Flat spacetime in a capsule

TL;DR

This paper offers a parallel introduction to Galilean and Einsteinian relativity focusing on causal structure and inertial motions, emphasizing geometric foundations over transformations.

Contribution

It presents a novel approach by emphasizing causal and geometric structures, minimizing reliance on transformation groups.

Findings

Clarifies the geometric basis of relativity theories

Highlights differences in causal structures between theories

Provides an accessible introduction to relativity concepts

Abstract

We propose a parallel introduction to Galilean and Einsteinian relativity based on the causal structure and inertial motions. Galilean and Poincare transformations, as objects secondary to the geometrical structure, are left aside.