Talk:Afshar experiment/Archive 12
This is an archive of past discussions about Afshar experiment. Do not edit the contents of this page. If you wish to start a new discussion or revive an old one, please do so on the current talk page. |
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- I'm afraid certain individuals here would have to eat crow pretty soon! The paper has been accepted by a prestigious peer-reviewed journal and has the strong support of a number of notable physicists, who are way too busy to sit around writing for Wikipedia. Thank you Dndn1011 for standing for objectivity. I'm glad the history of this page will show the extent of irrational subjectivity of some and the degree of animosity shown by them. Regards. P.S. Decoherence is really nothing to do with the experiment, and if someone wishes to link them, it is best to write a paper on the subject than pontificate in Wikipedia.-- Prof. Afshar 17:57, 13 November 2006 (UTC)
- I look forward to this article claim's being based on what is published. My earlier point stands, though: What should not happen is for someone to write up their own experiment here, which is in direct violation of Wikipedia's guidelines.--Michael C. Price talk 08:53, 14 November 2006 (UTC)
- I'm afraid certain individuals here would have to eat crow pretty soon! The paper has been accepted by a prestigious peer-reviewed journal and has the strong support of a number of notable physicists, who are way too busy to sit around writing for Wikipedia. Thank you Dndn1011 for standing for objectivity. I'm glad the history of this page will show the extent of irrational subjectivity of some and the degree of animosity shown by them. Regards. P.S. Decoherence is really nothing to do with the experiment, and if someone wishes to link them, it is best to write a paper on the subject than pontificate in Wikipedia.-- Prof. Afshar 17:57, 13 November 2006 (UTC)
- Yet we have quite a forum for your opinions on the matter, don't we? Judging articles by anything other than their content is scientifically very unsound. And guidelines are not policy and should be applied with common sense,Dndn1011 09:14, 14 November 2006 (UTC)
- My opnions, as you describe them, as they appear in the article are sourced. And common sense says originators of a subject typically lack objectivity. That's what the guidlines against self-promotion say and that's why they exist. --Michael C. Price talk 09:46, 14 November 2006 (UTC)
- Yet we have quite a forum for your opinions on the matter, don't we? Judging articles by anything other than their content is scientifically very unsound. And guidelines are not policy and should be applied with common sense,Dndn1011 09:14, 14 November 2006 (UTC)
- Again you ignore my point about judging an article by content not author. You also ignore my original argument:
. This seems quite clear to me. Whoever has listed all these references to people who take an opposing view may be providing sourced information, but is breaking the rule about unbiased presentation. It is not relevant here to list all these sources. It is enough to state the main criticisms. The talk pages might be the place for research into who believes what, but the article should simply describe the experiement and what it possibly means. Dndn1011 10:47, 14 November 2006 (UTC)Additionally the whole section makes it appear as if the entire world is against Afshar, and he alone believes in his experiement and his interpretation of it. This is for me clearly biased. We even have a list of named individuals, which creates the danger of this article becoming a petition against Afhsar. Of course if it is actually true that Afshar stands alone then that would be a different matter. However unless this can be verified it is dangerous to list all of the world and it's mother as being against Afshar and have some half hearted external references to his rebuttles.
- And also what it possibly does not mean.
- Sorry? 'Possibly' already covers that. That is what 'possibly' means. If I say "It possibly means" it means also the it possibly does not. Dndn1011 19:37, 14 November 2006 (UTC)
- So what is your problem with saying why it possibly does not mean what it possibly may mean? Why are you so intent on only providing one side of the issue? --Michael C. Price talk 21:42, 14 November 2006 (UTC)
- Sorry? 'Possibly' already covers that. That is what 'possibly' means. If I say "It possibly means" it means also the it possibly does not. Dndn1011 19:37, 14 November 2006 (UTC)
- You misunderstand the NPOV rule. Unbiased presentations are not achieved by deleting views you don't like, but by providing both sides of the debate. The article provides that: Afshar's views are presented and the contrary POV is presented.
