10 Pioneer 11 O Ager 1 O Ager 2 2163 2057

Total Page:16

File Type:pdf, Size:1020Kb

10 Pioneer 11 O Ager 1 O Ager 2 2163 2057 2 3 Gemini irgo 5 6 2059 Pioneer 10 Pioneer 11 oager 1 oager 2 2163 2057 1972 • United States 1973 • United States 2069 1977 • United States 1977 • United States Ursa Major THE VOYAGER AND PIONEER PROBES AREN’T DIRECTED TOWARDS A PARTICULAR 2054 2049 Cgnus Sagitta 2047 Draco Hdra LOCATION, AND ARE CURRENTLY FLOATING AIMLESSLY THROUGH INTERSTELLAR SPACE. 2057 2069 2051 2057 2067 Cetus 2059 Orion 2040 2047 2039 1998 Delphinus Andromeda 2044 2070 Eridanus Cassiopeia 2036 1996 Hercules Cancer 9 2044 2053 APPROX. 25974 APPROX. 8 Teen Age 10 Message C mic osm Cos 2001 • Crimea ic 1 Ca all ll 2 THIS BROADCAST C ea 200 rim 3 • C WASN’T AIMED AT • C rim 999 ea 1 A PARTICULAR LOCATION. 11 enus 7 C a ra ic M i t l s 20 gs e a te 05 e l o n ta • ss is P gi S U a t a ed n ge it it s n ed U S • t 6 at 98 e 1 s 1962 A F 12 o M 4 o c 2 r b e i 0 o e i g R 0 m c 8 s e a o s s t • E a r s r e C a g A e u r r e P i t M m h • e 4 a 7 9 1 A 2 a U c 0 e r e n 0 e 13 o g s m 8 i i 1 s r a r • s s e o C s S r t p e • s h M a e 2 e i M 6 n 9 Cosmic 1 S 2 ó 0 1 a n 7 G a s • r r t o J o N r t 2 Calls C N i e o 22 7 a r r • 3 l o d 14 b l 8 i a 0 D A n 0 g 2 A HISTORY OF REACHING OUT TO EXTRATERRESTRIAL INTELLIGENCE a A s n e t S E 2 a i 0 t l l m S l 2030 1 e e 6 i m p d h t Centarus l • e t S e t e S i n p n d R a a o t e i U a n • D o l s t 21 p 8 e S M o 0 h 0 h 15 2012 e n 2 T t Canis Major s s r s e a a g E e 2 01 3 ia • l U ra n st it u L ed A o S • lo h S n t 09 l t i e at 0 e ar gn es 2 H E a l om 20 Fr 16 Boötes 2 Libra 01 ico 2 • R Pue erto rto • Pu Rico 009 o ow 2 isC 2030 2029 ! RuB 2031 Re 2010 ge pl essa Break the M 19 Eerie Silence 17 18 2024 2450 2439 2022 Ursa Minor Aries “Where is everybody?”, asked physicist Enrico 1 Morse Message 7 Poetica Vaginal 12 A Message From Earth 16 Hello From Earth 20 Lone Signal Fermi in 1950, referring to a contradiction The first ever radio broadcast meant The sounds of the vaginal contractions This broadcast included 501 A collection of goodwill messages Consisted of brief, 144-character between the statistical probability of other for extraterrestrial civilizations of ballet dancers. Only a few minutes messages, pictures and drawings that from members of the public curated by statements by the public that were intelligent life in our universe and the puzzling featured the words ‘MIR’, meaning were transmitted before the U.S. Air were posted on the social networking Australian science magazine, Cosmos. posted to the Lone Signal website. lack of any evidence for it. The question peace in Russian, ‘LENIN’ and ‘SSSR’. Force shut the project down. site Bebo and selected by its users. mystifies science to this day, but hasn’t 17 RuBisCo Message 21 A Simple Response to stopped us reaching out into the darkness in 2 Pioneer 10 / Pioneer 11 8 Cosmic Call 1 / Cosmic Call 2 13 Across the Universe To mark 35 years since the Arecibo an Elemental Message an attempt to make contact. This visualization Both probes have a plaque depicting, Included a primer explaining basic Consisted of the song “Across the message, this broadcast featured a 3775 responses to the question; explores the messages we’ve beamed into the 3 among other things; human figures, a 10 aspects of human math, science, Universe” by The Beatles, marking depiction of ‘RuBisCo’, maybe the “How will our present, environmental cosmos over the last sixty years. Some are map of our solar system and the Sun’s and biology, followed by digitized the 40th anniversary of the song and most common protein molecule interactions shape the future?” Also serious scientific endeavours, others less so. position relative to adjacent stars. drawings, texts, videos and songs. the 50th anniversary of NASA. found in Earth’s lifeforms. included a series of images of Earth. Together they represent a time capsule of our planet, our species and