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.
12. So vast then are the distances at which the different bodies of the universe are distributed; and yet so numerous are those bodies. In the vastness of their distances, there is, indeed, nothing which need disturb our minds, or which, after a little reflection, is likely to do so: for when we have said all that can be said, about the largeness of these distances, still there is no difficulty in finding room for them. We necessarily conceive Space as being infinite in its extent: however much space the heavenly bodies occupy, there is space beyond them: if they are not there, space is there nevertheless. That the stars and planets are so far from each other, is an arrangement which prevents their disturbing each other with their mutual attractions, to any destructive extent; and is an arrangement which the spacious, the infinite universe, admits of, without any difficulty.
13. But we are more especially concerned with the Numbers of the heavenly bodies. So many planets about our sun: so many suns, each perhaps with its family of planets: and then, all these suns making but one group: and other groups coming into view, one after another, in seemingly endless succession: and all these planets being of the nature of our earth, as all these stars are of the nature of our sun:—all this, presents to us a spectacle of a world—of a countless host of worlds—of which, when we regard them as thus arranged in planetary systems, and as having, according to all probability, years and seasons, days and nights, as we have, we cannot but accept it as at least a likely suggestion, that they have also inhabitants;—intelligent beings who can reckon these days and years; who subsist on the fruits which the season brings forth, and have their daily and yearly occupations, according to their faculties. When we take, as our scheme of the universe, such a scheme as this, we may well be overwhelmed with the number of provinces, besides that in which man dwells, which the empire of the Lord of all includes; and, recurring to the words of the Psalmist, we may say with a profundity of meaning immeasurably augmented—"Lord, what is man?"
It was this view, I conceive, which Dr. Chalmers had in his thoughts, in pursuing the speculations which I have mentioned, in the outset of this Essay.
FOOTNOTES:
[1] It is quite to our purpose to recollect the impression which such discoveries naturally make upon a pious mind.
Oh! rack me not to such extent,
These distances belong to Thee;
The world's too little for Thy tent,
A grave too big for me!
[2] This thought is, however, older. Young expresses it in his Night Thoughts, Night IX., (published in 1744):
How distant some of these nocturnal suns!
So distant (says the sage) 'twere not absurd
To doubt if beams, set out at nature's birth,
Are yet arrived at this so foreign world.