Searching for Extraterrestrial Intelligence
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Interstellar Communication: the Case for Spread Spectrum
Interstellar Communication: The Case for Spread Spectrum David G Messerschmitta aDepartment of Electrical Engineering and Computer Sciences, 253 Cory Hall, University of California, Berkeley, California 94720-1770, USA, [email protected], 1-925-465-5740 Abstract Spread spectrum, widely employed in modern digital wireless terrestrial radio systems, chooses a signal with a noise-like character and much higher bandwidth than necessary. This paper advocates spread spectrum modulation for interstellar communication, motivated by robust immunity to radio- frequency interference (RFI) of technological origin in the vicinity of the receiver while preserving full detection sensitivity in the presence of natural sources of noise. Receiver design for noise immunity alone provides no basis for choosing a signal with any specific character, therefore failing to reduce ambiguity. By adding RFI to noise immunity as a design objective, the conjunction of choice of signal (by the transmitter) together with optimum detection for noise immunity (in the receiver) leads through simple probabilistic argument to the conclusion that the signal should possess the statistical properties of a burst of white noise, and also have a large time-bandwidth product. Thus spread spectrum also provides an implicit coordination between transmitter and receiver by reducing the ambiguity as to the signal character. This strategy requires the receiver to guess the specific noise-like signal, and it is contended that this is feasible if an appropriate pseudorandom signal is generated algorithmically. For example, conceptually simple algorithms like the binary expansion of common irrational numbers like π are shown to be suitable. Due to its deliberately wider bandwidth, spread spectrum is more susceptible to dispersion and distortion in propagation through the interstellar medium, desirably reducing ambiguity in parameters like bandwidth and carrier frequency. -
The Search for Extraterrestrial Intelligence
THE SEARCH FOR EXTRATERRESTRIAL INTELLIGENCE Are we alone in the universe? Is the search for extraterrestrial intelligence a waste of resources or a genuine contribution to scientific research? And how should we communicate with other life-forms if we make contact? The search for extraterrestrial intelligence (SETI) has been given fresh impetus in recent years following developments in space science which go beyond speculation. The evidence that many stars are accompanied by planets; the detection of organic material in the circumstellar disks of which planets are created; and claims regarding microfossils on Martian meteorites have all led to many new empirical searches. Against the background of these dramatic new developments in science, The Search for Extraterrestrial Intelligence: a philosophical inquiry critically evaluates claims concerning the status of SETI as a genuine scientific research programme and examines the attempts to establish contact with other intelligent life-forms of the past thirty years. David Lamb also assesses competing theories on the origin of life on Earth, discoveries of ex-solar planets and proposals for space colonies as well as the technical and ethical issues bound up with them. Most importantly, he considers the benefits and drawbacks of communication with new life-forms: how we should communicate and whether we could. The Search for Extraterrestrial Intelligence is an important contribution to a field which until now has not been critically examined by philosophers. David Lamb argues that current searches should continue and that space exploration and SETI are essential aspects of the transformative nature of science. David Lamb is honorary Reader in Philosophy and Bioethics at the University of Birmingham. -
October 2003 SOCIETY
ISSN 0739-4934 NEWSLETTER HISTORY OF SCIENCE VOLUME 32 NUMBER 4 October 2003 SOCIETY those with no interest in botany, the simple beauty of the glass is enough. Natural History Delights in Cambridge From modern-life in glass to long-ago life, it’s only a short walk. The museum houses ant to discuss dinosaurs, explore microfossils of some of the Earth’s earliest life Wancient civilizations, learn wild- forms, as well as fossil fish and dinosaurs – flower gardening, or study endangered such as the second ever described Triceratops, species? If variety is the spice of life, then and the world’s only mounted Kronosaurus, a the twenty-one million specimens at the 42-foot-long prehistoric marine reptile. Harvard Museum of Natural History show a Among its 90,000 zoological specimens the museum bursting with life, much of it unnat- museum also has the pheasants once owned urally natural. by George Washington. And many of the The museum will be the site of the opening mammal collections were put together in the reception for the 2003 HSS annual meeting. 19th century by “lions” in the history of sci- The reception begins at 7 p.m. Thursday, 20 ence, like Louis Agassiz. November, and tickets will be available at the Much of the museum’s collection of rocks and meeting registration desk. Buses will run from ores is the result of field work, but the museum the host hotel to the museum. houses not only that which has been dug up, but The Harvard MNH is an ideal spot for his- also that which has fallen out of the sky. -
