Wave Energy (Electromagnetic Waves)

Electric and magnetic fields can store energy, and its density relates to the strength of the fields within a given volume. In ideal (linear and non-dispersive) media, the energy density \(u\) is given by

\[u = \frac{1}{2} \left( \vec E \cdot \vec D + \vec H \cdot \vec B \right)\]

Here, \(\vec E\) is the electric field, \(\vec D\) is the electric displacement field, \(\vec H\) is the magnetizing field, and \(\vec B\) is the magnetic field.

Links:

1. Wikipedia — Energy density — Electric and magnetic fields

2. Wikipedia — Radiant energy density

Contents:

• Energy density via permittivity and electric field
  • energy_density
  • absolute_permittivity
  • electric_field_strength
  • law