- Yes, but you can go too far, when you create the appearance of a petition against a view, it can put people off looking into the matter for themselves. The article is biased for the reasons I have stated but you will not be convinced. This is perhaps because you hold a strong opinion on the matter. I do not, so perhaps I am better qualitifed to assess that there is a bias. Dndn1011 19:37, 14 November 2006 (UTC)
- Perhaps. And also perhaps because I understand QM better than you?--Michael C. Price talk 21:42, 14 November 2006 (UTC)
- Yes, but you can go too far, when you create the appearance of a petition against a view, it can put people off looking into the matter for themselves. The article is biased for the reasons I have stated but you will not be convinced. This is perhaps because you hold a strong opinion on the matter. I do not, so perhaps I am better qualitifed to assess that there is a bias. Dndn1011 19:37, 14 November 2006 (UTC)
- You also misunderstand the whole concept of Wikipedia when you state: Again you ignore my point about judging an article by content not author. It is a fundamental tenet of Wiki that it does not judge content; it reports it. If you have a problem with this then take it elsewhere. --Michael C. Price talk 12:48, 14 November 2006 (UTC)
- Wikipedia may not judge content. But WE do. And that's the purpose of the talk pages - ie. for some sense of democracy and intelligence (sic) in how the main article is put together. Given that you are currently ALONE in your desire to have "decoherency" listed there AND that you have only cited it as "relevant" (rather than as "criticism" ie. under which it is written), one still wonders why it should continue to exist there under criticism. The only reason remaining becomes increasingly like just one person's will - that of Michael Price? Is it written under "criticism" because it has nowhere else to go? Well too bad. And I note that Price has made some significant contributions to how the page on decoherence is written - so perhaps we can read this text on decoherence (within the Afshar page) as an advertisement for Michael Price's contribution to the decoherence page. CARL LOOPER
- Yes, I made significant contributions to decoherence; contributions that were sourced and generally accepted as valid. Your point is? --Michael C. Price talk 22:00, 14 November 2006 (UTC)
- So you understand the bit on "significant contribution" yet you fail to understand (or otherwise address) anything else. The main point is ... well what's the point ... it's becomming increasingly obvious that you don't want to address it - or more likely - can't. But I bet if somebody removed the reference you'd put it back in again. Why? Because that's all you know how to do in this game. If not then speak up man. Say something. If decoherence can function as criticism then make it function as such. I'll support you. I'm a critic of the Afshar experiment myself but that doesn't mean I support just any criticism. Or that I don't respect the experiment. Or that I don't respect Afshar. Critcisicm is not always a negation of something. Make your criticism stronger. Not in the main article - but here in the talk page. At the moment the only remotely critical aspect of the paragraph is the last sentence - which has no external links at all. Has anyone else written that Afshar needs to address decoherency or is it just you? That's okay if it's the case but then it really belongs here in the talk page - not in the main text. CARL LOOPER.
- I regard last sentence you refer to as the logical consequent of the preceeding sentences. Perhaps it could be expanded upon, but I did not wish the critique to be unreadably long and convoluted. As for the lack of sourced critiques of the Afshar experiment -- this is generally lacking for the simple reason that the experiment has not yet been published in a peer-reviewed journal. Which means that the entire article is subject to the claim of OR. --Michael C. Price talk 22:44, 14 November 2006 (UTC)
- There are a number of sourced criticques - far better than your meagre attempt. And as for the "logical" step? Decoherence exists therefore Afshar's experiment should address it? Well, maybe but why should anyone address anything? You pick and choose what you want to address - eh? But what - nobody else can? CARL LOOPER
- If you have the superior sourced critiques then please supply them. As for your question about why should anyone address anything, perhaps you fail to see the overlap between decoherence and complementarity? Is that the issue for you? --Michael C. Price talk 00:52, 15 November 2006 (UTC)
- Oh - just everything under "The following is a partial list of other specific critiques of Afshar's experimental design and analysis". Note the word "specific", ie. critiques that specifically address Afashar's experiment. Your "criticism" pales into insignificance compared to these. CARL LOOPER
- It depends on whether you prefer critiques argued from general theoretical principles or from specific experimental details. That's a matter of taste. --Michael C. Price talk 03:41, 15 November 2006 (UTC)
- The list of critques I mention all argue from general principles. But yours doesn't. Just because you put a link into decoherence doesn't make your critcicsm (that Afshar needs to address decoherency) any more worthy of the name "criticism". Anyone can do that. How hard is that? The others, at least had a good think about it. And yes, that's a question of taste. Quite right. CL.
