Langevin's `Twin Paradox' paper revisited

Abstract

An in-depth and mathematically-detailed analysis of Langevin's popular 1911 article on the special theory of relativity is presented. For the reader's convenience, English translations of large parts of the original French text are given. The self-contradictory nature of many of Langevin's assertions is pointed out. Of special interest is the analysis of the exchange of light signals between the travelling and stay-at-home twins in Langevin's thought experiment, in which antinomies are found in the conventional relativistic treatment. Their resolution shows that the physical basis of the differential aging effect in the experiment is not `length contraction', as in the conventional interpretation, but instead the application of the correct relative velocity transformation formula. The spurious nature of the correlated `length contraction' and `relativity of simultaneity' effects of conventional special relativity is also demonstrated. In consequence, an argument given, claiming to demonstrate that an upper limit of $c$ on the speed of any physical signal is required by causality, is invalid. Its conclusion is also in contradiction with astronomical observations and the results of a recent experiment.

55 pages, 10 figures, 1 table, V2 typos removed, text improved, refs. updated, conclusions unchanged

References in corpus (8)

• The Local Space-Time Lorentz Transformation: a New Formulation of Special Relativity Compatible with Translational Invariance
• Translational invariance and the space-time Lorentz transformation with arbitrary spatial coordinates
• The physics of space and time I: The description of rulers and clocks in uniform translational motion by Galilean or Lorentz transformations
• Spatially-separated synchronised clocks in the same inertial frame: Time dilatation, but no relativity of simultaneity or length contraction
• The physics of space and time III: Classification of space-time experiments and the twin paradox
• Primary and reciprocal space-time experiments, relativistic reciprocity relations and Einstein's train-embankment thought experiment
• Quantum electrodynamics and experiment demonstrate the non-retarded nature of electrodynamical force fields
• The physics of space and time II: A reassessment of Einstein's 1905 special relativity paper

Cited by in corpus (2)

• Space-time symmetry is broken
• The Hafele-Keating experiment, velocity and length interval transformations and resolution of the Ehrenfest paradox