CHAPTER XXII.

MANY SUNS.

Once more we have to wing our flight far, far away from the busy Solar System where we live; away from whirling planets, moons, meteorites, all shining with reflected sunlight; away from the great central sun himself, our own particular bright star. Once more we have, in imagination, to cross the vast, black, empty space--_is_ it black, and _is_ it empty, had we sight to see things as they are?--separating our sun from other suns, our star from other stars. For the sun is a star--only a star. And stars are suns--big, blazing suns. One is near, and the others are far away. That is the difference.

We have no longer to do with bodies merely reflecting another’s light--always dark on one side and bright on the other--but with burning bodies, shining all round by their own light. We have no longer to picture just one single star with his surrounding worlds, but we have to fix our thoughts upon the great universe of stars or suns in countless millions.

The earth is forgotten, with its small and ephemeral history. The sun himself, with all his immense system, has sunk in the infinite night. On the wings of inter-sidereal comets we have taken our flight towards the stars, the suns of space. Have we exactly measured, have we worthily realized the road passed over by our thoughts? The nearest star to us reigns at a distance of 275,000 times our distance from the sun; out to that star an immense desert surrounds us, the most profound, the darkest, and the most silent of solitudes.

The solar system seems to us very vast; the abyss which separates our world from Mars, Jupiter, Saturn, and Neptune, appears to us immense; relatively to the fixed stars, however, our whole system represents but an isolated family immediately surrounding us: a sphere as vast as the whole solar system would be reduced to the size of a simple point if it were transported to the distance of the nearest star. The space which extends between the solar system and the stars, and which separates the stars from each other, appears to be entirely void of visible matter, with the exception of nebulous fragments, cometary or meteoric, which circulate here and there in the immense voids. Nine thousand two hundred and fifty systems like ours, bounded by Neptune, would be contained in the space which isolates us from the nearest star!

It is marvelous that we can perceive the stars at such a distance. What an admirable transparency in these immense spaces to permit the light to pass, without being wasted, to thousands of billions of miles! Around us, in the thick air which envelops us, the mountains are already darkened and difficult to see at seventy miles; the least fog hides from us objects on the horizon. What must be the tenuity, the rarefaction, the extreme transparency of the ethereal medium which fills the celestial spaces!

The sun is center and ruler and king in his own system. But as a star, he is only one among many stars, some greater, some less than himself. From the far siderial heavens he is hardly recognized even as a star among the constellations, so faint is his light.

Do the suns which surround us form a system with that which illuminates us, as the planets form one round our solar focus, and does our sun revolve round an attractive center? Does this center, the point of the revolutions of many suns, itself revolve round a preponderating center? In a word, is the visible universe organized in one or several systems? No Divine revelation comes to instruct men on the mysteries which interest them most--their personal or collective destinies. We have now, as ever, but science and observation to answer us.

A problem so vast as this is still far from receiving even an approximate solution. From whatever point of view we consider it, we find ourselves face to face with the infinite in space and time. The present aspect of the universe immediately brings into question its past and its future state, and then the whole of united human learning supplies us in this great research with but a pale light, scarcely illuminating the first steps of the dark and unknown road on which we are traveling. However, such a problem is worthy of engaging our attention, and positive science has already made sufficient discoveries in the knowledge of the laws of nature to permit us to attempt to penetrate these great mysteries. What is it that the general observation of the heavens--what is it that sidereal synthesis teaches us on our real situation in infinitude?

[Illustration: A TELESCOPIC FIELD IN THE MILKY WAY.]

In the calm and silent hours of beautiful evenings, what pensive gaze is not lost in the vague windings of the Milky Way, in the soft and celestial gleam of that cloudy arch, which seems supported on two opposite points of the horizon, and elevated more or less in the sky according to the place of the observer and the hour of the night? While one-half appears above the horizon, the other sinks below it, and if we removed the earth, or if it were rendered transparent, we should see the complete Milky Way, under the form of a great circle, making the whole circuit of the sky. The scientific study of this trail of light, and its comparison with the starry population of the heavens, begins for us the solution of the great problem.