Interstellar Communication. Iii. Optimal Frequency to Maximize Data Rate
Draft version November 17, 2017 INTERSTELLAR COMMUNICATION. III. OPTIMAL FREQUENCY TO MAXIMIZE DATA RATE Michael Hippke1 and Duncan H. Forgan2, 3 1Sonneberg Observatory, Sternwartestr. 32, 96515 Sonneberg, Germany 2SUPA, School of Physics & Astronomy, University of St Andrews, North Haugh, St Andrews, Scotland, KY16 9SS, UK 3St Andrews Centre for Exoplanet Science, University of St Andrews, UK ABSTRACT The optimal frequency for interstellar communication, using \Earth 2017" technology, was derived in papers I and II of this series (Hippke 2017a,b). The framework included models for the loss of photons from diffraction (free space), interstellar extinction, and atmospheric transmission. A major limit of current technology is the focusing of wavelengths λ < 300 nm (UV). When this technological constraint is dropped, a physical bound is found at λ ≈ 1 nm (E ≈ keV) for distances out to kpc. While shorter wavelengths may produce tighter beams and thus higher data rates, the physical limit comes from surface roughness of focusing devices at the atomic level. This limit can be surpassed by beam-forming with electromagnetic fields, e.g. using a free electron laser, but such methods are not energetically competitive. Current lasers are not yet cost efficient at nm wavelengths, with a gap of two orders of magnitude, but future technological progress may converge on the physical optimum. We recommend expanding SETI efforts towards targeted (at us) monochromatic (or narrow band) X-ray emission at 0.5-2 keV energies. 1. INTRODUCTION believed to originate from intelligent beings on Mars. The idea to communicate with Extraterrestrial Intel- In the optical, William Pickering(1909) suggested to ligence was born in the 19th century. -
Appendix Relations with Alien Intelligences – the Scientific Basis of Metalaw1
Appendix Relations with Alien Intelligences – The Scientific Basis of Metalaw1 Ernst Fasan DK 340.114:341.229:2:133 1 The appendix was previously published by Berlin Verlag Arno Spitz in 1970. © Springer International Publishing Switzerland 2016 181 P.M. Sterns, L.I. Tennen (eds.), Private Law, Public Law, Metalaw and Public Policy in Space, Space Regulations Library 8, DOI 10.1007/978-3-319-27087-6 Contents Foreword by Wernher von Braun ����������������������������������������������������������������� 185 Introduction ����������������������������������������������������������������������������������������������������� 187 I: The Possibility of Encountering Nonhuman Intelligent Beings �������������� 189 Opinions in Ancient Literature ��������������������������������������������������������������������� 189 The Results of Modern Science �������������������������������������������������������������� 191 II: The Physical Nature of Extraterrestrial Beings �������������������������������������� 205 The Necessary Characteristics ��������������������������������������������������������������������� 205 Origin and Development of Protoplasmic Life ��������������������������������������� 209 Intelligent Machines – The Question of Robots �������������������������������������� 210 III: The Concept, Term, and Literature of Metalaw ����������������������������������� 213 Selection and Definition of the Term ����������������������������������������������������������� 213 A Survey of Literature ����������������������������������������������������������������������������� -
Lan's Lantern 28
it th Si th ir ©o Lmis £antmi 2 8 An Arthur £. £(ar£c Special Table of Contents Arthur C. Clarke................................................... by Bill Ware..Front Cover Tables of contents, artists, colophon,......................................................... 1 Arthur C. Clarke...............................................................Lan.......................................2 I Don’t Understand What’s Happening Here...John Purcell............... 3 Arthur C. Clarke: The Prophet Vindicated...Gregory Benford....4 Of Sarongs & Science Fiction: A Tribute to Arthur C. Clarke Ben P. Indick............... 6 An Arthur C. Clarke Chronology.......................... Robert Sabella............. 8 Table of Artists A Childhood's End Remembrance.............................Gary Lovisi.................... 9 My Hero.................................................................................. Mary Lou Lockhart..11 Paul Anderegg — 34 A Childhood Well Wasted: Some Thoughts on Arthur C. Clarke Sheryl Birkhead — 2 Andrew Hooper.............12 PL Caruthers-Montgomery Reflections on the Style of Arthur C. Clarke and, to a Lesser — (Calligraphy) 1, Degree, a Review of 2061: Odyssey Three...Bill Ware.......... 17 2, 3, 4, 6, 8, 9, 11, About the Cover...............................................................Bill Ware.......................17 12, 17, 18, 19, 20, My Childhood’s End....................................................... Kathy Mar.......................18 21, 22, 24, 28, 31 Childhood’s End.......................Words & Music -
The Drake Puzzle by Shane L
