2006/04/03 by J. H. Field, Field, J. H.
Physics and Astronomy · #Advanced Mathematical Theories and Applications #FOS: Physical sciences #General Physics (physics.gen-ph) #History and Developments in Astronomy #Relativity and Gravitational Theory
paper · pdf · doi:10.48550/arxiv.physics/0604010
openalex publication_date 2006/04/03 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
It is demonstrated that the measured spatial separation of two objects, at rest in some inertial frame, is invariant under space-time transformations. This result holds in both Galilean and Special Relativity. A corollary is that there are no `length contraction' or associated 'relativity of simultaneity' effects in the latter theory. A thought experiment employing four unsynchronised clocks and a single measuring rod reveals that the physical basis of the time dilatation effect is a relative velocity transformation law, not `length contraction'. Time dilatation, which is universal and translation invariant for all synchronised clocks at rest in any inertial frame, is the unique space-time phenomenon discriminating Special from Galilean Relativity.