From: fortunati.luigi@gmail.com   
      
   Hendrik van Hees il 10/06/2024 14:10:37 ha scritto:   
   > Or to put it simpler. In a local inertial reference frame, realized by a   
   point-like non-rotating body in free fall, you observe (e.g., by using   
   pointlike test particles) only the "true gravitational forces", i.e., the   
   tidal forces.   
   >   
   > If you sit on the surface of a planet, you are not in free fall, because   
   there are (electromagnetic) forces keeping you there.   
   >   
   > That's why the accelerometer of your smart phone at rest on Earth shows an   
   acceleration of 9.81 m/s^2, because it measures accelerations relative to a   
   local inertial frame of reference! See, e.g.,   
      
   Your reasoning is based on two preconceptions.   
      
   The first is that the accelerometer measures accelerations (and instead   
   it only measures forces) and the second is that free fall is an inertial   
   reference system despite its very evident mutual acceleration towards   
   the other body (also) in free fall.   
      
   Luigi Fortunati   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)