Contemporary Advances in Physics, XIX. 



Fusion of Wave and Corpuscle Theories. 



By KARL K. DARROW. 



In this article certain of the simple and familiar phenomena of optics and 

 of electronics — for instance, refraction at a boimdary between two media, 

 and diffraction by a grating — ^are interpreted by both of the theories, undu- 

 latory and corpuscular, which have so often been condemned as incom- 

 patible with one another; the attitude being, that the theories may be 

 brought into concordance by modifying one at least in ways which, extra- 

 ordinary as they seem, do not quite destroy its character. 



NOT quite five years ago I published in this journal an article 

 entitled Waves and Quanta, expounding there the data which 

 invited a corpuscular theory of light, regardless of the great array of 

 classical phenomena of optics which demanded with no less insistence 

 the long-triumphant undulatory theory. Today, not only are those 

 data still extant and undeniable; they have been reinforced by obser- 

 vations on electron-streams which have compelled a wave-theory of 

 free negative electricity, despite the very abundant evidence for free 

 corpuscular electrons. Most physicists expect that not only light and 

 negative electricity, but whatever other fundamentals there may be — 

 meaning, probably, positive electricity and nothing else — will be 

 found to conform in some ways to simple wave-theory, and in some to 

 simple particle-theory. Most physicists, I think, would concede that 

 the two ideas must be forced into one scheme, whatever violence it 

 may entail to others of our preconceptions, inborn or inbred. We 

 must stretch the theories and our minds, so that corpuscles and 

 waves shall appear no longer as alternatives of which election must 

 be made, but as complementary aspects of one reality. 



To make a beginning with this process of stretching, I propose to 

 treat some of the very simplest and most familiar of the phenomena, 

 which up to lately have been interpreted by ofie only of the theories: 

 phenomena such as the refraction of light in passing from air to water, 

 the bending of the paths of electrons in passing from vacuum into 

 metal, the diffraction of light and electrons from a ruled ditifraction- 

 grating. (None of these examples, incidentally, involves a theory of 

 the structure of the atom.) Each of them shall be interpreted by the 

 other theory — not in order to substitute the other for the one, but in 

 order to practice the art of using both theories in alliance. 



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