Contact with Alien Civilizations Our Hopes and Fears about Encountering Extraterrestrials
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Michael A. G. Michaud
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Contact with Alien Civilizations Our Hopes and Fears about Encountering Extraterrestrials
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Springer-Verlag
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9780387686189
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1
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CHF 33.10
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Astronomie: Allgemeines, Nachschlagewerke
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English
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472
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Wasserzeichen/DRM
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PC/MAC/eReader/Tablet
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PDF
What are the implications for Humankind of alien civilizations that may be"out there?" In thinking about contact with extraterrestrials, we have to grapple with a host of philosophical, religious, and societal questions. The biggest is whether the outcome of contact will be beneficial or harmful. Will contact uplift us, bringing a golden age of wisdom and prosperity? Or will it demoralize, even destroy us? This thought-provoking book presents a rainbow of opinions expressed by scientists, sociologists, historians, legal and political thinkers, and many others. The author takes into account not only scientific speculation, but also fiction and popular opinion. He challenges the most frequent assumptions that unerlie our thinking. He looks at both sides of the"where are they" debate, questioning the alleged paradox and proposing new ways of thinking about the issue. The serious practical questions raised by extraterrestrial intelligence are becoming harder to avoid as our search technologies and methods improve, as we identify ever-greater numbers of planets orbiting other stars, and as the wave front of our radio, television, and radar signals reaches out into the Galaxy. How should we deal with contact if it happens? What do we want to say to an extraterrestrial civilization? Will we speak as one, or as many? What should we do if we find alien technology in our solar system? Should we simply be watchers and listeners, or should we actively seek contact by sending out messages proclaiming our presence? Our answers reveal our hopes and our fears. TOC:Introduction.- A Belief in Other Minds.- Searching for Signals.- Probabilities.- The Visit Scenario.- The Paradox.- Foreseen Consequences.- Some Assumptions Examined.- What is Missing.- Some Conclusions Drawn.- Annex: Preparing.- References.- Bibliographic Essay.
"
The Drake Equation, Take Three
(p. 162-163)
The Drake equation was derived from an assumed mode of contact: the detection of electromagnetic signals from very distant stars. It rested on the assumption that technological civilizations do not expand beyond their home systems. The density of such civilizations was determined by the number of separate evolutions to life and intelligence. The equation did not take into account the possibility of interstellar exploration, interstellar colonization, and direct contact.
That gap has been challenged forcefully. The Drake equation is wrong, Dyson argued, because it says that the number of extraterrestrial civilizations is equal to the number of independently originating civilizations. In fact, life spreads, diversi? es, and speciates. Any community of intelligent creatures adapted to living freely in the vacuum of space will spread and speciate in the Galaxy. One intelligent species let loose in space may become a million intelligent species within an astronomically short time.
Consequently, the Drake equation gives only a lower bound to the number of civilized societies.1 Shostak and Barnett, while defending conventional SETI, acknowledged that one star system could seed others if interstellar travel happens. The number of technological societies might be large even if the chance of evolving intelligence at one particular location is small.2 David Viewing of the British Interplanetary Society proposed a revised Drake equation in 1975, introducing factors representing the average number of colonies established by each independent civilization, and colonies established by the colonies.
Brin argued later that the equation needs three new factors when we introduce star travel: V—the velocity at which an interstellar culture grows into space, pausing to settle likely solar systems and rebuild necessary industry before again continuing its expansion L(z)—the lifetime of a zone of colonization into which a species has expanded, after which the settled region becomes fallow again A—an approach/avoidance factor, different for each culture, representing a“crosssection” for discovery by contemporary human civilization. This encompasses motivations to initiate or avoid contact, life-style variations, abandonment of radio for other technologies, and anything else that might cause an extraterrerstrial culture to be more or less observable.
At a minimum, the equation should include a factor for the probability that another technological civilization would engage in interstellar exploration, expansion, or colonization. This could have powerful implications. The factors in the traditional equation can be seen as ? lters that reduce the probability of contact with technological civilizations. Adding an expansion and colonization factor could greatly increase that probability by expanding the range of locations where technological societies may exist. Those most devoted to the classic SETI paradigm continue to resist including interstellar expansion in their calculations. One can see why; opening the door to a direct encounter raises the question of why we have not seen evidence of alien technology nearby. The direct contact scenario also has signi? cant implications for the possible consequences."
Table of Contents
6
Introduction
13
Hopes and Fears
15
Searching
15
Consequences
17
Before and After 1960
19
The Book
20
An Apology
20
A Belief in Other Minds
21
An Ancient Idea
21
The Closed Universe
23
Copernicanism
25
The Triumph of Observation
26
Fictional Aliens
27
An Impersonal Universe
29
Evolution and Sharpened Questions
31
Lowell, and Alien Invaders
32
Expansion and Skepticism
34
Ubiquitous Life
36
A New Era
37
Searching for Life
37
Disappointment and Revival
38
A Metadiscipline
40
Panspermia
41
The Mars Rock
42
Was Arrhenius Right after All?
43
Searching for Intelligence
45
Radio Days
45
From Russia with Theories
48
American Initiatives
48
Privatizing SETI
52
Other Wavelengths, Other Technologies
56
Above the Clouds
57
Looking for the Astroengineers
58
Exotic Means
60
Sending Our Own Signals
61
Active SETI
61
The Arecibo Blast
62
Is This Research?
64
Probabilities
66
Probability and Analogy
66
The Drake Equation
67
Being Trendy
69
Probabilities: The Astronomical Factors
70
Stars
70
Planets
72
Habitable Zones
79
Probabilities: Life
80
Miracle, Rare Accident, or Probable Event?
80
Chancists Versus Convergionists
82
Teleology and Self-Organization
85
Gaia and Her Sisters
86
Extremophiles and Dual Biospheres
87
Probabilities: Intelligence
89
Inevitable, or a Fluke?
89
Social Animals
91
How Brains Evolve, or Don’t
92
The Debate Goes on
93
Our Intelligent Companions
94
Dolphins
95
Brother Apes
97
Future Minds
99
Probabilities: Civilization, Technology, and Science
101
Civilization
101
Technology and Science
103
Probabilities: Longevity
106
How Long Do Technological Civilizations Live?
106
The Shadow of the Bomb
107
Other Means of Self-destruction
108
Threatening Science
109
Hints of Optimism
111
Fear of Machines
112
Statistics
114
Extraterrestrial Terminators
115
Black Clouds, Dark Planets, Bursting Stars
118
A Growing Sun
121
The Drake Equation, Take Two
123