The Drake Puzzle by Shane L. Larson Department of Astronomy, Adler Planetarium “Our sun is one of 100 billion stars in our galaxy. Our galaxy is one of billions of galaxies populating the universe. It would be the height of presumption to think that we are the only living things in that enormous immensity.” ∼ Wernher von Braun Introduction The Search for Extraterrestrial Intelligence (SETI) has long been of interest to humankind. The problem is how would we communicate with extraterrestrial biological entities (EBEs) if we met them? It is said that in 1820, the famous German mathematician Karl Friedrich Gauss recommended that a giant right triangle of trees be planted in the Russian wilderness, an exercise that would demonstrate to EBEs that the inhabitants of Earth were civilized enough to understand geometry. It is also said that 20 years later, the Viennese astronomer Joseph von Littrow proposed digging a twenty-mile-long ditch in the Sahara, filling it with kerosene, and lighting it at night, again to communicate that there was intelligent life down here. In the modern era, the American radio astronomer Frank Drake is generally credited with beginning the first serious efforts geared toward communication with possible extraterrestrial intelligences. In 1960, at the Green Bank radio astronomy facility in West Virginia, he began the first modern search for radio signals of extraterrestrial origin, called Project Ozma. Communication without preamble In the years that followed Project Ozma, there was a great deal of debate as to whether or not we could actually decode a message if we received it, and even more to the point, whether or not an EBE could decode a message from us if it received one. -
Nasa and the Search for Technosignatures
NASA AND THE SEARCH FOR TECHNOSIGNATURES A Report from the NASA Technosignatures Workshop NOVEMBER 28, 2018 NASA TECHNOSIGNATURES WORKSHOP REPORT CONTENTS 1 INTRODUCTION .................................................................................................................................................................... 1 What are Technosignatures? .................................................................................................................................... 2 What Are Good Technosignatures to Look For? ....................................................................................................... 2 Maturity of the Field ................................................................................................................................................... 5 Breadth of the Field ................................................................................................................................................... 5 Limitations of This Document .................................................................................................................................... 6 Authors of This Document ......................................................................................................................................... 6 2 EXISTING UPPER LIMITS ON TECHNOSIGNATURES ....................................................................................................... 9 Limits and the Limitations of Limits ........................................................................................................................... -
SETI in VIVO: TESTING the WE-ARE-THEM HYPOTHESIS ∗ MAXIM A.MAKUKOV1 and VLADIMIR I
PREPRINT VERSION JULY 12, 2017. ACCEPTED IN THE INTERNATIONAL JOURNAL OF ASTROBIOLOGY Preprint typeset using LATEX style emulateapj v. 01/23/15 DOI: 10.1017/S1473550417000210 SETI IN VIVO: TESTING THE WE-ARE-THEM HYPOTHESIS ∗ MAXIM A. MAKUKOV1 and VLADIMIR I. SHCHERBAK2 ABSTRACT After it was proposed that life on Earth might descend from seeding by an earlier extraterrestrial civilization motivated to secure and spread life, some authors noted that this alternative offers a testable implication: microbial seeds could be intentionally supplied with a durable signature that might be found in extant organisms. In particular, it was suggested that the optimal location for such an artifact is the genetic code, as the least evolving part of cells. However, as the mainstream view goes, this scenario is too speculative and cannot be meaningfully tested because encoding/decoding a signature within the genetic code is something ill-defined, so any retrieval attempt is doomed to guesswork. Here we refresh the seeded-Earth hypothesis in light of recent observations, and discuss the motivation for inserting a signature. We then show that “biological SETI” involves even weaker assumptions than traditional SETI and admits a well-defined methodological framework. After assessing the possibility in terms of molecular and evolutionary biology, we formalize the approach and, adopting the standard guideline of SETI that encoding/decoding should follow from first principles and be convention-free, develop a universal retrieval strategy. Applied to the canonical genetic code, it reveals a nontrivial precision structure of interlocked logical and numerical attributes of systematic character (previously we found these heuristically). To assess this result in view of the initial assumption, we perform statistical, comparison, interdependence, and semiotic analyses. -
Lightspeed Magazine, Issue 78 (November 2016)
