May 23, 2023
Mass, inertia, preinertia, Lorentz symmetry, pendulum oscillations
This chapter examines new relativistic and non-relativistic aspects of mass and density in inertial reference frames that raise some interesting questions about the composition and the internal structure of matter. Although the most conflicting part of the chapter are the Sections 3-5, in two of which a real breaking of the Lorentz symmetry is demonstrated; and in the other absolute motion could be the only solution of the problem posed there. Saying symmetry breaking is a figure of speech, because what is demonstrated in this chapter are true formal contradictions derived from the Lorentz Transformation, in particular from length contractions and phase differences in synchronization.