Accelerate Charged Particle: Does Light Require Force?

[MackBlanch]

Does a charged particle need to experience a momentum changing force to emit light? Or is it sufficient for an observer to accelerate relative to the particle?

 

[mfb]

Light emission by a particle is independent of the reference frame. It does not matter what the observer does, it matters if the particle is inertial or not.

 

[MackBlanch]

Sorry, I'm not familiar with the term, "inertial particle".

So, it's not relative motion that drives emission, but changes in a charged particle's momentum?

For instance, if you shake one particle in a two particle system, the shaken particle will not experience an emission from the stationary particle? (at least not before its emission agitates the stationary particle)

 

[rkolter]

It comes down to this - if the charged particle accelerates relative to it's electric field, then it will emit. If it does not accelerate relative to it's electric field, it will not emit. The acceleration of the observer relative to the particle and it's electric field does not cause the particle to appear to accelerate relative to its electric field.

 

[mfb]

Inertial = no acceleration

So, it's not relative motion that drives emission, but changes in a charged particle's momentum?

Right.

For instance, if you shake one particle in a two particle system, the shaken particle will not experience an emission from the stationary particle?

Right.

 

[MackBlanch]

Inertial = no acceleration
Right.
Right.

Thanks!