1908] Thf Ether of Space. 61 



WEP]KLY EVENING MEETING, 

 Friday. Febniaiy 21, 1908. 



The Right Hon. Lord Raylei&h, O.M. P.O. M.A. D.C.L. LL.l). 

 Sc.I). Pres.R.8.. in the Chair. 



Sir Oliver LodCxE, LL.D. D.Sc. F.R.S. 3LRJ. 



The Ether of Space. 



[abstract.] 



Thirty years ago Clerk Maxwell g-ave in this place a remarkable 

 address on " Action at a Distance." It is reported in yonr Jonl^nal, 

 Vol. VII., and to it I wonld direct attention. Most natural philo- 

 sophers hold, and have held, that action at a distance across empty 

 space is impossible ; in other words, that matter cannot act where it 

 is not, but only where it is. The question '• where is it ? " is a 

 further question that may demand attention and require more than 

 a superlicial answer. For it can be argued on the hydrodynamic 

 or vortex theory of matter, as well as on the electrical theory, that 

 every atom of matter has a universal though nearly infinitesimal 

 prevalence, and extends everywhere ; since there is no definite sharp 

 laoundary or limiting periphery to the region disturbed by its 

 existence. The lines of force of an isolated electric charge extend 

 throughout illimitable space. And though a charge of opposite ?ign 

 will curve and concentrate them, yet it is possible to deal with 

 both charges, by the method of superposition, as if they each existed 

 separately without the other. In that case, therefore, however far 

 they reach, such nuclei clearly exert no " action at a distance " in the 

 technical sense. 



Some philosophers have reason to suppose that mind can act 

 directly on mind without intervening mechanism, and sometimes 

 chat has been spoken of as genuine action at a distance ; but, in the 

 first place, no proper conception or physical model can be made of 

 such a process, nor is it clear that space and distance have any par- 

 ticular meaning in the region of psychology. The links between mind 

 and mind may be something quite other than physical proximity, 

 and in denying action at a distance across empty space I am not 

 denying telepathy or other activities of a non-physical kind : for 

 although brain disturbance is certainly physical and is an essential 



