If ever humans should face creatures from outer space, they would ­surely have to find a way of dealing with the aliens and—supposing they would have such a thing: with their languages. The branch of linguistics dedicated to the study of such languages from outer space is commonly referred to as xenolinguistics. For the time being, xenolinguistics is an essentially speculative and certainly radical exercise of conceiving the diverse. We have asked a series of specialists from different fields that at some point or another have dealt—or still deal—with the possibility of alien communication their views on certain fundamental questions of xenolinguistics.

  José Antonio Millán was a pioneer in linguistic work with computers. He is the translator of several texts by Noam Chomsky, and has worked on visual metaphors as well as language rhythms.

  Dr. Rosalba Bonaccorsi is a research scientist in the fields of astrobiology, environmental Sciences, bio-sedimentology, marine geochemistry at SETI Institute, Mountain View, CA.

Dr. Sheri Wells-Jensen, associate professor of linguistics at Bowling Green State University, USA. Research interests: xenolinguistics, braille, applied phonology and syntax, psycholinguistics, disability studies, SETI, and language creation.

Douglas Vakoch, Ph.D., is president of METI (Messaging Extraterrestrial Intelligence, www.meti.org), a nonprofit research and educational organization dedicated to transmitting intentional signals to nearby stars. He led the construction of METI’s recent messages to Luyten’s Star, a red dwarf 12.4 light years from Earth, as part of the project Sónar Calling GJ 273b.

Michael P. Oman-Reagan is an anthropologist working with space exploration modalities that reach beyond our solar system, including astronomy, spacecraft, and the search for extraterrestrial intelligence, at Memorial University of Newfoundland.

In conversation with Mário Gomes.

The idea of communicating with extraterrestrials presupposes a common communicative ground, a kind of universal grammar that isn’t only limited to humans. How broad could the boundaries of such a universal grammar be?

Well, before having a common grammar, I think that (even more importantly) they should share a common experiential context with us. Maybe for example also having a physical body that functions by orienting itself in its environment (up/down, front/back). If there are gaseous extraterrestrials living in the atmosphere of a gigantic planet like Jupiter (as in some of Kilgore Trout’s creations), something like that would be impossible. From a strictly grammatical point of view, I think that elements such as recursion and deixis (linguistic or environmental) might be requirements for the economy of any communication system.

I have doubts that linguistic grammar (as a set of rules) could be the universal way to communicate between different extraterrestrial civilizations, which unlikely will be familiar with the human context. Some scientists have reasons to believe that a fundamental grammar could be math i.e. a set of prime numbers repeated in sequences, or some constant of physics (Planck constant, Pi, etc.). This is of course based on the main assumption that extraterrestrials share the same perception we have about the universal constants of physics and mathematics.

The term Universal Grammar is often taken in linguistics to mean the underpinning of all Earth languages. It doesn’t really mean “universal” … and it’s just a theory. Yes, there are some things that human languages have in common, but the list of what those things are specifically is pretty hard … impossible to lay out clearly. I mean, all our languages have consonant and vowel sounds… if they’re spoken (as opposed to signed), but that’s only because we have heads and throats and lungs. And we know signed languages are real languages, so you can toss that one out. Linguists often struggle to find things like “all languages have binary branching,” but I’m not sure what that’s good for … and I’ve seen people really distort data (real language data that is real sentences spoken by real people) to make that work. So throw away anything that you’ve read that has the words UG in it because it might not be talking about what I think you’re talking about. There was a great article in the 1980s by Marvin Minsky where he laid out a few things that I think are true: since anywhere you go there are objects (rocks, stars, liquids), a thing we would recognize as a language would probably have nouns. Since things happen (stuff falls, explodes, crashes into other stuff) there will probably be verbs. Beyond that, things get dicey.

You’d like to imagine that, since there can be more than one of something (2 rocks 50 jillion stars), any language would have ways of marking number, but we have Earth languages that mostly don’t bother to mark numbers, so that’s probably not necessary. Once you get much beyond verbs and nouns, all bets are off (in case you were wondering, there are plenty of Earth languages without adjectives).

