Xenology: An Introduction to the Scientific Study of Extraterrestrial Life, Intelligence, and Civilization

First Edition

© 1975-1979, 2008 Robert A. Freitas Jr. All Rights Reserved.

Robert A. Freitas Jr., Xenology: An Introduction to the Scientific Study of Extraterrestrial Life, Intelligence, and Civilization, First Edition, Xenology Research Institute, Sacramento, CA, 1979; http://www.xenology.info/Xeno.htm


24.2.4  Alien Message Contents

Once a genuine extraterrestrial signal of some kind has been detected, the acquisition phase ends and the communicative phase may begin. The recipient must then be able to puzzle out the meaning of the alien messages he receives.

If the signals are being transmitted purposefully, then it is likely that the ETs at the other end will have done their level best to ensure easy decipherability of their messages by the intended recipients. Coding should be relatively simple and considerably redundant, full of clues enabling SETI scientists to achieve a full translation with high validity. Since this is exactly the opposite goal to that of the science of cryptography (secret codes), xenologists often refer to it as the Principle of Anticryptography.

According to the Principle, a beacon message transmitted from another world, prima impressionis, should be optimized for easy decoding by intelligent recipients.

The Principle of Anticryptography suggests the basic format of messages we may expect to receive from the stars. Consider a sequential transmission consisting of a string of symbols of some kind. If the message is very lengthy, and later parts are of greater complexity in reliance upon our understanding of earlier parts, then if we tune in near the middle or the end we probably won’t be able to understand anything at all. On the other hand, if the message is kept very brief and repetitive then, in the words of one radio-astronomer, it "bores us to tears for decades while we try to acknowledge."80 In keeping with the Principle, we might expect to find "nested messages," involving a frequently repeated call signal interspersed with short but complete "language lessons."22 Every so often a self-contained package of basic information would be substituted for the language lesson. On yet rarer occasions, the basic information package would be replaced with a more advanced information package, and so on to higher and higher levels of sophistication. Such a message format is highly redundant, repetitive, error-proof, informative, and so may be tapped into at any point in the transmission without loss of meaning.

What about message contents? Will we understand what ETs are trying to say to us? A few xenologists have proposed that the "universal language" of mathematics will provide the bridge of understanding between man and alien. (See Hogben,1112 Oakley,329 Pryor,99 and Sagan and Drake.3143) According to one scientist, it is difficult to imagine the existence of communicative beings unfamiliar with numbers and counting. Thus the earliest messages may consist of a series of irreducible prime numbers, say, 1, 3, 5, 7, 11, 13, 17,..., or the value of pi out to the first twenty digits or so.

Assuming for the moment the validity of this approach, can we do better than mere counting? Dr. Hans Freudenthal, professor of mathematics at the University of Utrecht in the Netherlands, has designed a purely mathematical language which conceivably could be used in interstellar discourse between alien races. Freudenthal originally devised his system of "lingua cosmica" -- Lincos for short -- as an exercise in logical linguistics, but he admits it easily might serve as the contact and communicative mode among ETs.3290

Lincos consists of a variety of mathematical terms and phrases, to be encoded into specific combinations of radio pulses and signal shapes and then beamed out into space. It is devised purely in terms of semantics and human logic, and accomplishes understanding by building from simple beginnings. Statements are arranged in words, sentences, and paragraphs.

Freudenthal’s program begins by establishing the meaning of the terms "plus" and "equals." He would, for instance, send signals something like "beep bloop beep tweet beep beep" (1 + 1 = 2), perhaps followed by "beep bloop beep beep tweet beep beep beep" (1 + 2 = 3) and so on. Eventually it should become clear that "bloop" represents addition and "tweet" signifies equality. In the first chapter of his book on Lincos, Freudenthal goes on similarly to introduce the concepts of subtraction, multiplication, division, basic symbolic logic ("and," "or," and "follows"), negatives, integers, decimals, fractions, and zero. In the second chapter the concept of time makes its appearance, including "seconds," duration, wavelength, frequency, "before," "after," and "occurs."

