From: fortunati.luigi@gmail.com   
      
   Sylvia Else alle ore 10:52:40 del 17/07/2017 ha scritto:   
   >> 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?   
   >   
   > We're not told which of B and C is the upper end.   
      
     Let B be the top and C the lower one.   
      
   > However, the   
   > acceleration of the upper end is greater than that of M, and the   
   > acceleration of the lower end is less than that of M. Thus the stick   
   > gets shorter in the frame of the well (but not, of course, in the frame   
   > of the stick).   
      
     So ahead of B runs the shaft wall with greater acceleration than it   
   does run in front of C, right?   
      
   Luigi.   
      
   --   
   Luigi Fortunati   
      
   Credere e' piu' facile che pensare   
   Believing is easier than thinking   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)