The physics of space and time III: Classification of space-time experiments and the twin paradox

TL;DR

This paper introduces a clear nomenclature for describing space-time experiments in special relativity, clarifies the twin paradox, and attributes differential aging to relativistic velocity transformations rather than length contraction.

Contribution

It proposes a new notation and classification system for space-time experiments, providing a clearer understanding of relativistic effects and resolving misconceptions about the twin paradox.

Findings

Differential aging is caused by relativistic velocity transformations.

A new nomenclature clarifies the classification of space-time experiments.

The twin paradox is explained through relativistic velocity relations, not length contraction.

Abstract

A nomenclature for inertial frames and a notation for space and time coordinates is proposed to give an unambigous description of space-time experiments in special relativity. Of particular importance are the concepts of `base' and `travelling' frames and `primary' and `reciprocal' experiments. A detailed discussion of the twin paradox is presented. The physical basis of the differential aging effect is found to be a relativistic relative-velocity transformation relation, not, as hitherto supposed, the spurious `length contraction' effect.