The Plurality of Worlds Part 1

The Plurality of Worlds.

by William Whewell and Edward Hitchc.o.c.k.

PREFACE.

Although the opinions presented in the following Essay are put forwards without claiming for them any value beyond what they may derive from the arguments there offered, they are not published without some fear of giving offence. It will be a curious, but not a very wonderful event, if it should now be deemed as blamable to doubt the existence of inhabitants of the Planets and Stars, as, three centuries ago, it was held heretical to teach that doctrine. Yet probably there are many who will be willing to see the question examined by all the light which modern science can throw upon it; and such an examination can be undertaken to no purpose, except the view which has of late been generally rejected have the arguments in its favor fairly stated and candidly considered.

Though Revealed Religion contains no doctrine relative to the inhabitants of planets and stars; and though, till within the last three centuries, no Christian thinker deemed such a doctrine to be required, in order to complete our view of the attributes of the Creator; yet it is possible that at the present day, when the a.s.sumption of such inhabitants is very generally made and a.s.sented to, many persons have so mingled this a.s.sumption with their religious belief, that they regard it as an essential part of Natural Religion. If any such persons find their religious convictions interfered with, and their consolatory impressions disturbed, by what is said in this Essay, the Author will deeply regret to have had any share in troubling any current of pious thought belonging to the time. But, as some excuse, it may be recollected, that if such considerations had prevailed, this very doctrine, of the Plurality of Worlds, would never have been publicly maintained. And if such considerations are to have weight, it must be recollected, on the other hand, that there are many persons to whom the a.s.sumption of an endless mult.i.tude of Worlds appears difficult to reconcile with the belief of that which, as the Christian Revelation teaches us, has been done for this our World of Earth. In this conflict of religious difficulties, on a point which rather belongs to science than to religion, perhaps philosophical arguments may be patiently listened to, if urged as arguments merely; and in that hope, they are here stated, without reserve and without exaggeration.

All speculations on subjects in which Science and Religion bear upon each other, are liable to one of the two opposite charges;--that the speculator sets Philosophy and Religion at variance; or that he warps Philosophy into a conformity with Religion. It is confidently hoped that no candid reader will bring either of these charges against the present Essay. With regard to the latter, the arguments must speak for themselves. To the Author at least, they appear to be of no small philosophical force; though he is quite ready to weigh carefully and candidly any answers which may be offered to them. With regard to the amount of agreement between our Philosophy and Religion, it may perhaps be permitted to the Author to say, that while it appears to him that some of his philosophical conclusions fall in very remarkably with certain points of religious doctrine, he is well aware that Philosophy alone can do little in providing man with the consolations, hopes, supports, and convictions which Religion offers; and he acknowledges it as a ground of deep grat.i.tude to the Author of all good, that man is not left to Philosophy for those blessings; but has a fuller a.s.surance of them, by a more direct communication from Him.

Perhaps, too, the Author may be allowed to say, that he has tried to give to the book, not only a moral, but a scientific interest; by collecting his scientific facts from the best authorities, and the most recent discoveries. He would flatter himself, in particular, that the view of the Nebulae and of the Solar System, which he has here given, may be not unworthy of some attention on the part of astronomers and observers, as an occasion of future researches in the skies.

INTRODUCTORY NOTICE TO THE AMERICAN EDITION.

It is an interesting feature in the literature of our day, that so many minds are turning their attention to the bearings of science upon religion. With a few honorable exceptions, Christian scholars have regarded this as a most unpromising field, which they have left to the tilting and gladiators.h.i.+p of scepticism. But we owe it mainly to the disclosures of geology, that the tables are beginning to be turned. For a long time suspected of being in league with infidelity, it was treated as an enemy, and Christians thought only of fortifying themselves against its attacks. But they are finding out, that if this science has been seen in the enemy's camp, it was only because of their jealousy that it was compelled to remain there; like captives that are sometimes pushed forwards to cover the front rank and receive the fire of their friends. Judging from the number of works, some of them very able, that appear almost monthly from the press, in which ill.u.s.trations of religion are drawn from geology, we may infer that this science is beginning to be recognized by the friends of religion as an efficient auxiliary.

