More worlds than one: the creed of the philosopher and the hope of the Christian

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SIR DAVID BREWSTER.

MORE WORLDS THAN ONE : the Creed of the Philosopher, the Hope of the Christian.

THE MARTYRS OF SCIENCE : Galileo, Tycho Brahe, and Kepler.

More Worlds Than One

THE CREED OF THE PHILOSOPHER, AND THE HOPE OF THE CHRISTIAN.

BY

SIR DAVID BREWSTER, K.H., M.A., D.C.L. It

Sieuth (Thousand,

CORRECTED AND GREATLY ENLARGED.

NEW YORK:

G. P. PUTNAM'S SONS, Fourth Avenue and Twenty-Third Street.

QB54

By Transfer from U.S. Naval Academy Aug. 26 1932

5^

Contents

PAOa

Introduction, . - ... 1

Chap. I. Religious Aspect of the Question, ... 7

II. Description of the Solar System, . . . . 17

m. The Geological Condition of the Earth, . . 38

IV. Analogy between the Earth and the other Planets, 64

V. The Sun, Moon, and Satellites, .... 92

VI. The System of Comets, 115

VII. On the Nebular Hypothesis, .... 120

VIII. The Motion of the Solar System round a distant Centre, 125

IX. Religious Difficulties, 138

X. Single Stars and Binary Systems, . . . 163 XL Clusters of Stars and Nebulae, . . . .172

XII. General Summary, 182

XHL Reply to Objections drawn from Geology, . . 198

XIV. Objections from the Nature of Nebulae, . . 210 XV. Objections from the Nature of the Fixed Stars and

Binary Systems, ...... 218

XVI. Objections from the Nature of the Planets, . 230

XVH. The Future of the Universe, ..... 256

Preface

Having been requested by the Editor of the North British Revieiv to give an account of a work entitled Of a Plurality of Worlds, an Essay, I undertook the task, in the belief that it contained sentiments similar to my own, and that I should have the gratification of illustrating and recommending a doctrine which had long been the Creed of the Philosopher and the Hope of the Christian. I was surprised, however, to find that, under a title tending to mislead the public, the author had made an elaborate attack upon opinions consecrated, as I had thought, by Eeason and Eevelation ; and had, in conducting his argument, not only adopted the Nebular Hypothesis, so universally condemned as a

VI PREFACE.

dangerous speculation, but had taken a view of the condition of the Solar System, calculated to disparage the science of Astronomy, and to throw a doubt over the noblest of its truths.

Under ordinary circumstances I should have contented myself with such an analysis and criticism of the work as could be given within the narrow limits of a Keview ; but while the boldness of the author's speculations, and the ingenuity with which they were maintained, required a more elaborate examination of them, the new views which presented themselves to me during the study of the subject, demanded a copious detail of facts which could be given only in a separate Treatise. I have, therefore, devoted the principal part of the volume to a statement of the arguments in favour of a Plurality of Worlds, and have endeavoured, in the subsequent chapters, to answer the various objections urged against it by the author of the Essay, and to examine the grounds upon which he has attempted to establish the extraordinary doctrines that the Earth is "the oasis in the desert of

PREFACE. Vll

our system/' — "the largest solid opaque globe in it," and "really the largest planetary body in the Solar System, — its domestic hearth, and the only world in the Universe I"

St. Leonard's College, St. Anpeiws, April 25>th f 1864.

CHAPTEE II.

DESCRIPTION OF THE SOLAR SYSTEM.

In order to appreciate the force of the argument for a plurality of worlds, derived from the similarity of our Earth to the other planets of the Solar system, we must call the attention of the reader to a popular description of the magnitudes, distances, and general phenomena of the different bodies that compose it.

There is, perhaps, no sight in the material world more magnificent than that of the starry firmament. Seen from our earliest years, it may have ceased to excite our wonder, but no sooner has science taught us its true nature than it reappears in all its glory, like the gloomy landscape whose varied beauties a burst of sun-light has revealed. In the stillness of night, when the moral world is asleep, — when the aspen leaf has ceased to flutter, and no sound is heard save that of the remote waterfall, or the restless ocean, or the zephyr breath among the distant foliage, the silver Moon, the brilliant Planet, and the twinkling Star, are the beacon-lights which guide the eye through the brilliant expanse above.