When Noam Chomsky talks about universal grammar, he certainly doesn’t mean universal in a cosmic sense. Chomsky is talking about the fundamental structures of language that are universal across human languages. His explanation for these commonalities is biological. Humans have a built-in “language acquisition device” unlike any other animals on Earth, he says. Only humans among all animals, Chomsky claims, have an ability to pull language out of the noisy whirr of sounds they are bombarded with. This genetic endowment for language is universal across all cultures, and it’s central to being Homo sapiens.

What happens if aliens have language of their own? There’s no reason to expect it would be based on the same rules that guide terrestrial languages. According to Chomsky, human language is guided by a transformational grammar that links the deep structure of meaning with the surface structure of expressed language. Intelligent extraterrestrials may have an analogous connection between deep and surface language structures, but the structures of those levels themselves could differ radically from ours. So could the links between the hidden and the manifest structures of language.

If there were a “universal grammar,” would it be universal beyond life that evolves on Earth? Even on Earth we might ask how the idea of a grammar based on particular ideas about human brains could be called “universal.” Until we can parse and understand the languages of the non-human life here on Earth, we might not be able to answer these questions. Perhaps there is a way to communicate with extraterrestrial life, or terrestrial non-human life, without any pre-existing common communicative ground. It might take an extremely long time to develop such a framework for understanding across difference. The effort will require interdisciplinary collaboration between linguistics, biology, art, physics, social sciences, engineering, and other areas of thought and modes of research and activity. It will also require anthropological insights about intercultural contact, how we conceptualize difference, and especially a critical approach to understanding how we naturalize and universalize culturally specific behaviour and beliefs, transposing these from one culture to other cultures, and from humanity to other life. It will demand generosity, patience, imagination.

Of course, one may imagine communication beyond grammar. Yuri Lotman for instance assumes that, in the same way that the biosphere is the condition for the existence of vegetal and animal life, the semiosphere precedes all forms of interpersonal communication. But wouldn’t communication beyond the semiosphere also be conceivable?

How do we talk about “communication” within, and at the same time beyond, the environment in which we have built the concept of communication? Perhaps we need new concepts to resolve this. It is a key problem of inter-species communication already on Earth, and certainly of inter-species communication beyond Earth. As anthropologist Martin Holbraad has said: when we encounter profound differences, the concepts we already have might not be adequate to describe the data, let alone interpret or explain what we’re encountering.

Hmmm. If you don’t have meaning … or an intent… then there’s nothing to actually say. Any exchange of information has some meaning behind it. I wouldn’t class things like sunlight falling onto a flower as communication.

  As I mentioned earlier, I think that the semiosphere is necessarily influenced by the physical space where life unfolds. In our languages it is very common for the conception of time to be spatial (with the future at some point in front of us), and this fuels things from lexical choices to verbal circumlocution. The communication with beings that lack this metaphor (or another comparable one) could be complicated.

There is another element that (as far as I know) fuels most of the Earth’s languages: the possibility of resorting to metaphor and metonymy.

On the former: some of the human metaphors in use are related to physical corporeity (upright = active, healthy, potentially aggressive; prostrate = sick, dead, non-threatening). But there are many others (I think of Lakoff and Johnson’s line, Metaphors we live by), for example, a message or word being something that comes out of a container, crosses space, and reaches another, etc.

I’m also thinking of another element that is very present in our languages: the use of synecdoche and metonymy. To refer to a part of an object or action in order to allude to its totality, or to another part of itself is a vibrant resource both in the lexicon and in visual semiosis (signage, informal signs, sign language). I have no doubt that they correspond with a profoundly human communication trait. Again, this could be completely missing in radically different beings.

If some day we make contact with an extraterrestrial intelligence, in the process we will expand our notion of semiosphere, so that it is not restricted to communication between Umwelten indigenous to Earth, but also includes communication with beings who have evolved independently on different planets. Perhaps our best chance of doing this, so we can have a meaningful exchange with an extraterrestrial intelligence, is to learn from the study of sign systems that are not narrowly modeled on language as the prototype. Thus we might prefer a semiotics that is informed by sign systems found across species on Earth (as in zoosemiotics examined by Thomas Sebeok, drawing on Jakob von Uexküll’s work), as opposed to linguistically inspired semiology, as advanced by Ferdinand de Saussure through his semiology.

