From: augustin.coppey@gmail.com   
      
   On Saturday, 12 January 2019 11:50:36 UTC+7, Luigi Fortunati  wrote:   
   > The second principle says that F=m*a and F1=m1*a1. (1)   
   >   
   > The third principle says that for every action F corresponds an equal   
   > and opposite F1 reaction, ie an F1 such that F1=-F. (2)   
   >   
   > Substituting the (2) to (1) we have F=m*a and -F=m1*a1.   
   >   
   > Adding the first and second members we have: F-F=(m*a)+(m1*a1), from   
   > which the corollary: m*a=-(m1*a1) in which there are no forces but only   
   > equivalences between different masses with different accelerations.   
   >   
   > Can we therefore say that for every quantity of "accelerating mass"   
   > (m*a) there is always another equal quantity of "accelerating mass"   
   > (m1*a1) in the opposite direction?   
   >   
   > [[Mod. note -- No.   
   > -- jt]]   
      
   This is a good example of hopeless usage of mathematics. The problem   
   described does not use physical information to guide the development of   
   the equations (where does the opposing reaction come from? Is this an   
   equilibrium? if yes, of what? etc.).   
      
   Instead starts with an arbitrary assumption that F1 = -F.   
      
   From there, it derives the equivalent of 0 = 0, which is rather useless   
   proof of anything. It certainly does NOT lead to the proposed   
   conclusion!   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)