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The Planet-Girded Suns: Man's View of Other Solar Systems  by Sylvia Engdahl (1974) ~ Page 6 of 8 |
Chapter Five
(Please read the Introduction
if you haven't yet seen it.)Perhaps the strangest controversy in the history of past opinion about extrasolar worlds began in 1853 when, for the first time, their reality was questioned not by a supporter of tradition, but by a man who admitted that his arguments were “not published without some fear of giving offence.” He added, “It will be a curious ... event, if it should now be deemed as blameable to doubt the existence of inhabitants of the Planets and Stars, as three centuries ago, it was held heretical to teach that doctrine.”
It was no surprise to this author when his opinion aroused a furor. To a friend he had written, “I must publish my book without my name, in consequences of the heresies which it will thus contain.” He did not mean heresies of the sort that had proved fatal to Bruno; it would not have been dangerous to sign his name to an unpopular view. But anonymous publication was common in the nineteenth century, and he felt that because of his position it would be improper to become embroiled in something bound to stir up unfavorable publicity. He was already a noted figure. His name was William Whewell [pictured above], and he was Master of Trinity College at England’s Cambridge University. Furthermore, he had written distinguished books on the history and philosophy of science, and had in fact originated the term “scientist.” Until William Whewell used that term, scientists had been called natural philosophers.
Because Dr. Whewell had written so much that was well known, his style was recognizable, and the fact that he was the author of the controversial book soon became an open secret. That did not matter; he had aimed not to hide his opinions, but simply to keep Of the Plurality of Worlds: An Essay separate from his more official works. The topic itself was considered neither sensational nor inappropriate for the head of a major college to discuss. What caused all the excitement was William Whewell’s contention that there might be no intelligent beings on other planets, and that outside our solar system there might not even be any planets. “We scarcely expected,” said the London Daily News, “that in the middle of the nineteenth century, a serious attempt would have been made to restore the exploded ideas of man’s supremacy over all other creatures in the universe; and still less that such an attempt would have been made by any one whose mind was stored with scientific truths. Nevertheless a champion has actually appeared, who boldly dares to combat against all the rational inhabitants of other spheres; and though as yet he wears his vizor down, his dominant bearing, and the peculiar dexterity and power with which he wields his arms, indicate that this knight-errant of nursery notions can be no other than the Master of Trinity College, Cambridge.”
In a personal letter, Whewell said, “No one, so far as I know, has been the advocate of one world against many worlds, I mean in recent times.” In the book, referring to the cosmological views presented in Thomas Chalmers’ Astronomical Discourses, he wrote: “Such views are generally diffused in our time and country, are common to all classes of readers, and . . . are the popular views of persons of any degree of intellectual culture who have, directly or derivatively, accepted the doctrines of modern science. Among such persons, expressions which imply that the stars are globes of luminous matter, like the sun; that there are among them systems of revolving bodies, seats of life and intelligence; are so frequent and familiar that those who speak do not seem to be aware that, in using such expressions, they are making any assumption at all.”
It was Dr. Whewell’s avowed intent to show that people were indeed making assumptions, assumptions not warranted by the scientific evidence. Although he himself, in an earlier book called Astronomy and General Physics, had expressed the orthodox view, he had since come to the conclusion that science had no real proof for it. He was, of course, quite right. To the criticism, “Your arguments are merely negative. You only prove that we do not know the planets to be inhabited,” he replied: “If, when I have proved that point, men were to cease to talk as if they knew that the planets are inhabited, I should have produced a great effect.”
If he had left it at that, there might not have been so much angry debate. But William Whewell did not leave it there. He tried to prove that both science and religion supported the idea of Earth’s uniqueness, and therefore both scientists and religious leaders found good grounds on which to oppose him. His biographer wrote, “Rarely in recent times has a book received so much attention from reviewers.”
Nineteenth-century book reviews were long essays in themselves. Dr. Whewell’s most vehement critic devoted forty pages of a well-known magazine to defending plurality of worlds, and still did not feel he had said enough; shortly afterwards he published a book of his own in rebuttal. Most of the other magazine reviews discussed the two books together. What was said in those reviews shows first, that belief in extrasolar planets had indeed been considered unchallengeable; second, that the debate centered around issues that were largely irrelevant; and third, that almost everyone concerned was influenced more by emotion than logic.
