If we found aliens, how would we talk to them?

bobmcdonald-190.jpgBy Bob McDonald, Quirks & Quarks

NASA has just released a free online book about what to do when we make contact with another intelligent civilization in space. It turns out that just saying hello to an alien is a lot tougher than you might think.

Books on alien contact, both scientific and science fiction, could fill a library, but this one is different in that it brings in anthropologists, historians and archaeologists who look at our history of establishing contact with other civilizations right here on Earth - a history that, in many cases, has been full of misunderstandings, exploitation and even annihilation.

Of course, there are the more modern stories of European contact with Native North Americans, Mayans and Incas, as well as aboriginals in Australia. These encounters have provided the basis for many science fiction stories of all-powerful aliens arriving to conquer the Earth, or turn us into slaves.

But face-to-face contact with an alien race, although possible (especially if they come to us), is also highly unlikely, given the distances in the universe. The more plausible scenario is if we receive a signal from another star system containing some kind of message.

The book chronicles the feeble history of the Search for Extra-terrestrial Intelligence (SETI), starting with astronomer Frank Drake's effort to listen for signals coming from sun-like stars, using a large radio telescope in 1960. He later went on to send a message out from Earth, using the world's largest radio telescope in Puerto Rico. NASA funded several searches using its instruments, but the program was eventually cancelled for political reasons. Today, the SETI Institute, with Drake still involved, is largely funded from private sources and, so far, nothing has been found.

(Coincidentally, Drake's daughter, Nadia, wrote a blog this week about why it is so difficult to predict the number of intelligent civilizations in the Milky Way galaxy.)  

But with new planets orbiting nearby stars being discovered almost weekly, interest in alien contact is picking up again, which raises the more challenging problem of actually understanding a signal when it is detected, then trying to conduct some kind of meaningful long-distance communication with beings we know nothing about.

They certainly will not look like us; they could even have different chemistry. No telling what kind of culture they would have: highly structured like an ant colony, highly vocal like dolphins and whales, peace-loving or predators; they could be unimaginably far away from us in mind and body. But the fact that they sent a signal through space means we have one thing in common: a desire to reach out to anyone else in the galaxy.

The anthropologists point out how difficult it has been deciphering ancient hieroglyphs in Egyptian tombs, carvings on Mayan pyramids, the Dead Sea Scrolls, cave paintings in France and symbols carved into bone from distant human ancestors. Without a Rosetta stone or historical context, how are we going to understand alien symbols?

One scientist used the example of two triangles with their bases together forming a vertical line and their points aimed out to the sides. It's a symbol people see and use hundreds of times every day and has nothing to do with mathematics. It's the door-open button on an elevator. Without the context, the symbol would be meaningless or misunderstood.

Then, there is the opposite problem of trying to send a message to them that they can understand. We could, for instance, send them a global "selfie" of the Earth, which NASA just took last Earth Day. But is it enough to just send pictures of ourselves? How would we represent our planet, our people, our values, our religious beliefs, our knowledge - all in some kind of universal language that could be understood by aliens?

It's an interesting challenge in communications, one that we may not have to deal with for a long time - or a signal could arrive tomorrow. In either case, it will be one of the most profound occasions in human history. It's nice to know that some people have provided a preliminary handbook.

(And you might want to listen to our interview with the author of The Eerie Silence, who explains why we might have been looking in the wrong places, using the wrong tools and making some bad assumptions about alien intelligence.)