THE NEW ASTRONOMY.

This century has been conspicuous above all centuries for new things.  Man has grown into new relations with both nature and thought.  He has interpreted nearly everything into new phraseology and new forms of belief.  The scientific world has been revolutionized.  Nothing remains in its old expression.  Chemistry has been phrased anew.  The laws of heat, light and electricity have been either revised or discovered wholly out of the unknown.  The concept of universal nature has been so translated and reborn that a philosopher coming again out of the eighteenth century would fail to understand the thought and speech of even the common man.

In no other particular has the change been more marked than with respect to the general theory of the planetary and stellar worlds.  A New Astronomy has come and taken the place of the old.  The very rudiments of the science have to be learned as it were in a new language, and under the laws and theories of a new philosophy.  Nature is considered from other points of view, and the general course of nature is conceived in a manner wholly different from the beliefs of the past.

In a preceding study we have explained the general notion of planetary formation according to the views of the last century.  The New Astronomy presents another theory.  Beginning with virtually the same notion of the original condition of our world and sun cluster, the new view departs widely as to the processes by which the planets were formed, and extends much further with respect to the first condition and ultimate destiny of our earth.  The New Astronomy, like the old, begins with a nebular hypothesis.  It imagines the matter now composing the solar group to have been originally dispersed through the space occupied by our system, and to have been in a state of attenuation under the influence of high heat.  Out of this condition of diffusion the solar system has been evolved.  The idea is a creation by the process of evolution; it is evolution applied to the planets.  More particularly, the hypothesis is that the worlds of our planetary system grew into their present state through a series of stages and slow developments extending over aeons of time.

This is the notion of world-growth substituted for that of world-production en masse by the action of centrifugal force and discharge from the solar equator.  The New Astronomy proposes in this respect two points of remarkable difference from the view formerly entertained.  The first relates to the fixing of the planetary orbits, and the other to the process by which the planets have reached their present mass and character.  The old theory would place a given world in its pathway around the sun by a spiral flinging off from the central body, and would allow that the aggregate mass of the globe so produced was fixed once for all at the beginning.  The new theory supposes that a given planetary orbit, as for instance that of the earth, was marked in the nebula of our system before the system existed—­that is, that our orbit had its place in the beginning just as it has now; that the orbit was not determined by solar revolution and centrifugal action, but that it was mathematically existent in the nebular sheet out of which the solar system was produced.