Chapter 7 treated the problem of how electromagnetic fields are generated by time varying charge and current distributions. Electro-magnetic fields transport energy and momentum through space, and this chapter is concerned about how to calculate the energy density contained in those fields and how to calculate the rate of energy transport. Scattering from atoms or molecules is also discussed, as are the generation of the continuous X-ray spectrum produced in an X-ray tube.
Thumbnail: Animation of a half-wave dipole antenna transmitting radio waves, showing the electric field lines. (Public Domain; Chetvorno via Wikipedia)