Cracking the Stellar Primer

The modern Search for Extraterrestrial Intelligence (SETI) is based on the premise that a systematic search of the cosmos may reveal artificial signals, transmitted either intentionally or, somewhat like the leakage of TV and radio signals from Earth today, as electromagnetic noise.

Sometimes referred to as an ‘astrobiology matrix’, the language of a field that includes robotic probes to other planets and coded messages necessarily spans engineering, philosophy and linguistics
Credit: NASA Viking Project /Matrix

But will these signals, if we ever detect them, be more than simple beacons telling us that we are not alone? What if the signals bear messages from an alien civilization, attempting to describe the universe from the perspective of an intelligent species evolved completely independently of humankind?

If an extraterrestrial radio or optical signal is packed with information, we might not know for sure until well after we have determined that the signal is artificial. The SETI programs currently underway focus their energies on finding strong artificial signals – not on detecting fluctuations of those signals that might convey additional information. But with the detection of a sign of intelligent life beyond Earth, stronger search systems would no doubt follow, possibly revealing encoded messages from extraterrestrials.

How would we go about deciphering such messages?

SETI researchers have long contended that the content of messages intentionally beamed toward Earth would likely be heavy on math and science – at least in the early stages. These scientists reason that if extraterrestrials are intelligent enough to build radio telescopes or lasers capable of interstellar communication, they will also be familiar with many of the same principles of mathematics, physics, and chemistry that we use on Earth. And while that may be true for the initial steps in an interstellar codebook, how might extraterrestrials convey something about the more unique aspects of their world – such as their culture and history?

Anthropologists Ben Finney and Jerry Bentley of the University of Hawaii suggest that we might gain clues to decoding more complex extraterrestrial messages by examining past attempts to decode languages right here on Earth. But these scholars warn that we need to be cautious about which examples to use for our case studies.

Finney and Bentley note an oft-cited analogy for detecting a message-laden signal from space: the transmission of knowledge from ancient Greece to medieval Europe. Though any major bookstore today has a wide variety of classics available – often in paperback editions at bargain prices – during the Dark Ages, Plato and Aristotle weren’t so easy to come by.

The Very Large Array (VLA) radio telescope is used by SETI to listen for artificially produced radio signals from outside our solar system. Does this see the big picture, or does it look like a Greek letter, lambda, from a great enough height?

In fact, European scholars had lost vast numbers of Greek works on philosophy, literature, and science. But fortunately, copies of these works were well-protected by Islamic scholars, particularly in Spain and Sicily. Thus, as Europe entered the Renaissance, Western scholars were able to reclaim Greek classics from Islamic centers of learning, either directly from Greek editions or through Arabic translations. And thus, over decades and centuries, the "young" European civilization was able to learn from the older Greek civilization, although the two were separated by long expanses of time.

The analogy has natural affinities with contact between Earth and the much older extraterrestrial civilizations being sought by SETI. If we do detect information-rich signals, it is possible that they will come from civilizations long since dead. The impact, we expect, would be even more edifying than the influx of ancient thought was for early modern Europe. This reclaiming of ancient knowledge provided Europeans with alternative perspectives to some of their typical ways of viewing the world, in turn leading to new syntheses of modern European and ancient Greek insights. If some day we detect and decode messages from civilizations beyond Earth, we will have similar opportunities to juxtapose terrestrial and otherworldly views.

But, Finney and Bentley warn us, perhaps it won’t be quite that easy. While the Greek comparison is informative, as with any analogy, it does not tell the whole story. For a more nuanced understanding, we can turn to other examples of decoding ancient scripts. In the next article in this series, we will follow Finney and Bentley’s lead, and examine other analogues of decoding extraterrestrial messages, drawing on more recent attempts to translate ancient Maya and Etruscan texts.

Related Web Pages

SETI Institute
The Great Debate: Is Complex Life Common in the Universe?
Space Invaders
Cause for Optimism: Part III : The Drake Equation Revisited