swansont Posted February 27, 2005 Share Posted February 27, 2005 Is there a difference between being in a superpostion of states and being in an unknown but definite state? If measuring forces a random state, how do we know that that state didn't exist in the first place? This is mostly about entangles pairs, but I suppose it could apply to single particles as well. Yes. While hidden variables are still being investigated because of the subtleties of the QM involved, the standard experiments show that they don't exist. A superposition is not just an unknown state. Link to comment Share on other sites More sharing options...
J.C.MacSwell Posted February 27, 2005 Share Posted February 27, 2005 Is there a difference between being in a superpostion of states and being in an unknown but definite state? If measuring forces a random state, how do we know that that state didn't exist in the first place? This is mostly about entangles pairs, but I suppose it could apply to single particles as well. A particle in an unknown but definite state would presumably not be interfered with by it's "other" possible/unknown but "definitely not" states. Link to comment Share on other sites More sharing options...
J.C.MacSwell Posted February 27, 2005 Share Posted February 27, 2005 As for entangled pairs would a test on A which collapses the probability wave of both A and B not change the odds of a different test on B? Link to comment Share on other sites More sharing options...
swansont Posted February 27, 2005 Share Posted February 27, 2005 As for entangled pairs would a test on A which collapses the probability wave of both A and B not change the odds of a different[/b'] test on B? I depends on the test, but I think it's possible. The reason you have to be careful is because even if the operators don't commute, they may still use the same eigenstates - in that case you would still collapse the wavefunction. As long as that is not the case, I think you can do it. Link to comment Share on other sites More sharing options...
Kygron Posted March 10, 2005 Share Posted March 10, 2005 I've been considering the resent posts. Is this related to the wave/particle duality of light (or any particle). I mean, is superposition a way of explaining the wave properties while maintaining a particle viewpoint? Just as a "wave-packet" is the explaination of the particle properties while maintaining a wave viewpoint? I realize that if I'm correct the mathimatics of both would be identical, just easier to perform depending of the circumstances. Link to comment Share on other sites More sharing options...
swansont Posted March 10, 2005 Share Posted March 10, 2005 I've been considering the resent posts. Is this related to the wave/particle duality of light (or any particle). I mean, is superposition a way of explaining the wave properties while maintaining a particle viewpoint? Just as a "wave-packet" is the explaination of the particle properties while maintaining a wave viewpoint? I realize that if I'm correct the mathimatics of both would be identical, just easier to perform depending of the circumstances. No, I don't think so. You can entangle two spin states, which really has no connection to the duality. Link to comment Share on other sites More sharing options...
Kygron Posted March 12, 2005 Share Posted March 12, 2005 No, I don't think so. You can entangle two spin states, which really has no connection to the duality. Thanks, good info, however, I'm still interested in how I may be right or wrong. So, if you ignore spin (and any other property that would have produced the same response), how does my statement hold up? Link to comment Share on other sites More sharing options...
swansont Posted March 12, 2005 Share Posted March 12, 2005 Thanks, good info, however, I'm still interested in how I may be right or wrong. So, if you ignore spin (and any other property that would have produced the same response), how does my statement hold up? It's still a no, I think. The wave-particle duality is a result of trying to impress descriptions of macroscopic phenomena on a microscopic system, and finding that things behave differently. You can't segregate the conditions here - spin entanglement does not depend on wave-particle duality, so entanglement cannot be a result of that duality. Link to comment Share on other sites More sharing options...
5614 Posted March 12, 2005 Share Posted March 12, 2005 Wave/particle duality and the spin of a sub atomic particle are totaly differnt things. Wave/particle duality is how particles can behave, whereas spin is it's angular momentum. Whilst they both can apply to the same particles, they are unrelated. Similarly when I go out somewhere if it rains that affects me because I get wet, if the car works affects me because if it doesn't I can't go anywhere in that car... the car is kept in a garage and assuming the rain doesn't flood everything the two things, whilst both affecting me, are unrelated to each other. Link to comment Share on other sites More sharing options...
Kygron Posted March 14, 2005 Share Posted March 14, 2005 You can't segregate the conditions here - spin entanglement does not depend on wave-particle duality, so entanglement cannot be a result of that duality. Ok, it looks like you misunderstood me. What I meant was the opposite: that the duality exists because superposition/entanglement is a fact. This is why I COULD segregate the conditions, s/e could give rise to the duality and also could give rise to spin entanglement. Again, only if I've got things right. Link to comment Share on other sites More sharing options...
swansont Posted March 14, 2005 Share Posted March 14, 2005 Ok' date=' it looks like you misunderstood me. What I meant was the opposite: that the duality exists because superposition/entanglement is a fact. This is why I COULD segregate the conditions, s/e could give rise to the duality and also could give rise to spin entanglement. Again, only if I've got things right.[/quote'] The duality exists for unentangled particles. They are separate phenomena, within the context of QM. Link to comment Share on other sites More sharing options...
1veedo Posted March 14, 2005 Share Posted March 14, 2005 Quantum entanglement can be used for both communication and storage for quantum computers. http://colossalstorage.net/home_entangled.htm I do not know much about it, but I plan on reading it when I get back from school. The duality occurs where you get polorized entangled atoms. This would allow you to do something to one atom, and the other atom would do the oposite; causign a sort of duality. Not only can it communicate instentaniously, but it can also transfer much mroe data (bandwidth) then a simple electron could. This is how you can store information, and retrieve it w/o breaking the state. I know more about storing the data then I do sending it, however, if it can be done locally (ie, inside a computer), I see know reason why the data off that HD cant be transmited long distances as well. Link to comment Share on other sites More sharing options...
Kygron Posted March 18, 2005 Share Posted March 18, 2005 I think being in this "entanglement" thread is not helping me any. Anyway I found some applets here that show some simple waveforms, etc. It starts with duality showing waveforms. A later chapter is about superposition, and they use the SAME waveforms as examples. They just use a different interpretation of the formulas to represent a probability distribution. This is kinda what I was trying to say before. I particularly like the Young slit experiment applet (first one after the intro I believe), where they show individule photons randomly striking a target and ending up producing an interference patern. Too bad the explainations of the physics starts out simple but gets simpler as they go. Link to comment Share on other sites More sharing options...
swansont Posted March 18, 2005 Share Posted March 18, 2005 I do not know much about it, but I plan on reading it when I get back from school. The duality occurs where you get polorized entangled atoms. This would allow you to do something to one atom, and the other atom would do the oposite; causign a sort of duality. Not only can it communicate instentaniously... That's not how it works. Read the other threads on the topic. Link to comment Share on other sites More sharing options...
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