Whereas semiology takes human language as its model, semiotics doesn’t privilege human language, but instead is formulated on insights from communication across species, from slime molds to zebras, and across different modes of communication, from literature to the visual arts. Semiology may study all of those modes and subjects, but it does so from a framework initially defined by language, and this may be overly constraining.

At Messaging Extraterrestrial Intelligence (METI) instead of relying solely on arbitrary symbols in our first radio transmissions to other civilizations, we are emphasizing icons in which the radio signals resemble the ideas we want to communicate. When we communicate the notion of time, for example, we do so through radio pulses that have a specific duration, a specific start and stop point. As we talk about different radio frequencies, we illustrate them by sending radio signals at these different frequencies. Such a semiotic approach may be more restricted than the fullness of human language, but if we can get across anything to an extraterrestrial, no matter how rudimentary, we will have made a breakthrough.

Scientists and ethologists have demonstrated that a certain level of communication can be achieved between humans and not-human animals. Several species are able to communicate with us. Apes, birds, and other animals can understand the meaning of certain a number of words to fulfill their physical and emotional needs in relation to us. Our pets are very effective at telling us that they want food and attention. Ethologists, such as pioneer Konrad Lorenz, have been exploring animal behavior and hack basic quintessential information. Yet we have not fully decoded any non-human animal language. King Solomon’s ring has yet to be found. If we consider alien minds that have evolved on alien planets, we have now an unfathomable, yet theoretical range of possibilities: from alien life, intelligence, and minds as we (might) know them e.g., non-human animals, to life, intelligence, and minds as we do not know them.

Several science-fiction novels and films feature extraterrestrial languages, many of which are elaborated down to the smallest detail. To what extent could such artificial languages be relevant for xenolinguistics?

  When fictional alien languages are sufficiently developed, they can represent interesting mental experiments about communication. As far as I know, more attention has been paid to the creation of lexicons (and their gaps!) than to syntactic subtleties (which are always more abstract). I’m thinking about the Klingon language, for example, with its lack of forms of courtesy and its brutal phrases that reflect a bellicose and unrefined civilization.

The exercise to produce a fictional alien-like language, which could be studied and understood by human researchers, can inspire the general public to know more about xenolinguistics and communication with aliens. In the movie Arrival, for instance, the squid-like aliens’ written language consists of circular symbols of dark ink ejected from the heptapod’s body. Each circular symbol has a general meaning, while the elaborate set of tendrils emanating from any individual circles conveys specific meaning that humans are able to study, understand, and use to communicate with the aliens. In the movie, heptapods also have a spoken language, but this does not relate to the written symbols.

The term “xenolinguistics” is from science fiction. Star Fleet Academy, for example, has a department of xenolinguistics. But to have a true xenolinguistics, we need examples of alien languages, which we don’t yet have. So for now, xenolinguistics doesn’t exist.

Linguists have created science-fiction languages like Klingon and Vulcan for Star Trek, but these are largely derivative of terrestrial languages—understandable because they need to be spoken by human actors playing Klingons and Vulcans! These languages are designed for cinematic purposes. Phonemes were chosen for Klingon that would yield a guttural language, seen by its creator as a linguistic shorthand for a species prone to war. So these science fiction languages say a lot about humans and our preconceptions of what different languages on Earth connote, but they don’t yield great insights into the nature of language itself—beyond the insights we gain from linguistics in its traditional Earth-bound form.

While a close examination of fictional languages spoken by aliens in science fiction might not give us profound insights into the nature of language in general, the scenarios of first contact found in science fiction can help us reflect on our presuppositions about how we will understand extraterrestrials. In addition, science fiction sometimes draws on linguistic concepts to explain how first contact works, even though the concepts may get distorted in the process of being transformed into engaging cinema.

