Does the body mass depend upon its speed. Discussion via exchange of letters

Abstract

The presented letters covers an almost year-long discussion of the author and a Very Qualified scientist, VQS, about the dependence of mass upon speed if relativistic corrections are taken into account. VQS believes that since mass is a scalar, it cannot depend upon speed and has to be the same in all inertial coordinate frames. In his view, the very idea of speed dependence of the mass of a particle or a body is incorrect and misleading. As such, the notion of speed dependence of a particle mass has to be eliminated from textbooks on physics and from teaching of this subject. The author claims that this notion has the right to exist, is easily understandable and convenient for most of the students, both non physicists and even physicist. His view is that it is nothing wrong in expressions like particle mass increases with the growth of speed. His view upon the debate is that both approaches are equally correct. His view is that the dilemma depends or not depends is a matter of taste and convenience, not of scientific importance and unavoidable scientific rigor. Upon request of VQS, M. Amusia has commented the manuscript of academician L. B. Okun resent book ABC of physics. The comments are included into this letters exchange.