From: ram@zedat.fu-berlin.de   
      
   Kuan Peng  wrote or quoted:   
   >Please see this:   
   >Le 29/01/2026 à 23:13, ram@zedat.fu-berlin.de (Stefan Ram) a écrit :   
   >>Kuan Peng  wrote or quoted:   
   >>>Electromagnetism has many paradoxes. For example, Lorentz force violates   
   >>>Newton’s third law.   
   >>This is true. But it just means that Newton's laws have a limited   
   >>scope. I do not deem this to be an actual paradox, because we can   
   >>clearly see that here electromagnetism has priority over Newton.   
   >>|In electrostatics and magnetostatics the third law holds,   
   >>|but in electrodynamics it does not.   
   >>"Newton’s Third Law in Electrodynamics" in "Introduction to   
   >>electrodynamics" (2013) by David J. Griffiths.   
      
     Here's an example for this (taken from Griffiths):   
      
     Assume, q1 is moving along the x axis at constant speed,   
     and q2 has the charge of q1 and is moving along the y axis   
     at the same speed.   
      
     The electric force is repulsive.   
      
     The magnetic field of of q1 at q2 points into the page,   
     so the magnetic force on q2 is towards the /right/.   
     (The "page" on which the coordinate system is drawn.)   
      
     The magnetic field of of q2 at q1 points out of the page,   
     so the magnetic force on q1 is /upwards/.   
      
     So, the force of q1 on q2 is /not/ opposite to the force   
     of q2 on q1.   
      
     (We can assume additional forces guiding the two particles to move   
     along those two axes at constant speed to fulfill our preconditions.)   
      
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