Einstein and Planck on mass-energy equivalence in 1905-06: a modern perspective

TL;DR

This paper reviews Einstein's 1905 theoretical derivation of mass-energy equivalence and Planck's 1906 concepts of relativistic momentum and energy, defending their rigor and significance in modern physics.

Contribution

It provides a modern perspective on Einstein and Planck's early 20th-century work, clarifying misconceptions and emphasizing their foundational role.

Findings

Einstein's analysis was rigorous and foundational.

Planck's introduction of relativistic momentum and energy was pivotal.

The historical claims of flaws in Einstein's work are rebutted.

Abstract

Einstein's theoretical analysis of mass-energy equivalence, already, at the time, experimentally evident in radioactive decays, in two papers published in 1905, as well as Planck's introduction, in 1906, of the concepts of relativistic momentum, and, by invoking Hamilton's Principle, relativistic energy, are reviewed and discussed. Claims in the literature that Einstein's analysis was flawed, lacked generality, or was not rigorous, are rebutted.