From: fortunati.luigi@gmail.com   
      
   The BC stick is dropped vertically into an endless well.   
      
   Let M be the midpoint between B and C.   
      
   In this mental experiment, the  acceleration of M (relative to the   
   well) is constant.   
      
   When the stick speed becomes relativistic, does the acceleration of   
   points B and C (always in the well reference) remain equal to  or   
   is it greater or lesser?   
      
   --   
   Luigi Fortunati   
      
   Credere =E8 pi=F9 facile che pensare   
   Believing is easier than thinking   
      
   [[Mod. note -- I think this Gedanken-experiment is somewhat related   
   to Bell's spaceship paradox   
     https://en.wikipedia.org/wiki/Bell%27s_spaceship_paradox   
   -- jt]]   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)