Astrophysics (index)

Poynting Vector

(measures directional energy flux density)

A Poynting Vector is the directional energy Flux-density (energy transfer in watts per square meter) of an Electromagnetic (EM) field. It indicates the Magnitude and direction of the flow of energy in electromagnetic waves. It was conceived by John Henry Poynting.

S = E × H
  • E - electric field
  • H - magnetic field