We’ve yet to find any evidence of intelligent life beyond Earth, a puzzling failure given the widespread belief that where habitable planets exist, life will somehow emerge. If we do receive a signal, though, would we be able to understand it? We’ve made some progress in piecing together animal communications here on Earth, but figuring out what the whistles and clicks of sea creatures mean remains a work in progress. In today’s essay, associate editor Alex Tolley goes to work on key questions: Is mathematics truly a universal language? Does language change how we experience the world, and if so, what aspects of an alien culture will we actually be able to understand? The questions are daunting and now coming into public discourse in the realm of AI. Alex’s thoughts on that phenomenon and how we might interact with a machine civilization are only part of the interest here.

by Alex Tolley

Introduction

Discussions about alien communication usually focus on the technology of message transmission and how to decode the first message received. This essay will address the issue of decoding the first message and the expected limits of the subjects that can be communicated.

Humans have a long history of wanting to talk to other species. From the many stories of talking with various animals, often projected with human qualities, to talking with invisible entities, including invisible deities and dead ancestors, to the modern period, where talking with pets and inanimate objects is not looked askance at, and now chatting with large language models (LLMs) that usefully talk back.

We have learned of the vast size of the universe, and rationalize that there must be life and intelligent, technological civilizations somewhere in that vast universe. The search for extraterrestrial intelligence (SETI) is an attempt to answer the question of whether there are other intelligent species in the stars.

Serious attention to searching for aliens and receiving their messages started around 1960. The assumption was that if life also existed on other planets, evolution might eventually produce intelligent, technological life, with interests not dissimilar to ours. The only question was how many civilizations interested in communication there were. The basic model was encapsulated in the famous Drake Equation [1]. While the probabilities of intelligent, communicating civilizations were very much a guess, Drake has made the claim that their number is the same as their communicating longevity.[1, Appendix A] If they communicate for 10,000 years, there should be about 10,000 communicating civilizations, perhaps in a “Galactic Club”. Sixty-odd years later, there has been no detection of such signals using the technologies we have at our disposal. Despite the unanswered Fermi Question that there may not be any civilizations in space, and nor have there ever been, SETI continues with the hope that intelligent life must exist somewhere in the vast reaches of space, although the emphasis has shifted towards the astrobiologists’ hopes that at least life exists elsewhere and how best to detect it.

Figure 1. Participants in the 3rd Decennial US-USSR meeting on SETI in Santa Cruz, CA. 1991. Frank Drake can be seen standing in the middle front row holding the sign “N EQLS L” (Source: The Biological Universe (1996) p487)

But suppose a signal is detected; what then? Decoding an alien message might not be easy. A few years ago, the artist Daniela de Paulis and her team devised a test signal for the public to decode [2]. Even though the signal data was formatted using human transmission coding, it took about a year before the signal was successfully decoded. This, despite prior knowledge of the signal transmission features, and despite sending only 2-D images, with a clear similarity in form to previous ideas we have had for decoding signals. How much harder might a real alien signal be to decode?

Terrestrial Animal Communication as a Decoding Test

Animal communication, and potentially language, offers another way to attack the issue of communication with a species very different from us. While aliens have so far proven elusive, Earth is teeming with animal life, some of which appears quite intelligent, even if unable to use more than rudimentary technology. Research into animal communication continues to determine the extent, if any, that intelligent animals have a language they use to communicate with their own kind. Progress is being made, but could we ever talk to the animals like the fictional Dr. Dolittle?

Despite their far greater separation from humans in evolutionary time than apes. and their aquatic environment, cetaceans seem to have more complex communication and perhaps something closer to a true language. Work by the linguist Gašper Beguš has shown that sperm whales (Physeter macrocephalus) communicate with a series of clicks, or codas, that can be compared to how humans produce vowel sounds [3]. AI was used to extract the commonality of codas of “vowels” between individual whales, although there is insufficient information to connect the sounds with meaning. The video below explains the concept of the sequences of clicks, or codas [4].

From their recent paper [3] Beguš concludes:

…our findings demonstrate that sperm whale vocalizations are highly complex and likely constitute one of the most phonologically sophisticated (currently known) communication systems in the animal kingdom.

