I confess to not understanding the point John D is making below, by
introducing space-time language and the electro-magnetic tensor F, to
the discussion, however, more elaboration may help me.
Let me repeat my question in that language (ascii makes it hard, so ask
for clarifications if needed)
Choose any inertial frame you care, but choose one:
Find F in that frame,
Where F == 6/\A
Where 6 == the 4dim space-time version of the del operator.
We have a charge particle whose energy is increasing,
Is it the time-like components of F that are doing mechanical work on
the charge? And/or is it the spatial components of F?
________________________
Joel Rauber
Department of Physics - SDSU
Joel.Rauber@sdstate.edu
605-688-4293
. . .
|
| By the same token, in spacetime there is really only one critter, F.
| In any given observer's reference frame we can decompose F
| into an E piece and a B piece, but another observer may
| decompose it differently.
|
| Actually, the invariant gorm of F is equal to B^2 - E^2, so all
| observers agree on whether the field is "mostly" magnetic
| or "mostly"
| electric, but that is not very helpful to the present discussion.
| We have a mostly magnetic field which does/doesn't have a small but
| important electric component.
|