From: nospam@de-ster.demon.nl   
      
   Jonathan Thornburg [remove -color to reply]    
   wrote:   
      
   [ASCII parabola]   
      
   > But in any of the "complete" layers of water (vertical positions z=1 a   
   > through z=5 inclusive), the force (b) I described above has to accelerate   
   > the larger mass of fluid "1", "2", ..., "B".   
   >   
   > This argues that the inwards force (b) I described above is larger in   
   > the z=1 through z=5 vertical positions than it is in the z=9 layer vertical   
   > position.   
   >   
   > Working out the precise variation of the force with vertical position   
   > is left as an exercise for the reader.   
      
   Which is again made trivial by noting that the centrifugal force can be   
   derived from the centrifugal potential. The parabolic shape is an   
   equipotential surface, [1] when everything is stationary in co-rotating   
   coordinates,   
      
   Jan   
      
   [1] So the surface is given by   g z = 1/2 \Omega^2 (x^2 + y^2) if the   
   origin is chosen suitably.   
      
   [added] So the centrifugal `force' is not just a force that acts   
   somewhere, it is actually a force field. It appears as such in for   
   example meteorological models, which are of course done on a rotating   
   Earth. (but Coriolis is more important)   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)