Entangled Simultaneity: Testing Lorentz and Light-Speed Invariance with Quantum and Classical Entanglement

In a rod of length AB \(= L\), rotating uniformly, any two spatially separated points along the rod are connected in a way that shows analogies with the quantum entanglement of the spin of particles. This ”classical entanglement” reflects the simultaneity preset in the system, which can be used for syncing two distant clocks, one at A and the other at B. Since it differs from Einstein synchronization, this procedure can be adopted for testing the one-way light speed and Lorentz invariance. Applications to optical Sagnac effects confirm that a consistent interpretation requires the adoption of absolute versus relative simultaneity.