In 1999 an interstellar message was broadcast in the direction of four stars. This transmission took place at the Evpatoria radio telescope dish in Ukraine. With its 70 meter dish and a 150kW transmitter at 6cm, Evpatoria was one of the most powerful deep space radar at the time. The message was sent using unique characters made by small bitmaps of 5 x 7 pixels. The concept of the message was based on the work of two Canadian physicists, Stephane Dumas and Dr Yvan Dutil.
In 1999 an interstellar message was broadcast in the direction of four stars. This transmission took place at the Evpatoria radio telescope dish in Ukraine. With its 70 meter dish and a 150kW transmitter at 6cm, Evpatoria was one of the most powerful deep space radar at the time. The message was sent using unique characters made by small bitmaps of 5 x 7 pixels. The concept of the message was based on the work of two Canadian physicists, Stephane Dumas and Dr Yvan Dutil.

On Extraterrestrial Relativism

Daniel Oberhaus
In 1999 an interstellar message was broadcast in the direction of four stars. This transmission took place at the Evpatoria radio telescope dish in Ukraine. With its 70 meter dish and a 150kW transmitter at 6cm, Evpatoria was one of the most powerful deep space radar at the time. The message was sent using unique characters made by small bitmaps of 5 x 7 pixels. The concept of the message was based on the work of two Canadian physicists, Stephane Dumas and Dr Yvan Dutil.
In 1999 an interstellar message was broadcast in the direction of four stars. This transmission took place at the Evpatoria radio telescope dish in Ukraine. With its 70 meter dish and a 150kW transmitter at 6cm, Evpatoria was one of the most powerful deep space radar at the time. The message was sent using unique characters made by small bitmaps of 5 x 7 pixels. The concept of the message was based on the work of two Canadian physicists, Stephane Dumas and Dr Yvan Dutil.

The prospect of interstellar communication with an extraterrestrial intelligence has enchanted humans for centuries, but our species has developed the technical capacity to act on this dream only in the past few decades. More recently still, the general perception of the Search for Extraterrestrial Intelligence, or SETI, has changed from a fringe pursuit by wayward astronomers into a legitimate scientific enterprise. Today, SETI is backed by massive budgets and venerable institutions. But the legitimation of SETI only pushes us closer to two questions that have haunted the Search from its earliest days: (1) why haven’t we found evidence of extraterrestrial intelligence and (2) will we be able to understand one another if we make contact with ET?

Both of these questions ought to be considered through the lens of relativism. While relativism cannot judge whether continuing SETI is worthwhile or will ultimately be successful, it can suggest new pathways for studying the problems of interstellar communication between two intelligent species. Interstellar communication is just one of many goals of SETI and is not the sole criterion for judging its success. For example, merely detecting the presence of a non-communicating intelligence on a planet around another star – perhaps by discovering certain compounds associated with industrialisation in its atmosphere – would fundamentally change our understanding of the universe.

Receiving an intentional message from an extraterrestrial intelligence would certainly be the most extraordinary result of the Search. Indeed, this possibility is a major motivating factor for many, if not most, SETI scientists in the world. Thus, it is worthwhile to focus our attention on the primary problems with intentionally exchanging meaningful information across vast distances of time and space: scientific, linguistic, and cultural relativism.

Scientific Relativism and the Fermi Paradox

In 1950, the physicist Enrico Fermi posed a simple question that has rankled generations of alien hunters ever since: Where are they? The Earth is the only planet we know that hosts life, intelligent or otherwise. But there are billions of stars in our galaxy and billions of galaxies in our universe and we now know that most of these stars host planets. Some fractions of those planets appear to have conditions amenable to life as we know it. The odds seem to favour a universe teeming with life and it’s reasonable to expect that at least some of the alien lifeforms out there are intelligent. This is the crux of Fermi’s paradox: It seems as though life should be abundant in the universe and yet we can’t find even the slightest hint that we’re not totally alone.

