Abstract
The velocity of the electromagnetic radiation in a perfect dielectric, containing no charges and no conduction currents, is explored and determined on making use of the Lorentz transformations. Besides the idealised blackbody radiation, whose vacuum propagation velocity is the universal constant c, being this value independent of the observer, there is another behaviour of electromagnetic radiation, we call inertial radiation, which is characterized by an electromagnetic inertial density , and therefore, it happens to be described by a time-like Poynting four-vector field which propagates with velocity . is found to be a relativistic invariant expressible in terms of the relativistic invariants of the electromagnetic field. It is shown that there is a rest frame, where the Poynting vector is equal to zero. Both phase and group velocities of the electromagnetic radiation are evaluated. The wave and eikonal equations for the dynamics of the radiation field are formulated.
Highlights
In his famous lecture delivered for almost 93 years to the Nordic Assembly of Naturalists at Gothenburg [1], A
The concept of velocity for the radiation fields is a long stated problem. This problem of the velocity of the electromagnetic waves has been always considered as a definitely solved problem: these waves have a velocity equal to c = 1 μ0 0 in the vacuum. From this formula, it follows that in the medium the velocity of the electromagnetic wave obeys the same formula v c= 1, μ which is used to be written as v = c, where n is the refractive index of the medium
We have been able to relate this velocity to the true physical group velocity of the radiation which is always present
Summary
In his famous lecture delivered for almost 93 years to the Nordic Assembly of Naturalists at Gothenburg [1], A. Oziewicz [8] (1998) proposed that the transportation of the energy by e-m radiation field is possible if only if the density of the momentum does not vanish with respect to all inertial observers He has argued that this may happen only in the system of reference moving with light-velocity equal to c, because for other systems of reference moving with velocities less than light-velocity, one may find such a system where the Poynting vector vanishes. Which is valid for the radiation field in the vacuum, in the medium holds no more true This argument is taken as a pivoting idea to introducing the concept of inertial e-m radiation field, as a transversal e-m field, which is principally characterized by the main condition.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