- Oh - just everything under "The following is a partial list of other specific critiques of Afshar's experimental design and analysis". Note the word "specific", ie. critiques that specifically address Afashar's experiment. Your "criticism" pales into insignificance compared to these. CARL LOOPER
- If you have the superior sourced critiques then please supply them. As for your question about why should anyone address anything, perhaps you fail to see the overlap between decoherence and complementarity? Is that the issue for you? --Michael C. Price talk 00:52, 15 November 2006 (UTC)
- So you understand the bit on "significant contribution" yet you fail to understand (or otherwise address) anything else. The main point is ... well what's the point ... it's becomming increasingly obvious that you don't want to address it - or more likely - can't. But I bet if somebody removed the reference you'd put it back in again. Why? Because that's all you know how to do in this game. If not then speak up man. Say something. If decoherence can function as criticism then make it function as such. I'll support you. I'm a critic of the Afshar experiment myself but that doesn't mean I support just any criticism. Or that I don't respect the experiment. Or that I don't respect Afshar. Critcisicm is not always a negation of something. Make your criticism stronger. Not in the main article - but here in the talk page. At the moment the only remotely critical aspect of the paragraph is the last sentence - which has no external links at all. Has anyone else written that Afshar needs to address decoherency or is it just you? That's okay if it's the case but then it really belongs here in the talk page - not in the main text. CARL LOOPER.
- Yes, I made significant contributions to decoherence; contributions that were sourced and generally accepted as valid. Your point is? --Michael C. Price talk 22:00, 14 November 2006 (UTC)
- You play games, sir. You surely understand that when an article is presented in wikipedia it is judged against wikpedia standards. It is of course this which I mean. Who actualy wrote an article is of no importance if the article meets the wiki policies, primarily those of notability, neutral point of view and verifiability. The talk pages are an excellent place to debate this stuff. Here should be discussons on whether the articles are good or not as articles. This is a judgement, with decision reached by concensus. I think I understand how wikipedia works far better than you judging by your talk. What the article does is not just provide counter opinions to the claim of what the experiment demonstrates, but has a long list of those who disagree with the claim. It presents too much information against the claim without including rebuttles from Afshar to balance it. It is creating the impresion "Afhsar is a fool". This is not good in an article. As a general rule, if the article cannot be presented concisely and fairly, it should be less detailed. I am suggesting the article be simplified so as to state the major issues (as it does now) without appearing to be a petition against afshar, which is the way it is presented right now in my opinion. As for who actually contribute to an article, this is completely irrelevant apart from anything because it is unnforcable. Incidentaly, what you claim is policy about not writing concerning your own experiments, etc, is actually a guideline, not policy. Common sense should be applied, which you seem to be distincly lacking. Dndn1011 18:46, 14 November 2006 (UTC)
- Thank you for sharing your opinion of yourself. Anyone can see that the general criticisms in the critique sections are concise, with plenty of links for more background for those that wish it. They are also fair, IMO, although that judgement may require some technical background on the part of the reader: that's what the links are for. --Michael C. Price talk 22:00, 14 November 2006 (UTC)
- Dear Dndn1011, I had asked mr. "fair & balanced" to include a recent paper by O'Hara (http://arxiv.org/abs/quant-ph/0608202) that supports my views, but he conveniently ignored it. Here's what O'Hara says in the paper: "...it seems to me that the Afshar experiment has succeeded in demonstrating that these two properties [Interference and which-way information] can co-exist simultaneously..." I think it should be reflected in the article. There are other similar statements by important physicists, and given their permission I will put them in public domain soon. Best regards.-- Prof. Afshar
- Actually I did not ignore the paper; I note that the same conclusion (that interference and which-way information can co-exist simultaneously) has been previously reached, viz:
- Berthold-Georg Englert, Marlan O. Scully & Herbert Walther, Quantum Optical Tests of Complementarity , Nature, Vol 351, pp 111-116 (9 May 1991). Demonstrates that quantum interference effects are destroyed by irreversible object-apparatus correlations ("measurement"), not by Heisenberg's uncertainty principle itself. See also The Duality in Matter and Light Scientific American, (December 1994)
- The authors do not regard this result as violating complementarity. This link also appears in the article -- I added it awhile back. --Michael C. Price talk 22:09, 14 November 2006 (UTC)
- Actually I did not ignore the paper; I note that the same conclusion (that interference and which-way information can co-exist simultaneously) has been previously reached, viz:
- Wikipedia may not judge content. But WE do. And that's the purpose of the talk pages - ie. for some sense of democracy and intelligence (sic) in how the main article is put together. Given that you are currently ALONE in your desire to have "decoherency" listed there AND that you have only cited it as "relevant" (rather than as "criticism" ie. under which it is written), one still wonders why it should continue to exist there under criticism. The only reason remaining becomes increasingly like just one person's will - that of Michael Price? Is it written under "criticism" because it has nowhere else to go? Well too bad. And I note that Price has made some significant contributions to how the page on decoherence is written - so perhaps we can read this text on decoherence (within the Afshar page) as an advertisement for Michael Price's contribution to the decoherence page. CARL LOOPER
- And also what it possibly does not mean.
