The Natuke of Physical Keality 93 



the form in which they probably exist in the nuclei 

 of the atoms. If the two charges are of opposite 

 sign, then the outward equatorial flux from the 

 proton will be continuous with the inward equa- 

 torial flux of the electron, and the outward polar 

 flux from the electron will be continuous with the 

 inward polar flux of the proton, so as to form a 

 closed circuit which will link the proton with the 

 electron in such a manner as to cause attraction ; 

 but as the two are brought more closely together 

 the repulsion effect of their oppositely moving 

 adjacent surfaces will become more pronounced, 

 so that a point will be reached where this force of 

 repulsion will be equal to the force of attraction, 

 which appears to explain why the electrons in the 

 outer regions of the atoms do not coalesce with 

 the protons of the nucleus. 



Another attempt to enter into the realm of the 

 incomprehensible in order to find the true explana- 

 tion of a natural phenomenon has been the recent 

 suggestion that gravitation may be due to a curva- 

 ture of space and that it may therefore constitute 

 something fundamentally different from the other 

 forces of nature. One of the main reasons which 

 have been advanced in support of this theory is 

 the fact that gravitation cannot be screened in the 

 same manner as electricity and magnetism. The 

 apparent screening of electric and magnetic 