The second book was by Sir David Brewster, an eminent Scottish physicist. Its title was More Worlds than One: The Creed of the Philosopher and the Hope of the Christian. As the subtitle suggest, Brewster—though a qualified scientist—based his arguments primarily on religious considerations. Actually, William Whewell did so too, but he was more subtle and more tolerant. He did not say that those who disagreed with him were motivated by “some morbid condition of the mental powers, which . . . delights in doing violence to sentiments deeply cherished, and to opinions universally believed,” or by “a love of notoriety.” Nor did he accuse them of “folly and irreverence towards the God of Nature.” David Brewster used those phrases and similar ones. He asserted his opinions in an extremely dogmatic way. As one reviewer put it, “Sir David . . . is consequently continually laying himself open to attack. We regret to add that he is frequently deficient in common courtesy, and has allowed his temper and angry feelings to mingle in a discussion which is surely too remote from all meaner interests to deserve to be so sullied.”
Both books made some valid points. Unfortunately, both also drew conclusions that did not follow from the arguments presented. In addition, both authors—despite their extensive knowledge of science—introduced dubious scientific hypotheses to back up predetermined opinions. They even made careless errors, which their antagonists were quick to point out. For example, Dr. Whewell misstated the distance to the moon, illustrating it by saying that a month would be needed to get there at the ordinary speed of a railroad-carriage, whereas, according to one reviewer: “At thirty miles an hour, which is as fast as men wish to travel, it would take a little over three hundred and eighty-seven days.”
Sir John Herschel, the son of Sir William Herschel and himself an astronomer of great fame, wrote after Dr. Whewell’s death that the essay on plurality of worlds could “hardly be regarded as expressing his deliberate opinion.” He felt that surely, as another astronomer put it, “Whewell only advanced it in jest.” This tells more about the opinion of Herschel and the scientists of his time than about William Whewell’s opinion. Everything in the book and in his personal papers indicates that Whewell meant his ideas to be taken seriously. He maintained that many people were “still troubled and dismayed at the doctrines of the vastness of the universe, and the multitude of worlds, which they suppose to be taught and proved by astronomy.” His “essay” (which was nearly 300 pages long) suggests that he himself was one of those people.
Dr. Whewell used several main arguments, none of which could stand up under close scrutiny. He, and the reviewers, were most impressed by what he called the “argument from geology.” The discovery that the earth had evolved through many ages of past time, and that species of animals now extinct had existed in prehistoric eras, was a relatively new one. Whewell insisted that it countered the well-established belief that an uninhabited world would be wasted, for had not Earth itself been wasted for millions of years before man appeared? Some critics considered this idea “very ingenious and striking,” but most of them spotted the flaw in it. They pointed out that a world that was being prepared for intelligent life could not be called wasted since the ages of preparation on Earth had, presumably, been necessary.
Sir David Brewster wrote: “That is, The Earth, the ATOM OF SPACE, is the only one of the planetary and sidereal worlds that is inhabited, because it was so long without inhabitants, and has occupied only an ATOM OF TIME! If any of our readers see the force of this argument, they must possess an acuteness of perception to which we lay no claim. To us it is not only illogical;—it is a mere sound in the ear, without any sense in the brain . . . Reason and common sense dictate a very different opinion. If nearly infinity of time has been employed to provide for intellectual and immortal life so glorious an abode, is it not probable that nearly infinity of space will be devoted to the same noble purpose?”
This is a fair sample of Sir David’s style; he was very fond of italics and capital letters. The same criticism was voiced more soberly by other men. And the issue was a significant one despite its irrelevance to the question of waste; for the first time, some people began to realize that planets might be at different stages of development.
