Quantum Communication Discovery: Is There A Catch Here, Or Is It Really Possible Now?

[fear]

<p>I just read an article at physorg that seemed to be saying that readable information was sent across quantum channels. </p><p>Could someone with a good understanding of physics tell me if I'm interpreting the article correctly: </p><p>Physorg.com- In quantum channels, zero plus zero can equal non-zero</p><p>Also, if quantum communication is real then does that mean that #1 real time control of distant space probes is possible and that #2 Moore's Law might not stop as soon as predicted? </p> <div class="Discussion_UserSignature"> </div>

 

[DrRocket]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I just read an article at physorg that seemed to be saying that readable information was sent across quantum channels. Could someone with a good understanding of physics tell me if I'm interpreting the article correctly: Physorg.com- In quantum channels, zero plus zero can equal non-zeroAlso, if quantum communication is real then does that mean that #1 real time control of distant space probes is possible and that #2 Moore's Law might not stop as soon as predicted? <br />Posted by fear</DIV></p><p>Here is a link to the technical paper behind the popular article that you posted. <br /><br />http://arxiv.org/PS_cache/arxiv/pdf/0807/0807.4935v1.pdf</p><p>The article itself is theoretical and mathematical in nature and does not address a physical experiment.&nbsp; However, it is my understanding that some information and very crude computing has been done using quantum principles.&nbsp; http://en.wikipedia.org/wiki/Quantum_computer&nbsp;&nbsp;&nbsp;&nbsp; http://www.cs.rice.edu/~taha/teaching/05F/210/news/2005_09_16.htm</p><p>The article is interesting, but does not represent any major revolution or breakthrough in my opinion.</p><p>I have not read the article in detail but the gist seems to be that the ordinary notion of channel capacity does not behave as expected in the case of quantum communication.&nbsp; I will have to&nbsp;investigate to understand this better, but I am&nbsp;always a bit skeptical in the beginning because much relies on the definitions used and&nbsp;there is some relatively delicate mathematical analysis involved in the use of probability, Fourier analysis and the definition of information itself.</p><p>IF you are interested this is a link to Shannon's&nbsp;seminal paper on information theory.&nbsp;http://cm.bell-labs.com/cm/ms/what/shannonday/shannon1948.pdf </p> <div class="Discussion_UserSignature"> </div>

 

[centsworth_II]

<font color="#000080"><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>...if quantum communication is real then does that mean that... real time control of distant space probes is possible...<br /> Posted by fear</DIV><br /></font>This would require signals traveling faster than the speed of light.&nbsp; Still an impossibility, quantum communication or not. <div class="Discussion_UserSignature"> </div>

 

[DrRocket]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>..., if quantum communication is real then does that mean that #1 real time control of distant space probes is possible and that #2 Moore's Law might not stop as soon as predicted? <br />Posted by fear</DIV><br />&nbsp;</p><p>I think that perhaps you are confusing communication in a quantum computer with the apparently instantaneous action that is seen in quantum entanglement experiments.&nbsp; They are not the same thing.</p><p>The instantaneous action seen in quantum entanglement experiments is not capable of transmitting information.&nbsp; If it were there would be a major crisis in physics as a result of a violation of a key principle of special relativity.&nbsp; </p> <div class="Discussion_UserSignature"> </div>

 

[fear]

Thanks to both of you for the analysis. It's not as exciting as I'd hoped but I understand what they're trying to accomplish now. <div class="Discussion_UserSignature"> </div>

 

[et_earth]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>This would require signals traveling faster than the speed of light.&nbsp; Still an impossibility, quantum communication or not. <br />Posted by centsworth_II</DIV><br /><br />If I'm reading this article correctly.&nbsp; Your comment is no longer true.</p><p>edit add:&nbsp; "<em>Something</em> happens faster than the speed of light," Monroe said. "It's just not information. ...&nbsp; I guess the answer is yes and no.</p> <div class="Discussion_UserSignature"> </div>

 

[Bill_Wright]

Re: Quantum Communication Discovery: Is There A Catch Here, Or I

I believe that the jury is still out on entanglement. Super-luminal communication might be forbidden by relativity, however entanglement seems to communicate instantly at a distance. The hooker is for now that you need to send a sub-luminal "parity bit" to confirm that something has occurred. When (or if) we are able to get that back then you will have a real answer. For now, anyone claiming it violates any known laws of physics is stretching their results a bit too far. Anyone saying it can't / won't achieve everything from FTL communication or even teleportation has no right to make that claim at this point in the discovery process. Being an American, I see Science magazine as the premier publication in the world of science. They probably average an article a week on entanglement and what it might do to communication, transportation, and the laws of conservation of matter and energy.
Thanks --
-- Bill Wright: wwright21@att.net

 

[derekmcd]

Re: Quantum Communication Discovery: Is There A Catch Here, Or I

I believe that the jury is still out on entanglement. Super-luminal communication might be forbidden by relativity, however entanglement seems to communicate instantly at a distance. The hooker is for now that you need to send a sub-luminal "parity bit" to confirm that something has occurred. When (or if) we are able to get that back then you will have a real answer. For now, anyone claiming it violates any known laws of physics is stretching their results a bit too far. Anyone saying it can't / won't achieve everything from FTL communication or even teleportation has no right to make that claim at this point in the discovery process. Being an American, I see Science magazine as the premier publication in the world of science. They probably average an article a week on entanglement and what it might do to communication, transportation, and the laws of conservation of matter and energy.
Thanks --

I believe the jury is pretty confident that quantum entanglement is a real phenomena. I think the biggest issue is popular word usage you see in articles. Stating that the two particles 'communicate' instantly is terribly misleading. It might be better to state that the two particles have an intrinsic relationship.

Even if the two particles do 'communicate' in some way, it is really useless to us as we can not create a particle in a specific quantum state with any predictability. In other words, we, as humans, can not use this to transmit anything useful.