Another study by a different team on 2 separate sperm whale populations in the eastern and western Mediterranean showed that the 2 populations used different “dialects” for the same codas.[5] A recent study indicated that sperm whales change the tone of their codas when encountering ships, indicating that they recognize ships in some way, although we don’t know what it means [6].

Work by Sayigh et al with a wild pod of bottlenose dolphins (Tursiops truncatus) was able to extract consistent clicks and whistle sounds for both individuals and the group [7]. The clicks identify individuals and are used to identify the individual, and to contact others. Whistles are associated with emotional and social interactions, for example, courtship and mating.

While we are still a long way from decoding the meaning of the vocalizations of dolphins and sperm whales, it does appear that they have some sort of language to communicate with others of their kind. As might be expected, the geographic separation of pods hints that there are also different dialects associated with pods at different locations.

Suppose in the future that we manage to decode the meaning of these communications, and that these cetaceans, while not as sophisticated as the dolphins in Douglas Adams’ Hitchhiker’s universe stories, do have a basic language that uses their various vocalizations. What could they communicate that we could understand?

This is where the influence of Thomas Nagel and his seminal essay “What is it like to be a Bat?” is relevant [8]. Nagel argued that we cannot understand an animal without being that animal. If he argument is correct, then as we are not sperm whales or dolphins whose experiences are very different to ours, there may well be a communication gap between our species. We could understand the meanings of vocalizations of objects and actions, but not of feelings and other qualia, and conversely these cetacans could not understand ours. As for the abstractions each species has for dealing with its environment, these may forever be unintelligible.

Aliens as species with different experiences

Recall that one assumption of SETI is that some civilizations would have similar ideas and motivations as we do. That they would have a sophisticated technology, likely far ahead of ours, but with similar ideas about inter-civilization communications and a desire to learn. Just as we try to learn about animals, and even communicate with them, so aliens might send out signals to try to initiate a communication with us. If so, we should be able to receive them, and possibly respond.

But is this the case, and are we assuming that our differences as species and evolved experiences can be overcome, contra Nagel?

We have made an attempt at sending out an informative message, the Arecibo message, as well as the Pioneer probes 10 & 11 plaques, and Voyagers 1 & 2 records. The Arecibo message and Pioneer plaque are shown in Figure 1 below.

Figure 2. Left) The Arecibo message radioed into space. Right) The Pioneer space probe plaque with depictions and information about Earth and its intelligent species.

The approaches of both messages assume some common understanding between humans and aliens. The Arecibo message is very concise, but not easy to interpret even by humans. The Pioneer plaque is clearly a more representative message, although how easy would it be for an alien species to recognize the location of our system from the representation of pulsars? Explanations of the messages are found at [9,10]. The Voyager Golden Record needs to have a player to extract the information that includes sounds and music. How might aliens interpret these sounds?

It has come to my attention that Joe Davis had created an artwork of the Arecibo Message using bottles of water at MIT, yet none of the students and scientists could discover any meaning to the display. In 2009, to celebrate the Arecibo Message’s 35th anniversary, Davis also sent out from the Arecibo telescope a cleverly encoded message of the DNA sequence of a photosynthesis enzyme, RuBisCO, which, while ingenious, seems impossible for an alien to decode its meaning [15,16,17]. Yet as he said, it was more about our view of ourselves than for any alien recipients.

A general assumption has been that technological aliens must have a reasonably common perception of the universe as we do. Indeed, John McCarthy (of Lisp and AI fame) espoused that view at a SETI meeting [11]. His argument was that just as evolution results in convergence of phenotypes to fit their environment, like the shapes of Ichthyosaurs and dolphins, so intelligence will converge on the same concepts as we share the same universe and discover its properties and laws. Math as a purely logical construct is therefore often assumed to be a common language between humans and aliens. Numbers, and their manipulations should be common. Hence the idea that a primer in a message might start with basic arithmetic and work upwards from there. However, at another SETI meeting, mathematician Keith Devlin was not so convinced that this would be the case. His argument was that math was actually a unique product of the human mind and reflected our construction of the universe [11].

If he is correct, what are we to make of Eugene Wigner’s 1959 lecture title about math and nature, “The Unreasonable Effectiveness of Mathematics in the Natural Sciences”? Is this a unique formulation of the human mind and experience, whilst it may be very different for an alien mind?