B

18 MOKE WORLDS THAN ONE. CHAP. II.

The orbs of heaven seem at first fixed and motionless, like the scene around, but ere long, before our survey or our reverie is over, we perceive that they have all been in motion. The Moon has neared the horizon : one planet has descended in the West, — another has risen from the Eastern sea, and every star in the sky has shared in the general movement. When the observer has discovered that he alone has moved, — that, night after night, the Moon and Planets have alone changed their place among the stars, and that the Earth on which he stands, and the planets, whose motion he has observed, form a system of their own, while the thousands of stars, among which they moved, are fixed at distances invariable, he has arrived at the leading truths in astronomy.

But to the contemplative mind, the firmament of stars and planets has a deeper interest. Everything around us, save it, is in a state of transition. Beside the fleeting changes which the return of the seasons brings, the landscape around us is every year changing its aspect. The heath is robbed of its purple, and the yellow harvest waves over its once russet breast. The forests of our youth have ceased to give us shelter, — now the roof-trees of our homes, — now the floating bulwarks on the deep. The very places of our birth have been removed or effaced, and the lichen has encrusted the record on the tombstones of our fathers. All around is change, — but the gorgeous creations in the sky are still there, un-

Chap. II. Description Of The Solar System. 19

dimmed in brightness — unchanged in grandeur, — performing, with unflagging pace and unvarying precision, their daily, their annual, and their secular rounds. Upon these same heavens, just as we see them now, bespangled with the same planets and the same stars, our first parents gazed when they entered and when they quitted Paradise. The same constellations, Arcturus, Orion, and the Pleiades had sung together when the foundations of the world were laid. 1 and they rolled in darkness over Calvary, when the Prince of Life was slain. They are truly the only objects in the universe which all nations have witnessed, and all people admired. They presided at the horoscope of our birth, and they will throw their pale radiance over the green mounds beneath which we are destined to lie.

Such are the associations with which we look at the firmament above, and deep must be the interest with which we contemplate the history and purpose of its mysterious forms. It was, doubtless, under such associations that the great Philosopher of Mind 2 gave utterance to the feelings with which he contemplated the two cardinal phases of the physical and the moral world.

Methinks I ever tremble when I scan

The Starlit Heavens, the sense of Right in Man.

In surveying the material universe thus shadowed forth in the firmament, the first and the grandest

l Job ix. 9. 2 Immanuel Kant object which arrests our attention is the glorious Sun, — the centre and soul of the solar system, — the lamp that lights it, the fire that heats it, — the magnet that guides and controls it, — the fountain of colour which gives its azure to the sky, its verdure to the fields, its rainbow hues to the gay world of flowers, and the "purple light of love" to the marble cheek of youth and beauty. This globe, probably of burning gas, enveloping a solid nucleus, is 880,000 miles in diameter, above a hundred times that of our globe, and five hundred times larger in bulk than all the planets put together ! It revolves upon its axis in twenty-five days, and throws off its light with the velocity of 192,000 miles in a second. Sometimes by the naked eye, but frequently even by small telescopes, large black spots, many thousand miles in diameter, are seen upon its surface, and are evidently openings in the luminous atmosphere, through which we see the opaque solid nucleus, or the real body of the sun.

Around, and nearest the sun, at a distance of thirty-six millions of miles, revolves the planet Mercury, with a day of twenty-four hours, and a year of eighty-eight days. Supposing the light of the sun to decrease as the square of the distance, he will receive nearly seven times as much light and heat as the earth. Through the telescope some astronomers have observed spots on his surface, and mountains several miles in height.

CHAP. II. DESCRIPTION OF THE SOLAR SYSTEM. 21

Next to Mercury the planet Venus revolves at the distance of sixty-eight millions of miles, with a day of nearly twenty-four hours, and a year of 225 days. Her diameter is 7700 miles, a little less than that of the earth. She changes her phases like the moon. exhibits spots on her surface, and, according to Schroeter, has an atmosphere and mountains nearly twenty miles in height. The light and heat which she receives from the sun is about double of that which is received by the earth. 1

