The purpose of these notes is to describe antenna calculations in terms of Maxwell's equations. Here we do not attempt a tutorial in the development of electromagnetic theory and Maxwell's equations themselves. It is sometimes argued that electromagnetic theory is one of the chief intellectual achievements of the human species over the last two centuries. Surprisingly, the understanding of electromagnetism embodied in Maxwell's Equations is relativistically invariant, and correct when interpreted in the light of Einstein's theory of special relativity. Quantities and units.
Electricity is a difficult substance to appreciate with the human senses.
About the only way you get a feeling for it is to moisten the tongue and apply it between the terminals of a 9 volt battery. Here are some electrical quantities and their SI units and symbols. Electric fields form lines which are trajectories along which a very small free charge would travel in the absence of a magnetic field in the same place. The flow of charge constitutes a current. Currents often travel along electric field line directions and generate magnetic fields.