physics, greeting the return to the unseen with a tribal cheer:

     Once the space-element or point had lost its last 
     persistent relic of visualness and, instead of being 
     represented to the eye as a cut in co-ordinate lines, was 
     defined as a group of three independent numbers, there 
     was no longer any inherent objection to replacing the 
     number 3  by the general number n.  The notion of 
     dimension was radically changed. It was no longer a 
     matter of treating the properties of a point metrically 
     with reference to its position in a visible system, but of 
     representing the entirely abstract properties of a number-
     group. . .

      “Entirely abstract” means the nonvisual resonating 
interplay of the audile-tactile by which electricity and radio