Arrival also nicely depicts the complementary strategies we would use to establish intelligible communication with aliens. We can’t assume that they’ll know German or English, so we’ll need to look for some other means of communication. As Renner’s physicist character prepares for his first encounter with the visitors, he says he’s developed a scheme to tell them about binary numbers, then build up to the Fibonacci sequence and other mathematical concepts. And this is an approach very similar to what we do in METI. We try to anticipate what any alien has in common with us, simply by virtue of being able to make contact at all.

We don’t count on aliens being able to traverse the immense distances between stars, and instead we attempt to make contact by exchanging radio signals or laser pulses, both of which are electromagnetic signals that we can transmit and receive from Earth. But even if the nearest star is inhabited, a roundtrip exchange would take over eight years at minimum, even with signals travelling at the speed of light. If the nearest inhabited planet is much farther away, it could take centuries or millennia for a back-and-forth exchange.

Depends on the goal of the conlanger (the language builder). Lots of conlangs are designed as possible human languages or possible human languages with a twist.

Or as possible human languages that systematically defy norms set up by human languages. Or possible human languages designed with fun in jokes for other conlangers. And some are just beautiful. And they get people excited about language. As such, these are terrific fun and good for your sense of play, but probably add little to our understanding of ET languages. Some conlangs are designed to just be weird in marvelous ways. To the extent that they push the boundaries of what we can think up, they’re great. Practice in thinking outside the box is always useful. There’s an argument that anything a person can think up is by definition not alien. Maybe so … (we can’t know) but there are probably all kinds of aliens… some reasonably simliar to us, say furry little bunny critters, others, like squid monsters, pretty different… others, like maybe some kind of hive mind gas bag or sentient star… would have languages harder for us to work out. The closer the physical form to ours, probably the closer the cognition and the language. The more similar the conlang to a human language, probably the less useful it is… except as a brain stretcher… again, always a good thing.

Still, if you dedicate yourself to making up a language for a new race, and take that seriously, you learn things you would not have learned otherwise. And that’s good practice. If we ever get an ET message, there had better be a healthy handful of practiced conlangers on the decoding team.

In a recent article in the International Journal of Astrobiology, Nathalie Cabrol of the SETI Institute has asked how we might be able to step out of our own human brains enough to actually imagine alien intelligence. Similarly, when speculative fiction and fantasy author China Miéville was asked about how he approaches portraying “authentically alien intelligences,” he said it’s not just difficult, it’s impossible. But, Miéville said, it’s still worth trying because even if you can’t succeed, “you might just fail pretty wonderfully.” As an anthropologist thinking about extraterrestrial life and futures, I look at a lot of science fiction and other speculative writing to see how wonderfully we can fail at imagining extreme differences and other possible worlds, cultures, realities, and more. I’m interested in examples of what I call speculative ethnography, something I think we can also do within anthropology by opening ourselves to imagined others, and possible futures. Even just imagining, or building invented alien languages, and alien ideas, might make us more capable of imagining them as possible, and thereby building a present and future in which they might be encountered without repeating the ongoing violences of human history. As Ursula K. LeGuin wrote in Wave of the Mind “we cannot demand that anyone try to attain justice and freedom who has not had a chance to imagine them as attainable.” So perhaps such artificial languages, even if they “fail wonderfully” to capture anything we would find in an actual xenolanguage, still have value because they expand our ability to imagine possibilities, and hopefully possibilities that include more justice.

In the 1960s the artificial language Lincos was developed to send messages to extraterrestrials. Lincos was based on the idea that even if aliens would not share common language structures with humans, they might be able to understand arithmetic. Fourteen years later—in 1974—a radio message was broadcast from a space telescope in Arecibo, Puerto Rico, towards of the Great Globular Cluster in Hercules (Messier 13), hoping to meet a receiver there. The message contained information about the DNA structure of the human being, its physical constitution, as well as localization data of the Earth and other supposedly relevant information about the planet. The message was sent in binary code. Can we assume that the universe either thinks binarily or arithmetically?

