So all the delay was in the structure of the rings — and the communication between them was instantaneous.
My face plate fogged a bit more. Instantaneous communication: it was a technological prize second only in value to the hyperdrive itself...
The secret had to be quantum inseparability. When a single object is split up, its components can still communicate instantaneously. That's high school stuff, Bell's theorem from the twentieth century. But, everyone had thought, you couldn't use the effect to send meaningful messages.
The Xeelee had really got their fingers into the guts of the Universe this time. It was almost blasphemous.
-Vacuum Diagrams, "More Than Time or Distance"