Extraterrestrial Civilizations Read online

  It is not, then, tool making in itself that establishes a clear gulf between the human being and other intelligent animals.

  And yet there may be some one kind of tool that marks the clear boundary line separating the most intelligent species from all others.

  We have not far to seek. The key lies in the taming and use of fire. There is definite evidence of fire’s having been used in caves in China in which an earlier hominid species, Homo erectus, dwelt at least half a million years ago. The discovery has never been forgotten.

  No human society existing anywhere on Earth now lacks the knowledge of how to ignite and use a fire. No nonhuman species whatever has ever made the slightest advance in the direction of the use of fire, as far as we can tell.

  Suppose we define “human intelligence” as: A level of intelligence high enough to allow the development of methods for igniting and using fire.

  In that case, to the question of whether the equivalent of human intelligence exists on Earth in nonhuman species, the answer must be: No! —The human being stands alone.

  This might seem unfair; and the result of an arbitrary, self-serving definition. Let’s see if it is by comparing the dolphin and the human being.

  The dolphin spends his life in water and the human being spends his life in air. Water is a viscous medium, much more viscous than air. It takes much more effort to force one’s way through water at a given speed than it does through air. (Anyone who has tried to run when partly immersed in water knows this is so.)

  In order to attain speed in water, the dolphin has evolved a streamlined form to reduce water resistance. Moving through air, however, the human being does not require streamlining. The human being can develop a very irregular form and still be capable of fast motion.

  For that reason, the human being can develop complicated appendages, while the dolphin cannot. The dolphin’s streamlining allows it two stubby paddles and a fluke as its only maneuverable appendages, and these are useful only for propulsion and guiding.

  To put it most briefly, human beings, because they live in air, can develop hands with which they can manipulate their environment. Dolphins, because they live in water, cannot develop hands.

  Then again, the fire that early humans learned to handle is the radiation of heat and light that results from a rapid energy-yielding chemical reaction. The most common energy-yielding large-scale chemical reactions that are useful in this connection are those resulting from the combination of substances containing carbon atoms, hydrogen atoms, or both (“fuel”) with the oxygen in the air. The process is called combustion. Fire cannot exist under water since free oxygen is not present and combustion cannot take place.

  Therefore, even if dolphins had the intelligence to conceptualize fire, and to work out, mentally, the steps needed to tame and use it, they would be unable to put any of it into practice.

  We see now, however, that the human use of fire could be considered as no more than the accidental by-product of the fact that the human being lives in air, and is not in itself necessarily a true measure of intelligence.

  The dolphins, after all, even though they are unable to manipulate the environment and unable to build and use a fire, may have in their own way developed a subtle philosophy of life. They may have worked out, more usefully than we have, a rationalization of living. They may interchange more joy and good will with their feelings and understand more. The fact that we cannot grasp their philosophy and their modes of thought is no evidence of their low intelligence, but is perhaps evidence of our own.

  Well, perhaps!

  The fact is, though, that we don’t have any evidence of the dolphin’s philosophy of life. The lack of that evidence may be entirely our fault, but there’s nothing we can do about it. Without evidence, there is no way of reasoning usefully. We can look for the evidence and someday, perhaps, find it, but until then, we can’t reasonably assign human intelligence to the dolphin.

  Besides, even if our definition of human intelligence on the basis of fire is unfair and self-serving on some abstract scale, it will prove useful and reasonable for the purposes of this book. Fire sets us on a road that ends with a search for extraterrestrial intelligence; without fire we would never have made it.

  The extraterrestrial intelligences we are looking for, then, must have developed the use of fire (or, to be fair, its equivalent) at some time in their history, or, as we are about to see, they could not have developed those attributes that would make it possible for them to be detected.

  CIVILIZATION

  Throughout the history of life, species of living creatures have made use of chemical energy by the slow combination of certain chemicals with oxygen within their cells. The process is analogous to combustion, but is slower and much more delicately controlled. Sometimes use is made of energy available in the bodies of stronger species as when a remora hitches a ride on a shark, or a human being hitches an ox to a plow.

  Inanimate sources of energy are sometimes used when species allow themselves to be carried or moved by wind or by water currents. In those cases, though, the inanimate source of energy must be accepted at the place and time that it happens to be and in the amount that happens to exist.

  The human use of fire involved an inanimate source of energy that was portable and could be used wherever desired. It could be ignited or extinguished at will and could be used when desired. It could be kept small or fed till it was large, and could be used in the quantities desired.

  The use of fire made it possible for human beings, evolutionarily equipped for mild weather only, to penetrate the temperate zones. It made it possible for them to survive cold nights and long winters, to achieve security against fire-avoiding predators, and to roast meat and grain, thus broadening their diet and limiting the danger of bacterial and parasitic infestation.

  Human beings multiplied in number and that meant there were more brains to plan future advances. With fire, life was not quite so hand-to-mouth, and there was more time to put those brains to work on something other than immediate emergencies.

