nutting: the ether 199 



untenable, the electromagnetic Maxwell ether stands just where 

 it always stood. It has been attacked, without much effect, by 

 the extreme relativists, strengthened by the electron theory and 

 brought into prominence by the pruning away of the mechanical 

 theory. 



As the conservation of energy is the simplest general principle 

 which will make perpetual motion impossible, so the simplest 

 physical law that will permit of discarding all the mechanical 

 attributes of the ether is the principle of relativity. Each of 

 these principles are, however, but limited forms of more general 

 laws. 



Before 'outlining the properties of the ether let us consider 

 briefly its mathematical framework in the newer physics of which 

 the relativity theory is the most conspicuous landmark. Mathe- 

 matical physicists (Lorenz, Minkowski, Abraham, Einstein) have 

 found that apparent experimental contradictions disappear and 

 the mathematical framework of physics is greatly simplified if, 

 instead of referring phenomena to a set of three space axes and 

 one time axis of reference, they are referred to a set of four inter- 

 changeable axes involving 4 homogeneous coordinates, three of 

 space and one of time. There are an infinite number of ways 

 of projecting the four dimensional (x, y, z, t) space into the x, y, z, 

 and t space. Phenomena that are ambiguous and contradictory 

 when one projection is used are simple and harmonious with 

 another projection. Further, if a star, say, is in motion relative 

 to one x, y, z, t system, it will be at rest with respect to some other 

 system of axes. Relativity is a particular instance of the appli- 

 cation of these principles. Already gravitation, that most recon- 

 dite of all physical facts, is yielding to this four dimensional 

 analysis. What we have here to keep in mind is that in order to 

 explain the lack of ether drift it is unnecessary to annihilate or 

 ignore either space or time intervals but merely to generalize our 

 axes of reference. 



Three classes of physical phenomena may take place within or 

 across space void of matter: 



(a) Forces may act. Electric, magnetic, gravitational (and pos- 

 sibly chemical) forces act across space even when no matter inter- 





