Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. In physics, the Poynting vector can be thought of as representing the energy flux (in W/m2) of an electromagnetic field. It is named after its inventor John Henry Poynting. Oliver Heaviside independently co-discovered the Poynting vector. Sometimes, an alternative definition in terms of electric field E and the magnetic field B is used, which is explained below. It is even possible to combine the displacement field D with the magnetic field B to get the Minkowski form of the Poynting vector, or use D and H to construct another. A generalization to dispersive materials is possible under certain circumstances at the cost of additional terms and the loss of their clear physical interpretation.