Extraterrestrials: Where Are They?

doi:10.1017/CBO9780511564970

Is it possible that extraterrestrial life forms exist within our Galaxy, the Milky Way? This book offers a critical analysis by leading experts in a range of sciences, of the plausibility that other intelligent lifeforms do exist. Exploration of the Solar System, and observations with telescopes that probe deep space, have come up empty handed in searches for evidence of extraterrestrial life. Many experts in the fields of astronomy, biology, chemistry and physics are now arguing that the evidence points to the conclusion that technological civilisations are rare. After ten billion years, and among hundreds of billions of stars, we may well possess the most advanced brains in the Milky Way Galaxy. This second edition contains many new and updated aspects of extraterrestrial research, especially the biological viewpoint of the question.

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Contents

Frontmatter
pp i-vi
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Contents
pp vii-viii
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Preface to the Second Edition
pp ix-x
- By Ben Zuckerman, Los Angeles, California
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Preface to the First Edition
pp xi-xii
- By Ben Zuckerman, College Park, Maryland
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1 - An Explanation for the Absence of Extraterrestrials on Earth
pp 1-8
- By Michael H. Hart
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2 - One Attempt to Find Where They Are: NASA's High Resolution Microwave Survey
pp 9-19
- By Jill Tarter
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3 - An Examination of Claims that Extraterrestrial Visitors to Earth Are Being Observed
pp 20-28
- By Robert Sheaffer
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4 - The Likelihood of Interstellar Colonization, and the Absence of Its Evidence
pp 29-33
- By Sebastian von Hoerner
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5 - Pre-emption of the Galaxy by the First Advanced Civilization
pp 34-39
- By Ronald Bracewell
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6 - Stellar Evolution: Motivation for Mass Interstellar Migrations
pp 40-44
- By Ben Zuckerman
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7 - Interstellar Propulsion Systems
pp 45-49
- By Freeman Dyson
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8 - Interstellar Travel: A Review
pp 50-69
- By Ian A. Crawford
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9 - Settlements in Space, and Interstellar Travel
pp 70-85
- By Cliff Singer
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10 - Terraforming
pp 86-91
- By James Oberg
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11 - Estimates of Expansion Timescales
pp 92-102
- By Eric M. Jones
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12 - A Search for Tritium Sources in Our Solar System May Reveal the Presence of Space Probes from Other Stellar Systems
pp 103-107
- By Michael D. Papagiannis
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13 - Primordial Organic Cosmochemistry
pp 108-124
- By Cyril Ponnamperuma, Rafael Navarro-González
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14 - Chance and the Origin of Life
pp 125-138
- By Edward Argyle
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15 - The RNA World: Life before DNA and Protein
pp 139-151
- By Gerald F. Joyce
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16 - The Search for Extraterrestrial Intelligence
pp 152-156
- By Ernst Mayr
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17 - Alone in a Crowded Universe
pp 157-164
- By Jared Diamond
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18 - Possible Forms of Life in Environments Very Different from the Earth
pp 165-172
- By Robert Shapiro, Gerald Feinberg
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19 - Cosmological SETI Frequency Standards
pp 173-183
- By J. Richard Gott III
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20 - Galactic Chemical Evolution: Implications for the Existence of Habitable Planets
pp 184-191
- By Virginia Trimble
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21 - The Frequency of Planetary Systems in the Galaxy
pp 192-214
- By Jonathan I. Lunine
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22 - Atmospheric Evolution, the Drake Equation and DNA: Sparse Life in an Infinite Universe
pp 215-225
- By Michael H. Hart
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About the Editors and Contributors
pp 226-230
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Author Index
pp 231-235
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Subject Index
pp 236-239
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Extraterrestrials

Where Are They?

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