What do you know about the paradox of the Great Silence?
In 2006, the astrophysicist Alexander Zaitsev, stated1 what is known as the SETI paradox (SETI stands for Search for Extra-Terrestrial Intelligence.):
Two opposing tendencies paradoxically coexist in terrestrial consciousness – the insistent quest for intelligent signals from other civilizations and the persistent aversion to any attempts to transmit such signals from Earth toward probable fellow intelligent beings. If typical for our entire Universe, such manifestations of intelligence would make the search for other civilizations totally meaningless.
This paradox is also coined as the Paradox of the Great Silence.
To Zaitsev, we are living an "incomprehensible hope of finding extraterrestrial intelligence while keeping almost absolutely silent."
According to Amir Alexander's: The Search for Extraterrestrial Intelligence: A Short History the methodical search for other "intelligences" in other places of the universes can be possibly traced to the year 1959, with Philip Morrison and Giuseppe Cocconi's interest in the very shortwave band of radio communications.
The problem of finding "intelligent life" from alien civilizations somewhere in the cosmos is twofold:
- Catch some signal of their existence. That requires scanning the skies for some kind of message they may be sending us (or to anybody that catches the signal). This also requires discriminating when a signal is an "intelligent signal" from every other noise outside. In this aspect of listening, we are somewhat active, but not so active as when project Ozma and others similar searches were funded by NASA, and universities. In case of success in receiving some signal, the result for such an event would be immediate (joy? chaos?).
- Send them signals of our existence. This requires composing a reasonably simple and intelligent message, choosing a direction of possible existence of "intelligent life" in some nearby planets (out of our Solar System), send them the message, and let our future generations see the results. The results may take millennia.
In this article we'll focus on the second aspect of the Great Silence paradox: the messages sent from the Earth to the cosmos.
Messages to outer space: the Arecibo message
The first signal of our existence to the outer space was the Arecibo message. Cornell University, which was managing the Arecibo Radio Observatory on the island of Puerto Rico for the National Science Foundation (NSF), was celebrating a major upgrade to the radio telescope in 1974. To celebrate this event, Frank Drake, with several graduate students and professor Carl Sagan, devised a message that would be broadcasted to a selected constellation in our Milky Way Galaxy during the upgrade dedication ceremony on November 16, 1974.
The message is a string of 1679 on and offs (radio signals in binary system) that when "decoded", the civilization that receives it must first notice that 1679 is composite number that can only be decomposed as 23 times 73; 23 and 73 being the only two prime numbers, which when multiplied together equal 1679. Those1679 bits, when arranged in columns and rows must forcibly make the "message" shown at right. Assuming aliens with similar vision organs like ours, they will see a pictogram like this, but decoding its significance is another story.
Briefly, the constituents of the message are the following:
- Rows 1 to 4. The numbers 1 to 10 in the binary system.
Row 5 is a separator (a "filler").
- Rows 6 to 10. The atomic numbers for Hydrogen=1, Carbon=6, Nitrogen=7, Oxygen=8, Phosphor=15); the chemical elements of the organic life.
Row 11 is a separator (a "filler")
- Rows 12 to 30. The formulas for sugars, bases and phosphate in DNA nucleotides.
In rows 12-15, columns 1-5: Deoxyribose; columns 7-11: Adenine; columns 13-17, Thymine; the last block is the same first block repeated. Some other blocks are also repeated.
- Rows 27 to 55: the double helix structure of DNA surrounding the binary number that represents the number of nucleotides in the human genome.
The nucleotides in the DNA (as it was known to that date).
Row 56 is a separator (a "filler")
- Rows 57-60. Our Solar System. Third planet-our Earth- shown offset. The human figure is also standing on it.
- Rows 61-73. The emitting antenna, showing its diameter.
Recent picture of the Arecibo observatory. Courtesy of the NAIC - Arecibo Observatory, a facility of the NSF.
Messages to outer space: the Evpatoria message
The second signal of our existence is the Evpatoria message. Evpatoria (Eupatoria) is a city in Ukraine, a former state of the Soviet Union. Initial attempts of radio telescope transmissions were done as early as 1962, when on November 12 and 24, short signals with the words "Mir", "SSSR" and "Lenin" were sent to the planet Venus to receive its echo. At the time of transmission, Venus was in the Libra constellation2.
The Red Star newspaper informing about the Evpatoria transmission in 1962. In the signals can be seen the Morse Code equivalent of each word. Photo credit: Russian Academy of Sciences.
This three-word radio transmission experiment cannot be considered a "message" as such, but it opened the road for the future and more complicated message on May 24, 1999.
The 70-meter (230-ft.) diameter deep space antenna in Evpatoria, Ukraine used for interstellar radio transmissions. Photo courtesy of Dr. Alexander Zaitsev, Russian Academy of Science.