In chapter 3, Freudenthal develops concepts of correct and incorrect, right and wrong, good and had; to count, to search, to find, to describe, to prove, to change, to add or omit; to know, guess, understand, and mention; nearly and approximately, much and little, soon and long ago, age and now; necessary and possible, enable, be forced, allowed, forbidden; politely; conflict between necessity, duty, and desire; and so forth. For example, Freudenthal’s language lesson to teach the concepts "correct" and "incorrect" to ETs runs as follows:

*Ba Inq Hb•?x.100x=1010: Human-a asks Human-b: If 4x = 10, how much is x?
Hb Inq Ha.1/10: Human-b tells Human-a: x is 1/2.
Ha Inq Hb Mal: Human-a tells Human-b: That is incorrect.
Hb Inq Ha.101/10: Human-b tells Human-a: x is 5/2.
Ha Inq Rh Ben* Human-a tells Human-b: That is correct. End of lesson.

As vocabulary slowly builds, ever more sophisticated statements become possible. In chapter 4 of Freudenthal’s book, mechanics and spatial extent are dealt with, including concepts of distance, position, length, growth, volume, motion, waves and oscillations, speed of light, mass, and astronomical concepts. Later chapters delve into geography, anatomy and physiology including the human reproductive process. By staging "plays" between symbolic human "actors," Lincos ultimately should be capable of portraying diverse facets of human behavior, emotions, social conventions, philosophies and religious rituals.

Unfortunately, there are many problems with the "universal mathematical language" approach. As we know, no system of logic is or can be universal. Gödel’s Theorem suggests that alien systems of mathematics, logic and philosophy necessarily must be at least somewhat incongruent. ETs may not understand our system of numbers, our Euclidean geometry, our Aristotelian bimodal logic, our astronomically-derived Newtonian physics, or our sequential Periodic Table of the Elements, simply because they view the universe through different sensors and thus reach different conclusions based on different theories. So aliens may not understand human-designed artificial languages like Lincos.

Still, the possibility of totally nonintersecting systems of knowledge is probably remote in most first contact situations. It is unlikely that man and alien will have absolutely nothing in common. In most cases, ETs evolving on Earth-like worlds should have much in common with us by virtue of the similarity of our native environments. To the extent the two paradigms do intersect, a basis for communication may be established from which the areas of nonintersection later can be cautiously explored. The most likely region of intersection in this case probably is in the hard sciences -- physics, chemistry, geology, meteorology, and so on.

Other approaches to the problem of extraterrestrial message anticryptography have been proposed. Perhaps the most popular of these is the interstellar pictogram, anticipated by H.W. and C. Wells Nieman back in 1920.170 The basic idea is that a string of radio pulses, coded as on/off, black/white, or 0/1 could he arranged in a rectangular raster pattern to form a two-dimensional pictorial image much like modern television systems (Figure 24.5).

Imagine you receive a string of 1271 zeros and ones on an appropriate interstellar frequency band. How might this be translated? The mathematically-inclined reader will recognize that 1271 is the product of two prime numbers, 31 and 41. This suggests that the data should be laid out sequentially on a gridwork either of 41 rows and 31 columns or 31 rows and 41 columns. As illustrated in Figure 24.5, the former of these makes little sense whereas the latter appears highly informative.1056


Figure 24.5 Sample Interstellar Pictogram

Suppose the above string of 250 pulses ("1") and 1021 pauses ("0") is received by a terrestrial radiotelescope during a scan of the Epsilon Eridani star system. There are a total of 1271 data bits. 1271 is the product of two prime numbers, 31 and 41. This suggests a two-dimensional message, in which the data are laid out sequentially in a rectangular grid pattern of rows and columns. There are two possible ways of doing this -- 41 rows or 31 rows. As we see at below left, the choice of 41 rows produces an evidently random arrangement of dots. But if the same data are set out in a grid with 31 rows, as shown at below right, the pattern is striking and informative.1056


