Resumen:
It is shown that the generally accepted definition of the Poynting vector and the energy flux
vector defined by means of the energy density of the electromagnetic field (Umov vector) lead to the
prediction of the different results touching electromagnetic energy flux. The experiment shows that within
the framework of the mentioned generally accepted definitions the Poynting vector adequately describes
the electromagnetic energy flux unlike the Umov vector. Therefore one can conclude that a generally
accepted definitions of the electromagnetic energy density and the Poynting vector, in general, are not
always compatible.