Page:Popular Science Monthly Volume 4.djvu/305

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PAST AND FUTURE OF A CONSTELLATION.

PAST AND FUTURE OF A CONSTELLATION.
By CAMILLE FLAMMARION.

TRANSLATED FROM THE FRENCH, BY J. FITZGERALD, A. M.

THE notions hitherto entertained as to the stars and the heavens are destined to undergo a complete revolution. There are no fixed stars. Each one of those distant suns, naming in infinitude, is swept along in a stupendous movement which the imagination can hardly conceive. Notwithstanding the countless millions of miles of space between them and us, making them appear to us only as luminous points, whereas they are as great as our own sun, and thousands and millions of times greater than the earth, still, by means of the telescope and computation, astronomers have been able to come at them, and to demonstrate that they are all moving in every possible direction. The heavens are no longer motionless, nor can the constellations any longer be regarded as the symbol of the unchangeable. Take, for instance, Ursa Major, or the Great Bear, the first of the constellations to be observed and named. Who is there that has not taken that figure as the enduring symbol of the preestablished harmony, the unalterable duration of the firmament? Well, that ancient constellation will be destroyed. Each one of the stars which constitute it is endowed with a movement of its own. The result is that, in course of time, the form of Ursa Major will be changed. It now somewhat resembles in outline a wagon, and hence its popular title everywhere of car, or wain, while the learned have given it the name of the Bear, that being the only animal known to the ancients as living in polar regions. As every one knows, the four stars arranged in the form of a quadrilateral are* supposed to represent the four wheels, and the three stars in the front of the figure three horses. But the proper movement of the separate stars will alter this arrangement: it will bring the foremost horse to a point back of where he now is, while the other two will move onward. As for the two hinder wheels, they will proceed in contrary directions. When we know the annual value of the displacement of each of these seven stars, we can calculate their future relative positions. This I have done, and I here lay before the reader the curious results of my calculations.

In order to get an exact account of the difference in the form of this constellation, which will be observable at a given time, let us first portray its present state.

The Arabs gave these seven famous stars names which are sometimes applied to them still. Beginning with the hind off-wheel, and then taking in the order indicated by the Greek letters (β, γ, δ, ε, ζ, η) the other wheels and the horses, the Arab names are as follows: Dubhe,