Quantum telescope (different meaning)

[nic30]

Hello,
term quantum telescope is usually related to beating diffraction limit as described for example there. But my question is not related to it.

Recently I have read paper about Counterfactual quantum communication.
If this really works and someone is sending quantum engaged particles to our planet maybe is possible to establish quantum communication with sender.

It seems to very unreal to me. But if any method can check if particle was quantum engaged wit other and it was measured by someone else? I think not but I believe there could be some statistical method which can do this.

And If there is such a method and is possible to detect streams of incoming engaged particle, is it possible to use them to communicate with sender?

And finally if such a communication can be established does it mean that information can travel in infinite small time after engaged particles were collected and used for communication due infinite small time for propagation to other engaged particle which sender has?

(Do not blame I do not underestand quantum physics at all. I am just curious.)

 

[mfb]

But if any method can check if particle was quantum engaged wit other and it was measured by someone else?

No. Locally (without access to the partner) you cannot measure if the particle is entangled with anything.

Even if someone tells you the particles in some stream are entangled with something else, you cannot use that alone for communication. You still need a "classical" communication channel. If you don't care about eavesdropping, you can simply use this classical communication channel to communicate.

And finally if such a communication can be established does it mean that information can travel in infinite small time after engaged particles were collected and used for communication due infinite small time for propagation to other engaged particle which sender has?

No, as you need this classical communication channel.

Wikipedia has an article about it.