"The Plurality of Worlds," now republished, is the most recent work of this description that has fallen under our notice. We can see no reason why an Essay of so much ability, in which the reasoning is so dispa.s.sionate, and opponents are treated so candidly, should appear anonymously. True, the author takes ground against some opinions widely maintained respecting the extent of the inhabited universe, and seems to suppose that he shall meet with little sympathy; and this may be his reason, though in our view quite insufficient, for remaining incognito.

We think he will find that there are a secret seven thousand, who never have bowed their understandings to a belief of many of the doctrines which he combats, and he might reasonably calculate that his reasoning will add seven thousand more to the number. We confess, however, that though we have long been of this number to a certain extent, we cannot go as far as this writer has done in his conclusions.

All the world is acquainted with Dr. Chalmers' splendid Astronomical Discourses. a.s.suming, or rather supposing that he has proved, that the universe contains a vast number of worlds peopled like our own, he imagines the infidel to raise an objection to the mission of the Son of G.o.d, on the ground that this world is too insignificant to receive such an extraordinary interposition. His replies to this objection, drawn chiefly from our ignorance, are ingenious and convincing. But the author of the Plurality of Worlds doubts the premises on which the objection is founded. He thinks the facts of science will not sustain the conclusion that many of the heavenly bodies are inhabited; certainly not with moral and intellectual beings like man. Nay, by making his appeal to geology, he thinks the evidence strong against such an opinion. This science shows us that this world was once certainly in a molten state, and very probably, at a still earlier date, may have been dissipated into self-luminous vapor, like the nebulae or the comets. Immense periods, then, must have pa.s.sed before any organic structures, such as have since peopled the earth, could have existed. And during the vast cycles that have elapsed since the first animals and plants appeared upon the globe, it was not in a proper condition to have sustained any other than the inferior races. Accordingly, it has been only a few thousand years since man appeared.

Now, so far as astronomy has revealed the condition of other worlds, almost all of them appear to be pa.s.sing through those preparatory changes which the earth underwent previous to man's creation. What are the unresolvable nebulae and most of the comets also, but intensely heated vapor and gas? What is the sun but a molten globe, or perhaps gaseous matter condensed so as to possess almost the density of water?

The planets beyond Mars, also, (excluding the asteroids,) appear to be in a liquid condition, but not from heat, and therefore may be composed of water, or some fluid perhaps lighter than water; or at least be covered by such fluid. Moreover, so great is their distance from the sun, that his light and heat could not sustain organic beings such as exist upon the earth. Of the inferior planets, Mercury is so near the sun that it would be equally unfit for the residence of such beings.

Mars, Venus, and the Moon, then, appear to be the only worlds known to us capable of sustaining a population at all a.n.a.logous to that upon earth. But of these, the Moon appears to be merely a ma.s.s of extinguished volcanos, with neither water nor atmosphere. It has proceeded farther in the process of refrigeration than the earth, because it is smaller; and in its present state, is manifestly unfit for the residence either of rational or irrational creatures. So that we are left with only Mars and Venus in the solar system to which the common arguments in favor of other worlds being inhabited, will apply.

But are not the fixed stars the suns of other systems? We will thank those who think so, to read the chapter in this work that treats of the fixed stars, and we presume they will be satisfied that at least many of these bodies exhibit characters quite irreconcilable with such an hypothesis. And if some are not central suns, the presumption that the rest are, is weakened, and we must wait till a greater perfection of instruments shall afford us some positive evidence, before we know whether our solar system is a type of any others.

Thus far, it seems to us, our author has firm ground, both geological and astronomical, to stand upon. But he does not stop here. He takes the position that probably our earth may be the only body in the solar system, nay in the universe, where an intellectual, moral and immortal being, like man, has an existence. He makes the "earth the domestic hearth of the solar system; adjusted between the hot and fiery haze on one side, and the cold and watery vapor on the other: the only fit region to be a domestic hearth, a seat of habitation." He says that "it is quite agreeable to a.n.a.logy that the solar system should have borne but one fertile flower. And even if any number of the fixed stars were also found to be barren flowers of the sky, we need not think the powers of creation wasted, or frustrated, thrown away, or perverted." He does not deny that some other worlds may be the abodes of plants and animals such as peopled this earth during the long ages of preadamic history.