TABLE OF CONTENTS Issue 78, November 2016 FROM THE EDITOR Editorial, November 2016 SCIENCE FICTION Dinosaur Killers Chris Kluwe Under the Eaves Lavie Tidhar Natural Skin Alyssa Wong For Solo Cello, op. 12 Mary Robinette Kowal FANTASY Two Dead Men Alex Jeffers Shooting Gallery J.B. Park A Dirge for Prester John Catherynne M. Valente I've Come to Marry the Princess Helena Bell NOVELLA Karuna, Inc. Paul Di Filippo EXCERPTS The Genius Asylum Arlene F. Marks NONFICTION Media Review: Westworld The Geek’s Guide to the Galaxy Book Reviews, November 2016 Kate M. Galey, Jenn Reese, Rachel Swirsky, and Christie Yant Interview: Stephen Baxter The Geek’s Guide to the Galaxy AUTHOR SPOTLIGHTS Chris Kluwe Lavie Tidhar J.B. Park Alyssa Wong Catherynne M. Valente Mary Robinette Kowal Helena Bell Paul di Filippo MISCELLANY Coming Attractions Stay Connected Subscriptions and Ebooks About the Lightspeed Team Also Edited by John Joseph Adams © 2016 Lightspeed Magazine Cover by Reiko Murakami www.lightspeedmagazine.com Editorial, November 2016 John Joseph Adams | 1064 words Welcome to issue seventy-eight of Lightspeed! We have original science fiction by Chris Kluwe (“Dinosaur Killers”) and Alyssa Wong (“Natural Skin”), along with SF reprints by Lavie Tidhar (“Under the Eaves”) and Mary Robinette Kowal (“For Solo Cello, op. 12”). Plus, we have original fantasy by J.B. Park (“Shooting Gallery”) and Helena Bell (“I’ve Come to Marry the Princess”), and fantasy reprints by Alex Jeffers (“Two Dead Men”) and Catherynne M. Valente (“A Dirge for Prester John”). All that, and of course we also have our usual assortment of author spotlights, along with our book and media review columns. -
FRANK D. DRAKE Education 1952 Cornell University BA, Engineering
Biographical Sketch FRANK D. DRAKE Education 1952 Cornell University B.A., Engineering Physics (with honors) 1956 Harvard University M.S., Astronomy 1958 Harvard University Ph.D., Astronomy Professional Employment 1952-1956 U.S. Navy, Electronics Officer 1956-1958 Agassiz Station Radio Astronomy Project, Harvard University 1958-1963 National Radio Astronomy Observatory, Green Bank, West Virginia - Head of Telescope Operations & Scientific Services Division - Conducted planetary research and cosmic radio source studies 1963-64 Jet Propulsion Laboratory, Chief of Lunar & Planetary Sciences 1964-1984 Cornell University - Associate Professor of Astronomy (1964); then Full Professor (1966) - Associate Director, Center for Radiophysics & Space Research (1964-75) - Director, Arecibo Observatory, Arecibo, Puerto Rico (1966-1968) - Chairman, Astronomy Department, Cornell University (1969-71) - Director, National Astronomy & Ionosphere Center, part of which is the Arecibo Observatory (from its creation in 1970 until July 1981) - Goldwin Smith Professor of Astronomy, Cornell University (1976-84) 1984-Present University of California, Santa Cruz - Dean, Natural Sciences Division (1984-1988) - Acting Associate Vice Chancellor, University Advancement (1989-90) - Professor of Astronomy & Astrophysics (1984 – 1996) - Professor Emeritus of Astronomy & Astrophysics, (1996 –present) 1984-Present SETI Institute, Mountain View, California: - President (1984-2000) - Chairman, Board of Trustees, (1984-2003) - Chairman Emeritus, Board of Trustees, 2003- present - Director, Carl Sagan Center for the Study of Life in the Universe, 2004-present Professional Achievements 1959 Shared in the discovery of the radiation belts of Jupiter, and conducted early pulsar observational studies 1960 Conducted Project OZMA at NRAO, Green Bank, WV -- the first organized search for ETI signals 1961 Devised widely-known Drake Equation, giving an estimate of the number of communicative extraterrestrial civilizations that we might find in our galaxy. -
An Evolving Astrobiology Glossary
Bioastronomy 2007: Molecules, Microbes, and Extraterrestrial Life ASP Conference Series, Vol. 420, 2009 K. J. Meech, J. V. Keane, M. J. Mumma, J. L. Siefert, and D. J. Werthimer, eds. An Evolving Astrobiology Glossary K. J. Meech1 and W. W. Dolci2 1Institute for Astronomy, 2680 Woodlawn Drive, Honolulu, HI 96822 2NASA Astrobiology Institute, NASA Ames Research Center, MS 247-6, Moffett Field, CA 94035 Abstract. One of the resources that evolved from the Bioastronomy 2007 meeting was an online interdisciplinary glossary of terms that might not be uni- versally familiar to researchers in all sub-disciplines feeding into astrobiology. In order to facilitate comprehension of the presentations during the meeting, a database driven web tool for online glossary definitions was developed and participants were invited to contribute prior to the meeting. The glossary was downloaded and included in the conference registration materials for use at the meeting. The glossary web tool is has now been delivered to the NASA Astro- biology Institute so that it can continue to grow as an evolving resource for the astrobiology community. 1. Introduction Interdisciplinary research does not come about simply by facilitating occasions for scientists of various disciplines to come together at meetings, or work in close proximity. Interdisciplinarity is achieved when the total of the research expe- rience is greater than the sum of its parts, when new research insights evolve because of questions that are driven by new perspectives. Interdisciplinary re- search foci often attack broad, paradigm-changing questions that can only be answered with the combined approaches from a number of disciplines.