- Again you ignore my point about judging an article by content not author. You also ignore my original argument:
- Michael, your ignorance of the issue should really disqualify you from even commenting on my experiment. The paper you have referred to discusses intermediate levels of interference visibility (V), and which-way information reliability (K), obeying the relation V^2+K^2<=1, which is in no way a violation of Complementarity. My experiment shows the presence of high interference visibility V~=1 AND sharp which-way information K~=1. Thus Complementairty is violated in my experiment. Please read up about the topic before you make laughable statements.-- Prof. Afshar 01:05, 15 November 2006 (UTC)
- Time for a few more facts: (1) I did not block the inclusion of O'Hara's paper in the article, as Afshar's claims. (Nor was I was asked to include it - it was Carl that Afshar asked this of, not me.) (2) Note how Afshar conveniently doesn't finish the O'Hara quote about Afshar's experiment: ", in a way that is compatible with a realist interpretation of complementarity." In other words O'Hara does not regard Afshar's experiment as violating complementarity. Strange that Afshar omitted this, eh? (3) There is no statement about intermediate visibility nor V nor K nor D in the Scully et al Nature / Scientific American article. --Michael C. Price talk 03:14, 15 November 2006 (UTC)
- Yes, it was addressed to me and I'd be happy to see someone include it in the main article. I had a read of it and it's quite interesting, and does refer to Afshar's experiment. And Michael - if Afshar suggests O'Hara's paper be linked in then I don't see how this is consistent with your characterisation of Afshar as hiding something - it doesn't hold. CL
- By all means do include O'Hara's ref -- but it denies that Afshar's experiment violates complementarity. As for whether Afshar was hiding something by not completing the quote is fairly easy to see. --Michael C. Price talk 09:26, 15 November 2006 (UTC)
- "but (sic) it denies Afshar's experiment violates complementarity" says Michael Price. So what's your point? Is this meant as some argument against including a reference? CL.
- Yes, it was addressed to me and I'd be happy to see someone include it in the main article. I had a read of it and it's quite interesting, and does refer to Afshar's experiment. And Michael - if Afshar suggests O'Hara's paper be linked in then I don't see how this is consistent with your characterisation of Afshar as hiding something - it doesn't hold. CL
- Time for a few more facts: (1) I did not block the inclusion of O'Hara's paper in the article, as Afshar's claims. (Nor was I was asked to include it - it was Carl that Afshar asked this of, not me.) (2) Note how Afshar conveniently doesn't finish the O'Hara quote about Afshar's experiment: ", in a way that is compatible with a realist interpretation of complementarity." In other words O'Hara does not regard Afshar's experiment as violating complementarity. Strange that Afshar omitted this, eh? (3) There is no statement about intermediate visibility nor V nor K nor D in the Scully et al Nature / Scientific American article. --Michael C. Price talk 03:14, 15 November 2006 (UTC)
- Michael, your ignorance of the issue should really disqualify you from even commenting on my experiment. The paper you have referred to discusses intermediate levels of interference visibility (V), and which-way information reliability (K), obeying the relation V^2+K^2<=1, which is in no way a violation of Complementarity. My experiment shows the presence of high interference visibility V~=1 AND sharp which-way information K~=1. Thus Complementairty is violated in my experiment. Please read up about the topic before you make laughable statements.-- Prof. Afshar 01:05, 15 November 2006 (UTC)
- I've just re-read O'Hara's paper to find where he is supposed to deny that Afshar's experiment's violates complementarity. I can't actually find anything like that at all. Am I missing something? O'Hara refers to Afshar's experiment being compatible with a "realist interpretation of complementarity". Michael must be reading this to mean Bohr's interpretation of complementarity (which would support Michael's argument) but the context seems to suggest otherwise. Realism is a funny word. It could be used to mean the emperical observables (data) but not any theoretical construction of such observables. But this is not the traditional meaning of the word. For example, in Einstein's world view theoretical constructions were (candidate) realitys. O'Hara's use of the word, given the tenor of the peice, would tend to suggest he is using the word "realism" in this sense, Einstein's sense, - the traditional sense, - or what I would call the "rationalist" sense. In other words, when O'Hara refers to a "realist" interpretation of complementarity he is not, methinks, referring to Bohr's interpretation of complementarity. He is referring to something compatible with what might also be called Afshar's interpretation of complementarity. Of course, this puts the meaning of the word "complementarity" into a rather special place. If complementarity is not Bohr's interpretation of it then what is it? Well, as Humpty Dumpty once said, (at least I think it was him) "it means exactly what I say it means". Which is to say you need to read through O'Hara's paper to get the drift of what he means. CL.