There have been many attempts to theoretically resolve Fermi’s paradox. Solutions range from the pessimistic (perhaps intelligent life is abundant, but tends to destroy itself after reaching a certain level of technological maturity) to the fanciful (perhaps intelligent life conceals its location due to some danger lurking in the cosmos). One of the most compelling explanations invokes relativism: Perhaps intelligent life in the universe is abundant and communicative, but our technologies are based on a scientific understanding of the world that prevents us from recognising interstellar conversations.

Scientific relativism is a subspecies of epistemic relativism and is based on the idea that the interpretation of a given datum is bound by existing cultural, theoretical, or technological frameworks. While science is usually treated as the process of learning some ground truth about the ‘real’ world, the facts must be integrated into a theory about how the world works. In other words, there is no pure ‘fact,’ but multiple ways to correctly interpret a datum in different contexts. This idea was popularised by the philosopher Thomas Kuhn, who put forth the concept of scientific paradigms, which are perhaps best understood as shared understandings of the world by groups of scientists that allow them to meaningfully communicate and make progress. In this sense, a scientific paradigm is a way of defining the world rather than exploring a world that exists independent of that paradigm.

We can clearly see the impact of scientific paradigms in the history of physics. The slow march from Newtonian physics to relativity and quantum mechanics has fundamentally changed the way that physicists think about the world. Of course, you can still get by with Newton’s classical mechanics, but there is a limit to what is explainable within this paradigm. Einstein’s theories of relativity expanded our understanding of the world, but so did the quantum theories of Neils Bohr and Max Planck. Without these theories, technologies like GPS, computer chips, or LEDs wouldn’t exist.

And yet, even these theories aren’t the whole picture. Einstein’s relativity is great at describing the world at very large scales while quantum mechanics is best suited for describing the infinitesimal. Neither theory can be easily transposed to other scales and a unifying framework has eluded generations of physicists. Does this mean that one or all of these theories must be wrong? Not at all. Quantum mechanics didn’t negate Newtonian physics. It just expanded the world of scientific discourse.

This has several important implications for interstellar communication. Given the age of the Universe (~13 billion years), the relatively young age of Earth (~4 billion years), and the extremely young age of homo sapiens (~200,000 years), any extraterrestrial intelligence we communicate with is highly likely to be a significantly older – and by extension, more scientifically advanced – species. So even if we are observing the same universe as an extraterrestrial intelligence, the scientific paradigms we use to make sense of that universe may be radically different.

Our scientific understanding of the world influences our ability to control it. This is why we have mastered the art of heavier than air flight but have yet to develop gravity-based propulsion systems. (Indeed, with our limited understanding of gravity we can’t yet say whether such a device would even be possible.) This is important in the context of interstellar communication because we may not yet — or perhaps ever — have an understanding of the physical world that allows us to develop the technologies that enables us to converse with an extraterrestrial intelligence. Indeed, today’s primary SETI instrument is the radio telescope, which operates in a portion of the electromagnetic spectrum we’ve had access to for about a century. It seems probable that radio communication will turn out to be a relatively primitive communications technology. In that case, it’s like we are trying to detect telegrams from the cosmos when most extraterrestrial intelligence has already upgraded to broadband.

Linguistic Relativism and Interstellar Communication

Let us suppose that our extraterrestrial correspondents do in fact communicate with radio messages and the reason we haven’t heard from them is because they are listening for a message from us. If we decide to engage in an extraterrestrial messaging campaign, this raises a new intractable challenge: What language shall we use to establish basic conversation?

Language helps convey information between two parties, but there are many different modes of transmission, rules for exchange (i.e., grammar), and shared vocabularies. In the context of interstellar communication, any cosmic communiqué from Earth must be encoded in radio or light waves. But what should we say and how should we say it? Perhaps we can build a custom language for interstellar communication based on pictograms where patterns of radio signals represent different concepts. Or maybe we should send patterned radio bursts that represent numerical concepts like Pi or Euler’s number that would presumably be recognisable to any scientifically literate species. If we sent a message in a natural language like English, Greek, or Mandarin, would ET ever be able to decipher it?

