Recreations in Astronomy eBook

This eBook from the Gutenberg Project consists of approximately 235 pages of information about Recreations in Astronomy.

Recreations in Astronomy eBook

This eBook from the Gutenberg Project consists of approximately 235 pages of information about Recreations in Astronomy.

This movement would have no effect on the apparent place of the stars at either pole, if they were all equally distant; but it must greatly extend or contract the apparent space between them, since they are situated at various distances.

Independent of this, the stars themselves are all in motion, but so vast is the distance from which we observe them that it has taken an accumulation of centuries before they could be made measurable.  A train going forty miles an hour, seen from a distance of two miles, almost seems to stand still.  Arcturus moves through space three times as fast as the earth, but it takes a century to appear to move the eighth part of the diameter of the moon.  There is a star in the Hunting Dogs, known as 1830 Groombridge, which has a velocity beyond what all the attraction of the matter of the known universe could give it.  By the year 9000 it may be in Berenice’s Hair.

Some stars have a common movement, being evidently related together.  A large proportion of the brighter stars between Aldebaran and the Pleiades have a common motion eastward of about ten seconds a century.  All the angles marked by a, b, g, ch Orionis will be altered in different directions; l is moving toward g. l and e will appear as a double star.  In A.D. 50,000 Procyon will be nearer ch Orionis than Rigel now is, and Sirius will be in line with a and ch Orionis.  All the stars of the Great Dipper, except Benetnasch and Dubhe, have a common motion somewhat in the direction [Page 228] of Thuban (Fig. 67), while the two named have a motion nearly opposite.  In 36,000 years the end of the Dipper will have fallen out so that it will hold no water, and the handle will be broken square off at Mizar.  “The Southern Cross,” says Humboldt, “will not always keep its characteristic form, for its four stars travel in different directions with unequal velocities.  At the present time it is not known how many myriads of years must elapse before its entire dislocation.”

These movements are not in fortuitous or chaotic ways, but are doubtless in accordance with some perfect plan.  We have climbed up from revolving earth and moon to revolving planets and sun, in order to understand how two or ten suns can revolve about a common centre.  Let us now leap to the grander idea that all the innumerable stars of a winter night not only loan, but must revolve about some centre of gravity.  Men have been looking for a central sun of suns, and have not found it.  None is needed.  Two suns can balance about a point; all suns can swing about a common centre.  That one unmoving centre may be that city more gorgeous than Eastern imagination ever conceived, whose pavement is transparent gold, whose walls are precious stones, whose light is life, and where no dark planetary bodies ever cast shadows.  There reigns the King and Lord of all, and ranged about are the far-off provinces of his material systems.  They all move in his sight, and receive power from a mind that never wearies.

Copyrights
Project Gutenberg
Recreations in Astronomy from Project Gutenberg. Public domain.