The next body of the Solar system is our own Earth — our birthplace, and soon to be our grave. Its distance from the sun is ninety-six millions of miles ; its equatorial diameter 7926 miles ; the length of its year 365 days six hours, and of its day twenty-four hours. The form of the Earth is that of a sphere flattened at the poles like an orange, the difference of its diameters being 26^ miles. Its superficies is divided into continents and seas, the continents occupying one-third, and the seas two-thirds of its whole surface. The land, sometimes level and sometimes undulating, occasionally rises into groups and ranges of mountains, the highest of which does not exceed five miles. The Earth is surrounded with an aerial envelope or atmosphere, which is computed to be about forty-five miles in height, though the region

1 From the rare appearance and want of permanence in the spots of Mercury and Venus, Sir John Herschel is of opinion, " that we do not see as in the moon the real surface of these planets, but only their atmospheres, much loaded with clouds, and which may serve to mitigate the otherwise intense glare of their sunshine/* — Outlines of Astronomy, § 509.

of clouds does not reach much above the summits of the highest mountains.

The Earth is accompanied by a Moon or satellite, whose distance is 237,000 miles, her diameter 2160 miles, and the time of her revolution round the Earth twenty-eight days. Her surface is composed of hill and dale, of rocks and mountains nearly two miles high, and of circular cavities, sometimes five miles in depth, and forty in diameter, which are believed to be the remains of extinct volcanoes. She possesses neither lakes nor seas ; and we cannot discover with the telescope any traces of living beings, or any monuments of their hands, though we hope that these objects will be seen with some magnificent telescope which may yet be constructed. Viewing the Earth as the third planet in order from the sun, can we doubt that it is a globe like the rest, poised in ether like them, and, like them, moving round the central luminary ?

Next, beyond the Earth, is the red-coloured planet Mars, with a day of about twenty-five hours, and revolving round the sun in 687 days, at the distance of one hundred and forty-two millions of miles. His diameter is 4100 miles, and his surface exhibits spots of different hues, — the seas, according to Sir John Herschel, being green, and the land red. The spots which have been seen on this planet by several astronomers, are not always equally distinct, but when seen "they offer," as Sir John Herschel observes,

CHAP. II. DESCRIPTION OF THE SOLAR SYSTEM. 23

u the appearance of forms, considerably definite and highly characteristic, brought successively into view by the rotation of the planet, from the assiduous observation of which it has even been found practicable to construct a rude chart of tfye surface of the planet. The variety in the spots may arise from the planet not being destitute of atmosphere and cloud ; and what adds greatly to the probability of this, is the appearance of brilliant white spots at its poles, which have been conjectured, with some probability, to be snow, as they disappear when they have been long exposed to the sun, and are greatest when just emerging from the long night of their polar winter, the snow line then extending to about six degrees from the pole. 7 ' 1 In a sketch of this planet, as seen in the pure atmosphere of Calcutta by Mr. Grant, it appears, to use his words, " actually as a little world," and as the Earth would appear at a distance with its seas and continents of different shades.

Hitherto we have been surveying worlds at a respectful distance from each other, and having days, and nights, and seasons, and aspects, of the same character ; but we now arrive at a region in space where some great catastrophe has taken place. At the distance of about two hundred and fifty millions of miles from the sun, corresponding to a period of about 1500 days, astronomers long ago predicted the existence of a large planet, cccupying the wide

1 Outli?ies of Astronomy, § 510.

MORE WORLDS THAN ONE.

CHAP. II.

space between Mars and Jupiter. In the beginning of the present century, one very small planet was discovered in this locality by M. Piazzi; and after other two had been discovered, one by himself and the other by Mr. Harding, Dr. Olbers hazarded the opinion that the three planets were fragments of a larger one which had burst; and this remarkable theory has been almost placed beyond a doubt by the discovery, in the same place, of thirty fragments in all, chiefly by M. Gasparis of Naples, and our eminent countryman Mr. Hind, by whom no fewer than ten of these bodies have been discovered.

The following table contains the distances from the sun, and the periodic times of these remarkable bodies, the distance of the earth being unity or 1, —

Mean dis-

Periodic

Mean dis-

Periodic tance from

Time in tance from

Time in

Sun.

Years.

Sun.

Years.