Each of these ideas has been seriously proposed as the basis of an interstellar message. But the last suggestion – writing a message in a natural human language – seems absurd. It’s worth examining why. We have good reason to suspect that an extraterrestrial will not speak English or any other language found on Earth. The reason is that the emergence of English or any of the hundreds of other natural languages on Earth is effectively a random accident. These languages were shaped by our planet’s idiosyncratic history and we wouldn’t expect the same languages to evolve anywhere else in the universe. But does that mean an alien wouldn’t be able to understand them?

Under certain assumptions, it is perfectly reasonable to assume that an extraterrestrial intelligence would be able to decode a human language with the proper assistance. Consider our remarkable ability to bridge language barriers on Earth. We are perfectly capable of translating between, say, English and French to facilitate communication. We can even translate among cultures with no shared linguistic heritage. The reason this is possible at all is because both native English and French speakers share the same cognitive hardware. Although the exact physiological origins of language are still under investigation, there is an emerging consensus that our capacity for language is built into the very structure of the brain. The evidently embodied natured of language supports the theory of a ‘universal grammar,’ which explains why human children are capable of acquiring any natural language and why a Russian speaker can learn to understand a speaker of Urdu. It also sets hard limits on the design of interstellar messages.

If we send an extraterrestrial intelligence a message written in a natural language, we are presupposing that their brain is sufficiently similar to our own to make translation possible. But if the extraterrestrial has a radically different cognitive structure, this translation would be impossible. If the alien brain does not have a functionally equivalent ‘language module’ to our own, its language would violate our universal grammar. This would make decoding our message more akin to discovering new scientific laws than translation.

Given the rather large assumptions we must make about the nature of extraterrestrial intelligence to justify sending a natural language message, perhaps it is desirable to look for a more objective linguistic basis for interstellar communication. Languages based on science and maths seem like natural candidates since they don’t appear to be a product of human culture and physiology. If an octopus were capable of performing science experiments, we’d expect them to discover the same laws of physics as we have. But to paraphrase Wittgenstein, if a lion could speak we wouldn’t understand a word.

Yet as we saw above, even something as apparently objective as science is still distorted by relativism. The same may be true for math, which may be regarded as the ‘language of science.’ It ultimately depends on how you feel about the ontological status of mathematics. Is it something that exists independent of our minds such that mathematical truths are discovered much like one might discover a new species? Or is it more accurate to say that mathematics is something we create, a language used to describe the world once it has been filtered by our all-too-human cognition?

If mathematics exists independently of the human mind, we could expect any extraterrestrial intelligence to be familiar with our mathematical concepts. They may know more about mathematics than we do, but we can at least be comforted knowing we are reading from the same book. But if our mathematics is shaped by the capabilities and limitations of the human mind, a message written in a mathematical language would face the same challenges as one written in a natural human language.

Although we are accustomed to thinking of mathematics as something that exists independently of our minds, the ontological status of mathematics is still contested. The reason we tend to think of mathematics as something that exists independent of us is because it seems to correspond so well with physical reality, an uncanny congruence that has puzzled scientists from Galileo to Einstein. One alternative explanation for this ‘unreasonable effectiveness of mathematics in the natural sciences’ is that maths is always filtered through our embodied cognition. As human beings, there are limits to our sensory perception and cognition and these limits shape how we see the world. Perhaps the reason our mathematics corresponds so well with our world is because it is subject to these same limitations. An extraterrestrial with different physical and cognitive limitations would in a sense be inhabiting a different world and may have a very different mathematics that describes it.