It appears that the creatures depicted in the lower center part of the pictogram, presumably the species that sent the message, are beings having two arms, two legs, and an erect posture much like humans. Sexual cues suggest a mammalian physiology, with long-maturing offspring born one at a time and cared for during youth by pairs of bisexual parents. The crude circle and column of dots at the left suggest their sun and planets, and the being on the left is pointing at the fourth world which is evidently their home. The planets are numbered down the left-hand side in a ‘binary code" different from the one normally used by human computer scientists. The numbers one through eight are given in this new code. The creature on the right is pointing at the "binary number 1011, which is six in the alien code. Perhaps the ETs have 6 fingers on each hand. There is also a dimension line at far right. labeled with the "binary" number 11101. In the alien code, this is eleven, so we infer that the beings are eleven somethings tall. Since the only length we both know for certain is the wavelength of the radio waves upon which the message was transmitted (say, 10 centimeters, corresponding to 3 GHz), then the ETs must be 10 x 11 = 110 cm in height. (They are a race of pygmies.) The objects at the top of the pictogram represent atoms of hydrogen, carbon and oxygen, so their life chemistry is based on carbohydrates much like our own. The wavy line commencing at the third planet indicates it is a water world, and the fish-like form shows there is marine life there. Since the bipeds know this, they must have at least interplanetary space travel capability.


Variations may be imagined. For instance, we could use perfect squares rather than "rectangular primes." If the message has 1681 bits, which is 41 x 41 exactly, then there is only one way to lay the message out and the two-choice ambiguity is avoided. We might also receive a three-prime message, say with 2717 bits, which, when correctly arranged, permits the reconstruction of a spatial mode complete with height, width, and depth. If one of the three primes represents a time dimension, we will have the equivalent of an extra terrestrial Mickey Mouse cartoon. (The time-prime should be clearly distinguished from the spatial-primes for this purpose. The author suggests a message of 5819 bits, consisting of 11 sequential frames of 23 x 23 bits each.) Yet another twist, first proposed by Y.I. Kuznetzov of the Institute of Energetics in Moscow, is the possibility of transmitting a 3-D interstellar pictogram using variations in frequency, intensity, and pulse delay to build up each of the three physical dimensions of the image of a solid object.22 The pictogram mode of contact has appeared repeatedly in science fiction.70,1748

A number of chauvinisms associated with all pictogram schemes may render them significantly less universally interpretable.

First, the idea of laying data out in a grid-shaped raster seems logical enough to human scientists. Our TV sets work in essentially the same way. But aliens may have different ideas and technologies. Perhaps they use spiral scanning (either the Archimedean or logarithmic variety). At least one ancient human language was written in this format, and spiral tracing once was seriously proposed for use in Earthly television systems.1351 Aliens with spiral scanning video tubes may send messages of 1429 bits (an indivisible prime) to be laid out sequentially in a spiral pattern. Would we ever guess?

Another chauvinism is cultural in nature. According to Jan B. Deregowski, lecturer in psychology at the University of Aberdeen:

A picture is a pattern of lines and shaded areas on a flat surface that depicts some aspect of the real world. The ability to recognize objects in pictures is so common in most cultures that it is often taken for granted that such recognition is universal in man. Although most children do not learn to read until they are about 6 years old, they are able to recognize objects in pictures long before that; indeed, it has been shown that a 19-month-old child is capable of such recognition. If pictorial recognition is universal, do pictures offer us a lingua franca for intercultural communication? There is evidence that they do not: Cross-cultural studies have shown that there are persistent differences in the way pictorial information is interpreted by people of various cultures.66

Certain tribes in Africa, for example, are unable to recognize photographs as representations of the real world. They just don’t see things the way we do. And these are our fellow human beings. How much more difficult may be the problems of interpretation where ETs are involved?

A third and very serious chauvinism is the tacit assumption that all sentient alien creatures must necessarily be visually oriented. Consider a pelagic world inhabited by intelligent technological dolphins: These creatures have devised a special telescope which converts radio waves into acoustical signals which they can hear. One day their equipment is aimed at Earth and they receive the standard 31 x 41 pictogram, which they promptly arrange into an appropriate rectangular format of sonic pulses. But since the pictogram was assembled from the viewpoint of visual beings, the sentient dolphins cannot make head nor tail of our message. Reality just doesn’t sound that way to them.


Last updated on 6 December 2008