LECTURE IV NOTE B.—P. 127.

EVOLUTION IN INORGANIC NATURE—THE NEBULAR HYPOTHESIS.

This famous hypothesis of Kant and Laplace is frequently spoken of as if it had become an established fact of science; and it forms an integral part in most sketches of the process of cosmic evolution (as in Strauss, Spencer, Clodd, etc.). Yet so far is it from being established, that the objections to its sufficiency seem to multiply and strengthen as years go on, and many eminent men of science reject it altogether.

Mr. B. A. Proctor, in an article on the “Meteor Birth of the Universe,” contributed to the Manchester Examiner and Times, May 29, 1888, thus speaks of it:—

“The nebular theory of Laplace has long held a somewhat anomalous position. Advanced by its distinguished author as a mere hypothesis, in days when the word ‘hypothesis’ had still its proper significance (as shown in Newton’s saying, ‘Hypotheses non fingo’), it had from the beginning a fascination for most minds, which led to its acceptance as if it had been a veritable theory. Yet it has never been accepted as a theory by one single student of science who has possessed adequate knowledge of physics, combined with adequate knowledge of astronomy and mathematics.”

After sketching the theory, he proceeds: “The nebulous speculation of Laplace is open to two most serious objections. In the first place, as I have already pointed out, a vaporous mass of enormous size, and of the exceeding tenuity imagined, could not possibly rotate in a single mass in the manner suggested by Laplace. In the second place, some of the most characteristic peculiarities of the solar system remain altogether unaccounted for by this speculation, ingeniously though it accounts for others.”

These objections are then developed. Mr. Proctor’s rival theory is that of “Meteoric Aggregation.” See, further, his More Worlds than Ours, chapter on “Comets and Meteors.”

A searching examination of this theory, embodying the views of M. Babinet, may be seen in Stallo’s Concepts of Modern Physics (International Library), pp. 277–286.

Sir Robert S. Ball, Professor of Astronomy at Cambridge, says of it: “Nor can it be ever more than a speculation; it cannot be established by observation, nor can it be proved by calculation. It is merely a conjecture, more or less plausible, but perhaps m some degree necessarily true, if our present laws of heat, as we understand them, admit of the extreme application here required, and if also the present system of things has reigned for sufficient time without the intervention of any influence at present unknown to us.”—The Story of the Heavens, p. 506