Assuming the right equipment why won't this scenario work? Two source devices capable of producing entangled photon pairs at set intervals and two detectors capable of descriminating the state of the entanglement coupled with two devices capable of manipulating the entangled parameter and finally, two fiberloop delay devices. The source device output is in the form of individual pairs of entangled photons emitted at 180 degrees to each other. One photon will be sent to the detector and the other to a fiberloop delay device. The parameter manipulation device sits at the fiberloop output. Now invest the time required to transport the detector to a distant body in space. Upon arrival, the detector is in position. Now manipulate the entangled parameter leaving the earthside fiberloop delay device and the partner arriving at the detector complies instantly. Information can now be encoded in set intervals and flow instantly from the earthside source to the detector far away . The downside is detector transit time(getting there) and first signal transit time. Aside from the obvious technical hurdles why would this not work? Identical systems at both ends would provide two way instant communication. This scenario is not well enough explained but should provide enough to critique in concept.

  • $\begingroup$ Your first mistake occurs at "detectors capable of descriminating [sic] the state of the entanglement". Why bother with entanglement? Why not just postulate detectors capable of instantaneously gathering information from all over the universe? $\endgroup$ – WillO Feb 28 '17 at 22:55
  • $\begingroup$ -1. Unclear. Poor formatting and poor description of your scenario : as you admit, "not well enough explained". Consider inserting some spaces and perhaps a diagram, and simplifying the description. $\endgroup$ – sammy gerbil Mar 1 '17 at 2:05

You cannot determine the state of entanglement without destroying it.

Stripped of all the QM imagine you have a pair of boxes with either a black or white ball. When you open (measure the state of) one of the boxes you instantly know what the ball in the other box is.

However you cannot make a machine which can monitor the state of your box to know whether the other box has been opened and you cannot control if the ball in your own box is black or white.

So you cannot use this to transmit information

  • $\begingroup$ Once determined it does not matter,! $\endgroup$ – RaSullivan Mar 1 '17 at 1:12
  • $\begingroup$ @RaSullivan yes but you can't choose what state it collapses into, and you can't know if it has collapsed without collapsing it. So all you can do is effectively measure a random number $\endgroup$ – Martin Beckett Mar 1 '17 at 21:34
  • $\begingroup$ Martin.... Stern Gerleck(sp) type device is capable of detection and manipulation as I understand it..... $\endgroup$ – RaSullivan Mar 2 '17 at 22:39
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    $\begingroup$ But to use entanglement to transmit information you would have to either control which state "your" particle collapsed into (so you could force the other to have a known value) or be able to measure that your particle had collapsed (and so know that the other particle had been measured) without collapsing it - both are impossible $\endgroup$ – Martin Beckett Mar 3 '17 at 4:09

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