But he regards the creation of man as the great event of our world. He looks upon the s.p.a.ce between man and the highest of the irrational creatures, as a vast one: for though in physical structure they approach one another, in intellectual and moral powers they cannot be compared.

He does not think it derogatory to Divine Wisdom to have created and arranged all the other bodies of the universe to give convenience and elegance to the abode of such a being; especially since this was to be the theatre of the work of redemption.

Now we sympathize strongly in views that give dignity and exaltation to man, and not at all with that debasing philosophy, so common at this day, that looks upon him as little more than a somewhat improved orang.

But we cannot admit that man is the only exalted created being to be found among the vast array of worlds around us. Geology does, indeed, teach us, that it is no disparagement of Divine Wisdom and benevolence to make a world--and if one, why not many--the residence of inferior creatures; nay to leave it without inhabitants through untold ages. But it also shows us, that when such worlds have pa.s.sed through these preparatory changes, rational and immortal beings may be placed upon them. Nay, does not the history of our world show us that this seems to be the grand object of such vast periods of preparation. And is it not incredible, that amid the countless bodies of the universe, a single globe only, and that a small one, should have reached the condition adapted to the residence of beings made in the image of G.o.d? Of what possible use to man are those numberless worlds visible only through the most powerful telescopes? Surely such a view gives us a very narrow idea of the plans and purposes of Jehovah, and one not sustained in our opinion by the a.n.a.logies of science.

There is another principle to which our author attaches, as we think, too little importance in this connection. When we see how vast is the variety of organic beings on this globe, and how manifold the conditions of their existence; how exactly adapted they are to the solid, the liquid, and the gaseous states of matter, can we doubt that rational and intelligent beings may be adapted to physical conditions in other worlds widely diverse from those on this globe? May not spirits be connected with bodies much heavier, or much lighter, than on earth; nay, with mere tenuous ether; and those bodies, perhaps, be better adapted to the play of intellect than ours; and be unaffected by temperatures which, on earth, would be fatal? It does seem to us that such conclusions are legitimate inferences from the facts of science; and if so, we can hardly avoid the conclusion that there may be races of intelligent beings upon other worlds where the condition of things is widely different from that on earth. Yet there is a limit to this principle; and when we can prove another world to be in a similar condition to our earth, when it was inhabited by preadamic races, or not at all inhabited, the presumption is strong, that such a world has inhabitants of a like character, or none at all.

Our author makes but a slight allusion to some most important statements of revelation, that seem to us to bear strongly upon the hypothesis which he adopts. We refer to the existence of angels, holy and unholy.

In the history of the latter, we learn that _they kept not their first estate, but left their own habitation_. Have we not here an example of other rational creatures, more exalted than man, who, like him, have fallen from their first estate; and does not the presumption hence arise, that there may be similar examples in other worlds? And is there not a probability, that holy angels now in heaven, may be rational intelligences who have pa.s.sed a successful probation in other worlds? It does seem to us, that these biblical facts make the hypothesis of our author respecting man extremely improbable.

But though we must demur as to some of the views of this work, we can cordially recommend its perusal to intelligent and reasoning minds. It is an effort in the right direction, and we think will do much to correct some false notions respecting the Plurality of Worlds. And even the author's peculiar hypothetical views are sustained with much ability. He states the facts of geology and astronomy with great clearness and correctness, and seems quite familiar with mathematical reasoning. Nor does he advance opinions that come into collision with natural or revealed religion; though, as already stated, we think his favorite notions narrow our conceptions of the Divine plans and purposes. We predict for the work an extended circulation among scientific men and theologians; and commend it with confidence to all readers--and in our country they are numerous--who are fond of tracing out the connection between science and religion.