Let us point a telescope towards any point of this stupendous arch. Suddenly hundreds, thousands of stars show themselves in the telescopic field, like needle-points on the celestial vault. Let us wait for some moments, that our eye may become accustomed to the darkness of the background, and the little sparks shine out by thousands. Let us leave the instrument pointed motionless towards the same region, and there slowly passes before our dazzled vision the distant army of stars. In a quarter of an hour we see them appear by thousands and thousands. William Herschel counted three hundred and thirty-one thousand in a width of 5° in the constellation Cygnus, so nebulous to the naked eye. If we could see the whole of the Milky Way pass before us, we should see eighteen millions of stars.

This seed-plot of stars is formed of objects individually invisible to the naked eye, below the sixth magnitude; but so crowded that they appear to touch each other, and form a nebulous gleam which all human eyes, directed to the sky for thousands of years, have contemplated and admired. Since it is developed like a girdle round the whole circuit of the sky, we ourselves must be in the Milky Way. The first fact which impresses our mind is, that _our sun is a star of the Milky Way_.

Thought travels fast--faster than a comet, faster than light. A rushing comet would, it is believed, take twenty millions of years to cross the chasm between the nearest known fixed star and us. Light, flashing along at the rate of about one hundred and eighty-six thousand miles a second, will perform the same journey in four years and a third. But thought can overleap the boundary in less than a single moment.

Each star that we see in the heavens is to our eyesight simply one point of light. The brighter stars are said to be of greater magnitude, and the fainter stars of lesser magnitude; yet, one and all, they have no apparent size. The most powerful telescope, though it can increase their brilliancy, can not add to their size. A planet, which to the naked eye may look like a star, will, under a telescope, show a disk, the breadth of which can be measured or divided; but no star has any real, visible disk in the most powerful telescope yet constructed. The reason of this is the enormous distance of the stars. Far off as many of the planets lie, yet the farthest of them is as a member of our household compared with the nearest star.

I have already tried to make clear the fact of their vast distance. Light, which comes to us from the sun in eight minutes and a half, takes over four and a third years to reach us from Alpha Centauri. From this four-years-and-a-third length of journey between Alpha Centauri and earth, the numbers rise rapidly to twenty years, fifty years, seventy years, even hundreds of years. The distance of most of the stars is completely beyond our power to measure. The whole orbit of our earth, nay, the whole wide orbit of the far-off Neptune, would dwindle down to one single point, if seen from the greater number of the stars.

It used to be believed that, taking the stars generally, there was probably no very marked difference in their size, their kind, their brightness. Some of course would be rather larger, and others rather smaller; still it was supposed that they might be roughly classed as formed much on the same scale and the same plan. But doubts are now felt about this notion. For a very similar idea used to be held with regard to the Solar System. The wonderful variety of form and richness in numbers, now known to abound within its limits, are discoveries of late years. May not the same variety in kind and size be found also among the stars? The more we look into the heavens, the more we find that dull, blank uniformity is not to be seen there.

It is the same upon earth. Man builds his little rows of boxlike houses side by side, each one exactly like all the rest, or dresses his thousand soldiers in coats of the same cut and color, or repeats a neat leaf-design hundreds of times on carpets or wall-papers; but God never makes two leafs or two blades of grass alike. Wholesale turning out of things after one pattern is quite a human idea, not divine.

We know so much about the stars as that some are at least considerably larger and some considerably smaller than others. When one star is seen to shine brightly, and another beside it shines dimly, we are apt to think that the brightest must be the nearest. Yet it is often impossible for us to say how much of the difference is owing to the greater distance of one or the other, to the greater size of one or the other, or to the greater brilliancy of one or the other. In many instances we do know enough to be quite sure that there is a great difference, not only in the distance of the stars, but in their size, their kind, their brightness.

The stars have been lately classed by one or two astronomers into four distinct orders or degrees--partly depending on their color. The first class is that of the White Suns. These are said to be the grandest and mightiest of all. The star Sirius belongs to the order of White Suns. Secondly comes the class of Golden Suns. To these blazing furnaces of yellow light, second only to the white-light stars, belongs our own sun. Thirdly, there are numbers of stars called Variable Stars, the light of which is constantly changing, now becoming more, now becoming less. Fourthly, there is the class of small Red Suns, about which not much is known.

