For the life of me, I cannot understand why the following proposal should not work:
Exactly between two points (points A, B) in space time separated by an arbitrary distance (point C), position a photon generator and a beam splitter. Then generate photons, split them into entangled pairs, and send them towards (A) and (B).
An entangled pair of photons is linked; the destiny of the one is the destiny of the other. The effect is instantaneous, no matter how far the particles end up separated in space time.
At each endpoint (A, B), there are just two pieces of equipment: a photon detector, and a shutter positioned slightly ahead of the detector. Each endpoint takes turns sending and receiving.
When it's A's turn to send, sliding the shutter closed will intercept the incoming photon, causing its entangled partner also to extinguish; thus the detector at (B) will detect nothing; call that a 1. If A does not slide the shutter, the photon can continue, then the detector at (B) will register a photon; call that a zero.
When it's B's turn to send, the same situation obtains at (A).
Granted, this method requires a source of photons to be positioned in advance. Depending upon the separation of (A) and (B), it could be years before the stream of entangled photons is available to be manipulated. Also, it requires extreme coordination for the entangled pairs to arrive at both stations simultaneously.
This communication method could be tested using present-day equipment.
-Bill
