THE ELECTRON— COMPTON 223 



ress comes by spurts of advance as some big new idea opens up new 

 territory, alternating with periods of consolidation; (2) progress 

 comes not by revolution or discarding of past knowledge and experi- 

 ence, but is built upon past experience and is its natural extension 

 once the vision from new vantage points is secured; (3) there is 

 nothing so practical in its values as accurate knowledge, and the 

 pursuit of such knowledge has been most successful when not fettered 

 with the initial demand that it be directed toward practical ends. 



I would not give the impression that it is only the electron which 

 has given new life to modem physical science. A story of similar 

 interest could be built around the new concepts of radiation and 

 atomic energy as expressed in the quantum theory, or about the 

 electron's big brother, the proton, or his rather nondescript cousin, 

 the neutron. In the atomic nucleus is a field of further exploration 

 of enormous promise, now only beginning to be opened up by use of 

 radioactive materials, cyclatrons and high- voltage generators. 



Although these things have happened very recently, no one has 

 better described the process and intellectual value of this type of 

 scientific research than did Aristotle in the quotation which is 

 inscribed in Greek on the facade of the National Academy of Sciences 

 building in Washington: 



The search for truth is in one way hard and in another easy, for it is evident 

 that no one can master it fully nor miss it wholly. But each adds a little to our 

 knowledge of Nature, and from all the facts assembled there arises a certain 

 grandeur. 