E. H.

Amherst College, April, 1854.

THE PLURALITY OF WORLDS.

CHAPTER I.

ASTRONOMICAL DISCOVERIES.

"When I consider the heavens, the work of thy fingers, the moon and the stars, which thou hast ordained; What is man, that thou art mindful of him? and the son of man, that thou visitest him?"

1. These striking words of the Hebrew Psalmist have been made, by an eloquent and pious writer of our own time, the starting point of a remarkable train of speculation. Dr. Chalmers, in his _Astronomical Discourses_, has treated the reflection thus suggested, in connection with such an aspect of the heavens and the stars, the earth and the universe, as modern astronomy presents to us. Even from the point of view in which the ancient Hebrew looked at the stars; seeing only their number and splendor, their lofty position, and the vast s.p.a.ce which they visibly occupy in the sky; compared with the earth, which lies dark, and mean, and perhaps small in extent, far beneath them, and on which man has his habitation; it appeared wonderful, and scarcely credible, that the maker of all that array of luminaries, the lord of that wide and magnificent domain, should occupy himself with the concerns of men: and yet, without a belief in His fatherly care and goodness to us, thoughtful and religious persons, accustomed to turn their minds constantly to a Supreme Governor and constant Benefactor, are left in a desolate and bewildered state of feeling. The notion that while the heavens are the work of G.o.d's fingers, the sun, moon, and stars ordained by him, He is _not_ mindful of man, does not regard him, does not visit him, was not tolerable to the thought of the Psalmist. While we read, we are sure that he believed that, however insignificant and mean man might be, in comparison with the other works of G.o.d,--however difficult it might seem to conceive, that he should be found worthy the regards and the visits of the Creator of All,--yet that G.o.d _was_ mindful of him, and _did_ visit him. The question, "What is man, that this is so?"

implies that there is an answer, whether man can discover it or not.

"_What_ is man, that G.o.d is mindful of him?" indicates a belief, unshaken, however much perplexed, that man is _something_, of such a kind that G.o.d _is_ mindful of him.

2. But if there was room for this questioning, and cause for this perplexity, to a contemplative person, who looked at the skies, with that belief concerning the stars, which the ancient Hebrew possessed, the question recurs with far greater force, and the perplexity is immeasurably increased, by the knowledge, concerning the stars, which is given to us by the discoveries of modern astronomy. The Jew probably believed the earth to be a region, upon the whole, level, however diversified with hills and valleys, and the skies to be a vault arched over this level;--a firmament in which the moon and the stars were placed. What magnitude to a.s.sign to this vault, he had no means of knowing; and indeed, the very aspect of the nocturnal heavens, with the mult.i.tude of stars, of various brightness, which come into view, one set after another, as the light of day dies away, suggests rather the notion of their being scattered through a vast depth of s.p.a.ce, at various distances, than of their being so many lights fastened to a single vaulted surface. But however he might judge of this, he regarded them as placed in a s.p.a.ce, of which the earth was the central region. The host of heaven all had reference to the earth. The sun and the moon were there, in order to give light to it, by day and by night. And if the stars had not that for their princ.i.p.al office, as indeed the amount of light which they gave was not such as to encourage such a belief,--and perhaps the perception, that the stars must have been created for some other object than to give light to man, was one of the princ.i.p.al circ.u.mstances which suggested the train of thought that we are now considering;--yet still, the region of the stars had the earth for its centre and base. Perhaps the Psalmist, at a subsequent period of his contemplations, when he was pondering the reflections which he has expressed in this pa.s.sage, might have been led to think that the stars were placed there in order to draw man's thoughts to the greatness of the Creator of all things; to give some light to his mental, rather than to his bodily eye; to show how far His mode of working transcends man's faculties; to suggest that there are things in heaven, very different from the things which are on earth. If he thought thus, he was only following a train of thought on which contemplative minds, in all ages and countries, have often dwelt; and which we cannot, even now, p.r.o.nounce to be either unfounded or exhausted; as we trust hereafter to show. But whether or not this be so, we may be certain that the Psalmist regarded the stars, as things having a reference to the earth, and yet not resembling the earth; as works of G.o.d's fingers, very different from the earth with its tribes of inhabitants; as luminaries, not worlds. In the feeling of awe and perplexity, which made him ask, "What is man that thou art mindful of him?" there was no mixture of a persuasion that there were, in those luminaries, creatures, like man, the children and subjects of G.o.d; and therefore, like man, requiring his care and attention. In asking, "What is man, that thou visitest him?" there was no latent comparison, to make the question imply, "that thou visitest _him_, rather than those who dwell in those abodes?" It was the mult.i.tude and magnificence of G.o.d's works, which made it seem strange that he should care for a _thing_ so small and mean as man; not the supposed mult.i.tude of G.o.d's intelligent creatures inhabiting those works, which made it seem strange that he should attend to every _person_ upon this earth. It was not that the Psalmist thought that, among a mult.i.tude of earths, all peopled like this earth, man might seem to be in danger of being overlooked and neglected by his Maker; but that, there being only one earth, occupied by frail, feeble, sinful, short-lived creatures, it might be unworthy the regards of Him who dwelt in regions of eternal light and splendor, unsullied by frailty, inaccessible to corruption.