These four orders or divisions do not by any means include all the stars, or even all the single stars. Roughly speaking, however, the greater number of single stars, and many also of the double stars, belong to one or another of the above classes.

When we talk of the different sizes of the different stars, it should be plainly understood that we have no means of directly measuring them. A point of light showing no disk, no surface, no breadth, can not be measured, for there is nothing to measure.

In certain cases we are not entirely without the power of judging. The distances of a few of the stars from us have been found out. Knowing how far off any particular star is, astronomers are able to calculate exactly how bright our own sun would look at that same distance. If they find that our sun would shine just as the star in question shines, there is some reason for supposing that our sun and the star may be of the same size. If our sun would shine more brightly than the star shines, there is some reason for supposing that the star may be smaller than our sun. If our sun would shine more dimly than the star shines, there is some reason for supposing that the star may be larger than our sun.

Other matters, however, have to be considered. Suppose we find a star at a certain distance shining twice as brilliantly as our own sun would shine at that same distance. Naturally, then, we say, That star must be much larger than our sun.

The reasoning may be mistaken. We do not know the fact. What if, instead of being a much _larger_ sun, it is only a much _brighter_ sun? This possibly must be allowed for. It has, indeed, been strongly doubted by one astronomer, after close study of the sun, whether any surface of any star _could_ exceed the surface of our sun in its power of light and heat.

But Sirius sheds actually forty-eight times as much light around it as does our sun; we are not exactly entitled to say that Sirius is forty-eight times as big as the sun, but we can say that Sirius is forty-eight times as brilliant or as splendid. In making this calculation we have taken a lower determination of the brightness of Sirius relatively to the sun than some other careful observations would have warranted. It will thus be seen that if there be any uncertainty in our result it must only be as to whether Sirius is not really more than forty-eight times as bright as the sun.

When we picture to ourselves the star-depths, the boundless reaches of heavenly space, with these countless blazing suns scattered broadcast throughout, we have not to picture an universe in repose. On the contrary, all is life, stir, energy. Just as in the busy whirl of our Solar System no such thing as rest is to be found, so also it seems to be in the wide universe.

Every star is in motion. “Fixed,” as we call them, they are not fixed. Invisible as their movements are to our eyes through immensity of distance, yet all are moving. Those silent, placid, twinkling specks of light are, in reality, huge, roaring, seething, tumultuous furnaces of fire and flame, heat and radiance.

Each, too, is hurrying along his appointed pathway in space. Some move faster, some move more slowly. One mile per second; ten miles per second; twenty, thirty, forty, fifty miles per second,--thus varying are their rates of speed. But whether fast or whether slowly, still onward and ever onward they press. Some are rushing towards us, some are rushing away from us. Some are speeding to the right, some are speeding to the left.

The fine star Arcturus, which any one may admire every evening on the prolongation of the tail of the Great Bear, is slowly withdrawing from the fixed point where the celestial charts placed it two thousand years ago, and is moving towards the southwest. It takes eight hundred years to describe a space in the sky equal to the apparent diameter of the moon; nevertheless, this displacement was sufficiently perceptible to attract attention more than a century and a half ago, for Halley had noticed it in 1718, as well as those of Sirius and Aldebaran. However slow it may appear at the distance we are from Arcturus, this motion is, at a minimum, 1,637 millions of miles a year. Sirius takes 1,338 years to pass over the same angular space in the sky; at the distance of that star this is, at a minimum, 397 millions of miles per annum. The study of the proper motions of the stars has made the greatest progress in the last half-century, and especially in recent years. All the stars visible to the naked eye and a large number of telescopic stars show displacements of this kind.

Where are they going? Does any single star ever return to his starting-point--wherever that starting-point may have been? Do they journey in vast circles or ellipses, round some far-distant center? What controls them all? Is it the mighty power of some such center, or does each star, by his faint and distant attraction, help to control all his brother-stars, to guide them on their appointed path, to preserve the delicate balance of a universe?

How little we know about the matter! Only so much we can tell--that the controlling and restraining hand of God is over the whole. Whether by the attraction of one great center or by the united influences of a thousand fainter attractions, he steers each radiant sun upon its heavenly path, “upholding all things by the words of his power.” There is no blundering, no confusion, no entanglement. All is perfect order, calm arrangement, restrained energy.