Simple derivation of the special theory of relativity without the speed of light axiom

TL;DR

This paper presents a straightforward derivation of special relativity's core principles using basic symmetries and relativity principles, avoiding the traditional reliance on the speed of light as an axiom.

Contribution

It offers a simple, rigorous derivation of special relativity based solely on isotropy, homogeneity, and the relativity principle, omitting the speed of light axiom.

Findings

Derivation of space-time interval invariance without light speed assumption

Clarification of special relativity foundations using symmetry principles

Educational approach suitable for textbooks

Abstract

We show a very simple yet rigorous derivation of the invariance of the space-time interval (and hence the whole special relativity) just from the isotropy, homogeneity and a principle of relativity, without the need of the speed of light axiom. This article is intended as a textbook explanation of the special relativity.