Quantum nonlocality in relation to FTL Communication

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Discussion Overview

The discussion revolves around the concept of quantum nonlocality and its implications for faster-than-light (FTL) communication using entangled particles. Participants explore theoretical scenarios involving quantum bits and the limitations of entanglement over vast distances, including practical and conceptual challenges.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • Some participants suggest that using entangled particles for communication over vast distances, such as to the moon or interstellar space, is not viable due to the nature of quantum entanglement.
  • Others argue that entangled particles cannot be used for FTL communication because the correlation between measurements cannot be observed locally and requires bringing together outcomes, which cannot occur faster than light.
  • One participant compares the situation to writing on two pieces of paper, questioning if it could be analogous to manipulating entangled particles, but others clarify that such manipulation is not possible.
  • It is noted that measuring one of the entangled particles disrupts the entanglement, preventing any further manipulation from affecting the other particle.
  • Participants express that the values of the entangled particles are random and cannot be controlled, which limits their utility for communication.

Areas of Agreement / Disagreement

Participants generally agree on the limitations of using entangled particles for FTL communication, particularly regarding the inability to manipulate the particles to convey information. However, there are competing views on the implications of these limitations and the analogy of writing on paper.

Contextual Notes

The discussion highlights the dependence on the definitions of entanglement and measurement, as well as the unresolved nature of how information is understood in the context of quantum mechanics.

Gary0509
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With a modest understanding of 'spooky action at a distance', I've been informed that using entangled particles as a form of quantum bit system would not work for vast distances. It wouldn't be a viable option to communicate instantly with points like our moon, satellites orbiting Jupiter, or interstellar distances.

Hypothetically if one could create two quantum computers, each with the other half of an entangled set of particles (that could be accurately measured), you could leave one on Earth and send the other off to deep space. Any quantum bit information would be spontaneously emulate in both directions.

Was hoping someone could share what I'm overlooking.
http://static1.techinsider.io/image/562a8cb0bd86ef16008c4635-1097-470/screen%20shot%202015-10-23%20at%203.36.58%20pm.png
 
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Gary0509 said:
With a modest understanding of 'spooky action at a distance', I've been informed that using entangled particles as a form of quantum bit system would not work for vast distances. It wouldn't be a viable option to communicate instantly with points like our moon, satellites orbiting Jupiter, or interstellar distances.
You can't use entangled particles for any kind of FTL communication anyway.
 
If you wrote down something on two pieces of paper and sent them far away, isn't that the same thing?
 
The correlation between the values of the two particles can't be observered locally; one has to bring together the outcomes of the two measurements, and that can't be done faster than light. Locally (at one particle of the pair) one observes randomness.
 
Just to say the same thing as the above answers but with different words: the bit you are discussing will have a random value. Not a lot to be gained from looking at random bits of information.

I.e. you cannot "force" an entangled particle to take on a specific value.
 
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DrChinese said:
I.e. you cannot "force" an entangled particle to take on a specific value.
Thank you. That answer was clear. So one limitation is the inability to manipulate particles into specific values.

My understanding is that the original concept would overcome FTL communication because there is no information "traveling". They are two particles that intrinsically behave as opposites. Probably should have avoided the FTL reference.
 
Vanadium 50 said:
If you wrote down something on two pieces of paper and sent them far away, isn't that the same thing?
Wouldn't be the same thing if you could manipulate what you wrote on the paper at either end. Change what is written on one page and have it intrinsically reflected in the other. But from 'DrChinese' response it is that very manipulation that would be a stumbling block.
 
Gary0509 said:
Wouldn't be the same thing if you could manipulate what you wrote on the paper at either end. Change what is written on one page and have it intrinsically reflected in the other. But from 'DrChinese' response it is that very manipulation that would be a stumbling block.
If measured, the systems are no longer entangled. So doing a further measurement (or manipulate) one of the systems won't cause the other system to react to the further activity conducted.
 
StevieTNZ said:
If measured, the systems are no longer entangled.
Ah! That's helpful too.
Thanks Stevie.
 

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