Exploiting a Built-In Simultaneity: Perhaps, the Simplest Way to Show that the One-Way Speed of Light is Measurable in Principle

We consider a physical system composed of a rod of length AB = L rotating uniformly. Two points on the rod cross-sections at A and B are connected in a way that reflects the simultaneity built-in into the system. This preset simultaneity can be exploited to synchronize two distant clocks, one at A and the other at B, with an internal procedure that, in principle, may differ from Einstein synchronization. The natural built-in simultaneity can be used for testing the one-way light speed and Lorentz invariance. PACS: 03.30.+p, 42.25.Bs, 45.50.−j.