The 1999 message ─Encounter 2001 "Cosmic Call"─ is also known as the Evpatoria Message, following, as Arecibo, the city from which it was sent to the space.
Contrary to the Arecibo message that looks like a scroll, or like an ancient codex, the message of the year 1999 is a 23 page "book" of square pages each 129 bits by 129 bits. Each page has a border of one bit around its four borders making them self-contained chunks of information, except pages 19-20 that are a two-page map of our continents. Taken as whole, the Evpatoria message is 370,967 bits with enough redundancy so that in the event that one bit is lost or interfered, or any page become unreadable on its long travel, the message as whole can still be deciphered.
The message was coded by Yvan Dutil y Stephane Dumas from the Defense Research Establishment, Valcartier, near Quebec City, Canada[3].
In the following paragraphs we'll make an analysis of the pictograms of page 1 of the message and see how it is supposed to be deciphered.
Page 1 of the Encounter 2001 Evpatoria radio transmission. The numbers outside the square are for analysis purposes. Page number 00001 is shown at left and repeated at right. The center pictogram is just a "chapter title".
As mentioned above, every page is in square format (129 x 129 bits). Each page has a one-bit border, and a one-bit margin, so the interior of each page of 127 x 127 bits.
From this page, the first symbol that captures our attention (aside from the "header") is this:
Why this pictogram stands for the equality ( = ) concept?
A symbol doesn't have any meaning by itself. It is by its cultural content that symbols acquire meaning. So, the above pictogram requires some thinking as to what does it means; that meaning should be derived by the pictograms that surrounds it.
The numbers from 0 to 9 in the Encounter 2001 radio message.
Note the dots at the left, the binary representation of this quantity at the center, and the right symbol that stands for each quantity.
Using a pictogram twice for the equality idea reinforces the idea of this concept.
We can read this as: "dot-dot-dot equals 0011 equals the symbol shown". Mathematically, in our earthly notation, this is written as;
● ● ● = 0011 = 3
Next, we can see how alien civilizations can understand our decimal positioning system, and how here on Earth we recycle the numerals from 0 to 9 to represent any number.
Using the decimal positioning system in the Evpatoria message. See above the numbers 1 and 5 represented independently, and the see below the number 15 using the same pictograms of 1 and 5.
Next in this "page" of this "book" we find the first 24 prime numbers. See how all of them can be represented by the pictograms previously introduced in the code:
The first 24 prime numbers are visible in this radio-message. The numeration above them are for easy identification of the primes to our readers.
The last ideogram in this first page takes a little mind readiness to perceive that something unusual is in it.
First we must notice that there is a misalignment of "characters", and that there is one ideogram not previously used among the initially introduced. The misalignment is for the number 3021377 that is slightly above the number 2, the first character in the sequence of the pictogram. Then, the last two characters are aligned again with the first character. Thus, we have
2 3021377 ? 1.
But, being this pictogram continuous with the preceding 24 primes, it may have some relation with them. For any civilization like ours, they must be related not only with the binary system, but also with the basic notions of the number theory. One of those notions is that
sometimes 2n + 1 is prime, and sometimes 2n - 1 is prime.
Of the two possibilities, numbers of the type 2n - 1 are curious because of some special properties[4].
The whole pictogram must be conveying the idea of exponentiation, together with the concept of subtraction. Therefore, the pictogram is the representation of the expression 23021377 - 1[5], [6].
The book is too long to analyze here in every detail ─some pages are really hard. So what follows is sample pages of this message. The set of all 23 pages of the message by Y. Dutil and S. Dumas are found in the Encounter 2001 Message
Page 14 ...6
On this page, you will find some description of the Earth’s biosphere: atmosphere, soil and water composition. The last item indicates the value of the gravity at the surface. Top of Land = 8848 m (Mount Everest), Bottom of Ocean = 11000 m (Mariana’s Trench)[7].
Page 16 ...
The group of symbols at the right, talks about acoustic in term of frequencies. It gives the range of our earing capabilities[6].
The unbelievable last page 23 ...
Now we simply ask the receiver to answer back some questions. Basically, it is the same notions we have introduced in the message. We ask them about their understanding of their world and about themselves. The huge symbol at the center is the same used to introduce variables. It is the equivalent of the question mark [6].
Messages to outer space: the Teen-Age Message to the Stars
A third wave of messages was also sent on August 29, September 3 and 4, 2001 from the same 70-m dish of the Evpatoria Deep Space Center. Zaitsev describes the origin of this event in this way:
In 2001, a group of Russian teens from Moscow, Kaluga, Voronezh, and Zheleznogorsk participated directly and via the Internet in composing a Teen-Age Message (TAM) to extraterrestrial intelligence ...