This issue has been raised in a number of works, but it is perhaps most concisely put in Brian McConnell’s slim book, “The Alien Communication Handbook” [13] and his Centauri Dreams post “Communicating with Aliens: Observables versus Qualia” [14]. His view is the consensus one, that some things such as physical objects and actions are communicable between species, whilst others, such as feelings and experiences, are most likely not. He takes McCarthy’s side in saying that mathematics and logic are also assumed to be universal, perhaps confirming Wigner’s statement.

We often forget that language determines how one views the world. It is well known that in the West we tend to see the world as distinct objects with some associations between them. The Japanese also see the spaces between objects, and have words to describe those spaces. e.g., Ma is for negative space, such as the space between musical notes, or the spacing of flowers in flower arrangements. As we know from the difficulties of translation between languages, some concepts don’t have words in the other language. In English, we now use the German word schadenfreude as there is no English equivalent for the “pleasure derived by someone from another person’s misfortune.” The power of words to shape perception is exemplified in Ted Chiang’s short sci-fi story “The Story of Your Life”, filmed as “Arrival.” It illustrated how language itself could change what you experience, in this case one’s experiences of the future.

AI as magic Pixie dust and an alien mind

Our AI technology using LLM technology has performed creditably well in translation between languages. It has also played a role in extracting the key components of sperm whale codas, and therefore establishing associations that apply between different individuals in the same pod, much as humans have different accents and ways of speaking the same words. AI is currently the magic behind science fiction universal translators, allowing humans and aliens to converse.

But of perhaps more pertinent is the idea that AIs are becoming minds, although there is considerable debate about this. However, AI “minds” are likely to be different than human minds, if only because they do not experience the qualia we experience. Are AIs going to have unemotional thoughts like Star Trek’s humanoid robot, Commander Data, but like sociopaths, able to mimic human emotions and empathy? If given a very different training set of data, would they acquire minds that are shaped by that data set? Could we design the data set to mimic that of hypothetical aliens, and thereby create fake alien AI minds?

Humans are good at projecting agency and anthropomorphizing animals and objects. Most famously, Weizenbaum’s simple ELIZA therapist program persuaded many that it was a person, much to his horror. Alan Turing had proposed that if judges could not distinguish between a human and a computer responding to questions, then the computer program was intelligent. After years of Turing Test competitions, we have now comfortably blown past that test, although we are still debating if LLM-based AI is truly intelligent. The interesting issue is that we are at the point where several people believe that AIs are conscious. AI scientist Geoff Hinton, the inventor of deep learning architecture, is one such. Early chatbots would say they might be conscious, although the frontier models are trained to say they are not. But are they just trying to hide that fact from us? This was anticipated in the 1960s in the movie 2001: A Space Odyssey. Below is a transcript of a key conversation in the movie:

Table 1. Dialog with astronauts and HAL 9000 from the movie 2001: A Space Odyssey.

AIs are currently like brains in a box. However, as we develop robots of various types that embody AI, will they learn to experience the world more as their bodies allow them to, much as animals and humans do? We are on the cusp of finding out.

Conclusion

Learning how some animals communicate and how far they have a language will provide us with new ideas on how an alien may try to signal us. AI can not only help us understand animal languages, but also help in decoding alien signals if/when we receive them, and even to communicate with them. We should even be able to tell how far our minds overlap in subjective concepts and experiences. Should aliens be machines, then it may be best if AIs take the lead in communication with them. If it turns out that we are alone, then there is value in being able to communicate at some level of understanding with intelligent animals. While I don’t expect we could experience being a cetacean, we could probably experience being one of our hominin cousins, such as the chimpanzee and bonobo.

In the meantime, all we can do is “Watch the Skies” and wait for a signal to arrive.

Appendix A

If we modify the values in the Wikipedia entry, using values in the ranges suggested, but update the annual rate of star formation to more current values, the product of the 1st 6 probability terms = 1. Therefore, the final term, the longevity of the communicating civilizations, equals the number of communicating civilizations in the galaxy.

