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Can quantum entanglement provide a faster way of transfer of information than the speed of light as it travells at a speed which is 10000 times faster than the speed of light

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    $\begingroup$ The answer is basically no: changing one entangled particle also changes its counterpart on the other side, but in a way that essentially can't be measured. See en.wikipedia.org/wiki/No-communication_theorem $\endgroup$ – Ian Sep 26 at 14:42
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    $\begingroup$ " as it travells at a speed which is 10000 times faster than the speed of light" - what? $\endgroup$ – Stéphane Rollandin Sep 26 at 16:18
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I want to add a point: entanglement not only does not allow for faster than light communication, but entanglement alone does not allow for any communication at all! By the no communication theorem local operations on a quantum system cannot cause measurable consequences to a far away quantum system, entanglement notwithstading.

Entanglement can be used to improve communication, such as with superdense coding, but all such protocols require physical transmission of bits or qubits, which of course is limited by special relativity.

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Short answer: No.

Longer answer: No, it doesn't. There is no way to use entanglement to communicate faster than the speed of light.

If you want an answer that's more detailed than that, you will need to provide a more detailed question explaining why you thought otherwise.

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No.

In a very oversimplified explanation: entangled particles will have the opposite 'spin' along their axis of measurement. If you wanted to encode data into them, there isn't really any way to do that, the only input you could have is to measure them along an axis, which does nothing to help you communicate with an observer.

You could theoretically use it as a verification key, I guess. If you measure all your particles along a consistent axis you will have a binary string as a result, somebody with the entangled particles could then measure their particles along the same axis and have the exact opposite binary string - thus identifying eachother as being from the same origin. But you can't really use that to communicate.

EDIT: here is a similarly oversimplified video saying this more intuitively (https://www.youtube.com/watch?v=ZuvK-od647c)

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You have two shoes: left one, and right one.

Your mom quietly pack into cartoon every shoe, separately, and sent one package to your girlfriend, and the second to you.

You have this present, open it and it is left! Immediately you know, your girlfriend has right!

Speed of light is nothing compared to the speed you know something about shoe your girlfriend has! You are amazing.

Excercise: Try to use it to communicate something to your girlfriend...

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    $\begingroup$ Second exercise: read an introductory textbook on quantum information to understand how the model in this answer (the technical name for which is a local-hidden-variable model) has been conclusively proved to be insufficient for the description of entanglement. $\endgroup$ – Emilio Pisanty Sep 26 at 16:01
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    $\begingroup$ @EmilioPisanty Isn't the point of the answer precisely to demonstrate that there is nothing quantum mechanical about the seemingly "faster-than-light" communication? (See the Exercise?) -- For me this rather reads like a sarcastic answer. $\endgroup$ – Norbert Schuch Sep 26 at 16:08
  • $\begingroup$ @NorbertSchuch I don't see how this answer helps; instead, it just helps cement a misconception which is extremely hard to clear up down the line. The model here is strictly weaker than entanglement, so the fact that this cannot do FTL communication does not imply that entanglement can't either, i.e., as far as this model is concerned, entanglement could still do it. $\endgroup$ – Emilio Pisanty Sep 26 at 16:09
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    $\begingroup$ @kakaz That's a fair-enough approach, so long as it is suitably qualified, i.e. so long as you're crystal clear that the model you're using as an analogy is not a full model for entanglement. $\endgroup$ – Emilio Pisanty Sep 26 at 16:13
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    $\begingroup$ I complain all the time about people using the leftshoe/rightshoe "analogy" for quantum entanglement, just as @EmilioPisanty does here. But in this case, I think it was perfectly appropriate. The point is that correlations don't transmit information, and that general point applies both to the leftshoe/rightshoe scenario and to the (very different) entanglement scenario. Using the first (easier) scenario seems fine to me. $\endgroup$ – WillO Sep 26 at 17:35

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