Cultural Relativism and Designing a Message for ET

Suppose that we do have the same mathematics as an extraterrestrial intelligence and we use this shared understanding as the basis for an interstellar language. Can we say anything meaningful about life on Earth or what it means to be human? Or are we destined to only swap mathematical axioms? On Earth, cultural relativism is the idea that one culture’s values should not be evaluated based on the values of another culture. This is particularly important in the context of communication – both interstellar and terrestrial – to ensure that a message is not misinterpreted due to cultural differences. While many cultures on Earth share at least some values, such as ethical prohibitions against killing, there are vanishingly few universal values. And even these ostensibly universal values may be context dependent – for example, cultures that prohibit homicide may still condone killing during war.

Cultural relativism is a massive challenge for interstellar communication. Since we cannot know anything about the extraterrestrial civilisation in advance, we must be extremely cautious about the assumptions we are making when crafting the content of a message or interpreting a message received from space. Perhaps we receive a message from an extraterrestrial intelligence that functions as a hivemind where individuals are subservient to the macro-organism. This may create very perverse value frameworks for a culture accustomed to individual sovereignty. Or what if a race of superintelligent extraterrestrials rears extraterrestrials of human-level intelligence on their planet as food, much as we raise cattle for beef on Earth? These scenarios may make it incredibly difficult to find a shared basis of understanding. Our implicit and explicit cultural and personal values shape our interpretation of the world in profound and often imperceptible ways.

Earthlings are faced with a further challenge when designing a message for interstellar communication due to the wide variety of cultures on the planet. Interstellar communication is fundamentally different from everyday conversation because it occurs between species instead of individuals. Furthermore, the conversation may occur over thousands of years due to the distances between the transmitter and receiver. The civilisation that sends a message may change a lot over the millennia and be very different from the one that receives a reply. We can see the challenges of communicating across time on our own planet in the context of deciphering ancient languages such as the Egyptian hieroglyphs. If it weren’t for the discovery of the Rosetta Stone we may never have been able to read the messages of ancient Egypt, even though it was written by the same species on the same planet only 4000 years ago. The problems are magnified in the context of interstellar communication, which may involve much larger time scales and radically different intelligent species.

These factors require careful consideration about how the values of humans as a species, rather than the values of a particular culture in a particular time period, are to be conveyed in an extraterrestrial message. In the past, messages that have been sent into space from Earth have had a significant Western bias, which would hardly give the recipient an accurate picture of the diversity of life on Earth. Similarly, it will be challenging to determine whether any extraterrestrial message received on Earth speaks on behalf of an entire planet or only its dominant culture.

Is There Hope for Interstellar Communication?

The challenges that scientific, linguistic, and cultural relativism pose for extraterrestrial communication are immense. But they are not insurmountable. In fact, engaging with the challenges of extraterrestrial relativism poses a unique opportunity for Earthlings to learn more about the universe and ourselves, even if we never make contact with an alien intelligence. Addressing these issues forces us to critically examine everything from science and technology to our language and cultural values. We must identify the preconceptions that haunt our most cherished beliefs and explicitly state all that we take for granted. We must adopt an extraterrestrial mindset, which means searching for universals in the strongest sense of the term. This is the only path to truly understanding what it means to be human. Even if we never make contact with ET, the Search may still lead us to amazing discoveries.


Daniel Oberhaus is a science writer in New York City whose work primarily focuses on space exploration and the future of energy. He was previously a staff writer at Wired magazine and has published journalism and essays in The Atlantic, The Guardian, VICE, The Baffler, Nautilus, and other publications. He received BA degrees in English and Philosophy from Arizona State University and worked as a Fulbright scholar in New Delhi, India. His first book, Extraterrestrial Languages, was published by MIT Press in 2019. It explores the art, science, and philosophy of interstellar communication with the aim of creating a framework for overcoming the practical and theoretical challenges of communicating with an alien intelligence.

This article appears in full in COSMOS AS A JOURNAL, NO. 2.