The generalized photon moves with velocity v of magnitude [parallel]v[parallel] = c in any inertial reference frame.

This transformation holds for the volume dV of a material particle that is at rest in the inertial reference frame S'.

The elementary volume of the generalized photon in the inertial reference frame S ' is

We initially calculate the energy density D' in the inertial reference frame S' in which the material particle is at rest.

Tangherlini's formula (2) gives an explanation to the results obtained in the Michelson-Morley experiment [9] and also in the Kennedy-Thorndike experiment [10], because, according to Tangherlini's formula, the common time of the travel of a light beam toward and backward doesn't depend on the velocity v the inertial reference frame K' moves with respect to the "preferred" inertial reference frame K.

However just the anisotropy of the cosmic microwave background was found in 1977, the scientists have understood that fact that our inertial reference frame, connected to the Earth, moves with a velocity of about 360 km/sec with respect to a "preferred" inertial reference frame, where the microwave background radiation is mostly isotropic so that the common momentum of all space masses of our Universe is zero.

In other word, the synchronizing procedure suggested by Tangherlini leads to the kinematic relativistic transformations of the spatial coordinates and time (1), which are unexpected, but very adequate in the description of the transfer from one inertial reference frame into another one.

In the Tangherlini transformations, c' (2) is the velocity of light in the inertial reference frame K' measured by an observer who is located in the inertial reference frame K.