CETI (Communication with Extraterrestrial Intelligence, or METI, Messaging to Extraterrestrial Intelligence) is a branch of SETI research that focuses on composing and deciphering messages that could theoretically be understood by another technological civilization. The best-known CETI experiment was the 1974 Arecibo message composed by Frank Drake and Carl Sagan. This article is about the search for extra-terrestrial intelligence. ... Arecibo Observatory This is the message with color added to highlight its separate parts. ... Professor Frank Drake Frank Drake (born May 28, 1930, Chicago, Illinois) is an American astronomer and astrophysicist. ... Insert non-formatted text here Carl Edward Sagan (November 9, 1934 – December 20, 1996) was an American astronomer and astrobiologist and a highly successful popularizer of astronomy, astrophysics, and other natural sciences. ...

CETI research has focused on three broad areas: mathematical languages, pictorial systems such as the Arecibo message, and algorithmic communication systems (ACETI).

History

In the nineteenth century there were a lot of books and articles about the possible inhabitants of other planets. Many people believed that intelligent beings might live on the moon, Mars, and Venus; but since travel to other planets was not yet possible, some people suggested ways to signal the extraterrestrials even before radio was discovered. Apparent magnitude: up to -12. ... Adjectives: Martian Atmosphere Surface pressure: 0. ... Adjectives: Venusian or (rarely) Cytherean Atmosphere Surface pressure: 9. ...

Karl Gauss suggested that a giant triangle and three squares, the Pythagoras, could be drawn on the Siberian tundra. The outlines of the shapes would have been ten-mile wide strips of pine forest, the interiors could be rye or wheat. Johann Carl Friedrich Gauss Johann Carl Friedrich Gauss (Gauß) (April 30, 1777 - February 23, 1855) was a legendary German mathematician, astronomer and physicist with a very wide range of contributions; he is considered to be one of the greatest mathematicians of all time. ... Pythagoras of Samos (Greek: ; circa 580 BC – circa 500 BC) was an Ionian (Greek) philosopher[1] and founder of the religious movement called Pythagoreanism. ...

The Pythagoras.

Joseph Johann Littrow proposed using the Sahara as a blackboard. Giant trenches several hundred yards wide could delineate twenty-mile wide shapes. Then the trenches would be filled with water, and then enough kerosene could be poured on top of the water to burn for six hours. Using this method, a different signal could be sent every night. Image File history File links Pythagorean. ... Image File history File links Pythagorean. ... Joseph Johann Littrow (March 13, 1781 – November 30, 1840) was an Austrian astronomer. ...

Meanwhile, other astronomers were looking for signs of life on other planets. In 1822, Franz von Gruithuisen thought he saw a giant city and evidence of agriculture on the moon, but astronomers using more powerful instruments refuted his claims. Gruithuisen also believed he saw evidence of life on Venus. "Ashen light" had been observed on Venus, and he postulated that it was caused by a great fire festival put on by the inhabitants to celebrate their new emperor. Later he revised his position, stating that the Venusians could be burning their rainforest to make more farmland. Baron Franz von Paula Gruithuisen (March 19, 1774 – 1852) was a Bavarian physician and astronomer. ... Adjectives: Venusian or (rarely) Cytherean Atmosphere Surface pressure: 9. ...

By the late 1800s, the possibility of life on the moon was put to rest. Astronomers at that time believed in the Kant-Laplace hypothesis, which stated that the farthest planets from the sun are the oldest--therefore Mars was more likely to have advanced civilizations than Venus. It was evident that Venus was perpetually shrouded in clouds, so the Venusians probably wouldn't be very good astronomers. Subsequent investigations focused on contacting Martians. In 1877 Giovanni Schiaparelli announced he had discovered canals on Mars--this was followed by thirty years of Mars enthusiasm. To meet Wikipedias quality standards, this article or section may require cleanup. ... Giovanni Virginio Schiaparelli (March 14, 1835 – July 4, 1910) was an Italian astronomer. ...

The inventor Charles Cros was convinced that pinpoints of light observed on Mars and Venus were the lights of large cities. He spent years of his life trying to get funding for a giant mirror to signal the Martians with. The mirror would be focused on the martian desert, where the intense reflected sunlight could be used to burn figures into the martian sand. Charles Cros (October 1, 1842 - August 9, 1888) was a French poet and inventor. ...

In 1899, the inventor Nikola Tesla "recorded" signals of what he believed were Extraterrestrial radio signals, but the scientific community rejected these announcements and his data. Tesla spent the latter part of his life trying to signal Mars. Nikola Tesla (1856-1943)[1] was a world-renowned Serbian inventor, physicist, mechanical engineer and electrical engineer. ...