Hans Freudenthal’s Lincos is structured in a way that would have pleased René Descartes, who argued that in order to have reliable knowledge of the world, we need to start with “clear and distinct” truths. Then we can see what logically follows from those indisputable truths. Freudenthal takes the same approach. Any rational being, anywhere in the universe, must know that “2 + 2 =4,” he argued. Once you have established some essential truths, you see what logically follows. For example, multiplication is the same thing as addition done over and over and over again. So if an extraterrestrial recognizes that you’re giving a bunch of examples of addition, they should be able to understand your explanation of multiplication. The beauty of Lincos is also its greatest weakness. Step by step, Freundenthal reconstructs our understanding of the world, from the simple to the complex. If you can follow each step, you gain entry into a rational, coherent description of the world as seen through human eyes. If you miss one step, you could be hopelessly lost, and all that follows will be gibberish.

We can see Freudenthal’s focus on rationality as the essential characteristic of being human if we look at the order he treats various topics. Lincos starts with a chapter on mathematics, which is followed by a concise introduction to time. The third chapter provides a lengthy exposition on human behavior. Finally, the book closes with a discussion of mass, space, and motion. If you think about it for a moment, this sequence means that much of Freudenthal’s discussion of people happens before he tells extraterrestrials that we have bodies that have mass, that take up space, and that can move. In fact his chapter on “human behavior” portrays people through a series of dialogues between disembodied ghosts. When Freudenthal turns to a physical description of humans in his last chapter, it’s almost a mechanistic afterthought, akin to Descartes’ notion that the human body is a material shell that somehow encloses an eternal soul within.

While there are SETI researchers who believe that science and mathematics might constitute a “universal language,” I think they are usually mistaking the universe for one of our many systems of describing that universe. The map is not the territory. So no, I don’t think we can assume anything about how the rest of the universe thinks, and especially not how the rest of the universe describes, inscribes, and communicates those thoughts. But we can work on the question of all the possible ways that they might think and be and do and live and exist in other manners and modes.

We usually assume that, if they got the message, they did that by building a receiver. So they had built up some science and applied that science in ways that are similar enough to ours that… they made some of the same marvelous things we have made. That implies an understanding of EM radiation and mostly like smelting of metals. To make a radio and to find that useful, you have to have some math. On the other hand, if they don’t have science… then they won’t get the message in the first place. The point is not: do they think that way naturally? The point is that if they built a radio receiver, then we have ideas in common that we can obviously build on. Ask a first-century human about binary numbers and you’d get the blankest of blank responses. It’s not natural: we learn it from exploring and asking questions and learning and doing science.

  Both in fiction and in real-world experiments, when it becomes necessary to design a universal means of communication, it usually leads to mathematics... or to music (which might be the same thing). This not only represents the Platonic view (according to which mathematical entities have an autonomous existence) but also the need to minimize the complexities of communication. Intelligent beings from the far reaches of the universe may not think arithmetically (seeing as their globular members are bobbing in the currents of a giant planet’s stratosphere), but—we hope—they may recognize some formal constraints, and thereby advance from increasing strings of binary numerals to the Pythagorean theorem, and from there so much farther...

It makes sense to assume that logical universals of physics and fundamental arithmetic (primary numbers, pi, etc.) may be consistent anywhere in the universe (as we know it), and that intelligent aliens could be familiar with them. However, the universe is a very big place, and alien cultures may perceive it in a very different way from us. Regarding binary, aliens and humans will need a common ground to share an agreed primer communicating in binary, or in any other language. We have sent messages in the bottle to alien space explorers based on the assumption that the entire universe operates on logical universals. Voyager Pioneers 10 and 11, as well as Voyager (1977) spacecrafts carried metal plaques with basic information on humans and their planet location. The Voyager engraved a gold-plated disk including a representation of the Solar System, photographs of humans and other animals, plants, and panoramas. The golden record also included diagrams, music, mathematical and physical elements, DNA’s structure and chemistry with the hope they could be read and correctly understood by aliens.

For decades, so-called “cosmic calls” have been cast into the depths of the universe. Can we assume that there is an actual hope of ever receiving an answer to these calls? Or are they just a by-product of despair and loneliness?

