Extraterrestrial Civilizations - Isaac Asimov [0]
EARTH: OUR CROWDED SPACESHIP
REALM OF NUMBERS
EXTRATERRESTRIAL CIVILIZATIONS
THIS BOOK CONTAINS THE COMPLETE TEXT OF THE
ORIGINAL HARDCOVER EDITION.
Published by Fawcett Columbine Books, a unit of
CBS Publications, the Consumer Publishing Division of
CBS Inc., by arrangement with Crown Publishers, Inc.
Copyright ©1979 by Isaac Asimov
ALL RIGHTS RESERVED
eISBN: 978-0-307-79230-3
v3.1
To the memory of Paul Nadan (1929-1978)
for whom I should have
started the book sooner.
Contents
Cover
Other Book by This Author
Title Page
Dedication
Copyright
1 ·The Earth
Spirits
Animals
Primates
Brains
Fire
Civilization
2 · The Moon
Phases
Another World
Waterlessness
Moon Hoax
Airlessness
3 · The Inner Solar System
Nearby Worlds
Venus
Martian Canals
Mars Probes
4 · The Outer Solar System
Planetary Chemistry
Titan
Jupiter
5 · The Stars
Substars
The Milky Way
The Galaxy
The Other Galaxies
6 · Planetary Systems
Nebular Hypothesis
Stellar Collisions
Nebular Hypothesis Again
The Rotating Stars
The Wobbling Stars
7 · Sunlike Stars
Giant Stars
Midget Stars
Just Right
8 · Earthlike Planets
Binary Stars
Star Populations
The Ecosphere
Habitability
9 · Life
Spontaneous Generation
Origin of Life?
The Primordial Earth
Meteorites
Dust Clouds
When Life Started
Multicellular Life
Land Life
Intelligence
10 · Civilizations Elsewhere
Our Giant Satellite
Our Captured Satellite?
Intelligence
Extinction
Cooperation
Exploration
Visits
11 · Space Exploration
The Next Targets
Space Settlements
Space Mariners
Stepping Stone
12 · Interstellar Flight
The Speed of Light
Beyond the Speed of Light
Time Dilatation
Coasting
Worlds Adrift
13 · Messages
Sending
Receiving
Photons
Microwaves
Where?
Why?
CHAPTER 1
The Earth
The question is: Are we alone?
Are human beings the only possessors of eyes that probe the depths of the Universe? The only builders of devices to extend the natural senses? The only owners of minds that strive to understand and interpret what is seen and sensed?
And the answer is, just possibly: We are not alone! There are other kinds that seek and wonder, and do so perhaps even more effectively than we.
Many astronomers believe this is so, and I believe this is so.
We don’t know where those other minds are, but they are somewhere. We don’t know what they do, but they do much. We don’t know what they’re like, but they are intelligent.
Will they find us if they are somewhere out there? Or have they found us already?
If they have not found us, can we find them? Better yet, should we find them? Is it safe?
These are the questions that must be asked once we agree that we are not alone, and astronomers are asking them.
The whole matter of the search for extraterrestrial intelligence has now become so common, in fact, that it has been abbreviated to save trouble in referring to it. Astronomers now refer to it as SETI, from the initials of the phrase “the search for extraterrestrial intelligence.”
The first scientific discussion of SETI that offered a hope of carrying through the search successfully came only in 1959. It is natural to suppose, then, that the question of intelligence other than our own is of recent vintage. It would seem to be entirely a twentieth-century phenomenon arising out of the advance of astronomy in recent decades. It would seem to be the child of rocketry and of manned flight in outer space.
Perhaps you may feel that prior to the last few decades, human beings took it for granted that we were alone, and that the new view of other-intelligence is coming as a great shock to people and is forcing them willy-nilly to undergo an internal revolution of outlook.
Nothing could be farther from the truth!
It has been taken for granted by almost all people through almost all of history that we are not alone. The existence of other intelligences has been accepted as a matter of course.
Such beliefs have not arisen through the advance of science. Quite