The rest of the arguments Dr. Whewell employed were even less effective, although many reviewers got sidetracked and failed to note the deficiencies in them. What seems most peculiar today is that everybody on both sides assumed it was a matter of all or nothing. If some planets besides the earth were inhabited, or were becoming habitable, they all must be; if some stars were the centers of solar systems, then they all were—and vice versa. William Whewell contended that it was unlikely that double stars had planets, or that nebulae were composed of stars as most astronomers believed; to him, this seemed to point toward the conclusion that no other solar systems existed. David Brewster felt obliged to assert that double stars must have more complex systems of planets than single ones. The commentators took one position or the other. It did not occur to them that some stars besides our sun might have planets even if others had none.
The most hotly debated irrelevant question was the state of the planets in our own solar system. Dr. Whewell thought those planets uninhabitable; in this he was right, as far as is known today. But he was wrong in thinking that it had any bearing on the existence of habitable worlds in other solar systems. He certainly could not legitimately pronounce Earth unique on such grounds. Nevertheless, in his zeal to show that most planets were not abodes of life, he counted all 34 of the asteroids that were then known. His opponents, although in most cases willing to concede the asteroids and even the moons, were entirely unwilling to give up the primary planets. They agreed that their whole case would be weakened if even one “useless” world were to be acknowledged.
At the time of the Whewell/Brewster controversy, the evidence against habitation of the planets in our solar system was by no means conclusive. The following comment by an Oxford professor was justified: “The Essayist attempts to show that the ascertained conditions of the planetary bodies exclude the ascertained conditions of organic life . . . by the expressly-stated assumption that life is impossible except under conditions almost exactly similar to those under which we have an opportunity of studying it at the surface of our own planet. We think it a question whether this last position be a tenable one. Disguise it as we may, it comes in fact to this, that we may take our knowledge of what exists here for an exact measure of what may exist elsewhere. And in such an assumption there is considerable danger. It implies what we believe to be an exaggerated idea of the completeness of our physical knowledge.”
Dr. Whewell held that to say animal life does not require the same environment on other planets as it does on ours would be to “run into the error which so long prevented many from accepting the Newtonian system:—the error of thinking that matter in the heavens is governed by quite different laws from matter on earth.” This comparison was worth considering, and many present-day biologists might agree with it. But the professor argued that knowledge of the laws that govern organic life was “wholly and absolutely wanting,” which in the 1850s was true. Moreover, Whewell could not say whether the environments of extrasolar worlds were like ours or not. He did not extend his principle of universal natural law into as wide a realm as those who believed in plurality of worlds; that was their chief weapon against him.
Perhaps the fairest estimate of Dr. Whewell’s contribution was that of the reviewer who said, “Let us, then, conclude that the highly-gifted writer of this striking Essay has shown good grounds for a re-examination of the belief which has grown up by such gradual and imperceptible steps into a religion amongst us, that there are MEN in other worlds.”
However, no widespread reexamination of the belief in other worlds occurred as the result of Whewell’s book. Most people did not want to stop believing. “There is no subject within the whole range of knowledge so universally interesting as that of a Plurality of Worlds,” wrote Sir David Brewster in the introduction to More Worlds Than One. “It commands the sympathies, and appeals to the judgment of men of all nations, of all creeds, and of all times.”
Although as usual, Sir David may have somewhat overstated the case, this declaration was—and still is—substantially true. During eras not dominated by contrary ideas, people have tended toward a conviction that mankind is not alone. Some well-known nineteenth century figures recorded their opinions on the subject. Alfred Tennyson, whose poetry contains many references to other solar systems, wrote of Whewell’s Essay: “It is to me anything but a satisfactory book. It is inconceivable that the whole Universe was merely created for us who live in this third-rate planet of a third-rate sun.”
William Whewell had been Tennyson’s tutor at Cambridge University. That was long before Dr. Whewell began to doubt the existence of other inhabited worlds, and there is no way of knowing whether the two ever discussed the subject. But young Alfred was interested in it even then, for the poem Timbuctoo (from which the title of this book, The Planet-Girded Suns, is taken) was written while he was in college and it won the Cambridge Prize Medal. He had competed for the prize only to please his father; he did not really think the poem good enough, and later, when he became poet laureate of England, he did not include it in collected volumes of his work.