- For example, Michael Price might like to offer an interpretation of the following from O'Hara's paper: "By associating quantum interference with rotationally -invariant states induced by the slits, we have succeeded in showing that it is possible for an object such as an electron or photon to exhibit both particle and wave properties in a non-mutually exclusive way." Does this sound like O'Hara is supporting a conventional interpretation of Bohr's complementarity? I don't think so. CL.
- I think this demonstrates the importantance of interpretation - that it's not enough to rely on "accepted" meanings when building a criticism. One has to dig a bit deeper. Price used a localised quote from O'Hara as the basis for his accusation that Afshar was hiding something. He thought the quote meant something different than what it arguably does. He then jumped to the conclusion that if it did mean what he thought it did then the reason Afshar did not mention the quote was because Afshar was trying to hide it. Michael Price might like a lesson on the purpose of a quote - that it's not a way of hiding something. It constitutes an index - a shorthand - an abbreviation - a reference - a hyperlink. A pointer to where one can find the rest of the referenced material. CL.
- I might also add that I when I corresponded with Afshar (prior to Michael's accusation) I mentioned O'Hara's use of the word "realism" and Afshar had no issue with it whatsover. Indeed Afshar offered a tentative interpretation without any anxiety at all. So I don't know where Michael's theorys about Afshar come from. His brain? He should try using some other implement. CL.
Prof. Afshar: I suggest that you add a section here with such references, and we can all look at including in the article it appropriate. This section is far too long and unmanageabl now, also I can't look into it atm because I away for a conference. Dndn1011 19:46, 14 November 2006 (UTC)
At long last, have you no sense of decency Sir?
Michael, you say above: "What should not happen is for someone to write up their own experiment on Wikipedia." You have repeatedly made similar assertions in the past which gives a newcomer the impression that I have created the Afshar experiment page, or written the article as what you call "self-promotion". This is a shameless lie and I will no longer tolerates such visceral disregard for facts just because you happen to dislike my work. I have not written a single sentence of the article, and have only made suggestions in the talk page on corrections of errors. On the other hand you have had free rein to change and add anything you like, regardless of it being verified in published material. There are good reasons for rules against individuals closely affiliated with a subject to write about it in Wikipedia, but equally, there should be rules against allowing those with animosities against the topic or the scholar associated with the work to have undue influence on the article's content. You have turned the article into a "public tribunal" as Drezet puts it, with a patently biased POV. At any rate, if you do not cease and desist from spreading misinformation on Wiki articles and talk pages, I will take up the issue with the administrators and higher ups which may lead to your ban from Wikipedia. Enough is enough. -- Prof. Afshar 13:36, 14 November 2006 (UTC)
- Empty threats we have all heard before. Afshar has made numerous edits of the article, stretching back years, which are in violation of Wikipedia policy since 17 Feb 2006 . --Michael C. Price talk 14:51, 14 November 2006 (UTC)
- This is no empty threat. Others like Danko Georgiev learned the hard way that I do not play around. To prove your claim, show me the part of the article I have written.-- Prof. Afshar 14:58, 14 November 2006 (UTC)
- Anyone who checks your contribs history can see that your claim that you "have only made suggestions in the talk page on corrections of errors." is false. --Michael C. Price talk 15:20, 14 November 2006 (UTC)
- Well then, it should be very easy for you to just quote the part of the article that you claim I have written. Let's see it.-- Prof. Afshar 15:43, 14 November 2006 (UTC)
- Still waiting...-- Prof. Afshar 19:39, 14 November 2006 (UTC)