  In short, the use of fire put into motion an accelerating series of technological advances.

  About 10,000 years ago, in the Middle East, a series of crucial advances were made. These included the development of agriculture, herding, cities, pottery, metallurgy, and writing. The final step, that of writing, took place in the Middle East about 5,000 years ago.

  This complex of changes stretching over a period of 5,000 years introduced what we call civilization, the name we give to a settled life, to a complex society in which human beings are specialized for various tasks.

  To be sure, other animals can build complex societies and can be composed of different types of individuals specialized for different tasks. This is most marked in such social insects as bees, ants, and termites, where individuals are in some cases physiologically specialized to the point where they cannot eat, but must be fed by others. Some species of ants practice agriculture and grow small mushroom gardens, while others herd aphids; still others war on and enslave smaller species of ants. And, of course, the beehive and the ant or termite colony have many points of analogy with the human city.

  The most complex nonhuman societies, those of the insects, are, however, the result of instinctive behavior, the guidelines of which are built into the genes and nervous systems of the individuals at birth. Nor does any nonhuman society make use of fire. With insignificant exceptions, insect societies are run by the energy produced by the insect body.

  It is fair, then, to consider human societies basically different from other societies and to attribute what we call civilization to human societies only.

  A third group of changes began about 200 years ago with the development of a practical steam engine, leading on to an Industrial Revolution, which is still in progress. And about 20 years ago we began to dispose of types of energy that could leak out into space in noticeable quantities. We became detectable.

  In short, we are not looking merely for extraterrestrial life. We are not even looking merely for extraterrestrial intelligence. We are looking for extraterrestrial civilization that disposes of enough energy of a sufficiently sophisticated kind to be detectable over interstellar distances. After all, if the level of life/intelligence/civilization on some world is such that it is indetectable, we are not going to detect it.

  And now, you see, it is fair to say that on Earth there is exactly one civilization of the kind we are looking for; just one, our own. As far as we know, there has never been any other civilization of this kind on Earth, and it was only a few years ago that our own civilization became the kind I’m referring to—a detectable civilization.

  Of course, now that I’ve demonstrated that, in our role of civilization-makers, we are alone on Earth—that is no great tragedy after all. Earth is no longer the only world in the consciousness of human beings. We need only look for civilizations elsewhere, on other worlds, and it may then be discovered that we are not alone after all.

  * Here was an example of another “world” but one that was never visible or in any way sensed in the ordinary way.

  * I do not wish to denigrate the value of inventing fantasy. It is a noble art, requiring great skill. I know. I have been making my living out of it for years. It is one thing, however, to invent an amusing fantasy, and quite another to confuse it with reality.

  † I won’t bother trying to define a “reasonable man.” I suspect that one convenient assumption we can make is that anyone bothering to read this book is a “reasonable man”.

  * Such disputation can be quite nasty and polemical at times, for scientists are quite human, and any given individual among them can be, at times, petty, mean, vindictive—or simply stupid.

  * I make an exception of those
inanimate objects, called computers, that have come to exist in the last quarter-century, and that, in some ways, give evidence of properties that can easily be mistaken for intelligence. These are, however, human products, and can fairly be considered as extensions of human intelligence, and not as nonhuman intelligence.

  * There are books that have been written describing how plants seem aware of human speech and react with apparent intelligence to it. As far as biologists can tell, however, there is no scientific merit whatever to such views.

  CHAPTER 2

  The Moon

  PHASES

  If we imagine ourselves looking about at our surroundings with no knowledge concerning them at all, we might be forgiven for thinking the Earth was the only world there was. What, then, made people think there were other worlds?

  It was the Moon. Consider—

  The predominant characteristic of the objects in the sky is their glow. The stars are little bits of sparkling light. The planets are somewhat brighter bits of sparkling light. The Sun is a round circle of blazing light. There is an occasional meteor that produces a brief line of light. There is an even more occasional comet that is an irregular hazy patch of light.

  It is the light that makes the heavenly objects seem altogether different from the Earth, which in itself is dark and gives off no light.

  To be sure, light can be produced on the Earth in the form of fire, but that is altogether different from the heavenly light. Earthly fires have to be fed constantly with fuel or they would flicker and go out, but the heavenly light continues forever without change.

  In fact, the Greek philosopher Aristotle (384–322 B.C.) maintained that all the heavenly objects were composed of a substance called aether, separate and distinct from the elements that made up the Earth. The word aether is from the Greek word meaning to blaze. The heavenly objects blazed and the Earth did not, and as long as that was thought to be true there was only one world; one solid, dark object on which life could exist, and many blazing objects on which life could not exist.

  Except that there is the Moon. The Moon is the one heavenly object that changes shape in a regular way and in a fashion that is clearly visible to the unaided eye. These different shapes of the Moon (its “phases”) are ideally suited to attract attention and, except for the succession of day and night, were probably the first astronomical changes to catch the attention of primitive human beings.

