On the concept of relativistic mass

TL;DR

This paper reviews the historical and conceptual debate over relativistic mass versus proper mass, aiming to clarify definitions and promote a unified understanding in relativity theory.

Contribution

It provides a comprehensive analysis of all types of mass in relativity, including overlooked aspects like point particles, extended objects, and gravitational mass, advocating for the continued use of relativistic mass.

Findings

Clarifies distinctions among different mass concepts

Highlights importance of relativistic mass in certain contexts

Proposes a unifying perspective on mass definitions

Abstract

Within the past fifteen years the use of the concept of "relativistic mass" has been on the decline and has been replaced by the concept of "proper mass" (aka "rest mass") - ?simply referred to as "mass" and labeled "m" by its proponents. This decline in usage appears to be due to arguments presented in several journal articles over the last thirty-five years, as well as to standard practices in the field of particle physics. The aforementioned debate consists of arguments as to how the term "mass" should be defined to maximize logic as well as to be less confusing to the layman and people just starting to learn relativity. Lacking in the debate is a clear definition of all types of mass and all its usages in a wide variety of cases. The purpose in this article is to bring a unifying perspective to the subject. In doing so I will explore those things omitted from previous articles on this subject including the importance of point particles vs. extended objects; open vs. closed systems and gravitational mass. Although I argue for the usage of relativistic mass I do "not" argue that proper mass is not an important tool in relativistic dynamics.