3. This, we can have no doubt, or something resembling this, was the Psalmist's view, when he made the reflection, which we have taken as the basis of our remarks. And even in this view, (which, after all that science has done, is perhaps still the most natural and familiar,) the reflection is extremely striking; and the words cannot be uttered without finding an echo in the breast of every contemplative and religious person. But this view is, as most readers at this time are aware, very different from that presented to us by Modern Astronomy. The discoveries made by astronomers are supposed by most persons to have proved, or to have made it in the highest degree probable, that this view of the earth, as the sole habitation of intelligent subjects of G.o.d's government; and of the stars, as placed in a region of which the earth is the centre, and yet differing in their nature from this lower world; is altogether erroneous. According to astronomers, the earth is not a level s.p.a.ce, but a globe. Some of the stars which we see in the vault of heaven, are globes, like it; some smaller than the earth, some larger. There are reasons, drawn from a.n.a.logy, for believing that these globes, the other planets, are inhabited by living creatures, as the earth is. The earth is not at rest, with the celestial luminaries circulating above it, as the ancients believed, but itself moves in a circle about the sun, in the course of every year; and the other planets also move round the sun in like manner, in circles, some within and some without that which the earth describes. This collection of planets, thus circulating about the sun, is the SOLAR SYSTEM: of which the earth thus forms a very small part. Jupiter and Saturn are much larger than the earth. Mars and Venus are nearly as large. If these be inhabited, as the Earth is, which the a.n.a.logy of their form, movements and conditions, seems to suggest, the population of the earth is a very small portion of the population of the solar system. And if the mere number of the subjects of G.o.d's government could produce any difficulty in the application of his providence to them, a person to whom this view of the world which we inhabit had been disclosed, might well, and with far more reason than the Psalmist, exclaim, "Lord, what is man, that thou art mindful of him? the inhabitants of this Earth, that thou regardest him?"

4. But this is only the first step in the a.s.serted revelations of astronomy. Some of the stars are, as we have said, planets of the kind just described. But these stars are a few only:--five, or at most six, of those visible to the una.s.sisted eye of man. All the rest, innumerable as they appear, and numerous as they really are, are, it is found, objects of another kind. They are not, as the planets are, opaque globes, deriving their light from a sun, about which they circulate.

They s.h.i.+ne by a light of their own. They are of the nature of the sun, not of the planets. That they appear mere specks of light, arises from their being at a vast distance from us. At a vast distance they undoubtedly are; for even with our most powerful telescopes, they still appear mere specks of light;--mere luminous points. They do not, as the planets do, when seen through telescopes, exhibit to us a circular face or disk, capable of being magnified and distinguished into parts and features. But this impossibility of magnifying them by means of telescopes, does not at all make us doubt that they may be far larger than the planets. For we know, from other sources of information, that their distance is immensely greater than that of any of the planets. We can measure the bodies of the solar system;--the earth, by absolutely going round a part of it, or in other ways; the other bodies of the system, by comparing their positions, as seen from different parts of the earth. In this manner we find that the earth is a globe 8,000 miles in diameter. In this way, again, we find that the circle which the earth describes round the sun has, in round numbers, a radius about 24,000 times the earth's radius; that is, nearly a hundred millions of miles.