- I am also waiting for you to acknowledge that your edits of the main article (which you denied making) are in violation of Wikipedia policy. --Michael C. Price talk 21:25, 14 November 2006 (UTC)
- Still waiting...-- Prof. Afshar 19:39, 14 November 2006 (UTC)
- Well then, it should be very easy for you to just quote the part of the article that you claim I have written. Let's see it.-- Prof. Afshar 15:43, 14 November 2006 (UTC)
- Anyone who checks your contribs history can see that your claim that you "have only made suggestions in the talk page on corrections of errors." is false. --Michael C. Price talk 15:20, 14 November 2006 (UTC)
- This is no empty threat. Others like Danko Georgiev learned the hard way that I do not play around. To prove your claim, show me the part of the article I have written.-- Prof. Afshar 14:58, 14 November 2006 (UTC)
- It's quite entertaining to watch you digging a deeper hole for yourself, and losing credibility by the minute. As a "physicist" you should know that the burden of proof is always with the initiator of a claim. As the accuser YOU are required to produce evidence that the article was written by me. We are still waiting to see the evidence. P.S. Promoting one's other article's in Wikipedia without discussing it in the talk page are blatant violations of Wikipedia rules. You insist on linking decoherence (subject of a wiki article written by you) to my experiment, while other editors fully disagree with you.-- Prof. Afshar 21:59, 14 November 2006 (UTC)
- I note you are now making the same accusation about me (that I wrote an article), which is true to the same extent as it is with you -- the big difference is that my writing is about the claims of others, yours is about your own claims. And that is what is clearly prohibited by Wiki policy/ guidelines. --Michael C. Price talk 22:17, 14 November 2006 (UTC)
- It's quite entertaining to watch you digging a deeper hole for yourself, and losing credibility by the minute. As a "physicist" you should know that the burden of proof is always with the initiator of a claim. As the accuser YOU are required to produce evidence that the article was written by me. We are still waiting to see the evidence. P.S. Promoting one's other article's in Wikipedia without discussing it in the talk page are blatant violations of Wikipedia rules. You insist on linking decoherence (subject of a wiki article written by you) to my experiment, while other editors fully disagree with you.-- Prof. Afshar 21:59, 14 November 2006 (UTC)
- Still waiting...--Prof. Afshar 22:42, 14 November 2006 (UTC)
- Try re-reading instead. :-) --Michael C. Price talk 22:47, 14 November 2006 (UTC)
- Still waiting...--Prof. Afshar 22:42, 14 November 2006 (UTC)
- I have, that's why I'm still waiting for your evidence that I wrote the article. Give us a sentence I wrote. --Prof. Afshar 22:49, 14 November 2006 (UTC)
- Obviously you missed the bit where I said: "which is true to the same extent as it is with you". --Michael C. Price talk 22:53, 14 November 2006 (UTC)
- I have, that's why I'm still waiting for your evidence that I wrote the article. Give us a sentence I wrote. --Prof. Afshar 22:49, 14 November 2006 (UTC)
- Is this a stalemate? If so then drop it. CL.
Decoherence
Medieval scholars allowed what they called "marginalia" to exist in the margins of their otherwise main body of text. The purpose of marginalia was to allow for debate, criticism, or just pure grafitti, so as not to spoil the coherency and aesthetics of the main text.
Without marginalia the main text would become indistinguishable from marginalia.
In the domain of quantum computing decoherence is an obstacle to be overcome. And in teleportation as well. During the interval (sic) in which quantum computations must occur we're dealing with almost pure quantum states. Any residual noise from the environment is mitigated through error correction algorithms. Once decoherence is minimised (and this has been done in experimental quantum computers) it is decoherence that becomes irrelevant - because it is has been manufactured to be irrelevant. But only for the duration of the computation.
Either side of this interval one is back in an environment describeable in terms of decoherence but with one exception. Having obtained the results of a quantum computation one can not describe such information in terms of decoherence since it was manufactured while decoherence was held at bay.
