Excerpt from Philosophical Transactions of the Royal Society of London, Vol. 199: Series A, Containing Papers of a Mathematical or Physical Character; November 1902 The principal question involved in the nebular hypothesis seems to be the stability of a rotating mass of gas; but, unfortunately, this has remained up to now an untouched field Of mathematical research. We can only judge of probable results from the investigations which have beeri made concerning the stability of a rotating mass of liquid. In so far as the two cases are parallel, the argument by analogy will, Of course, be valid enough, but the compressibility Of a gas makes possible in the gaseous nebula a whole series of vibrations which have no counterpart in a liquid, and no inference as to the stability Of these motions can be drawn from an examination of the behaviour Of a liquid. Thus, although there will be unstable vibrations In a rotating mass Of gas similar to those which are known to exist in a rotating liquid, it does not at all follow that a rotating gas will become unstable, in the first place, through vibrations which have a counterpart in a rotating liquid it is at any rate conceivable that the vibrations through which the gas first becomes unstable are vibrations in which the compressibility Of the gas plays SO prominent a part, that no vibration Of the kind can occur in a liquid. If this is so, the conditions Of the formation of planetary systems will be widely different in the two cases. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.