Around 1900, The Guzman Prize was created; the first person to establish interplanetary communication would be awarded 100,000 francs under one stipulation: Mars was excluded because Madame Guzman thought communicating with Mars would be too easy to deserve a prize. ^[1]

When the Martian canals proved illusory, it seemed that man was alone in the solar system.

Mathematical and scientific languages

Astraglossa

Published in 1953 by Lancelot Hogben describes a system for combining numbers and operators in a series of short and long pulses. In Hogben's system, short pulses represent numbers, while trains of long pulses represent symbols for addition, subtraction, etc. 1953 (MCMLIII) was a common year starting on Thursday. ... Lancelot Thomas Hogben (9 December 1895- 22 August 1975) was a versatile English zoologist and geneticist. ...

Lincos (Lingua cosmica)

Lincos: Design of a Language for Cosmic Intercourse, published in 1960 by Hans Freudenthal, expands upon Astraglossa to create a general-purpose language derived from basic math and logic symbols. Lincos (an abbreviation of the Latin phrase lingua cosmica) is an artificial language first described in 1960 by Dr. Hans Freudenthal and described in his book LINCOS: Design of a Language for Cosmic Intercourse. ... 1960 (MCMLX) was a leap year starting on Friday (the link is to a full 1960 calendar). ... Hans Freudenthal (September 17, 1905 – October 13, 1990) was a Dutch mathematician born in Luckenwalde in Germany into a Jewish family. ...

Carl Sagan

The science fiction novel Contact by Carl Sagan explored in some depth how a message might be constructed to allow communication with an alien civilization, using the prime numbers as a starting point, followed by various universal principles and facts of mathematics and science. Sagan also authored a non-fiction book on the subject.^[2] Science fiction is a form of speculative fiction principally dealing with the impact of imagined science and technology, or both, upon society and persons as individuals. ... Contact is a science fiction novel written by Carl Sagan and published in 1985. ... In mathematics, a prime number (or a prime) is a positive integer that has exactly two (distinct) natural number divisors, which are 1 and the prime number itself. ...

A language based on the fundamental facts of science

Published in 1992 by Carl Devito and Richard Oehrle, is similar in syntax to Astraglossa and Lincos but builds its vocabulary around known physical properties. 1992 (MCMXCII) was a leap year starting on Wednesday. ...

Pictorial messages

Pictorial communication systems seek to describe fundamental mathematical or physical concepts via simplified diagrams sent as bitmaps. These messages assume that the recipient has similar visual capabilities (weak assumption) and can understand basic math and geometry (strong assumption because both are prerequisites for building the optimal shape for a radio or optical telescope). A common critique of these systems is that they assume a shared understanding of special shapes, which may not be the case with a species with substantially different vision, and therefore a different way of interpreting visual information.

Pioneer probes

The two Pioneer plaques were launched on Pioneer 10 and Pioneer 11 in 1972 and 1973, depicting the location of the Earth in the galaxy and the solar system, and the form of the human body. The illustration on the Pioneer plaque The Pioneer plaques are a pair of aluminum plaques which were placed on board the Pioneer 10 and Pioneer 11 spacecraft, featuring a pictorial message from humanity, in case either the Pioneer 10 or 11 are intercepted by extraterrestrial beings. ... Pioneer 10 was the first spacecraft to travel through the asteroid belt, and was the first spacecraft to make direct observations of Jupiter. ... Position of Pioneer 10 and 11 Pioneer 11 was the second mission to investigate Jupiter and the outer solar system and the first to explore the planet Saturn and its main rings. ...

Voyager probes

Launched in 1977, the Voyager probes carried two golden records that were inscribed with diagrams depicting the human form, our solar system and its location. Also included were recordings of pictures and sounds from Earth. For the album by Ash, see 1977 (album). ... Voyager Project redirects here. ... The Voyager Golden Record. ...

The Arecibo message

The Arecibo message, transmitted in 1974, was a 1679 pixel image with 73 rows and 23 columns. It shows the numbers one through ten, the atomic numbers of hydrogen, carbon, nitrogen, oxygen, and phosphorus, the formulas for the sugars and bases in the nucleotides of DNA, the number of nucleotides in DNA, the double helix structure of DNA, a figure of a human being and its height, the population of Earth, our solar system, and an image of the Arecibo telescope with its diameter. Arecibo Observatory This is the message with color added to highlight its separate parts. ... This example shows an image with a portion greatly enlarged, in which the individual pixels are rendered as little squares and can easily be seen. ...