our values, and while 4 Arecibo message 9 Teen Age Message 14 Doritos Advert 18 Break the Eerie Silence 22 Sónar Calling GJ273b the contents and destinations may differ, they Maybe the most famous interstellar Featured a theremin concert, The advert, featuring some doritos Penguin UK broadcast 5000 messages To celebrate its 25th anniversary, all carry a singular message; “here we are”. broadcast, it included the numbers images and text. So named because dancing around a jar of salsa, was solicited from the public, to mark the Sónar Festival broadcast a series of 1-10, atomic numbers for the elements the content was largely provided by broadcast on repeat for six hours, launch of the book ‘The Eerie Silence: 33 pieces of music to ‘Luyten’s Star’. Reading the Data Visualization that make up DNA, a visual of a human teenagers from Russia. which will no doubt prove fairly Are We Alone in the Universe?’ and a map of our solar system. confusing for any inhabitants of the Constellation Messages are listed 11 Craigslist Messages star system 47 Ursae Majoris. 19 Wow! Reply 2019 around the circle 5 Voyager 1 / Voyager 2 Over 100,000 postings from Around 10,000 tweets and celebrity Note: Broadcasts are often directed to Year of arrival chronologically, Each probe has an audio-visual disc craigslist.org. The message also 15 The Day the Earth Stood Still video messages, for the promotion specific stars, for the purposes of the with the lines 6 with images of Earth and its lifeforms, included a time stamp, and an audio As part of the marketing for the 2008 of a Nat Geo TV show. Named after visualization only constellations are shown. Message name, mapping broadcasts year sent and scientific information, spoken track identifying the message as remake, 20th Century Fox beamed the ‘Wow! Signal’, a mysterious radio Sources: Wikipedia, New Scientist, Mental to their destination. country of origin greetings, music and other sounds. originating from Earth. the entire movie to Alpha Centauri. signal received in 1977. Floss, MIT and Atlas Obscura. A Data Visualization by James Round. www.jamesrounddesign.com.
Recommended publications
  • A Direct Communication Proposal to Test the Zoo Hypothesis
    Space Policy 38 (2016) 22e26 Contents lists available at ScienceDirect Space Policy journal homepage: www.elsevier.com/locate/spacepol Viewpoint A direct communication proposal to test the Zoo Hypothesis Joao~ Pedro de Magalhaes~ Institute of Integrative Biology, University of Liverpool, Biosciences Building, Room 245, Crown Street, Liverpool, L69 7ZB, UK article info abstract Article history: Whether we are alone in the universe is one of the greatest mysteries facing humankind. Given the >100 Received 3 March 2016 billion stars in our galaxy, many have argued that it is statistically unlikely that life, including intelligent Accepted 16 June 2016 life, has not emerged anywhere else. The lack of any sign of extraterrestrial intelligence, even though on a Available online 26 July 2016 cosmic timescale extraterrestrial civilizations would have enough time to cross the galaxy, is known as Fermi's Paradox. One possible explanation for Fermi's Paradox is the Zoo Hypothesis which states that Keywords: one or more extraterrestrial civilizations know of our existence and can reach us, but have chosen not to Active SETI disturb us or even make their existence known to us. I propose here a proactive test of the Zoo Hy- Astrobiology fi Fermi's Paradox pothesis. Speci cally, I propose to send a message using television and radio channels to any extrater- Messaging to extraterrestrial intelligence restrial civilization(s) that might be listening and inviting them to respond. Even though I accept this is METI unlikely to be successful in the sense of resulting in a response from extraterrestrial intelligences, the possibility that extraterrestrial civilizations are monitoring us cannot be dismissed and my proposal is consistent with current scientific knowledge.
