On the Notion of the Measure of Inertia in the Special Relativity Theory

Abstract

The concept of the relativistic mass and its equivalence to the energy was recently negated within the framework of the special relativity theory (SRT). As a consequence, the relativistic mass notion was excluded from majority modern textbooks and books on SRT. The analysis of this negation is carried out in this paper. By the definition, the mass is the measure of inertia. Therefore everywhere, where inertia exists, the measure of this inertia, that is the mass, should exist. The inertia exists at relativistic velocities. Hence, the relativistic mass is obliged to be presented in SRT. The founders of SRT were right in their formulations from the very beginning and there is no need to revise their physical approaches concerning the relativistic measure of inertia. At the correct approach to the problem, the relativistic mass is returned to SRT. The relativistic mass is the measure of inertia, but it is not a scalar in SRT. It is the component of a 4-vector here. Since the relativistic mass is the component of the 4-vector, the fundamental equivalence of the measure of inertia and the energy is valid at all velocities (less or equal to the light velocity). The above mentioned negation is not harmless for science because it closes the road to some basic researches and generates the confusion in the students' brains.