Planetary Theory

Abstract

THERE are various definite theorems bearing on the impossibility of solving the problem of three (or n) attracting bodies. What is certain, in a practical sense, is that no general solution is attainable in a form suitable for comparison with observations even for a limited interval of time. Special methods have been devised for the two distinct types of motion which are present in the solar system, the motion of the planet and the motion of the satellite. In the latter case, when the satellite is identified with the moon, there results a problem of quite special character and quite extraordinary complexity. At the same time, it is essentially a single problem not lending itself naturally to piecemeal treatment. Adams, it is true, succeeded in discussing some of its leading features in an elementary way, besides obtaining some original results of value in theory and method. G. W. Hill, again, laid the foundations of a new theory without pursuing the subject beyond the preliminary stage. But in general the lunar theory is a theme for the specialist prepared to make it his life's work. Such a devotee was found in Prof. E. W. Brown, who has had the satisfaction of seeing his vast undertaking completed in every detail. Now, with a collaborator, he has brought his experience gained in the more special field to bear on the wider and more varied problem of planetary motion.

Planetary Theory.

Par By Prof. Ernest W. Brown Prof. Clarence A. Shook. Pp. xii + 302. (Cambridge: At the University Press, 1933.) 15s. net.