    [Show full text]
  • Strangest of All
    Strangest of All 1 Strangest of All TRANGEST OF LL AnthologyS of astrobiological science A fiction ed. Julie Nov!"o ! Euro#ean Astrobiology $nstitute Features G. %avid Nordley& Geoffrey Landis& Gregory 'enford& Tobias S. 'uc"ell& (eter Watts and %. A. *iaolin S#ires. + Strangest of All , Strangest of All Edited originally for the #ur#oses of 'EACON +.+.& a/conference of the Euro#ean Astrobiology $nstitute 0EA$1. -o#yright 0-- 'Y-N--N% 4..1 +.+. Julie No !"o ! 2ou are free to share this 5or" as a 5hole as long as you gi e the ap#ro#riate credit to its creators. 6o5ever& you are #rohibited fro7 using it for co77ercial #ur#oses or sharing any 7odified or deri ed ersions of it. 8ore about this #articular license at creati eco77ons.org9licenses9by3nc3nd94.0/legalcode. While this 5or" as a 5hole is under the -reati eCo77ons Attribution3 NonCo77ercial3No%eri ati es 4.0 $nternational license, note that all authors retain usual co#yright for the indi idual wor"s. :$ntroduction; < +.+. by Julie No !"o ! :)ar& $ce& Egg& =ni erse; < +..+ by G. %a id Nordley :$nto The 'lue Abyss; < 1>>> by Geoffrey A. Landis :'ac"scatter; < +.1, by Gregory 'enford :A Jar of Good5ill; < +.1. by Tobias S. 'uc"ell :The $sland; < +..> by (eter )atts :SET$ for (rofit; < +..? by Gregory 'enford :'ut& Still& $ S7ile; < +.1> by %. A. Xiaolin S#ires :After5ord; < +.+. by Julie No !"o ! :8artian Fe er; < +.1> by Julie No !"o ! 4 Strangest of All :@this strangest of all things that ever ca7e to earth fro7 outer space 7ust ha e fallen 5hile $ 5as sitting there, isible to 7e had $ only loo"ed u# as it #assed.; A H.
    [Show full text]
  • Searching for SETI: the Social Construction of Aliens and the Quest for a Technological Mythos
    Searching for SETI: The Social Construction of Aliens and the Quest for a Technological Mythos John Marvin Bozeman Dissertation submitted to the faculty of the Virginia Polytechnic Institute and State University in partial fulfillment of the requirements for the degree of Doctor of Philosophy In Science and Technology Studies Janet A. Abbate, Co-Chair Shannon A. Brown, Co-Chair Lee L. Zwanziger Paul D. Renard March 24, 2015 Falls Church, Virginia Keywords: Search for Extraterrestrial Intelligence, SETI, Actor Network Theory, Social Construction of Technology, Rational Choice Theory of Religion, Transhumanism, Xenosalvation Copyright John M. Bozeman Searching for SETI: The Social Construction of Aliens and the Quest for a Technological Mythos John M. Bozeman ABSTRACT This dissertation uses Actor Network Theory (ANT) and Stark and Bainbridge’s rational choice theory of religion to analyze an established but controversial branch of science and technology, the Search for Extraterrestrial Intelligence (SETI). Of particular interest are the cultural, and sometimes religious, assumptions that its creators have built into it. The purpose of this analysis is not to discredit SETI, but instead to show how SETI, along with other avant-garde scientific projects, is founded, motivated, and propelled by many of the same types of values and visions for the future that motivate the founders of religious groups. I further argue that the utopian zeal found in SETI and similar movements is not aberrant, but instead common, and perhaps necessary, in many early- stage projects, whether technical or spiritual, which lack a clear near-term commercial or social benefit. DEDICATION In memory of my parents, James E.
