The Complete Works of Edgar Allan Poe - Edgar Allan Poe [710]
All this was strictly logical—admitting the medium or ether; but this ether was assumed, most illogically, on the ground that no other mode than the one spoken of could be discovered, of accounting for the observed decrease in the orbit of the comet:—as if from the fact that we could discover no other mode of accounting for it, it followed, in any respect, that no other mode of accounting for it existed. It is clear that innumerable causes might operate, in combination, to diminish the orbit, without even a possibility of our ever becoming acquainted with one of them. In the meantime, it has never been fairly shown, perhaps, why the retardation occasioned by the skirts of the Sun's atmosphere, through which the comet passes at perihelion, is not enough to account for the phenomenon. That Enck's comet will be absorbed into the Sun, is probable; that all the comets of the system will be absorbed, is more than merely possible but, in such case, the principle of absorption must be referred to eccentricity of orbit—to the close approximation to the Sun, of the comets at their perihelia; and is a principle not affecting, in any degree, the ponderous spheres, which are to be regarded as the true material constituents of the Universe.—Touching comets, in general, let me here suggest, in passing, that we cannot be far wrong in looking upon them as the lightning-flashes of the cosmical Heaven.
The idea of a retarding ether and, through it, of a final agglomeration of all things, seemed at one time, however, to* be confirmed by the observation of a positive decrease in the orbit of the solid moon. By reference to eclipses recorded 2500 years ago, it was found that the velocity of the satellite's revolution then was considerably less than it is now; that on the hypothesis that its motions in its orbit is uniformly in accordance with Kepler's law, and was accurately determined then—2500 years ago—it is now in advance of the position it should occupy, by nearly 9000 miles. The increase of velocity proved, of course, a diminution of orbit; and astronomers were fast yielding to a be lief in an ether, as the sole mode of accounting for the phænomenon, when Lagrange came to the rescue. He showed that, owing to the configurations of the spheroids, the shorter axes of their ellipses are subject to variation in length; the longer axes being permanent; and that this variation is continuous and vibratory—so that every orbit is in a state of transition, either from circle to ellipse, or from el lipse to circle. In the case of the moon, where the shorter axis is decreasing, the orbit is passing from circle to ellipse and, consequently, is decreasing too; but, after a long series of ages, the ultimate eccentricity will be attained; then the shorter axis will proceed to increase, until the orbit becomes a circle; when the process of shortening will again take place;—and so on forever. In the case of the Earth, the orbit is passing from ellipse to circle. The facts thus demonstrated do away, of course, with all necessity for supposing an ether, and with all apprehension of the system's instability—on the ether's acount.
It will be remembered that I have myself assumed what we may term an ether. I have spoken of a subtle influence which we know to be ever in attendance upon matter, although becoming manifest only through matter's heterogeneity. To this influence—without daring to touch it at all in any effort at explaining its awful nature—I have referred the various phenomena of electricity, heat, light, magnetism; and more—of vitality, consciousness, and thought—in a word, of spirituality. It will be seen, at once, then, that the ether thus conceived is radically distinct from the ether of the astronomers; inasmuch as theirs is matter and mine