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Will Extraterrestrials Understand A Message We Send?
by Michael Chorost

One day a message is received from the sky. It consists of a long string of bits - 400,000 of them, in fact. After some puzzlement, scientists figure out that it consists of 22 pages. Can we even begin to understand a message like that? Is it the product of minds that we couldn't comprehend?

Actually, this isn't a message from aliens. But it is a message from humans. It was transmitted from the Evapatoria Deep Space Antenna in Evapatoria, Ukraine to four target stars between May and July 1999. It's called the Cosmic Call.

Can we assume that this message will be understood by any intelligent alien mind? What hidden assumptions of ours might not be shared?

The actual message is just a long string of bits. It starts like this:


This is clearly not random. There is that suspiciously long string of 1's at the beginning, 128 of them in fact - and 128 is a suspiciously important number, two to the seventh power. It's followed by 125 zeros, and the rest of it looks patterned too, with plenty of 000 triplets. This does not look like noise. It looks like a message.

Let's skip over the complexities of figuring out that this is a message and reconstructing it properly. Our alien recipient has 22 pages of cryptic glyphs. What could stop them from understanding it?

We have to assume several things: that the recipients understand the idea of sequentially numbered pages, that they understand left-to-right, top-to-bottom reading, and that they understand the concept of information stored in a two-dimensional format. And, they have to understand the idea of writing itself. How reasonable are these assumptions?

Sequentially numbered pages are relatively new in the history of humankind. The Gutenberg Bible, printed in 1455, had no page numbers. Page numbers emerged gradually as writers and readers learned their value in clarifying and organizing content. Indeed, bound pages themselves are relatively new, developed by the Romans to replace scrolls in the first few centuries A.D. (The problem with the scroll is that it doesn't permit random access or easy use of both sides of the paper; bound pages do.)

And pages themselves are dependent on having a lightweight but durable medium that can be written upon. Sunlight is so abundant on planetary surfaces that it's hard to imagine a planet not having life that collects energy from photosynthesis and binds it in some durable material that can be pulped, pounded flat, and dried. It seems like a low-hanging fruit that just about any civilization would figure out. To be sure, there are clay tablets and parchment (animal skins), but paper has so many advantages that to me it seems all but inevitable.

I think pages are inevitable, and once developed, numbering them for information retrieval seems inevitable too. I think that just about any smart alien will understand pages. And once you have pages, you have the concept of information storage on a two-dimensional surface.

The idea of writing is trickier, as human writing is an encoding of speech. Speech is based on muscular vibrations in our throats, which we combine with lung exhalations and tongue and lip motion to convert into a flow of distinctive sound vibrations. Is there something about sound that is more attractive than any other option, such as gestural language (used by deaf people), pheromonal signaling (used by ants), or visual signaling (which might be used by octopi by manipulating chromatophores in the skin)?

Sound certainly seems to be ubiquitous: it's used by phyla that diverged from each other many millions of years ago, including birds, primates, dolphins, and whales. Perhaps sound is the most metabolically efficient mode of communication, requiring the least expenditure of energy, and it doesn't require close proximity or eye contact. It may also be the easiest for intelligent minds to segment into representational units (e.g. phonemes) and code in a written form. There is a direct and easily memorizable connection between a phoneme and the letters that represent it. (For this editorial, I'm setting aside ideographic languages like Chinese, which present a whole different set of issues.)

It's worth noting that American Sign Language has no widely accepted written form. Why this is, I don't know. One reason is certainly that ASL users can use English for writing, though that's not easy, since it requires translating as well as transcribing. (ASL has a completely different syntax than English.) It's also probably harder to break gestures down into a limited repertoire of handwritten shapes. English has about 40 phonemes and 26 letters, and once you master that you can write any spoken word. I don't see how one could do that for a signed language except by using an ideographic language - and perhaps that's too much work. However, signed languages are also much younger than spoken ones, so it may simply be that their users haven't had the time nor the motivation to develop written forms.

Anyway, my point is that sound may simply meet more of an intelligent mind's needs than other modalities. If this is so, then writing may follow more or less inevitably - and writing on some kind of mashed-cellulose product, along with page numbers and all.

Left-to-right, top-to-bottom writing is hardly guaranteed. Humans may write left-to-right because most of us are right-handed. (Writing in the other direction smears the ink.) I know, this doesn't explain Hebrew or Arabic, and some ideographic languages are written top to bottom, like Japanese. (At least it's written that way in the Japanese translation of my first book, REBUILT.) But in any case, it doesn't matter. The convention is easy to explain. In the first page of Cosmic Call 1999, the primes are written left to right, top to bottom. Simple. Done. The recipients can easily translate it into any other format they like.

In any case, it'll only make sense if they read it left-right, top-bottom. It won't make sense any other way.

As I write this I wonder if I am telling just-so stories, accounts in which our way of doing things is justified as the only possible way. But SETI fascinates me because it's an attempt at peeling back the surface of our own assumptions. What is accidental? What is fundamental? Since we have only ourselves and a handful of moderately intelligent co-dwellers on Earth to go by, we can't really answer this question. Yet. But it is fun to try.

Disclaimer: The opinions expressed in editorials are those of the individual authors, and do not necessarily reflect the position of The SETI League, Inc., its Trustees, officers, Advisory Board, members, donors, or commercial sponsors.

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