    [Show full text]
  • Communication with Extraterrestrial Intelligence Through Radio Signals and Messages 1A
    ISSN : 2230-7109 (Online) | ISSN : 2230-9543 (Print) IJECT VOL . 5, ISSU E SPL - 2, JAN - MAR C H 2014 Communication with Extraterrestrial Intelligence Through Radio Signals and Messages 1A. B. Bhattacharya, 2A. Sarkar 1,2Dept. of Physics, University of Kalyani, Kalyani, WB, India Abstract hundred yards wide could delineate twenty-mile wide shapes and The paper summarizes the present day research knowledge based then the trenches would be filled with water after which enough on communication with extraterrestrial intelligence through four kerosene could be poured on top of the water to burn for six hours. distinct means covering mathematical languages, pictorial systems Using this technique, a different signal could be sent every night. like the Arecibo message, algorithmic communication systems and In the mean time other astronomers were looking for signs of life computational approaches for detecting and deciphering ‘natural’ on other planets. In 1822, Franz von Gruithuisen [Cattermole and language communication. Moore, 1997] imagined a giant city and evidence of agriculture on the moon and believed evidence of life on Venus but astronomers Keywords using more sophisticated instruments refuted his claims. By the Arecibo Message, Communication, Extraterrestrial Intelligence, late 1800s, Astronomers believed the Kant-Laplace hypothesis, Resonant Receiver which stated that the farthest planets from the sun are the oldest and so Mars was more likely to have advanced civilizations than I. Introduction Venus. Subsequent investigations focused on contacting Martians. Communication with Extraterrestrial Intelligence (CETI) is Charles Cros [Ley, 1958] was convinced that pinpoints of light a subject matter under the SETI (Search for Extraterrestrial observed on Mars and Venus were the lights of large cities and Intelligence) research which focuses on composing and was attempted to get funding for a giant mirror with which to deciphering messages that could be understood theoretically signal the Martians.
    [Show full text]
  • A Profile of Humanity: the Cultural Signature of Earth's Inhabitants
    International Journal of A profile of humanity: the cultural signature of Astrobiology Earth’s inhabitants beyond the atmosphere cambridge.org/ija Paul E. Quast Beyond the Earth foundation, Edinburgh, UK Research Article Abstract Cite this article: Quast PE (2018). A profile of The eclectic range of artefacts and ‘messages’ we dispatch into the vast expanse of space may humanity: the cultural signature of Earth’s become one of the most enduring remnants of our present civilization, but how does his pro- inhabitants beyond the atmosphere. tracted legacy adequately document the plurality of societal values and common, cultural heri- International Journal of Astrobiology 1–21. https://doi.org/10.1017/S1473550418000290 tage on our heterogeneous world? For decades now, this rendition of the egalitarian principle has been explored by the Search for Extra-Terrestrial Intelligence community in order to draft Received: 18 April 2018 theoretical responses to ‘who speaks for Earth?’ for hypothetical extra-terrestrial communica- Revised: 13 June 2018 tion strategies. However, besides the moral, ethical and democratic advancements made by Accepted: 21 June 2018 this particular enterprise, there remains little practical exemplars of implementing this gar- Key words: nered knowledge into other experimental elements that could function as mutual emissaries Active SETI; data storage; deep time messages; of Earth; physical artefacts that could provide accessible details about our present world for eternal memory archives; future archaeology; future archaeological observations by our space-faring progeny, potential visiting extrasolar long-term communication strategies; SETI; time capsules denizens or even for posterity. While some initiatives have been founded to investigate this enduring dilemma of humanity over the last half-century, there are very few comparative stud- Author for correspondence: ies in regards to how these objects, time capsules and transmission events collectively dissem- Paul E.