No, no, no: it’s a byproduct of hope, curiosity and faith.

We’ll either get an answer (which could come tomorrow) or we won’t … which will cause us to think up other ways of trying. Because we’re hopeful folk.

As Nathalie Cabrol recently told me in a conversation at the SETI Institute, in order for a message we send to be received there has to be an incredible alignment of bodies in space across vast distances. Everything would have to be in just the right place for such a signal to be received. However, I do not think transmissions and the desire to send signals are a product of despair or loneliness, but are a product of hope. When I look at the efforts and research in METI (messaging to extraterrestrial intelligence), like those undertaken by Douglas Vakoch at METI International, I see hope that we can find others out there who are also encountering the mysteries of the universe, and perhaps learn from one another. When I think about this moment in history, marked by the greatest refugee crisis since the Second World War, along with the rise and normalization of oppression in governments, and continuing threats of war, the impulse to reach out to the stars strikes me as very optimistic, and perhaps sadly sometimes a bit too optimistic about the possibility that most of our species is open to learning anything at all. I still have hope though, and I can imagine better futures, and I encourage everyone to imagine better futures.

  Better than anyone else, it is authors like Stanisław Lem who have analyzed the hopes placed in broadcasts in search of intelligence... and the dangers of their discovery. We already know that either one of the two possible answers to the question “Are we alone in the cosmos?” is terrifying. Meanwhile, in despair and loneliness we can think that signs of intelligent life could have arrived back in the Pleistocene, or that they will arrive when our sun is going nova. Why not?

I do see this endeavor not as the result of our despair and loneliness, but rather as an essential component of our human curiosity. I also believe that when we carefully work to produce a message that represents us all as one humanity, we put forward the better part of our human self, telling us who we are, who we want to be and be known by the universe. Furthermore, some believe that we are not finding extraterrestrial civilizations (Fermi’s Paradox) because an extraterrestrial civilization advanced enough to perform interstellar communication would face a technological breakdown before they could do so. If we find someone out there who actually survived self-destruction, then there is hope for us as well.

If anyone is hoping to overcome a sense of despair or loneliness through interstellar communication, I think they’re going to be very disappointed. Despite the encouraging images of aliens that we get in movies like Steven Spielberg’s ET, we shouldn’t count on aliens ever becoming our friends. In the most realistic scenario, we will be separated by the huge distances between the stars and we will never make face-to-face contact. Even if extraterrestrials share some fundamental mathematical and scientific concepts with us, and so we have some basis for a common universal language, mutual comprehension will be painfully slow.

Couldn’t the field of xenolinguistics be extended to other beings, such as cephalopods?

Research into cephalopods’ world is progressing. We know that cephalopods such as cuttlefish and octopuses can communicate by signals associated with voluntary changes of their size, shape, texture, and color. Therefore, theoretically, cephalopod-like aliens could develop a body-based language, similar to the hectapods portrayed in Arrival. Because of their outstanding biology, octopuses are thought to be “terrestrial aliens.” In captivity, octopuses seem to recognize individual facial features and exhibit a wide array of personalities by interacting differently with their human handlers. Research has proven that they are highly creative. They can plot escapes from their tanks by hacking the tanks system and learn to solve problems by looking at other octopuses around them. They can also retrieve hidden objects from complex cubes, quickly solve mazes, and use natural and newly encountered objects as tools.

We have plenty of intelligent beings on Earth who are not human, such as cephalopods—octopuses—and we can learn much that is relevant to interstellar communication by studying them. It’s not so much that xenolinguistics can help us understand cephalopods better, but it’s the reverse—the study of octopuses can help us anticipate the varied forms and approaches to communication that extraterrestrials might take.

We also need to re-examine continually the nature of intelligence itself. As a species with a big brain, we often imagine aliens will also have large brains, and indeed, our popular stereotypes of aliens include little green men with massive heads. But we know of other highly intelligent creatures here on Earth who have most of their neurons distributed throughout their limbs—the octopus with its eight arms that collectively have more intelligence than that animal’s central brain. If there are intelligent aliens out there, they might look more like octopuses than humans—as in the case of the aliens in Arrival.