Cosmic Call messages

The Cosmic Call messages consisted of few digital sections - "Rosetta Stone", copy of Arecibo Message, Bilingual Image Glossary, the Braastad message, as well as text, audio, video and other image files submitted for transmission by everyday people around the world. The "Rosetta Stone" was composed by Stephane Dumas and Yvan Dutil and represents a multi-page bitmap that builds a vocabulary of symbols representing numbers and mathematical operations. The message proceeds from basic math to progressively more complex concepts, including physical processes and objects (such as a hydrogen atom). The message is designed with noise resistant format and characters, which make it resistant to alteration by noise. These Messages were transmitted in 1999 and 2003 from Evpatoria Planetary Radar under scientific guidance of Alexander Zaitsev. Richard Braastad coordinated the overall project. General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ... There have been more than one well-known Russians named Alexander Zaitsev, including: Alexander Zaitsev (chess player) Alexander Zaitsev (skater) This is a disambiguation page — a navigational aid which lists other pages that might otherwise share the same title. ...

Multi-modal messages

Teen-Age Message

The Teen-Age Message, composed by Russian scientists (Zaitsev, Gindilis, Pshenichner, Filippova) and teens, was transmitted from the 70-m dish of Evpatoria Deep Space Center to six Sun-like stars on August 29 and September 3 and 4, 2001. The message consists of three parts:

Section 1 represents coherent sounding radio signal with slow Doppler wavelength tuning to imitate transmission from Sun's center. This signal was transmitted in order to help Extraterrestrials detect the TAM and diagnose the radio propagation effect of interstellar medium.

Section 2 is analog information and represents musical melodies, performed on the Theremin. This electric musical instrument produces quasi-monochromatic signal, which is easily detectable across interstellar distances. There were seven musical compositions in the 1st Theremin Concert for Aliens.

Section 3 represents a well-known Arecibo-like binary digital information: Logotype of TAM, bilingual Russian and English Greeting to Aliens and Image Glossary.

Cosmic Call 2003 message

The Cosmic Call 2003 message contained text, images, video, music, the Dutil/Dumas message, a copy of the 1974 Arecibo message, BIG = Bilingual Image Glossary, the AI program Ella, and the Braastad message.

Algorithmic messages

Algorithmic communication systems are a relatively new field within CETI. In these systems, which build upon early work on mathematical languages, the sender describes a small set of math and logic symbols that form the basis for a rudimentary programming language that the recipient can run on a virtual machine. Algorithmic communication has a number of advantages over static pictorial and mathematical messages, including: localized communication (the recipient can probe and interact with the programs within a message, without transmitting a reply to the sender and then waiting years for a response), forward error correction (the message might contain algorithms that process data elsewhere in the message), and the ability to embed proxy agents within the message. In principle, a sophisticated program when run on a fast enough computing substrate, may exhibit complex behavior and perhaps intelligence. In computer science, a virtual machine is software that creates a virtualized environment between the computer platform and its operating system, so that the end user can operate software on an abstract machine. ... In telecommunication, forward error correction (FEC) is a system of error control for data transmission, whereby the sender adds redundant data to its messages, which allows the receiver to detect and correct errors (within some bound) without the need to ask the sender for additional data. ...

CosmicOS

CosmicOS, designed by Paul Fitzpatrick at MIT, describes a virtual machine that is derived from lambda calculus. CosmicOS is a self-contained message designed to be understood primarily by treating it as a computer program and executing it. ... Mapúa Institute of Technology (MIT, MapúaTech or simply Mapúa) is a private, non-sectarian, Filipino tertiary institute located in Intramuros, Manila. ... In computer science, a virtual machine is software that creates a virtualized environment between the computer platform and its operating system, so that the end user can operate software on an abstract machine. ... The lambda calculus is a formal system designed to investigate function definition, function application, and recursion. ...

Logic Gate Matrices

Logic Gate Matrices (aka LGM), developed by Brian McConnell, describes a universal virtual machine that is constructed by connecting coordinates in an n-dimensional space via math and logic operations, for example: (1,0,0) <-- (OR (0,0,1) (0,0,2)). Using this method, one can describe an arbitrarily complex computing substrate as well as the instructions to be executed on it. In computer science, a virtual machine is software that creates a virtualized environment between the computer platform and its operating system, so that the end user can operate software on an abstract machine. ...

CETI researchers

• Frank Drake (SETI Institute) : SETI pioneer, composed the Arecibo message with Carl Sagan
• Laurence Doyle (SETI Institute) : studies animal communication, and has developed statistical measures of complexity in animal utterances as well as human language.
• Stephane Dumas : developed Cosmic Call messages, as well as a general technique for generating 2-D symbols that remain recognizable even if corrupted by noise.
• Yvan Dutil : developed Cosmic Call messages with Stephane Dumas.
• Paul Fitzpatrick (MIT) : developed CosmicOS system based on lambda calculus
• Brian McConnell : developed framework for algorithmic communication systems (ACETI) from 2000-2002.
• Marvin Minsky (MIT AI researcher) : first proposed the idea of including algorithms within an interstellar message.
• Carl Sagan (deceased) : co-authored the Arecibo message, and was heavily involved in SETI throughout his life.
• Douglas Vakoch (SETI Institute) : studies CETI and has published numerous articles, as well as an upcoming book from MIT Press about interstellar communication.
• Alexander Zaitsev (IRE, Russia) : composed Teen Age Message with Boris Pshenichner, Lev Gindilis, Lilia Filippova, et al., composed Bilingual Image Glossary for Cosmic Call 2003 Message, Scientific Manager of transmitting from Evpatoria Planetary Radar the Cosmic Call 1999, the Teen Age Message 2001, and the Cosmic Call 2003.

