A Novel Proposal to Test One-Way Light Speed Anisotropy via Stellar Interferometry

The constancy of the one-way speed of light,a foundational postulate of special relativity ,has not yet been directly tested in a synchronization-independent manner, as highlighted in frameworks such as those of Reichenbach and Mansouri-Sexl.While round-trip experiments (e.g., Michelson–Morley,Kennedy–Thorndike) confirm Lorentz covariance,the one-way speed remains conventionally defined by Einstein’s synchronization procedure,leaving open the possibility of directional anisotropy.All previous experiments designed to test one-way light propagation can be categorized into two distinct groups: full-terrestrial and source-moving. However, neither approach deals with one-way propagation effects directly.The full-terrestrial method infers it from a closed path geometry measurements,while the source-moving method relies on clock synchronization.We propose a novel stellar interferometry with dual-track approach employing a short-baseline terrestrial telescope ($<1m$) designed to detect variations in the one-way speed of light without requiring clock.By measuring fringe shifts (or visibility alteration) induced by Earth's orbital motion, we aim to test:(1) the isotropy assumed by Einstein synchronization,and (2)the possibility of dynamical anisotropy (the preferred frame's effect).Unlike the previous experiments,these observer-moving approaches directly probe the alterations in one-way propagation of light from distant stars,induce by motion of the Earth.They are sensitive not to absolute quantities but to relative variations induced by the Earth's motion.This paper is a conceptual feasibility proposal without a final claim about special relativity as no data has been taken yet.A non-null result has no contradiction with previous observations but would indicate the existence of a preferred frame of reference. This finding would refine the physical interpretation of the speed of light by demonstrating that Lorentz covariance is a matter of convention rather than a reflection of fundamental symmetry.Consequently, while the mathematical formalism of special relativity remains entirely valid,its ontological interpretation would require revision.A null result would empirically validate the second postulate,elevating it from a conventional definition to a fundamental physical principle.