About the same time Alfred Tennyson was attending college in England, Ralph Waldo Emerson—later renowned as a philosopher and poet—was gaining fame as a young minister in America. Among the few of his sermons that have been published is one that dealt with “all the worlds of God”: “To suppose that the constitution of the race of yesterday that now plants the fields of this particular planet, should be the pattern for all the orders that people the huge globes in the heaven is too improbable to be entertained. Rather believe that the benignant Power which has assigned each creature to its own element, the fish to the sea, the bird to the air, the beast to the field, has not less nicely adjusted elsewhere his creatures to their habitation . . . We are assured in any speculation we may indulge concerning the tenants of other regions . . . the moral law, justice and mercy would be at home in every climate and world where life is; that we can go nowhere but wisdom will not be valuable . . . truth, sacred, and charity divine. We then feel that there is no grandeur like moral grandeur. Before one act of courage, of love, of self devotion, all height and distance are ineffectual and the stars withdraw their shining. This only is real, absolute, independent of all circumstance and all change.”
Another man who had a good deal to say about life on extrasolar worlds was the Danish scientist Hans Christian Oersted, the discoverer of electromagnetism. At a meeting of Scandinavian philosophers in 1844 he said, “He who is convinced by the proofs I have mentioned, that living beings are distributed through the whole of existence, will contemplate the stars with very different thoughts and views, and have a far wider field for the scope of his imagination than he who is ignorant of these secrets of nature.”
Oersted believed that “futurity promises to reveal still more secrets” and that “we are not isolated beings, but . . . are related to the whole universe.” The next year, at a meeting of scientists, he gave a long speech arguing that the principles of intelligence, beauty and morality were the same on all worlds. He concluded it with his hope that this world would be continually gaining more knowledge, which would give “a much deeper insight of what happens on distant planets,” and suggested that the same would happen there with regard to ours.
The idea of unity among all the intelligent inhabitants of the cosmos was fairly widespread in the first half of the nineteenth century. Today this seems a very modern concept, one that people are only now beginning to take seriously. Yet even in the 1830s and 1840s some gave deep thought to it. Among them was a clergyman named Thomas Dick, who wrote several popular books about plurality of worlds including one called “Celestial Scenery.” In speculating on differences in species based on their environments he concluded that if a planet’s atmosphere was invisible, it was “purer” than ours and that the “moral and physical condition” of such planets’ inhabitants was therefore “probably superior to what is enjoyed upon earth.” At the same time, however, he maintained, “Truth, and every branch of knowledge by which the mind of a rational being can be adorned, must be substantially the same in every world throughout the amplitudes of creation.”
On the next page he went still further, with comments astonishingly farsighted: [See note below.] “Whether we may ever enjoy an intimate correspondence with beings belonging to other worlds, is a question which will frequently obtrude itself on a contemplative mind. It is evident that, in our present state, all direct intercourse with other worlds is impossible. The law of gravitation, which unites all the worlds in the universe in one grand system, separates man from his kindred spirits in other planets, and interposes an impassable barrier to his excursions to distant regions, and to his correspondence with other orders of intellectual beings. But in the present state he is only in the infancy of his being . . .
“He will, doubtless, be brought into contact and correspondence with numerous orders of kindred beings, with whom he may be permitted to associate on terms of equality and of endearing friendship. All the virtuous intelligences throughout creation may be considered as members of one great family . . . and it is not improbable that it is one grand design of the Deity to promote a regular and progressive intercourse among the several branches of his intelligent offspring, though at distant intervals and in divers manners, and after the lapse of long periods of duration. Such an intercourse may be necessary . . . to the full expansion of the moral and intellectual faculties, and to the acquisition of all that knowledge which relates to . . . the physical and moral government of the universe. For this purpose it may be necessary that branches of the universal family that have existed in different periods of duration, and in regions widely separated from each other, should be brought into mutual association, that they may communicate to each other the results of their knowledge and experience.”
The ideas Dr. Dick expressed there bear a striking resemblance to recent speculations about galactic federations of worlds. Not even science fiction had then ventured to suggest the underlying thought that must have prompted his statements: the thought of a universal family of mortal peoples, destined to eventually communicate through some inconceivable means, and to share knowledge gained through varied experience “on terms of equality.”