  The Moon goes through its complete cycle of phases in a little over 29 days, which is a particularly convenient length of time. To the prehistoric farmer and hunter, the cycle of seasons (the year) was very important, but it was difficult to note that, on the average, the seasons repeated themselves every 365 or 366 days. The number was too large to be kept track of easily. To count 29 or 30 days from each new Moon to the next, and then to count 12 or 13 new Moons to each year, was much simpler and much more practical. The making of a calendar that would serve to keep track of the seasons of the year in terms of the phases of the Moon was a natural result of very early astronomical observations.

  Alexander Marshak, in his book The Roots of Civilization, published in 1972, argues persuasively that long before the beginning of recorded history, early human beings were marking stones in a code designed to keep track of the new Moons. Gerald Hawkins, in Stonehenge Decoded, argues just as persuasively that Stonehenge was a prehistoric observatory also designed to keep track of the new Moon, and to predict the lunar eclipses that occasionally came at the time of the full Moon. (A lunar eclipse was a frightening “death” of the Moon upon which human beings depended for keeping track of the seasons. To be able to predict its occurrence reduced the fear.)

  It was very likely the overriding practical necessity of working out a calendar based on the phases of the Moon that forced human beings into astronomy, and from that to a careful observation of natural phenomena generally, and from that to the eventual growth of science.

  The fact that the phase changes were so useful could not help, it seems to me, but reinforce the notion of the existence of a benevolent deity who, out of his love of humanity, had arranged the skies into a calendar that would guide mankind into the proper ways of insuring a secure food supply.

  Each new Moon was celebrated as a religious festival in many early cultures, and the care of the calendar was usually placed in priestly hands. The very word calendar is from the Latin word meaning to proclaim, since each month only began when the coming of the new Moon was officially proclaimed by the priests. We could conclude, then, that a considerable portion of the religious development of mankind, of the belief in God as a benevolent parent rather than a capricious tyrant, can be traced back to the changing face of the Moon.

  In addition, the fact that close study of the Moon was so important in controlling the daily lives of human beings could not help but give rise to the notion that the other heavenly objects might be important in this respect, also. The face of the Moon may in this way have contributed to the growth of astrology and, thereby, of other forms of mysticism.

  But in addition to all this (and it would scarcely seem that if the Moon has given rise to science, religion, and mysticism, more should be required of it) the Moon gave rise to the concept of the plurality of worlds—the notion that the Earth was only one world of many.

  When human beings first stared at the Moon from night to night in order to follow its phases, it was natural to suppose that the Moon literally changed shape. It was born as a thin crescent, waxed to a full circle of light, then waned to a crescent and died. Each new Moon was literally a new Moon, a fresh creation.

  Quite early on, however, it became apparent that the horns of the lunar crescent always faced away from the Sun. That alone was sufficient to indicate some connection between the Sun and Moon’s phases. Once the notion of that connection arose, further observation would show that the phases were connected with the relative positions of the Sun and Moon. The Moon was full when it and the Sun were at precisely opposite parts of the sky. The Moon was in the half-phase when it and the Sun were separated by 90 degrees. The Moon was in crescent shape when it was close to the Sun, and so on.

  It became apparent that if the Moon were a sphere that was as dark as the Earth, and if the Moon shone only by the light that fell upon it from the Sun and was reflected by it, then it would go through precisely the cycle of phases that were actually observed. The idea arose and grew to be more and more accepted that the Moon, at least, was a dark body like Earth and was not composed of blazing “aether.”

  ANOTHER WORLD

  If the Moon were like the Earth in being dark, might it not be like the Earth in other ways? Might it not be a second world?

  As early as the fifth century B.C., the Greek philosopher Anaxagoras (500–428 B.C.) expressed his opinion that the Moon was an Earthlike world.

  To imagine the Universe as consisting of one world plus bits of light is intellectually acceptable. To imagine it to consist of two worlds plus bits of light is difficult. If one of the objects in the sky is a world, why not some or all the rest? Gradually, the notion of the plurality of worlds spread. Increasing numbers of people began to think of the Universe as containing many worlds.

  But not empty worlds. That thought apparently filled people with revulsion—if it occurred to them at all.

  The one world we know—Earth—is full of life, and it is only natural to think that life is as inevitable a characteristic of worlds generally as solidity is. Again, if one thinks of the Earth as having been created by some deity or deities, then it is logical to suppose the other worlds to have been so created as well. It would then seem nonsensical to suppose that any world would be created and left empty. What motivation could there be in creating empty worlds? What a waste it would be!

  Thus, when Anaxagoras stated his belief that the Moon was an Earthlike world, he also suggested that it might be inhabited. So did other ancient thinkers, as for instance the Greek biographer Plutarch (A.D. 46–120).