363f3d85   
   From: d.goncz@replikon.net   
      
   [Moderator's note: The first post in this thread was borderline, this   
   one even more so.  Followups to the group should include substantial   
   PHYSICS content. -P.H.]   
      
   I'll try!   
      
   1) I can explain how, given constraints at a circular rim, the   
   manufacturers of my Snow Slider used hydraulic oil to form a parabolic   
   dish of 24 inch diameter sheet steel which I use with a 4G receiver to   
   reduce local interference and provide measureable gain to the tower,   
   where the constraint is in the polar coordinate system in the plane   
   initially, and how a trough of sheet metal forms a similar parabolic   
   reflector when sprung into place between parallel rails.   
      
   2) I can continue the analogies to Dassios's article to provide a STEM   
   teaching tool in chart form that I don't see anywhere else: from   
   confocal elliptic coordinates I can show first-, second- and third-   
   order degenerate cases, vertically in a list on the left, and   
   rightwards, the corresponding projections, par-axial rotations, and   
   trans-axial rotations that make up most of the orthogonal coordinate   
   systems, which are so much more easily remembered this way than   
   alphabetically, which is the usual presentation.   
      
   3) I can look for coordinate systems native to 4D space.   
      
   So I am asking for some direction in the face of the constraint, the   
   options I am providing being experimental, educational, and theoretical.   
      
   4) I can order Dassios's book and hold the posts.   
      
   Doug   
   LD/G@76/166IQ   
   100hr weeks   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)