From: phch@notmail.com   
      
   Dr John Stockton  wrote in   
   news:+IpzOkB1XhOBFw4F@merlyn.demon.co.uk:   
      
      
      
   > To be elementary, the body must be spherically symmetrical, but need   
   > not otherwise be homogeneous.  It is, of course, the field of the body   
   > to which you refer; the total field at the centre of a tennis ball is   
   > one gee.  In that case, symmetry alone is sufficient; any symmetrical   
   > law of gravity would give the same result.   
   >   
   > The interesting result, requiring the inverse square law and otherwise   
   > only elementary arguments, is that the field *anywhere* within a   
   > homogeneous spherical shell due to the shell is zero.   
   >   
   > I lack an equally elementary argument for the field outside a   
   > spherical shell; but I have Ramsey's version of Newton's.   
   >   
      
      
      
   Are you saying that all spherical bodies have their   
   own gravitational field, simply based on their   
   spherical shape, and perhaps density and size?   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)