Re: Path of light...

[David Bowman <dbowman@tiger.gtc.georgetown.ky.us>]

James McLean wrote:
> I don't see how the E- and B- parts of the EM wave can be meaningfully
> added together to get a "resultant."  Wouldn't that be like adding a force
> and a velocity?

Actually it is more like adding the x-component of a force to the y-component
of force for the same force vector.  The 6 components of the E and B fields
are different components of the antisymmetric 2nd rank electromagnetic
4-tensor.  The E field comprises the off diagonal time_space components of
this tensor and the B field comprises the antisymmetric part of the
space_space components of this tensor.  The time_time and the diagonal part
of the space_space components of this tensor vanish by antisymmetry.

Therefore adding E to B is essentially adding together different components
of the same tensor (like adding together two different components of the
same vector).

David Bowman
dbowman@gtc.georgetown.ky.us