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Re: Waves

I just realized that I probably need to clarify a point in my last post.
I had said:
...
BTW, the momentum flux is given by the stress tensor, not c times the
momentum density anyway. ....

I should point out that the engineering dimension that this symmetric
2nd rank (stress) tensor comes in depends on the spatial dimensionality
of the medium. If the medium is 3-dimensional then its dimension is that
of force/area. If the medium is 2-dimensional then its dimension is
force/length. If (as is the case for James' string example) the medium
is 1-dimensional then its dimension is just plain force and the tensor
then only has 1^2 = 1 component.

David Bowman
dbowman@georgetowncollege.edu