Today, scientists who are devising mathematical codes suitable for interstellar communication would find nothing outdated in that passage from the voluminous writings of Dr. Dick. Some such scientists would not agree with the part about Deity, while others would—but in either case the rest would seem highly relevant.
There is no indication that anyone besides Thomas Dick thought actual contact between solar systems might ever be feasible, let alone that it might be a necessary feature of cosmic design. His readers, if they interpreted what he said in that light, do not appear to have adopted the thought; and it did not arise again until much, much later. [Note: I have recently had occasion to examine Dick's statement along with its surrounding text and have discovered that it is not as far-sighted as I assumed when I wrote the book. In context, it refers not to space travel or interplanetary communication, but to the idea of peoples of different worlds meeting in an afterlife.]
The feeling of universal kinship, considered apart from hope of contact, was more common. In the American poet Walt Whitman it was particularly strong. He wrote, “It is not enough to have this globe, or a certain time—I will have thousands of globes, and all time.” Many of his poems express this feeling. For example, in "Kosmos" he said:
Who, out of the theory of the earth, and of his or her body, understands by subtle analogies all other theories.Walt Whitman was one of the first prominent men to think of worlds and their intelligent species as being at various stages of evolution. Although evolutionary concepts of planetary formation, of geology, and to a lesser extent of biology, had been discussed by a number of thinkers for some years, the vast majority of people still pictured everything in the universe as having been created simultaneously. If they accepted the evidence of fossils as proof of a long period of development on Earth, they tended to assume that development on alien planets—both in our solar system and in others—had reached exactly the same stage. There was no general change in public opinion about this until the 1870s.Who believes not only in our globe, with its sun and moon, but in other globes, with their suns and moons;
Who, constructing the house of himself or herself, not for a day, but for all the time, sees races, eras, dates, generations,
The past, the future, dwelling there, like space, inseparable together.
The issue of evolution, which brought new ways of thinking, was complex. It was not merely a matter of whether man did or did not descend from the apes. Long before controversy arose over the origin of man, there was debate over evolutionary theories of cosmogony and geology. Early supporters of those theories did not suggest that similar ideas of gradual change applied to the physical characteristics of intelligent beings. They viewed man (and the inhabitants of other worlds also) as essentially different from animal species, even when the basic principle of evolution was extended to organic life. They agreed with opponents of this principle that a planet was designed and prepared for the benefit of its inhabitants, however long the process might take; and usually they assumed the planet’s environment to have been made to fit the inhabitants’ needs rather than the reverse. In other words, to them the question was not why man was comfortable with the amount of heat and light received from the sun, but why Earth was at the proper distance from the sun for his comfort.
During the latter part of the nineteenth century this outlook was challenged. Scientists began to investigate the possibility that Earth’s environment might have had an effect on man’s development. One result of the new attitude was acceptance of the idea that Earth’s position in the universe was no more central in terms of time than in terms of space. “It appears to me,” wrote the astronomer Richard Anthony Proctor, “that the belief that life in this earth corresponds with a period special for the universe itself is as monstrous as the old belief that our earth is the centre of the universe.”
Richard Proctor was especially interested in other worlds, and in the 1870s he wrote many books and articles about them. He also lectured to hundreds of audiences in both Great Britain and America. Commenting on this experience, he said, “None save astronomers, and few only of those, care for researches into the star-depths, except in connection with the thought that every star is a sun, and therefore probably the light and fire of a system of worlds like those which circle around our own sun.”
In an article and in his book Our Place Among Infinities, Proctor presented what he called “a new theory of life in other worlds,” which he contrasted to the opposing “Whewellite” and “Brewsterian” theories. “Men have not been so bold in widening their conceptions of time as in widening their conceptions of space,” he wrote. “It is here and thus that, in my judgment, the subject of life in other worlds has been hitherto incorrectly dealt with.” He went on to say: “Brewster and Dick and Chalmers, all in fact who have taken that doctrine under their special protection, reason respecting other worlds as though, if they failed to prove that other orbs are inhabited now, or are at least now supporting life in some way or other, they failed of their purpose altogether. The idea does not seem to have occurred to them that there is room . . . in eternity of time not only for activity but for rest.”
