80 Dificonthmity in the Phenomena of Radiation 



which could absoib continuously and radiate discontinuoosly. 

 The truth is that there is at present little to choose between the 

 two views. It should be I'emarked that the former view could 

 be pushed still further and interpreted as the result of the fact 

 that there was an atomicity in energy itself, a s])eculation that 

 has been more or less implicit in the recent work of some of the 

 English school of Physicists, notably Sir J. J. Thomson. How- 

 ever, there does not appear to be any phenomena yet which 

 actually compel us to adopt such a revolutionary view ; but it is 

 doubtful if we will be able to escape from some form or other of 

 Planck's hypothesis. In itself it may turn out to be only one 

 result of a new scheme of dynamics, of which we are now getting 

 the first inklings in the case of these small scale vibratory 

 occurrences. 



The key-note of the new mechanics is discontinuity. Ac- 

 cording to it " A physical system is only susceptible of a finite 

 number of distinct states. It leaps from one of these states to 

 another without passing through a continuous series of inter- 

 mediate states." Such a statement bristles with difficulties, 

 which even the least conservative of minds may well shrink from 

 facing. Yet it seems that only by solving these difficulties can 

 real progress in physical science be effected. 



It may not be out of place to point out, in conclusion, that 

 this develoi)ment in physical theory is almost contemporaneous 

 with a movement in philosophy, associated with the name of 

 Professor Bergson, which regards the intellect as unable to grasp 

 the reality of Life ; as being only designed to isolate discrete 

 states and apply logical principles to their relations one with 

 another, but unadapted to apprehend the continuous fiow of 

 " becoming things." It is a well known fact that in any historical 

 epoch, a central idea seems to permeate all human institutions 

 and activities ; and the parallelism between Bergson's view and 

 the quotation in the previous paragraph, which is H. Poincare's 

 generalised form of the quantum hypothesis, seems sufficiently 

 striking to call for comment. 



