Universal one-way light speed from a universal light speed over closed paths

TL;DR

This paper proves that if the speed of light over closed paths is universally constant, then clocks can be synchronized to make the one-way speed of light also universally constant, supported by elementary proofs and experimental evidence.

Contribution

It provides two complete proofs and experimental support for the claim that a universal closed-path light speed implies a universal one-way light speed.

Findings

Elementary proof that closed-path light speed universality implies one-way speed synchronization

High precision experimental evidence supporting clock synchronization for universal light speed

Discussion of Weyl's historical incomplete proof

Abstract

This paper gives two complete and elementary proofs that if the speed of light over closed paths has a universal value $c$, then it is possible to synchronize clocks in such a way that the one-way speed of light is c. The first proof is an elementary version of a recent proof. The second provides high precision experimental evidence that it is possible to synchronize clocks in such a way that the one-way speed of light has a universal value. We also discuss an old incomplete proof by Weyl which is important from an historical perspective.