Good resources for learning a little about the wave vector

[phantomvommand]

TL;DR Summary

Hi, I am looking for a short document discussing the usage of the wave vector. Any recommendations? Thank you!

Alternatively, you could give a brief introduction here; I’m mainly confused about how k can be a vector.

Hi, I am looking for a short document discussing the usage of the wave vector. Any recommendations? Thank you!

 

[etotheipi]

Do you have access to Griffiths E&M? Chapter 9 ought to do the trick.

 

[etotheipi]

Also, I'd forgotten that David Morin also published a draft textbook on waves, available for free: https://scholar.harvard.edu/david-morin/waves

Take a look at section 8.3.1 here: https://scholar.harvard.edu/files/david-morin/files/waves_electromagnetic.pdf

 

[robphy]

It might be helpful to think about "the surfaces of constant phase", then the wave vector is akin to the gradient.
(An electrostatics analogy would be "equipotential surfaces", then the electric field is [minus] the gradient.)

Possibly useful:
https://atmos.washington.edu/~hakim/542/wave_properties.pdf
(the accepted answer for) https://physics.stackexchange.com/q...rms-as-introduced-in-gravitation-kip-s-thorne