SECTIONAL ADDRESSES. 
PROBLEMS OF PHYSICS. 
ADDRESS TO SECTION A (MATHEMATICS AND PHYSICS) BY 
PROFESSOR O. W. RICHARDSON, D.Sc., F.R.5., 
PRESIDENT OF THE SECTION. 
My predecessor in office a year ago reminded you that the theoretical 
researches of Hinstein and Weyl suggest that not merely the material 
universe but space itself is perhaps finite. As to the probabilities | 
do not wish to express an opinion; but the statement is significant 
of the extent of the revolution in the conceptions and fundamental 
principles of physics now in progress. That space need not be infinite 
has, I believe, long been recognised by geometricians, and appropriate 
geometries to meet its possible limitations have been devised by 
ingenious mathematicians. I doubt, however, whether these inventive 
gentlemen ever dreamed that their schemes held any objective validity 
such as would assist the astronomer and the physicist in understanding 
and classifying material phenomena. It is not certain that they will; 
but the possibility is definite. Apart from this, the whole development 
of relativity is an extraordinary triumph for pure mathematics. Had 
Einstein not found his entire calculus ready to hand, owing to the 
purely mathematical work of Christoffel, Riemann, and others, it seems 
certain that the development of generalised relativity would have been 
much slower. It is a pleasure to be able to acknowledge this indebted- 
ness of physics and astronomy to pure mathematics. 
Relativity is the revolutionary movement in physics which has 
caught the public eye, perhaps because it deals with familiar concep- 
tions in a manner which for the most part is found pleasantly incom- 
prehensible. But it is only one of a number of revolutionary changes 
of comparable magnitude. Among these we have to place the advent 
of the quantum, the significance of which I hope we shall thoroughly 
discuss early next week. The various consequences of the electronic 
structure of matter are still unfolding themselves to us, and are increas- 
ing our insight into the most varied phenomena at a rate which must 
have appeared incredible only a few decades ago. 
The enormous and far-reaching importance of the discoveries being 
made at Cambridge by Sir Ernest Rutherford cannot be over-empha- 
sised. These epoch-making discoveries relate to the structure and 
properties of the nuclei of atoms. At the present time we have, I 
think, to accept it as a fact that the atoms consist of a positively 
charged nucleus of minute size, surrounded at a fairly respectful distance 
oC ® 
