If humanity encounters intelligent extraterrestrials, they may possess the intellect to decipher our language. But they may also want to gauge our capacity to cooperate in deciphering theirs, echoing the plot of the 2016 sci-fi movie Arrival. Decoding an intelligent signal from space is the dream of researchers at the SETI Institute (Search for Extraterrestrial Intelligence), but how to develop this skill when our planet has no intelligent aliens to converse with. Yet our planet is home to some highly intelligent and alien-like creatures: whales. While this may sound like another sci-fi movie, Star Trek IV: The Voyage Home, where an alien probe attempts to communicate with humpback whales, it’s a serious research question: Can studying whale communication systems improve our ability to detect and comprehend extraterrestrial messages?
To help answer this question, researchers from SETI, UC Davis and the Alaska Whale Foundation have joined forces to study the communication systems of humpback whales. In a landmark experiment published in the journal PeerJ in November 2023, the research team repeatedly broadcast a recorded humpback “contact” call—the whale equivalent of a human greeting—into the ocean off the coast of Alaska. A curious female humpback responded, circling the boat and replying in a conversational style in a 20-minute exchange. “We believe this is the first such communicative exchange between humans and humpback whales in the humpback ‘language’,” said lead author Brenda McCowan in a statement.
Searching for intelligent signals in whales
But these researchers are not actually trying to decipher “whale speak.” Instead, by studying these intelligent, non-human communications and applying the mathematics of information theory, SETI aims to develop intelligence filters capable of extracting intelligent signals in their surveys of the cosmos.
Another team of researchers is tackling whale communication head-on, using advanced machine learning and state-of-the-art robotics to try to “converse” with sperm whales. The ambitious five-year initiative, called Project CETI (Cetacean Translation Initiative), in a deliberate nod to SETI, is perhaps the most extensive interspecies communication effort in history. Spearheaded by marine biologist David Gruber, CETI has received $33 million in funding from The Audacious Project, a philanthropic collaborative whose backers include billionaires Richard Branson and Ray Dalio.
CETI focuses on a group of 30 families of sperm whales that inhabit the waters around the Caribbean island of Dominica. Sperm whales boast the largest brains on Earth, six times heavier than ours, enabling them to engage in complex problem solving. They’re one of the few animals that can recognise themselves, for example. Living in female-dominated social networks, they communicate through a series of deafening, 200-plus decibel clicking sounds, known as “codas,” which sound similar to Morse code or data transmission noises. Sperm whales segregate into clans of hundreds or thousands, using distinct codas for identification, akin to dialects. Unlike the haunting songs of humpback whales, sperm whale codas, which were only discovered in 1957, can be translated into binary data and analysed using natural language processing and deep machine learning.
The key to sperm whale communication
Deciphering an unknown language is easier with something like the famous Rosetta Stone, but of course there is no human-whale dictionary and we know nothing about sperm whale grammar. But when large amounts of language data are fed into large language models, the algorithms can find structures from statistical observations without knowing anything about the content. However, truly vast quantities of data are required.
In their 2022 paper, the CETI scientists estimate that they could collect between 400 million and 4 billion sperm whale clicks per year—one challenge being to distinguish echolocation clicks from coda clicks—which would be combined with behavioural and environmental data. Gathering all this data requires a mountain of high-tech equipment, including multiple underwater listening stations, drones equipped with hydrophones, drones that can tag whales, and soft robotic fish that collect audio and video as they swim among the whales.
CETI is still in the data collection phase, racing against time to amass sufficient data before their funding expires in 2025. Yet once the data is collected, the real challenge awaits—the even more difficult task of deciphering the codas using machine learning, which will require significant extension of the theory and practice of unsupervised language translation.
If CETI eventually succeeds in decoding sperm whale communication, who knows what the impact will be. After all, the discovery of whale songs in the late 1960s catalysed the Save the Whales movement, sparked the end of large-scale whaling, and saved several whale species from extinction. But if one day we can actually converse with sperm whales and they learn that we are the ones responsible for the growing noise, worsening pollution and rising temperatures in their ocean home, or that we once hunted them for the waxy oil that fills their gigantic heads and allows them to generate their clicks, they may decide they want nothing to do with us. So perhaps it would be wise to begin the first conversation with a sincere apology.
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