Is there an experiment that shows though that light in a vacumm travels with out any medium ? Quantum Entanglements if true thoughout the Universe , would interfere with each other . Trillions of quantum particles would be entangled with each other . Only to be criss-crossed by other entanglements by other quantum particles . Which would interfere in their communication with other quantum particles . Hence communication , entanglement would be lost . Hence " quantum entanglement " is more local than Universal .