    [Show full text]
  • Vol 11 No 2, Spring 2005
    SearchLites Vol. 11 No. 2, Spring 2005 The Quarterly Newsletter of The SETI League, Inc. Offices: 433 Liberty Street Scaling Back on SETICon PO Box 555 Little Ferry NJ Little Ferry, NJ.., 19 February 2005 -- Five years after initiating its SETICon Technical 07643 USA Symposium, the nonprofit, membership-supported SETI League has had to scale back the annual membership event to more modest proportions. Because The SETI League chose Phone: to make its meetings affordable and accessible to a wide range of amateur radio astrono- (201) 641-1770 Facsimile: mers, the events have proved a steady drain on the grassroots science group's limited fi- (201) 641-1771 nancial resources. Hence, the organization's 2005 annual meeting will be held in conjunc- Email: tion with another, much larger and well-established conference. [email protected] Web: "The last few SETICons cost us about $4,000 each to put on," notes Dr. H. Paul www.setileague.org Shuch, volunteer executive director of The SETI League. "Depending as we do upon President: membership dues and individual contributions, we thought our limited funding would be Richard Factor better spent on SETI science than on hosting scientific meetings." Consequently, Shuch Registered Agent: announced, The SETI League's 2005 Annual Membership Meeting will be held on the Marc Arnold, Esq. campus of The College of New Jersey, in conjunction with the annual Trenton Computer Secretary/Treasurer: A. Heather Wood Festival. Executive Director: H. Paul Shuch, Ph.D. This year's Trenton Computer Festival is scheduled to run the weekend of 16-17 April, 2005, with The SETI League's membership meeting to be held there on Sunday morning, 17 April, from 10 AM until Noon.
    [Show full text]
  • Lincos with Dr
    Lincos with Dr. Yvan Dutil http://library.thinkquest.org/C003763/index.php?page=interview01 Most people see SETI (the Search for Extra-Terrestrial Intelligence) as a project for merely listening for signals from other stars, but Dr. Yvan Dutil and Stephane Dumas from the Defence Research Establishment Valcartier in Canada had other ideas in mind when they composed a message sent to the stars last year. The message they sent was only the second serious attempt to actively signal civilizations around other stars; the first was in 1974 by the founder of the SETI Institute Frank Drake (also known for 'Drake's equation). Unlike's Drake's message, the message sent last year was written in the Lincos mathematical language. The Lincos encoded message was sent from the Lincos was devised by Professor Hans Freudenthal in Evpatoria transmitter in the Ukraine. Courtesy 1960, and it was aimed to be the most Yvan Dutil understandable language in existence - in other words, a language that would be very easy for aliens to decode. Each symbol in Lincos is defined by symbols that come before it, so that you don't have to know anything apart from pure mathematics to understand it. Some of the components of the message included humanity's knowledge of basic physics, our location in the universe and the solar system, as well as some elementary biology. Adrian Hon talked to Dr. Yvan Dutil in this interview. Astrobiology: Why did you choose Hans Freudenthal's Lincos language to encode your message over any other method? Dr. Dutil: Lincos is not exactly what we might call a language.