Ceres,

2.767

4.604

Psyche,

2.947

5.058

Pallas,

2.772

4.617

Thetis,

2.480

3.904

Juno,

2.669

4.360

Melpomene,

2.294

3.475

Vesta,

2.361

3.629

Fortuna,

2.446

3.825

Astrsea,

2.577

4.138

Massilia,

2.449

3.833

Hebe,

2.425

3.777

Calliope,

2.913

4.972

Iris,

2.385

3.684

Lutetia,

2.434

3.800

Flora,

2.201

3.267

Thalia,

2.625

4.257

Metis,

2.387

3.681

Proserpine,

2.653

4 324

Hygeia,

3.151

5.594

Phocea,

2.393

3.704

Parthenope,

2.448

3.830

Themis,

3.160

5.622

Victoria,

2.335

3.568

Enterpe,

3.347

5.597

Egeria,

2.582

4.150

Bellona,

2.781

4.640

Irene,

2.582

4.149

Amphitrite,

2.557

5.153

Eunomia,

2.640

4.289

Another, not named.

CHAP. IT. DESCRIPTION OF THE SOLAR SYSTEM. 25

The distance of Flora, the nearest of these asteroids, is 2.201, and its period 3.267 years ; and that of Euterpe, the most distant, 3.347, with a period of 5.597 years. While this sheet was printing, Mr.. Hind discovered the thirtieth of these planets, making the tenth discovered by himself.

Beyond this remarkable group is situated the planet Jupiter, a world of huge magnitude, 1320 .times greater in bulk than our Earth, revolving round its axis in ten hours, and round the sun in 4333 days, (a little less than twelve years,) at the distance of four hundred and eighty-five millions of miles. His form is that of an oblate spheroid, his equatorial being to his polar diameter as 107 to 100. His diameter is 90,000 miles, and he is attended by four Moons, or satellites, the average size of which is a little greater than that of our moon. His surface exhibits bright spots and dark bands or belts, which, though they have always the same direction, vary in breadth and in position, occasionally running out into branches or subdivisions, and dark spots. Sir John Herschel is of opinion, that the belts are tracts of corresponding clear sky in the planet's atmosphere, through which the darker body of the planet is seen, and that they are produced by currents like our trade-winds, but of a more steady and decided character, owing to the great velocity of his daily rotation.

26 MORE WORLDS THAN ONE. CHAP. IL

The following are the periods and distances of Jupitei's satellites, —

Periods.

Distances in

Days.

Hours.

Min.

Radii of Jupiter.

6.049

9*623

15.350

26.998

Next to Jupiter is the remarkable planet Saturn, accompanied with eight satellites, and surrounded by a ring. The distance of Saturn from the sun is eight hundred and ninety millions of miles, his annual period twenty-nine and a half years, and the length of his day ten and a half hours. His diameter is 79,000 miles, and his equatorial is to his polar diameter as 12 to 11. According to very recent observations, the ring is divided into four different rings, as shewn in the gilt figure of Saturn. Mr. Jacob has distinctly seen a fine division through more than half the circumference of the outer ring. It appears from some recent observations of Mr. Hippisley, that the middle ring is convex, and thicker in the middle than at either of its edges, and that the outer ring is sensibly raised above the edge of the inner. Mr. Bond, who thinks that the rings are fluid, is of opinion that the number of rings is continually changing, and that their maximum number, in the normal condition of the mass, does not exceed twenty. According to Mr. Bond, the power which sustains the centre of gravity of the ring is not in the planet itself,

CHAP. II. DESCRIPTION OF THE SOLAR SYSTEM. 27

but in his satellites ; and the satellites, though constantly disturbing the ring, actually sustain it in the very act of perturbation.

Mr. Otto Struve and Mr. Bond have lately studied, with the great Munich telescope, at the observatory of Pulkowa, the third ring of Saturn, which Mr. Lassell and Mr. Bond found to be fluid, from having observed through it the body of the planet, which is of an amber brown colour, as if seen through a film of smoke, the colour of the ring, when seen off the planet being of a slaty character. The principal division of the outer ring is not black, but of an amber brown. 1 They saw distinctly the dark interval between this fluid ring and the two old ones, and even measured its dimensions ; and they perceived at its inner margin an edge feebly illuminated, which they thought might be the commencement of a fourth ring. These astronomers are of opinion, that the fluid ring is not of very reoent formation, and that it is not subject to rapid change ; and they have come to the extraordinary conclusion, that the inner border of the ring has, since the time of Huygens, been gradually approaching to the body of Saturn, and that we may expect sooner or later, perhaps in some dozen of years, to see the rings united with the body of the planet

1 These observations on the colour of the part of Saturn seen through the transparent ring, and on the division of the outer ring, were made by Mr. Jacob at Madras.

