Resumen:
We demonstrate the utility of self-dual fields in electrodynamics. Stable configurations of free
electromagnetic fields can be represented as superpositions of standing waves, each possessing zero
Poynting vector and zero orbital angular momentum. The standing waves are themselves
superpositions of self-dual and anti-self-dual solutions. The idea of self-duality provides additional
insights into the geometrical and spectral properties of stable electromagnetic configurations, such
as those responsible for the formation of ball lightning