This message was different in content from the two previous already mentioned messages. It was divided in three aspects: a sounding section, an analog section, and digital section.
We can think of three kinds of information which our IRMs [interstellar radio messages] can deliver to the proposed addressee: (1) astrophysical characteristics of interstellar medium, (2) our feelings and (3) our thoughts. Thus, section (1) of our IRM has to be a coherent-sounding radio signal, which will give to aliens an opportunity to investigate the interstellar medium by examination of small variations in phase/amplitude/polarization of the received wave. Section (2) of our message has to carry analog information about our internal emotional world. It may be music and other possible displays of Art. Section (3) is well-known digital information as a sum of knowledge and understanding about ourselves and nature.
The analog section consisted of a Theremin concert to Aliens of well-known musical compositions excerpts, among them, by Beethoven, Vivaldi, and Rachmaninov.
One of the images sent with message was a "picture" called Nature of some of the components living around us. The standing man beside the dog is holding objects with his hand; that conveys the idea of his ability to manipulate his surroundings. The human figure is standing in the center of graphic thus communicating to the alien receptors that it was this creature the one who sent the message. There is a clear distinction of what
We can clearly see a bird, a tree with its roots below the human's feet, a fish below the water level, the emitting radio telescope, a dog, the Mir space station (launched -1985. The man and the dog seem to be hollow, showing the idea of exoskeletons; the space station is also hollow.
Among the all the information sent, there is a sincere and friendly welcome note ─in Russian, and in English─ that reads as follows:
Dear friends from the universe!
We are the children from the Earth planet, sending this Message to you. We want you to know, that you are not alone in the Universe. We offer to be your friends. The Galaxy where you and we live, is our common Home. We named it the Milky Way. The Earth planet is moving around a star named Sun. The planet itself is covered by ocean and land. There are many creatures living in our plane; but only people have created a technological civilization.
We live in families: parents and children. Children like to play. We would like to show you our games, drawings, music. The duration of our life is about 80 years. While writing this Message, we are from 13 to 18 years old. So, we hope to receive your answer.
People have many cultures, languages and religions. People have reached the technical progress, but scientists have also invented horrible weapons, which may destroy the life on our Earth.
Our planet is very beautiful, but it is ill. Our problems are wars, ecology, exhaustion of natural resources. But we hope we shall overcome these problems and all people on Earth will be happy! We would like to learn about you! Please, reply. We would be very glad. We wish you peace and love.
The children from the Earth, August-September, 2001[8].
Are there other messages like this one frequently passing through our Solar System coming from unknown remote places of the cosmos?
Final words (its all about questions)
Is it worth to continue listening? Should more messages like this one be sent to more places in the cosmos? Is it fair that a group of people ─no matter how well intentioned they be─ keep talking for the whole humanity? Does it make sense that we send messages knowing in advance with almost all certainty that we will never receive a response? Shouldn't we wait until we know more about the true deep laws of physics? Maybe some unexpected instantaneous way of messaging is waiting to be discovered. Is it too much to say that every radio telescope message like all mentioned above are just scientists (even the TAM) playing risky games with their tools?
E. Pérez
Oct-09
In these messages to the stars it stands out that the invention of the imaginary numbers is not mentioned ─much less the complex number system. Without their use, any type of radio communication is impossible. For a brief introduction about how they can be derived, see the article: The imaginary numbers are not so imaginary, and the complex numbers are not so complex .
Notes
[1] Zaitsev, A. The SETI Paradox. Bull. Spec. Astrophys. Obs., 60, 2006.
[2] Interstellar Radio Messages: Mir, Lenin, SSSR.
[3] The press release for the Encounter 2001 "Cosmic Call" event of 12 Jan 1999 can be found here . This page is about an Interview with Dr. Yvan Dutil .
[4] This type of number is called Mersenne prime .
[5] This prime number was found by Roland Clarkson (a 19 year-old student at California State University Dominguez Hills), on January 27th, 1998, on his home computer! When this expression is evaluated, it gives rise to a 909,526 digit number!
[6] Prime numbers are very important in mathematics, because the natural numbers 1, 2, 3, .... (and therefore every integer) are either primes or the product of other primers, and nothing else in between. Primes are catchy, misleading, and somewhat difficult to reason about them. See the article Historical Quotations About Prime Numbers - a humor page, to see how easy it is to miss the point with them.
[7] For an explanation in French-English of each of the pages of the Evpatoria message, see Le message décodé (The message decoded) in the Internet Archive.
[8] Concert program and complete listing of the images and target stars are available at: Messages to E.T.
References
For a colorful explanation of each of the constituents of the Arecibo message, see the Arecibo message in Wikipedia.
For the special qualities of the Theremin ─the very special electronic musical instrument─ and its impact on movie music see: Theremin , in Wikipedia.