The earth is, at one time, a hundred millions of miles on one side of the sun; and at another time, half a year afterwards, a hundred millions of miles on the other side. Of the bright stars which s.h.i.+ne by their own light,--the _fixed stars_, as we call them, (to distinguish them from the planets, the _wandering stars_,)--if any one were at any moderate distance from us, we should see it change its apparent place with regard to the others, in consequence of our thus changing our point of view two hundred millions of miles: just as a distant spire changes its apparent place with regard to the more distant mountain, when we move from one window of our house to the other. But no such change of place is discernible in any of the fixed stars: or at least, if we believe the most recent a.s.serted discoveries of astronomers, the change is so small as to imply a distance in the star, of more than two hundred thousand times the radius of the earth's...o...b..t, which is, itself, as we have said, one hundred millions of miles.[1] This distance is so vastly great, that we can very well believe that the fixed stars, though to our best telescopes they appear only as points of light, are really as large as our sun, and would give as much light as he does, if we could approach as near to them. For since they are thus, the nearest of them, two hundred thousand times as far off as he is, even if we could magnify them a thousand times, which we can hardly do, they would still be only one two-hundredth of the breadth of the sun; and thus, still a mere point.

5. But if each fixed star be of the nature of the sun, and not smaller than the sun, does not a.n.a.logy lead us to suppose that they have, some of them at least, planets circulating about them, as our sun has? If the Sun is the centre of the Solar System, why should not Sirius, (one of the brightest of the fixed stars,) be the centre of the _Sirian System_?

And why should not that system have as many planets, with the same resemblances and differences of the figure, movements, and conditions of the different planets, as this? Why should not the Sirian System be as great and as varied as the solar system? And this being granted, why should not these planets be inhabited, as men have inferred the other planets of the solar system, as well as the earth, to be? And thus we have, added to the population of the universe of which we have already spoken, a number (so far as we have reason to believe) not inferior to the number of inhabitants of the solar system: this number being, according to all the a.n.a.logies, very many fold that of the population of the whole earth?

And this is the conclusion, when we reason from one star only, from Sirius. But the argument is the same, from each of the stars. For we have no reason to think that Sirius, though one of the brightest, is more like our sun than any of the others is. The others appear less bright in various degrees, probably because they are further removed from us in various degrees. They may not be all of the same size and brightness; it is very unlikely that they are. But they may as easily be larger than the sun, as smaller. The natural a.s.sumption for us to make, having no ground for any other opinion, is, that they are, upon the average, of the size of our sun. On that a.s.sumption, we have as many solar systems as we have fixed stars; and, it may be, six or ten, or twenty times as many inhabited globes; inhabited by creatures of whom we must suppose, by a.n.a.logy, that G.o.d is mindful, if he is mindful of us. The question recurs with overwhelming force, if we still follow the same train of reflection: "What is man, that G.o.d is mindful of him?"

6. But we have not yet exhausted the views which thus add to the force of this reflection. The fixed stars, which appear to the eye so numerous, so innumerable, in the clear sky on a moonless night, are not really so numerous as they seem. To the naked eye, there are not visible more than four or five thousand. The astronomers of Greece, and of other countries, even in ancient times, counted them, mapped them, and gave them names and designations. But Astronomy, who thus began her career by diminis.h.i.+ng, in some degree, the supposed numbers of the host of heaven, has ended by immeasurably increasing them. The first application of the telescope to the skies discovered a vast number of fixed stars, previously unseen: and every improvement in that instrument has disclosed myriads of new stars, visibly smaller than those which had before been seen; and smaller and smaller, as the power of vision is more and more strengthened by new aids from art; as if the regions of s.p.a.ce contained an inexhaustible supply of such objects; as if infinite s.p.a.ce were strewn with stars in every part of it to which vision could reach. The small patch of the sky which forms, at any moment, the field of view of one of the great telescopes of Herschel, discloses to him as many stars, and those of as many different magnitudes, as the whole vault of the sky exhibits to the naked eye. But the magnifying power of such an instrument only discloses, it does not make, these stars. There appears to be quite as much reason to believe, that each of these telescopic stars is a sun, surrounded by its special family of planets, as to believe that Sirius or Arcturus is so. Here, then, we have again an extension, indefinite to our apprehension, of the universe, as occupied by material structures; and if so, why not by a living population, such as the material structures which are nearest to us support?

