Sir James Jeans, O.M., F.R.S

Abstract

SIR JAMES JEANS the celebrated mathematician and astronomer, died on September 16, at the age of sixty-nine. Expositor of science, philosopher, musician, he was above all a powerful and prolific applied mathematician, who made fundamental advances, in the theory of gases and the physics of the atom of the photon and of quanta on one hand, and the physics of the stars and nebulæ, their structure and evolution, on the other. As life went on, he became more and more devoted to astronomy, cosmogony and allied fields; but he interpreted these disciplines in the widest sense, able to combine simultaneously the most minute detail with the grandest generality. No one can read his treatises, even his text-books, without experiencing an under-current of growing excitement as solution succeeds to formulated problem; the reader feels himself in the presence of a master-mind. Indeed, his name will always be linked with those masters in the true Newtonian tradition—with Roche, Poincaré, Schwarzschild, Sir George Darwin and Liapounoff, who formulated, grasped the cosmic importance of, and by degrees solved, the question of the stability of equilibrium configurations of rotating masses of fluid. Of these, Jeans may be most fitly compared with Poincaré; both were attracted by, and both took part in the birth of, modern atomic physics and the quantum theory; both attached great importance to thermodynamics; both made some of their most characteristic contributions in the theory of rotating fluids and cosmogonic hypotheses; both were possessed of a fine mathematical style which banished dullness even from apparently arid calculations; and both wrote extensively on the philosophical aspects of science.