The following are the dimensions of Saturn's rings, when they were supposed to be only two in number, according to the measurements of Struve, one second corresponding to 4400 miles —

Miles.

1. Exterior diameter of the Exterior ring, 40".095 176,418

2. Interior diameter of the Exterior ring, 35 ".289 155,272

3. Exterior diameter of the Interior ring, 34".475 151,690

4. Interior diameter of the Interior ring, 26".668 117,389

5. Equatorial diameter of Saturn, . 17" 991 79,160

6. Distance of the Interior ring from planet, 4' , .339 19,090

7. Breadth of the division between the rings, 0".408 1,791

8. Thickness of the ring, . . . 0".050 220

A singular fact in the structure of Saturn, not yet explained, was observed by Struve, who found that the inner edge of the interior ring was 943 miles nearer the body of the planet on the west side than on the east side.

The following table shews the distances and periodic times of the satellites of Saturn, —

Periods. Distance in Radii

Days. Hours. Min. of Saturn.

The seventh satellite, Hyperion, was lately discovered on the same night by Mr. Lassell, Liverpool, and Professor Bond of Cambridge, U.S.

CHAP. II. DESCRIPTION OF THE SOLAR SYSTEM. 29

Beyond Saturn, at a distance from the sun of one thousand eight hundred millions of miles, is placed the planet Uranus, discovered by Sir William Herschel. Its year, or annual period, is eighty-four years, and the length of its day nine and a half hours. Its diameter is 34,500 miles, and it is attended by eight satellites, six of which were discovered by Sir William Herschel, and the other two, a few years ago, by Mr. Lassell of Liverpool.

The following are the periods and distances of the satellites of Uranus.

Periods.

Distances in Radii

Days.

Hours.

Min.

of Uranus.

17.0

19.8

22.8

45.5

91.0

The remotest planet of our system, the planet Neptune, discovered theoretically in 1846 by Adams and Leverrier, and first recognised in the heavens by M. Galle of Berlin, is about 42,000 miles in diameter, and performs its annual revolution in 60,127 days, (about 165 years,) at the distance of nearly three thousand millions of miles from the sun. It is accompanied with one, or probably two, satellites ; and there is reason to believe that it is surrounded with a ring like Saturn. The satellite discovered by Mr. Lassell revolves round the planet in five days and twenty-one hours, at the distance of about 252,000 miles, or twelve radii of the planet.

Having thus travelled from the centre to the verge of the planetary system, — from the effulgent orb of day to that almost Cimmerian twilight where Phoebus could scarcely see to guide his steeds, let us ponder a while over the startling yet instructive sights which we have encountered in our course. Adjoining the sun, we find Mercury and Venus, with days and seasons like ours. Upon reaching our own planet, we recognise in it the same general features, but we find it larger in magnitude, and possessing the additional distinction of a satellite and a race of living beings to rejoice in the pre-eminence. In contrast with Mars, our earth still maintains its superiority both in size and equipments ; but, upon advancing a little farther into space, our pride is rebuked and our fears evoked, when we reach the part of our system where thirty asteroids, relics of a once mighty planet, are revolving in dissevered orbits, and warning the vain astronomer of another world that a similar fate may await his own. Dejected, but not despairing, we pass onward, and, as if in bright contrast with the confusion and desolation we have witnessed, there bursts upon our sight the splendid orb of Jupiter, proudly enthroned amid his four attendant satellites. When compared with so glorious a creation, our own earth dwindles into insignificance. It is no longer the monarch of the planetary throng,

