Impossibility of the fission hypothesis

According to the fission theory, the origin of binary stars is regarded as due to the break-up of a single mass by its rotation. There are a number of grave astrophysical difficulties in this theory such as the question of the source of the necessary angular momentum, whether the density distribution in stars and its evolution are consistent with fissional disruption, whether the distribution of mass-ratios and separations are explicable on the theory, and the whole general problem of stellar evolution itself. We will not attempt to discuss these here but will concern ourselves solely with examining the fission process itself, as proposed by its advocates, on purely dynamical grounds. A general secular increase of angular momentum will be assumed, with the density remaining uniform, since this is equivalent to constant angular momentum with density increasing gradually. These are the assumptions on which both Darwin and Jeans based their ideas on fission.

Now, as already explained in the introduction, had Darwin's conclusion, that the pear-shaped figure is secularly stable, been correct, it might then have been fairly plausible to suppose that the deepening of the furrow with evolution along the series was some indication that the mass would eventually divide into two parts in orbital motion about each other (though information on the initial stages of this process by no means necessarily secured that the pear-shaped series itself did not bifurcate later to some new form). But when Jeans's studies, in agreement with those of Liapounoff, contradicted Darwin's conclusion, the sole grounds on which Darwin based his description of the fissional process were completely removed. Yet Jeans nevertheless finally maintained exactly the same outcome of the process as Darwin, namely, fission into two detached masses moving in almost circular orbits about each other. Jeans's view obviously amounted to asserting that the evolution of the mass would be quite independent of whether the pear-shaped series happened to be secularly stable or unstable, and hence that the whole of the investigations establishing the incorrectness of Darwin's conclusions, or indeed any studies of this problem at all, were valueless from the point of view of cosmogony, since the outcome of the process in either case would be the same.