That we’re not alone in the universe is something no one knows but most suspect – not only because it is highly probable that there is another advanced form of life somewhere out there, but also because it is a highly fascinating subject that does a beautiful job at spurring our imagination. However, in imagining what such form of life could look like or behave like, we readily make a number of anthropocentric assumptions (that is, we assume they are like us to an unnecessary degree), some of which we are not even aware of. Our common idea of what an extraterrestrial being should look like has been largely shaped by depictions in arts and entertainment that were, in one way or another, created to be relatable and convenient for storytelling purposes, while compromising verisimilitude. If we live in a multiverse, then practically any kind of being we could possibly conceive has existed or will exist at some point. But let’s pretend that humanity is on the verge of making first contact with a single species, a civilization that dwells on a planet close to ours. What can and what can we not assume about them? What do we have to wonder about them? Let us explore, in the spirit of speculation, a number of factors that merit some thought – and how they are related to both science fiction and real science.
It’s not just that we imagine them to be humanoid (standing on two legs, two limbs coming out of the sides of the upper torso, a head with a nose, a mouth, ears, and eyes); it’s that we imagine them to appear earthling-like at all. Even when we try to diverge most from the typical humanoid appearance that science fiction gives to extraterrestrials, we can’t help but envision them as sharing a general morphology with Earth’s fauna: reptiles, crustaceans, or, at best, insects – only of human size or slightly bigger. The rationale behind this is actually not as faulty as it may seem. If we build our imagined extraterrestrial from the ground up, we make anthropocentric assumptions about their morphology out of necessity. After all, we are the only intelligent species that we know of, and therefore the only instance that we can study of evolution reaching such a state. First, we assume that any intelligent species had to arise from some sort of biochemistry similar to ours. Then the resulting life form had to achieve a multicellular state, so as to develop a dedicated brain. It had to develop a skeleton of sorts to cope with gravity, and its body had to grow up to a minimum size such that its brain developed the level of cognition that we enjoy. It had to grow at least a pair of limbs to move around with and a pair to use tools. It also has to have a set of senses to interact with its world and a body big and strong enough to thrive in its ecosystem. In the end, it’s just simpler to not think outside the box.
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.
Whatever shape they have, extraterrestrials need some sort of energy source to live – that much we know, at least in our universe with our particular laws of physics. What could it be, then? Evolution is a powerful force, but I doubt there are beings with integrated cores prancing around fusing hydrogen atoms like it’s going out of fashion in the vicinity of our galaxy. Again, this variable powerfully hinges on their biochemistry, and the effects are many to be left without discussion. Given the availability of the elements that make up the compounds that make us up, it isn’t a stretch to think that there are aliens who have a diet similar in chemistry to ours. But whatever they specifically eat defines many of their characteristics and traits, ranging from their anatomy to their social structure to their economy to their attitudes toward other life forms. Do they see us as prey; as predators; as competition; as the intrusive dwellers of an earthy, delicious planet; as a waste of precious iron and other minerals in our bloodstream; or as nasty, smelly blobs of excrement? Conversely, are their diets something that makes them inherently disgusting and undesirable to us (say, ammonia-based beings)? Are they out in search of food or is their planet so plentiful and their hearts so altruistic that they are out to feed the starved (and their definition of “starved” so convenient that it includes us but doesn’t make us their inferior)?
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.
8 What’s their Story?
It has taken life approximately 3.5 billion years to get from our last universal ancestor (i.e., the most recent forebear of all organisms on Earth) to where we are today. Along the way, there have been natural disasters, giant dinosaurs, more natural disasters, early empires, religions, nations, navies, colonization, Theodore Roosevelt, world wars, and a cold war. Whatever we’re responsible for, we’re equal parts proud and ashamed of, but undoubtedly, it is a very interesting story to tell. What do they have to tell us, then? Did their evolution yield as diverse an array of life forms as ours did? If so, did their planet endure extinction events, perhaps involving other intelligent species? Did their civilization break up into different nations? If so, is their world still governed by different nations?
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).