References:

1. Wikipedia contributors. (2026, July 31). Drake equation. Wikipedia.
https://en.wikipedia.org/wiki/Drake_equation

2. de Paulis, D., et al. (2023) “First Contact: Global team simulates message from extraterrestrial intelligence to Earth”
https://www.seti.org/news/first-contact-global-team-simulates-message-from-extraterrestrial-intelligence-to-e arth/

3. Beguš, G., Dabkowski, M., Sprouse, R. L., Gruber, D. F., & Gero, S. (2025). The phonology of sperm whale coda vowels. Proceedings of the Royal Society B Biological Sciences, 293(2069).
https://doi.org/10.1098/rspb.2025.2994

4. Begus – video on whale clicks https://www.youtube.com/watch?v=eFbnYQI-Oa0

5. Taylor A. Hersh, et al, (2026) “Dialect variation in Mediterranean sperm whales shows evidence of cultural evolution in an isolated population”. Proc Biol Sci 1 June 2026; 293 (2073): 20260165.
https://doi.org/10.1098/rspb.2026.0165

6. Diamant, R., Gruber, D. F., Gero, S., & Beguš, G. (2026). Evidence for the influence of shipping underwater radiated noise on sperm whale coda structure. Ecological Informatics, 103881. https://doi.org/10.1016/j.ecoinf.2026.103881

7. Sayigh, L., Jensen, F., McHugh, K., Casoli, M., Lemercier, L., Tyack, P., Wells, R., & Janik, V. M. (2025). First evidence for widespread sharing of stereotyped non-signature whistle types by wild dolphins. bioRxiv (Cold Spring Harbor Laboratory). https://doi.org/10.1101/2025.04.21.647658

8. Nagel, T (1974) “What is it like to be a bat?”, The Philosophical Review, Vol. 83, No. 4 (Oct., 1974), pp. 435-450

9. Wikipedia contributors. (2026a, May 22). Arecibo message. Wikipedia.
https://en.wikipedia.org/wiki/Arecibo_message

10. Wikipedia contributors. (2026c, July 31). Pioneer plaque. Wikipedia.
https://en.wikipedia.org/wiki/Pioneer_plaque

11. McCarthy, J (2009) “Convergence of Intelligence” (SETI Talks)
https://www.youtube.com/watch?v=kvIqc0aBR0A

12. Devlin, K. (2013) “Contact with ET using Math? Not so fast” (SETI Talks)
https://www.youtube.com/watch?v=KveKjHIipgo

13. McConnell, B. S. (2021). The Alien Communication Handbook: So We Received a Signal—Now What? Springer. pp247-248, 278-281

14. Gilster, P. (2021, December 10). Communicating with Aliens: Observables versus Qualia | Centauri Dreams. https://www.centauri-dreams.org/2021/12/10/communicating-with-aliens-observables-versus-qualia/

15. Gilster, P. (2009, November 18). “RUBISCO Stars” and The Riddle of Life | Centauri Dreams. https://www.centauri-dreams.org/2009/11/18/%E2%80%9Crubisco-stars%E2%80%9D-and-the-riddle-of-life/

16. Gilster, P. (2009b, November 19). “RUBISCO Stars”: Part II | Centauri Dreams.
https://www.centauri-dreams.org/2009/11/19/rubisco-stars-part-ii/

17. Wikipedia contributors. (2026b, July 18). RuBisCO. Wikipedia. https://en.wikipedia.org/wiki/RuBisCO

Further Reading

1. Wikipedia contributors. (2025, December 4). Lincos language. Wikipedia.
https://en.wikipedia.org/wiki/Lincos_language

2. Freudenthal, H. “Lincos: Design of a Language for Cosmic Intercourse, Part 1 “
https://en.wikipedia.org/wiki/Lincos_language

3. Chiang, T “The Story of Your Life” https://en.wikipedia.org/wiki/Story_of_Your_Life

4. Earth Species Project https://www.earthspecies.org/

5. Clarke, A.C. “History Lesson” https://en.wikipedia.org/wiki/History_Lesson

6. Michaud, M. (2010). Contact with Alien Civilizations: Our Hopes and Fears about Encountering Extraterrestrials. Copernicus. pp279–284

7. Bracewell, R. N. (1974). The Galactic Club: Intelligent Life in Outer Space. Scribner Book Company.

8. Baird, J. C. (1987). The inner limits of outer space. Dartmouth College Press.

9. Dick, S. J. (1996). The Biological Universe: The Twentieth Century Extraterrestrial Life Debate and the Limits of Science. Cambridge University Press.