Carl Looper
- OK, proudly showing my badge of naivety, I shall stride forth and say something without regard to the possible humilating consqeuences... When I was 11 years old, I wondered about mistakes that humans make. I did this especially because I made lots of them at the time (I still do, heh) and it bugged me. Why can't we be perfect? Why do we make errors? And I had this thought... that maybe making mistakes is a necessary part of how our brains work... that if we were 'prefect' we would no longer be able to function the way we do. It is part of what gives our minds the kind of power that eludes the "perfect" computer. In fact now I consider the possibility that consciousness requires non-deterministic processes. There are theories that suggest that consciousness operates at the quantum level (for example, see: Shadows of the mind). This would seem to fit nicely, as quantum effects have a non-deterministic component. So now I am going to postulate that if you ever did manage to create a quantum computer, it would necessarily have to operate in a non-deterministic manner. Perhaps it would be impossible to create a quantum computer that was deterministic? Dndn1011 23:26, 13 November 2006 (UTC)
- Hi dndn1011. I wouldn't go around bragging naivety. I mean it's an affable quality but there does come a time , at the end of the day, or the next morning, when one needs to sober up and think about things with a little more discipline. But be that as it may, lets have a look at what you're proposing.
- Michael C. Price: You obviously missed the joke. It was meant as a self effacing comment. I am stating ahead of time that I may not know what I am talking about, because I am what you could call an armchair physicist. And yet I keep asking questions and seek understanding of things in my own way, and I have found that I am generally very good at asking awkward questions. Except that I never know if they are actually awkward until I ask them. Dndn1011 09:46, 14 November 2006 (UTC)
- That comment was meant to be addressed to the unsigned contributor (Carl Looper?), I take it? It certainly was not made by me. --Michael C. Price talk 12:25, 14 November 2006 (UTC)
- Indeed, sorry about that, Looper should really get an account and sign his posts. Dndn1011 19:15, 14 November 2006 (UTC)
- That comment was meant to be addressed to the unsigned contributor (Carl Looper?), I take it? It certainly was not made by me. --Michael C. Price talk 12:25, 14 November 2006 (UTC)
- Michael C. Price: You obviously missed the joke. It was meant as a self effacing comment. I am stating ahead of time that I may not know what I am talking about, because I am what you could call an armchair physicist. And yet I keep asking questions and seek understanding of things in my own way, and I have found that I am generally very good at asking awkward questions. Except that I never know if they are actually awkward until I ask them. Dndn1011 09:46, 14 November 2006 (UTC)
- Heh - whether it was me (who did write it) or Michael (who didn't) doesn't matter. It's a fair comment anyway. I missed the joke. Carl.
After all it need not be naive at all. First of all, a quantum computer is still a very deterministic machine. It would be useless otherwise.
- Why? Actually I do not agree with this assertion. Have you heard of fuzzy logic? What is fuzzy logic if not a non-deterministic computation? Isn't fuzzy logic basically computation performed in the domain of probability? When one wishes to make actual use of fuzzy logic in practice the probability functions must be collapsed somehow. The point is that such computations are deterministic in the domain of probability but non-deterministic in the domain of individual cases. The classic example is gambing in a casino. The process can be viewed as deterministic overall (the house always wins), however individual transactions are not. So your assertion that "it would be useless otherwise" is plain wrong Dndn1011 09:46, 14 November 2006 (UTC)
- Hmmm. I should clarify. The deterministic nature of the way wave functions evolve, allow such functions to process the entire problem space, instead of just a non-deterministic (ND) subset thereof. ND algorithms were developed (amongst other things) to make conventional computations more efficient. Of course, one could also use ND algorithms on a quantum system to boost efficiency even more. CARL LOOPER.
Indeed, part of the problem in getting a quantum computer to work is to elliminate the "noise" the environment brings to the sensitive computations being sought. In quantum theory the wave functions are completely deterministic. They evolve over time in a completely predictable way. The non-deterministic aspect occurs in the interface between what is physically happening out here in the real world and what is theoretically happening within the isolated system performing the computation.