    [Show full text]
  • Is Anybody out There? Julia Bandura, Michael Chong, Ross Edwards
    Is Anybody Out There? Julia Bandura, Michael Chong, Ross Edwards ISCI 3A12 - LUE March 23rd, 2017 -graphic of scientists believe that with our rapid technological advancement, there may be ways to “We stand on a great communicate with them. This article will explore attempts to transmit threshold in the human messages to potential intelligent life forms, history of space attempts to search for incoming alien signals, and analyze explanations for the silence that we have exploration” (Sara Seager, 2014) insofar encountered. However, before considering any form of communication, whether receiving or radiation levels (since high UV radiation can be transmitting, we must first consider where to look. damaging to replication molecules like DNA), and Where is Life in the Universe? liquid water. Water is especially important: all known life on Earth requires liquid water to Logically, a scientist that hopes to communicate survive. As such, within a solar system, the with extraterrestrial beings must assume that: 1) traditional ‘habitable zone’ is defined as the extraterrestrial intelligent life exists in the universe, imaginary disc around the host star where water 2) it exists in high enough abundance that radio will remain in liquid form. A significant number of communication is possible, 3) a transmitted radio exoplanets have been discovered within this zone signal from Earth will be picked up by a receiver, around their host star, but only a fraction of them and 4) the message will be translated successfully. are considered ‘Earth-like’, meaning that their Each assumption comes with challenges that make surface conditions and sizes are similar to Earth’s the process of creating a radio message appropriate (Rekola, 2009).
    [Show full text]
  • Classification of Interstellar Radio Messages
    Классификация межзвёздных радиопосланий (авторизованный перевод с английского статьи [1]) А. Л. Зайцев ИРЭ им. В. А. Котельников РАН, Фрязинский филиал [email protected] Использование предлагаемых ниже критериев классификации позволяет разделить все известные межзвездные радиопослания на две кардинально отличающиеся группы – научно обоснованные и псевдосообщения. Имитация межзвездных радиопередач большинством экзоцивилизаций может объяснить Молчание Вселенной. В процессе создания и передачи любого межзвѐздного радиопослания (МРП) приходится решать ряд вопросов как научного, так и чисто технологического характера. В статье «METI: Messaging to Extra- Terrestrial Intelligence» [2] приведѐн так называемый «Список METI», представляющий собой перечень из десяти подобных вопросов. Классифицировать как проектируемые, так и уже отправленные МРП предлагается в зависимости от того, насколько грамотно решены в них три основных вопроса METI. К числу этих основных вопросов мы относим грамотный (1) выбор звѐзд- адресатов, достаточность (2) энергии, приходящейся на бит информации и наличие (3) в теле Письма ключа к его расшифровке, что даѐт возможность декодирования сообщения инопланетянами. Иными словами, для классификации МРП необходимо выяснить, есть ли серьѐзные возражения относительно правильности решения как минимум этих трѐх базовых вопросов. Соответствующий анализ показывает, что только пять МРП удовлетворяют всем трѐм критериям. Это «Arecibo Message 1974» («Аресибское послание») [3], «Cosmic Call 1999» («Космический зов 1») [4], «Детское радиопослание
    [Show full text]
  • NO EXIT a Gripping Thriller Full of Heart-Stopping Twists
    NO EXIT A gripping thriller full of heart-stopping twists TAYLOR ADAMS First published 2017 Joffe Books, London www.joffebooks.com This book is a work of fiction. Names, characters, businesses, organizations, places and events are either the product of the author’s imagination or are used fictitiously. Any resemblance to actual persons, living or dead, events or locales is entirely coincidental. The spelling used is American English except where fidelity to the author’s rendering of accent or dialect supersedes this. Please join our mailing list for free Kindle crime thriller, detective, mystery, and romance books and new releases. http://www.joffebooks.com/contact/ ©Taylor Adams DEDICATION For Riley. CONTENTS Sent: 12/23 6:52 p.m. DUSK 7:39 p.m. 8:17 p.m. NIGHT 9:25 p.m. 9:39 p.m. 10:41 p.m. 11:09 p.m. 11:55 p.m. MIDNIGHT 12:01 a.m. 12:04 a.m. 12:09 a.m. 1:02 a.m. 1:09 a.m. 1:23 a.m. 2:16 a.m. 2:56 a.m. WITCHING HOURS 3:33 a.m. 3:45 a.m. 4:05 a.m. 4:26 a.m. 4:55 a.m. 6:01 a.m. DAWN 6:15 a.m. 6:22 a.m. DRAFT EMAIL (UNSENT) EPILOGUE FREE KINDLE BOOKS AND OFFERS OTHER BOOKS BY TAYLOR ADAMS Sent: 12/23 6:52 p.m. To: [email protected] From: [email protected] We’ll do it tonight. Then we'll need a place to sleep for a few weeks.
