nutting: the ether 197 



all the evidence afforded by the propagation of radiation through 

 space is against that space being void and in favor of an ether 

 with very definite electric and magnetic but without mechanical 

 properties. 



3. A third group of evidence bearing on the existence of the 

 ether consists in those phenomena indicating a storage of energy 

 in the neighborhood of an electric charge in actual motion. These 

 phenomena correspond with self induction in the case of ordinary 

 electric currents. Cathode ray particles, the Beta particles from 

 radium and similar objects carrying electric charges with high 

 velocities, carry more energy than corresponds with their material 

 mass and velocity, electro-magnetic energy of the adjacent me- 

 dium. This may even be separated from the matter and charge 

 and measured as energy in the form of Rontgen or of Gamma 

 rays. 



These phenomena, to my mind, supply the most direct evidence 

 of the existence of a medium. If there were nt> medium how could 

 a moving charge carry or conduct along with itself, outside it- 

 self energy of motion. How could a bullet moving in void space 

 possess energy of motion exterior to itself? It may be thought 

 that the assumption of lines and tubes of force as physical entities 

 would provide an escape from the assumption of a medium. But 

 such an assumption merely displaces the dilemma. If we con- 

 sider that the region adjacent to a moving charge is filled with 

 actual tubes of force instead of merely being an electromagnetic 

 field, how, without a medium, could the sizes and shapes of these 

 tubes be a function of the velocity of the charge. 



4. To most of us it is a significant fact that not one of those 

 whose work has been largely instrumental in the overthrow of 

 the mechanical theory — H. A. Lorenz, Poincare, Planck, Larmor, 

 J. J. Thomson, Schuster, Whittaker, Heaviside, Wiechert, or 

 Michelson — appears to question the existence of an ether without 

 mechanical properties. 



The no-ether school may fairly be compared with the no-atom 

 school of Energetics. If we ignore the ether or the atom we may 

 treat a considerable portion of physics quite satisfactorily but we 

 must ignore a great many vital and significant phenomena in so 

 doing. 



