Re: [Phys-l] Force on a charged particle from a magnetic field

[John Mallinckrodt <ajm@csupomona.edu>]

On Nov 28, 2006, at 9:58 AM, Bob LaMontagne wrote:

> But my question is how we justify the answer to this narrowly posed  
> question
> in terms of the E&M available in an introductory physics course.  
> Where does
> the electric field that the (assumed stationary) proton experiences  
> come
> from since there is no time varying magnetic flux from a uniform  
> field?

But there is time varying flux in the frame of the proton.  The only  
way to avoid that involves using an infinitely large magnet.

> Is an appeal to a relativistic transform of the field tensor the only
> answer? Is it correct that Maxwell's equations alone, with no  
> appeal to
> relativity, cannot answer the question?

Maxwell's equations have relativity built into them so they are, in  
principle, fully capable of answering the question.

John Mallinckrodt

Professor of Physics, Cal Poly Pomona
<http://www.csupomona.edu/~ajm>

and

Lead Guitarist, Out-Laws of Physics
<http://outlawsofphysics.com>