7. Even yet we have not finished the series of successive views which astronomers have had opened to them, extending more and more their spectacle of the fulness and largeness of the universe. Not only does the telescope disclose myriads of stars, unseen to the naked eye, and new myriads with each increase of the powers of the instrument; but it discloses also patches of light, which, at first at least, do not appear to consist of stars: _Nebulae_, as they are called; bright specks, it might seem, of stellar matter, thin, diffused, and irregular; not gathered into regular and definite forms, such as we may suppose the stars to be. Every one who has noticed the starry skies, may understand what is the general aspect of such nebulae, by looking at the milky way or galaxy, an irregular band of nebulous light, which runs quite round the sky; "A circling zone, powdered with stars;" as Milton calls it. But the nebulae of which I more especially speak, are minute patches, discovered mainly by the telescope, and in a few instances only discernible by the naked eye. And what I have to remark especially concerning them at present is, that though to visual powers which barely suffice to discern them, they appear like mere bright clouds, patches of diffused starry matter; yet that, when examined by visual powers of a higher order, by more penetrating telescopes, these patches of continuous feeble light are, in many instances at least, distinguishable into definite points: they are found, in fact, to be aggregations of stars; which before appeared as diffused light, only because our telescopes, though strong enough to reveal to our senses the aggregate ma.s.s of light of the cl.u.s.ter, were not strong enough to enable us to discern any one of the stars of which the cl.u.s.ter consists. The galaxy, in this way, may, in almost every part, be _resolved_ into separate stars; and thus, the mult.i.tude of the stars in the region of the sky occupied by that winding stream of light, is, when examined by a powerful telescope, inconceivably numerous.

8. The small telescopic nebulae are of various forms; some of them may be in the shape of flat strata, or cakes, as it were, of stars, of small thickness, compared with the extent of the stratum. Now, if our sun were one of the individuals of such a stratum, we, looking at the stars of the stratum from his neighborhood, should see them very numerous and close in the direction of the edge of the stratum, and comparatively few and rare in other parts of the sky. We should, in short, see a galaxy running round the sky, as we see in fact. And hence Sir William Herschel has inferred, that our sun, with its attendant planets, has its place in such a stratum; and that it thus belongs to a host of stars which are, in a certain way, detached from the other nebulae which we see. Perhaps, he adds, some of those other nebulae are beds and ma.s.ses of stars not less numerous than those which compose our galaxy, and which occupy a larger portion of the sky, only because we are immersed in the interior of the crowd. And thus, a minute speck of nebulous light, discernible only by a good telescope, may contain not only as many stars as occupy the sky to ordinary vision, but as many as is the number into which the most powerful telescope resolves the milky light of the galaxy. And of such resolvable nebulae the number which are discovered in the sky is very great, their forms being of the most various kind; so that many of them may be, for aught we can tell, more amply stocked with stars than the galaxy is. And if all the stars, or a large proportion of the stars, of the galaxy, be suns attended by planets, and these planets peopled with living creatures, what notion must we form of the population of the universe, when we have thus to reckon as many galaxies as there are resolvable nebulae! the stock of discoverable nebulae being as yet unexhausted by the powers of our telescopes; and the possibility of resolving them into stars being also an operation which has not yet been pursued to its limit.

