Question about Quantum Eraser

[Anomalocaris]

Okay, if what you suspect is right, then that means you could, at least sometimes, infer whether a photon was acting as a particle or a wave from the resultant spread pattern.  But I guess that's true anyway-- if you are engaged in an experiment, and I walk into the room after it's done, I assume I will be able to see a 2-stripe pattern, and say, "Aha!  I know you were detecting activity at the slits!"  If certain apparatus could also do this, then the results themselves might actually be useful.

My problem is that if you could do this experiment at very long range, it seems you could actually send information at a speed faster than light.  You could, for example, send a burst of photons from the moon, and then use their entanglement with the transmitting apparatus to set their state just before they arrive at a receptor.  Isn't this "illegal"?

If you want to trip me out, show me a 4-state superposition (essentially a uniform distribution, right?), that only resolves itself to me when I look up my random symbols in a book.

I think what you are trying to ask is, can you affect the state of one of the two entangled particle in such a way as to instantly sets the state of the other some distance away.  If you do this you are communicating faster than speed of light.    I believe the answer is no.  You can only observe the state of one so as to collapse the probabilities of the state of the other.   But no new information that is predicated upon the outcome of your observation can possibly influence any event at the location of the other particle before light had time to travel from one particle to another.

(Looking nervously in fear of contradiction at Alex)