The evolutlon of stellar systems1

ABSTRACT ABOUT a century ago Laplace presented to the world an hypothesis concerning the mechanics of the heavens, basing it on sound dynamical principles, and working it out with that

genius which he alone at that time could bring to bear. This hypothesis, grand and general as it was and still is, has made his name familiar to every student of astronomy of to-day; and the

equipment of a modern observatory enables us to observe more minutely the stellar systems (which he could not see, but only imagine), and wonder at his far-reaching mind in expounding such

a simple scheme of evolution for them. Modern investigations have necessitated, however, a modification of Laplace's original hypothesis. In his time the view was held that figures of

equilibrium of rotating bodies were necessarily surfaces of revolution about the axes of rotation, but thanks to the mathematical researches of Jacobi, Darwin, Poincaré, &c, this is

found now not to be universally true. To-day, for instance, if we consider the revolution of two separate fluid masses so close to one another that they are caused to coalesce and form a

rigid system, through tidal distortions, then the form of the resulting mass will be dumbbell shaped, approximating to Poincare's apioid. It is regarding the mutual reaction of two such

bodies as these that the author of the volume under consideration has recently made mathematical investigations, and he has not limited himself to the purely mathematical side of the

problem, but has extended the view to the stars in space, which according to the ideas now held are not solid bodies, but masses of matter in which tidal action can have full play. It seems

exceedingly probable, he says, “that the great eccentricities now observed among double-stars have arisen from the action of tidal friction during immense ages: that the elongation of the

real orbits, so unmistakably indicated by the apparent ellipses described by the stars, is the visible trace of a physical cause which has been working for millions of years. It appears that

the orbits were originally nearly circular, and that under the working of the tides in the bodies of the stars they have been gradually expanded and rendered more and more eccentric.”

ARTICLE PDF Authors * WILLIAM J. S. LOCKYER View author publications You can also search for this author inPubMed Google Scholar RIGHTS AND PERMISSIONS Reprints and permissions ABOUT THIS

ARTICLE CITE THIS ARTICLE LOCKYER, W. The Evolutlon of Stellar Systems1. _Nature_ 56, 295–296 (1897). https://doi.org/10.1038/056295a0 Download citation * Issue Date: 29 July 1897 * DOI:

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