9. For, (and this is the last step which I shall mention in this long series of ascending steps of mult.i.tude apparently infinite,) it now begins to be suspected that not some nebulae only, but _all_, are resolvable into separate stars. When the nebulae were first carefully studied, it was supposed that they consisted, as they appeared to consist, of some diffused and incoherent matter, not of definite and limited ma.s.ses. It was conceived that they were not stars, but Stellar Matter in the course of formation into stars; and it was conceived, further, that by the gradual concentration of such matter, whirling round its centre while it concentrated, not only stars, that is, suns, might be formed, but also systems of planets, circling round these suns; and thus this _Nebular Hypothesis_, as it has been termed, gave a kind of theory of the origin and formation of systems, such as the solar system. But the great telescope which Lord Rosse has constructed, and which is much more powerful than any optical instrument yet fabricated, has been directed to many of the nebulae, whose appearance had given rise to this theory; and the result has been, in a great number of cases, that the nebulae are proved to consist entirely of distinct stars; and that the diffused nebulous appearance is discovered to have been an illusion, resulting from the acc.u.mulated light of a vast number of small stars near to each other. In this manner, we are led to regard every nebula, not as an imperfectly formed star or system, but as a vast mult.i.tude of stars, and, for aught we can tell, of systems; for the apparent smallness and nearness of these stars are, it is thought, mere results of the vast distance at which they are placed from us. And thus, perhaps, all the nebulae are, what some of them seem certainly to be, so many vast armies of stars, each of which stars, we have reason to believe, is of the nature of our sun; and may have, and according to a.n.a.logy has, an accompaniment of living creatures, such as our sun has, certainly on the earth, probably, it is thought, in the other planets.

10. It is difficult to grasp, in one view, the effect of the successive steps from number to number, from distance to distance, which we have thus been measuring over. We may, however, state them again briefly, in the way of enumeration.

From our own place on the earth, we pa.s.s, in thought, as a first step, to the whole globe of the Earth; from this, as a second step, to the Planets, the other globes which compose the Solar System. A third step carries us to the Fixed Stars, as visible to the naked eye; very numerous and immensely distant. The transition to the Telescopic Stars makes a fourth step; and in this, the number and the s.p.a.ce are increased, almost beyond the power of numbers to express how many there are, and at what distances. But a fifth step:--perhaps all this array of stars, obvious and telescopic, only make up our Nebula; while the universe is occupied by other Nebulae innumerable, so distant that, seen from them, our nebula, though including, it may be, stars of the 20th magnitude, which may be 20 times or 2,000 times more remote than Sirius, would become a telescopic speck, as their nebulae are to us.

11. Various images and modes of representation have been employed, in order to convey to the mind some notion of the dimensions of the scheme of the universe to which we are thus introduced. Thus, we may reckon that a cannon-ball, moving with its usual original velocity unabated, would describe the interval between the sun and the earth in about one year. And this being so, the same missile would, from what has been said, occupy more, we know not how much more, than 200,000 years in going to the nearest fixed star: and perhaps a thousand times as much, in going to other stars belonging to our group; and then again, 200,000 times so much, or some number of the like order, in going from one group to another. When we have advanced a step or two in this mode of statement, the velocity of the cannon-ball hardly perceptibly affects the magnitude of the numbers which we have to use.

And the same nearly is the case if we have recourse to the swiftest motion with which we are acquainted; that of Light. Light travels, it is shown by indisputable scientific reasonings, in about eight minutes from the sun to the earth. Hence we can easily calculate that it would occupy at least three years to travel as far as Sirius, and probably, three thousand years, or a much greater number, to reach to the smallest stars, or to come from them to us. And thus, as Sir W. Herschel remarked, since light is the only vehicle by which information concerning these distant bodies is conveyed to us, we do, by seeing them, receive information, not what they are at this moment, but what they were, as to visible condition, thousands of years ago. Stars may have been created when man was created, and yet their light may not have reached him.[2] Stars may have been extinguished thousands of years ago, and yet may still be visible to our eyes, by means of the light which they emitted previous to their extinction, and which has not yet died away.