The Whewellite theory, Proctor continued, was “not held in very great favour.” He felt that even those who, like himself, did not think “the ways and works of God are to be judged by our conceptions of the fitness of things” preferred the Brewsterian theory. “Nevertheless,” he said, “we must be guided in these matters by evidence, not by sentiment—by facts, not by our feelings. It is well, therefore, to note that the decision does not lie between the two theories which have just been dealt with.”
More than twenty years had passed since the publication of Whewell’s book and Brewster’s reply to it. From the modern viewpoint, the delay in recognition of the third alternative is difficult to understand. It seems strange that Richard Proctor considered it a “new theory,” for he had studied the subject thoroughly and must have been aware that the possibility of not all planets being ready for habitation had been mentioned; in fact he had mentioned it himself in earlier works. But apparently not even he had seen the implications before. His ideas do not seem to have been thought revolutionary or startling, and his name is not prominent in the history of science. His theory may merely have spelled out what others were beginning to grasp.
“This present time . . . is a random selection, so to speak, regarded with reference to the existence of life in any other world, and being a random selection, it is much more likely to belong to the period when there is no life there . . . This applies to the planets of our solar system only in so far as we are ignorant of their conditions . . . As respects the members of those systems of worlds which circle, as we believe (from analogy) around other suns than ours, the probability that any particular world is inhabited at this present time is exceedingly small . . . Have we then been led to the Whewellite theory that our earth is the sole abode of life? Far from it . . . The very argument from probability which leads us to regard any given sun as not the centre of a scheme in which at this moment there is life, forces upon us the conclusion that among . . . the millions of suns which people pace, millions have orbs circling around them which are at this present time the abode of living creatures.”
This seems obvious because it is so close to current theories; it seems to belong to the 1970s instead of the 1870s. Yet Proctor was by no means a hundred years ahead of his time. On the contrary, he was quite representative of it. Between his outlook and today’s came a long era of upheaval, a time of changing views and disturbing thoughts in many fields of knowledge. Few positive statements can be made about the effects of these changes on the idea of plurality of worlds. But it is a fact—and in many ways a strange one—that what had not happened in Whewell’s era did happen later. Gradually, as the nineteenth century ended and the twentieth began, people abandoned the conviction that habitable planets circle the stars. A still stranger fact is that they forgot such a conviction had ever been prevalent.
Some of the reasons for the shifts in opinion during the century just past are known. For example, it is definitely known why astronomers revised their estimates of how many stars are likely to have planets, and why they later returned to estimates closer to those of the nineteenth century. Yet these reasons do not appear to fully account for the reversal of people’s attitudes toward the existence of some inhabited worlds. They surely do not account for previous opinions having been forgotten.
Most scientists today who are interested in extrasolar life would be surprised by what the eighteenth and nineteenth-century scholars wrote about it. Even they do not realize how widespread a concept it used to be. One of them, a Fellow of the Royal Astronomical Society, recently wrote, “Starting at the turn of the century with H.G. Wells’ famous War of the Worlds, we have been nurtured in the belief that the wandering planets . . . might contain beings of an intelligent kind.” But though H. G. Wells’ science fiction was certainly very popular, more nonfiction expressed this belief before Wells wrote it than afterwards. The same present-day astronomer maintained, “It is only within comparatively recent times that the general idea of planets existing at interstellar distances has come to be accepted.” Similar statements are to be found in many recent science books.
This is not to say that today’s astronomers ought to know better, for unless they have time to seek out books and magazines of the past—which busy scientists do not—they are not likely to come across any information on the subject. Nor should historians be criticized. Historians write only about things they consider important, and extrasolar worlds were not considered important at the time most modern [as of 1974] historians received their education in science.
The significance of statements like the one above is that they prove
that somewhere between the 1870s and the 1970s, there is a puzzling gap in
the story of man’s view of other solar systems.
Lots more that I have written, or collected, about space! |
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