Professor Frank Drake Frank Drake (born May 28, 1930, Chicago, Illinois) is an American astronomer and astrophysicist. ... This article is about the search for extra-terrestrial intelligence. ... Arecibo Observatory This is the message with color added to highlight its separate parts. ... Insert non-formatted text here Carl Edward Sagan (November 9, 1934 – December 20, 1996) was an American astronomer and astrobiologist and a highly successful popularizer of astronomy, astrophysics, and other natural sciences. ... Mapúa Institute of Technology (MIT, MapúaTech or simply Mapúa) is a private, non-sectarian, Filipino tertiary institute located in Intramuros, Manila. ... The lambda calculus is a formal system designed to investigate function definition, function application, and recursion. ... Marvin Lee Minsky (born August 9, 1927), sometimes affectionately known as Old Man Minsky, is an American cognitive scientist in the field of artificial intelligence (AI), co-founder of MITs AI laboratory, and author of several texts on AI and philosophy. ... Mapúa Institute of Technology (MIT, MapúaTech or simply Mapúa) is a private, non-sectarian, Filipino tertiary institute located in Intramuros, Manila. ... // This disambiguation page covers alternative uses of the terms Ai, AI, and A.I. Ai (as a word, proper noun and set of initials) can refer to many things. ... Insert non-formatted text here Carl Edward Sagan (November 9, 1934 – December 20, 1996) was an American astronomer and astrobiologist and a highly successful popularizer of astronomy, astrophysics, and other natural sciences. ... This article is about the search for extra-terrestrial intelligence. ...

See also

• Time capsule
• Message in a bottle

A time capsule is a histori c cache of goods and/or information, usually intended as a method of communication with people in the future. ... A message in a bottle is a form of communication whereby a message is sealed in a container (archetypically a glass bottle, but could be plastic) and released into the sea or ocean. ...

References

• Braastad, Richard, The Extraterrestrial Sermons, http://www.richardb.us/project.html
• Dutil, Dumas, ACTIVE SETI PAGE, http://www3.sympatico.ca/stephane_dumas/CETI/default.htm
• Martin, Martin C. 1991 SETI Puzzle, posted to sci.crypt, sci.astro, sci.space, rec.arts.sf-lovers and rec.puzzles. http://www.metahuman.org/martin/SETIPuzzle.html
• Communication with Alien Intelligence, 1985, Marvin Minsky, http://web.media.mit.edu/~minsky/papers/AlienIntelligence.html
• Devito, C. and Oerle, R. A Language Based on the Fundamental Facts of Science, Journal of the British Interplanetary Society, 1990, Vol 43, pp. 561-568
• EllaZ Systems, http://www.ellaz.com/AI/Default.aspx
• Freudenthal H 1960 Lincos: Design of a Language for Cosmic Intercourse. North-Holland, Amsterdam.
• Hogben, Lancelot. Science in Authority. New York: W. W. Norton (1963)
• Ley, Willy. Rockets, Missiles, and Space Travel (revised). New York: The Viking Press (1958)
• McConnell, Brian S. 2001 Beyond Contact: A Guide to SETI and Communicating with Alien Civilizations. O'Reilly, Cambridge, MA
• McConnell, Brian S. 2002 Algorithmic Communication with ETI & Mixed Media Message Composition
• McConnell, Brian S at al, 2006?, Between Worlds, SETI Institute/MIT Press
• Minsky, Marvin, talk given at Communication With Extraterrestrial Intelligence (CETI), Proceedings of a conference held at the Byurakan Astrophysical Observatory, Yerevan, USSR, 5-11 September, 1971. Edited by Carl Sagan. Cambridge, MA: The Massachusetts Institute of Technology, 1973., p.ix
• Morrison, P. "Interstellar Communication." Bulletin of the Philosophical Society of Washington, 16, 78 (1962). Reprinted in A. G. W. Cameron, ed., Interstellar Communication.
• Team Encounter, Cosmic Call 2003, http://web.archive.org/web/20040406151735/www.teamencounter.com/missions/message.asp
• Zaitsev, A. Teen-Age Message, http://www.seti.housenet.org/msg_idx_tam.html
• Zaitsev, A. Interstellar Radio Messages (http://www.cplire.ru/html/ra&sr/index.html in English, http://www.cplire.ru/rus/ra&sr/index.html in Russian)