La invariancia de la masa en Relatividad Especial

TL;DR

This paper clarifies that in Special Relativity, mass is invariant and does not depend on velocity, correcting common misconceptions and emphasizing that only momentum and kinetic energy vary with speed.

Contribution

It corrects a frequent misconception by emphasizing the invariance of mass in Special Relativity and clarifies the distinction between mass and other quantities like momentum.

Findings

Mass is invariant in Special Relativity.

Linear momentum and kinetic energy increase with velocity.

Common misconceptions about velocity-dependent mass are addressed.

Abstract

We correct an error that occurs with certain frequency in popular literature of Special Relativity, namely that supposedly that mass of moving objects depends on the relative velocity of the object and the observer. In this pedagogical paper, we explain that it is more correct to state that the linear momentum and the kinetic energy increase with velocity, while the mass is in fact an invariant, independent of the motion of the object and of the observer. We give a few paradoxes that arise if one assumes a mass-dependent velocity.