CHAP. II. DESCRIPTION OF THE SOLAR SYSTEM. 31

and we blush at the recollection that sovereigns and pontiffs, and even philosophers, made it the central ball, around which the Sun and Moon and planets, and even the stars themselves, revolved in obsequious subjection. The dignity of being the seat of intellectual and animal life, however, still seems to be our own ; and if our globe does not swell so largely to the eye, or shine so brightly in the night, it has yet been the seat of glorious dynasties, — of mighty empires, — of heroes that have bled for their country, — of martyrs who have died for their faith, — and of sages who have unravelled the very universe we are surveying. Pursuing our outward course, a new wonder is presented to us in the gorgeous appendages of Saturn, encircled with his brilliant rings, and with eight moons, for the use, doubtless, of living beings. Advancing onwards, we encounter Uranus, with his eight pledges that he is the seat of life ; and after passing the new planet Neptune, and his one or probably two attendants, at the frontier of our system, we reach what is the region, and what may be regarded as the home, of comets.

Comets, or wandering stars, as they have been called, are those celestial bodies most of which appear occasionally only within the limits of the Solar system. They move in elliptical orbits, in one of the foci of which the sun is placed; but, unlike the planets, which always move from west to east, the comets revolve in orbits inclined at all possible

32 MORE WORLDS THAN ONE, CHAP. IL

angles, and move in all possible directions. The movements of several hundred comets which have been observed, must be chiefly executed within that vast and untenanted region, which lies between the nearest known fixed star and the orbit of Neptune, an interval equal to six thousand times the distance of that planet from the sun, or twenty-one million million of miles. What is their occupation there, or what it is here, when they are our visitors, we cannot venture to guess. That they do not perform the functions of planets is obvious, from their very nature ; and there is no appearance of their importing anything but vapour into our system, or of their exporting anything to another.

The general appearance of a comet is that of a faint round nebula, densest in the centre, like a piece of pale cloud through which stars are visible. Many of these comets have tails, increasing as they approach the sun. These tails are sometimes short, and sometimes so long as to stretch from the horizon to the zenith. The great comet of 1680, which produced such a sensation in London, was visible for four months. Its greatest distance from the sun was estimated at 127 times the distance of the earth from the sun. Its tail was 120 millions of miles long, and its velocity 880,000 miles in an hour. When it was nearest the sun its distance from him was only 144,000 miles, or about one-sixth of the sun's diameter, and its heat from this cause so great that Sir

CHAP. II. DESCRIPTION OF THE SOLAR SYSTEM. 33

Isaac Newton computed it to be 2000 times that of red hot iron. Dr. Halley made its period only 575 years, but Encke makes it 8800, and Argelander 2888 years.

A comet still more remarkable was seen in England on the 17th March 1843. Its nucleus had the appearance of a planetary disc, and had the brightness of a star of the first or second magnitude. It had a double tail divided by a dark line. At the Cape of Good Hope it was seen in full daylight, and in the immediate vicinity of the sea ; but the most remarkable fact in its history was its near approach to the sun, its distance from his surface being only one fourteenth of his diameter. The heat to which it was exposed, therefore, was much greater than that which Sir Isaac Newton ascribed to the comet of 1680. Sir John Herschel has computed that it must have been 24 times greater than that which was produced in the focus of Parker's burning lens, 32 inches in diameter, which melts crystals of quartz and agate. In the interesting work On cometic orbits by Edward Cooper, Esq. of Markree Castle, the periods of those comets that move in elliptic orbits vary from four years to about 15,000 ; but for obvious reasons, we cannot place much confidence in the higher numbers.

The tails of comets have occasionally exhibited very remarkable phenomena. In some, such as that of 1825, the tail consists of several streams of diverging light in a state of quick and constant change.

The nucleus of the comet of 1811 sent out rapid coruscations to the very end of its tail ; and the comet of 1824 exhibited two tails diametrically opposite, the one directed to the sun being the smallest and faintest.

Some comets have passed near the earth, and others may pass still nearer it ; but even if they should not produce those tremendous effects which Laplace has indicated, and if their great rarity and rapid motion should hinder them from acting upon our seas, or changing the axis of our globe, a sweep of their train of gas or of vapour would not be a pleasing salutation to living beings. The greatest distance of the most distant comet that has been observed, falls short of the distance of the nearest fixed star by nine million million of miles. Placing ourselves at this distance, how ridiculous appears the idea, so long and devoutly cherished, that the heavens, with all their host, revolved round our little planet ! At that point the earth is not even visible, and the whole starry creation, and our sun itself dwindled into a star, stand fixed and immovable.