I recently came across a question that got me thinking: "Does the electric field of a charged particle affect the particle itself?"
Here’s my reasoning against it:
Newton’s Second Law: According to Newton’s second law, the net external force experienced by a particle is equal to the rate of change of its momentum. A force exerted by the particle’s own electric field would not qualify as an external force. If such a self-force existed, it would imply that the charged particle must accelerate and move, even in the absence of external forces.
Direction of Motion: If a particle could exert a force on itself, it would raise the question: in what direction would the particle move? The electric field of a stationary charge is spherically symmetric, so there’s no preferred direction for motion. This makes the idea of self-induced acceleration problematic.
Balanced Forces: One might also argue that the particle could experience forces from its own electric field in all directions. However, due to the symmetry of the field, these forces would balance out, leading to no net motion.
Question: Am I correct in concluding that the electric field of a charged particle cannot affect the particle itself in classical physics? How do the concepts of self-force and self-energy fit into this picture in more advanced theories?