At the end of the day, the only intelligent aliens we’ll be able to make contact with are the ones who are savvy enough to create a technology that lets them bridge the vast distances between the stars. There may be highly intelligent dolphin-like creatures on other worlds, singing wonderful symphonies together, but if they don’t have the arms or tentacles that let them build powerful transmitters, we’ll never know about them. In addition to their technologies, the aliens we finally make contact with will have at least one other characteristic in common with humans: curiosity.

In many ways we have gone about this backwards. For generations Euro-American science has mostly discounted the intelligence, culture, and technology of the wide variety of non-human life on our home planet, or at least always subordinated it to human beings (and without good reason). We have talked about trying to communicate with extraterrestrial intelligence when we are surrounded by obviously intelligent social, cultural, and technological life from insects to cetaceans to cephalopods to other primates and birds and more. I have often argued that attempts to think about extraterrestrial intelligence should always begin by recognizing the other intelligences all around us, and many people working in SETI research have argued this long before I had even thought about it. Denise Herzing has worked on this question through her Wild Dolphin Project, and Lori Marino and others have done related research on non-human intelligence, inter-species communication, and more. In my work on a Radical First Contact protocol, I propose that we should correct the long history of ignoring life here on Earth by approaching any potential life, object, or structure as though it is also a potential intelligence, culture, or agent inviting communicative contact and moral consideration. We know so little about what might constitute life, intelligence, minds, sentience, and other factors, that I think we should approach everything we encounter as though it might be more than we assume.

Absolutely. And whales. We haven’t had much luck with them either.

  I think so: after all, fiction’s “Martians” have borrowed their physical characteristics from marine creatures for a long time now, tentacles and all. The advantage that we would have with beings such as these is knowing their bodies, the environment in which they live...

Couldn’t xenolinguistics be seen as a component of an (anything but trivial) exercise that would consist of thinking of ourselves as extraterrestrials?

Yes! Anything that unites us, that pushes us to understand that we share one small, profoundly vulnerable planet, is something we desperately need.

In the final story of Ray Bradbury’s The Martian Chronicles the parents of a family living on Mars promise their children they will take them out to see the Martians. When they finally drive the family to a canal, they tell the children to look into the water, where they see the faces of the whole family reflected back at them. Bradbury ends with the line: “The Martians stared back up at them for a long, long silent time from the rippling water...”

As we attempt to identify plausibly universal concepts for interstellar communication, we inevitably need to find a way to challenge our own most precious preconceptions—to make ourselves alien to ourselves. In the process, we need to call into question some of the assumptions that we take as the bedrock of understanding the world. “Are these epistemological and ontological foundations really as solid as we think?” we need to ask ourselves.

Some of the concepts from math and science that we think of as universal, embedded in the nature of physical reality, could in fact be in part manifestations of our minds. Just as a language-using extraterrestrial may have a radically different universal grammar than we do, so too could its scientific description of the same shared universe differ from ours.

  That would be the fulfillment of one of anthropologies tenets, to be a “professional stranger” to our fellow humans. Probably, considering an other who speaks an unknown language—or, better yet, a disfavored variant of our own language—as an alien could be a valuable way to advance our understanding of them.

Yes. We always look at the familiar and unfamiliar world in the context of our Earth-bound experience. We understand about what is living (e.g. a sea gull) and what is not (a sail boat) based on our experience here on Earth and our understanding of the context. This understanding is fundamental to communicate with the surrounding world and establish a basic vocabulary: alive/not alive. When I go with undergraduate students in the field, I often invite them to do a simple exercise: we pretend to be extraterrestrial explorers visiting Earth for the first time. As such, we do not have any context to decide whether a human, a sea gull, a rock, and a sailboat are alive or not alive. Our overall goal is establishing a common ground for communication with the earthlings. So, we observe the behavior of sailboats and sea gulls entities we encounter to attach a meaning of what these Earthlings are doing, with possible communication as end result.