- Yes, this is exactly what I am saying. However it is only the probability functions that are deterministic. Actual events that occur are not. This leaves the possibility open to errors. You reduce errors by integrating many results of course (a fundemental principle of statistical research), but you can never eliminate them. To be deterministic a system must by 100% deterministic. Any amount of non-deterministic behavior, however small, results in a non-deterministic system.Dndn1011 09:46, 14 November 2006 (UTC)
- In quantum computation "actual events" do not occur in the computation itself (it is protected from actuality). Only the answer is actualised - and this must be done through strategys such as multisampling - as you say. And it can be 100% correct because the problem/answer is defined digitally - so it's as accurate as the number of qubits allow. (apart from how well you've protected the system from decoherence). Pi to nth decimal place but not beyond so to speak. CARL LOOPER
By carefully separating these two domains we can get a quantum computer to perform non-classical computations ie. as if a large number of classical computers were operating simultaneously where otherwise there is but one machine. This increase in computer power is mathematically expressible as 2^(2^numbits) compared with 2^numbits. For example, using three quantum bits (qubits) one can uniquely signify one of 2^(2^3) numbers - ie. one of 256 numbers, versus the conventional one of 8 numbers. Lets look at five bits. 2^5 = 32 numbers. 2^(2^5) = 4294967296 numbers. And 6 qubits = 18446744073709551616 numbers. And very quickly you'll be approaching the number of every atom in the known universe - with just a handful of quantum bits. In other words with a handful of qubits one can uniquely specify a single atom out of all the atoms in the known universe. Or two atoms out of half the number of atoms in the known universe. And so on. Storage power and processing power are interchangeable. So one can also see in these numbers the vast processing power of a quantum computer. The challenge is getting information into the system and back out again - circumnavigating decoherence. But there are all sorts of ways of doing this and quantum theory, in all it's various manifestations, is there to guide us.
- I will need to read up on this, a reference would be good, thanks.Dndn1011 09:46, 14 November 2006 (UTC)
- Consciousness as a quantum system? Well, to the extent that our brains can perform operations in parallel our brains, at least, do a good job of simulating a quantum computer but they don't really work like a quantum computer.
- Has this been proven? Dndn1011 09:46, 14 November 2006 (UTC)
- The onus of proof is on Penrose but the critique section provides some useful counter-arguments. - CL
The signals being interchanged everywhere are not protected from decoherence in any way. So our brains are just classical information processors - but operating in parallel - as some newer computers do (dual core etc). Non-deterministic algorithms - on a classical computer - can be used to simulate quantum computations as well. So our brains could very well use non-deterministic algorithms.
- A turing machine is incapable of non-deterministic behavior... User:Dndn1011. And you theorise that our brains are just classical information processors, other disagree with you (e.g. Penrose, Shadows of the mind).
- By non-deterministic algorithms I mean algorithms such as fuzzy logic, genetic algorithms, neural networks, which make heavy use of 'random' numbers. These algorithms sample the solution space more efficiently than a brute force approach - on a Turing machine. CARL LOOPER
I'd be surprised if they didn't. The value in a quantum computer is that it would exceed what can be acheived using non-deterministic algorithms on a mono or parallel computer. But for the time being we have to "make do" with what we've got. Even with a quantum computer we're limited by the number of qubits. Running non-deterministic algorithms on a quantum computer might be interesting. Quantum computing means we could cross reference an entire DNA sequence in milliseconds. Of course, we still need to program these beasts, ie. define the problems to be solved and define how they'll solve them. They just do the grunt work.
- But more to the point - whose to say consciousness has anything to do with computing or our brains? CARL LOOPER
- Or with Afshar's experiment? --Michael C. Price talk 08:28, 14 November 2006 (UTC)
- The reference to consciousness was 'marginalia' Dndn1011 09:46, 14 November 2006 (UTC)
- Or with Afshar's experiment? --Michael C. Price talk 08:28, 14 November 2006 (UTC)
- But more to the point - whose to say consciousness has anything to do with computing or our brains? CARL LOOPER
- Yes, that's right. It is marginalia :) I'd say consciousness is a complex philosophical subject which does not lend itself readily to simple or even complex mathematical expression. At least most of the stuff I read on the subject is like this. But one can certainly try. CARL LOOPER.
Archiving talk page
This talk page is getting very hard to follow. Can somebody archive this page? We can discuss decoherence in the new page. I will be happy to engage with Michael on the issue given he behaves objectively.-- Prof. Afshar 23:34, 14 November 2006 (UTC)
I second that. Carl