    [Show full text]
  • Interplanetary Species Society (ISS) 16:30–18:30 Dialoguing with the More-Than-Human
    Interplanetary Species Society (ISS) 16:30–18:30 Dialoguing with the More-Than-Human Introduction – Exosemiotics [16:30–16:40] Vincent W.J. van Gerven Oei 10 min = 1,200 words [x] zacalo lec aibo zacalab biaibca bi ac biaibca'ju eclal-ecalale c'beo alelud biaio luc bu befuc, ef ec ci, cicaodol ucluc, leo! The desire to communicate with other species is an old one. I just read you the first lines of the poem "Oath of the Inventor" written in the language AO, designed in 1919 by the Russian anarchist Vol'f L'vovič Gordin. In a pamphlet from 1924, Gordin declares: Everyone, establish anarchy, speak in human language, in AO! Boycot natural, national, state, and international languages. Esperanto is the language of European "international" imperialism. Invent pan-anarchism!1 The main cultural task of AO was the "eradication of religion and science and the proclamation of a new civilization: pan-inventism."2 The language was featured in the "First International Exhibition of Interplenatary Machines and Mechanisms" organized by the Interplanetary Detachment of the Association of Inventors in April 1927.3 [x] "Students who study and speak the language 'AO' are cosmopolites (citizens of the Universe) who have expressed the desire to embark on interplanetary travels,"4 it said in one of the exhibits. [x] The way in which Gordin conceptualized AO presages much of the way in which interplanetary communication becomes thought in the twentieth century. For example, he equated "the language of humanity" with the invention of humanity itself5: humanity invents itself by speaking the universal cosmic language.
    [Show full text]
  • Too Damned Quiet?
    Too Damned Quiet? Adrian Kent Perimeter Institute, 31 Caroline Street N, Waterloo, Ontario, N2L 2Y5, Canada.∗ (Dated: February 2005; minor revision April 2005) Abstract It is often suggested that extraterrestial life sufficiently advanced to be capable of interstellar travel or communication must be rare, since otherwise we would have seen evidence of it by now. This in turn is sometimes taken as indirect evidence for the improbability of life evolving at all in our universe. A couple of other possibilities seem worth considering. One is that life capable of evidencing itself on interstellar scales has evolved in many places but that evolutionary selection, acting on a cosmic scale, tends to extinguish species which conspicuously advertise themselves and their habitats. The other is that – whatever the true situation – intelligent species might reasonably worry about the possible dangers of self-advertisement and hence incline towards discretion. These possibilities are discussed here, and some counter-arguments and complicating factors are also considered. arXiv:1104.0624v1 [physics.pop-ph] 4 Apr 2011 ∗Permanent address: Department of Applied Mathematics and Theoretical Physics, University of Cam- bridge, Wilberforce Road, Cambridge CB3 0WA, United Kingdom. 1 I. COMMENTS: APRIL 2011 This article was written in early 2005, and submitted then to Science. Perhaps predictably enough, it was rejected. Since then it has languished in my filespace, while I occasionally wondered whether to try to make it more publishable in a peer-reviewed science journal (and indeed whether that was possible). Having recently noticed 2003 and 2005 arxiv papers by Beatriz Gato-Rivera expressing some very similar ideas [1, 2], I decided now to bite the bullet and distribute it as is.
    [Show full text]