardless, we’re not flying out in search of aliens any time soon. If we are to see them in our lifetimes, it’s probably because they will come to us – not the other way around – but I don’t think we’ll see that very soon, either. Regardless, extraterrestrial life is a captivating subject, and I do hope that one day humans will greet creatures of another planet and establish a mutually beneficial relationship. The end of a life-sustaining universe is not an encouraging scenario to contemplate, so it would be nice to know we’re not the only ones concerned with preserving life forever.