Talk:Bell's theorem/Archive 1

message: Though most accept that experiments have indeed violated Bell's inequalities, few are finding it easy to live with the consequences.  There are currently two main ways whereby reconciliation can be attempted between local realism and the facts.  The logic of Bell's theorem itself can be disputed, or the experimental evidence challenged.
------
I like some of the new information, however I do have two problems with the new
text....
1) First of all, the really, really important thing that Bell showed was that
quantum mechanics was incompatible with local realism.  This demonstration is
theoretically very important not withstanding the experimental issue over which
is correct.
2) Second, there is the wiki rule "no original research"
Roadrunner 03:18, 17 Aug 2004 (UTC)
thread_title: Living with "Bell test violations"

message: Lethe is right. The sentence on loopholes is loaded, POV and merits removal.CSTAR 23:37, 20 Nov 2004 (UTC)
thread_title:  Loaded sentence 

message: In reading this page, I'm struck by the same reaction I often have to Wikipedia articles - we aren't thinking enough about writing for our (non-specialist) audience, as opposed to the (specialist) writers of the article. This article remains heavy going for me, even though I have a technical education, and have been interested in the whole Bell/EPR/etc are for some decades now. I would like to draw people's attention to the following article:
: N. David Mermin, Is the moon there when nobody looks? Reality and the quantum theory, in Physics Today, April 1985, pp. 38-47.
which to me remains, almost 20 years later, the best introduction to the issues at hand, and the one that best combines rigour and understandability. I would really encourage the maintainers of this article (and no, I don't have time to do it myself!) to obtain this work, review it, and see if they can't get to this level of approachability here. Noel (talk) 16:55, 22 Nov 2004 (UTC)
replies: text:  I'm afraid that you can either have "approachability" or something near to the true facts, which are complicated.  Yes, I'm aware of Mermin's article, and, in its way, it is very good.  But it is wrong!  His thought-experiment does not allow for the kind of "stochastic" model (one in which the hidden variables predict probabilities rather than actual results) that is relevant to the real experiments.  He introduces Aspect's experiments, complete with photo of the apparatus, but nowhere mentions the fact that not all "photons" are detected.  The reader is left to assume that the real experiment produced infringements of Bell tests and followed the same, deterministic, rules as the thought-experiment.  Yesterday I checked a more recent article by him: http://arxiv.org/abs/quant-ph/0207140.  He is still, I'm afraid, disseminating a misleading picture in which it is implied that an experiment with no non-detections has been conducted and has infringed a rigorous Bell test.  [Incidentally, in order to understand where Aspect's results come from there is, in my opinion, no way of avoiding the issue of "accidentals".  See Bell test loopholes.] Caroline Thompson 11:42, 23 Nov 2004 (UTC)
thread_title: Presentation

message: #Bell's inequality is a (completely classical) inequality about correlations of random variables defined on probability spaces.
# The inequality is meaningful in other situations in which pairwise correlations make sense.
# The inequality can be used to test whether situations in which pairwise correlations can be imbeded in a classical probability space. 
As the article currently reads it never explains the basic fact 1 above, at least not in any comprehensible way. It goes to great lengths to talk about seven different versions without ever saying the most important fact.
I hope to write this up carefully within in the next few days. CSTAR 06:28, 20 Jan 2005 (UTC)
replies: text: Excellent, CSTAR.  I noticed that the article is weighted heavily towards a discussion of the various inequalities that can be derived from Bell, as well as tests of these inequalities.  There is a lot about the debate on local reality vs. QM which is probably over-emphasized here and should be largely moved elsewhere.  There is relatively little about the historical context, EPR, Von Neumann, Bohm, etc.  The Theorem is important, as you point out, on its own and regardless of the experimental tests.  I would also like to see a little more on Bell, his comments on the paper, and its enduring value (how many times has this been cited, for example).--DrChinese 17:50, 20 Jan 2005 (UTC)
replies: text:  OK, there is something there now, although a bit more is needed on quantum correlation. The article is now too long. What should be removed? Do we need all this stuff on the various Bell inequalities other than just a passing mention?  Bell test experiments probably should be in some other article as well as "loopholes". CSTAR 21:25, 20 Jan 2005 (UTC)
thread_title:  The article fails to mention 

message: Unfortunately, I can't seem to find the original Latex source. The version on his page was deLatexed but the program didn't do a great job. I think a straightforward gawk program could have done a better job.CSTAR 22:07, 23 Jan 2005 (UTC)
thread_title:  Re: Landau reference 

message: Von Neumann's "proof" was for hidden variables, period. No local.  Moreover, Bell's 1966 paper is specifically concerned with the same problem (although he also addresses local hidden variables).CSTAR 23:03, 28 Jan 2005 (UTC)
thread_title:  Hidden variables 

message: CSTAR, I started to edit the page to replace the term "correlation" (which necessarily means the standard statistical kind) by "quantum correlation", but came across statements that are either just plain false or (as I've tried to say many times) irrelevant.  They hinge around the fact that in real experiments outcomes are often zero, which is the reason Clauser and Horne in 1974 produced what should have been the definitive version of the Bell test -- one in which non-detections simply don't matter.  If you read the 1969 CHSH paper carefully, you will find that test they actually recommend is not what is now known as the "CHSH test" but the 1974 version, relying on comparing counts with polarisers both sides with those with one or other or both absent.
Anyway, the relevance of the above to your two sections is that the following is wrong:
:"Notice however, that the definition of quantum correlation makes sense more generally, regardless of whether or not there is an underlying probability space on which the variables X, Y are defined.  The important conditions are that
:* The experiment which produces the values X and Y be repeatable;
:* That on each trial of the experiment, both variables X and Y can be observed."
I added the qualification "[which is not actually the case in real optical Bell test experiments]" then realised that the result was complete nonsense!  What's the point of making this condition only to say that it is never met?
Your section goes on to say:
:"The proof of the CHSH inequality for random variables taking only values -1 or +1 is trivial: for each sample point, 
:: W = X_A X_B + X_A Y_B + Y_A X_B - Y_A Y_B = X_A (X_B + Y_B) + Y_A (X_B - Y_B) \leq 2. 
:This holds since for each sample point one of the values
::  X_B + Y_B, \quad X_B - Y_B 
:is zero."
But again, in real experiments this is not so!  If, for example, X_B is 1 and Y_B is zero then the sum and difference are both 1.
What is the point of presenting in wikipedia a "proof" that bears no relation either to any usable Bell inequality or to the real world?
Caroline Thompson 18:58, 30 Jan 2005 (UTC)
thread_title: But in real experiments outcomes are more often zero than +-1

message: The (or "your") proof of CHSH, in the Wikipedia CHSH article says 
:: We start with the standard assumption of independence of the two sides,
This really requires clarification. As I'm sure you know, variables which are stochastically independent (and have zero mean) have zero correlation, which is certainly not true here.  BTW, you incorrectly foisted your "independence" assumption on the Bell theorem page, which I will correct soon enough.  The only assumption needed there is locality and realism.
In Bell's 1971 paper, which I have in front of me, particularly on section 4, immediately after eq (6), Bell indeed says that 
: \overline{A} 
is independent of 
: \hat{b} 
but does not assert independence "of the two sides" which is much too vague and actually misleading. I suppose it would be too much to ask you to correct this? 
ThanksCSTAR 20:50, 31 Jan 2005 (UTC)
replies: text: Thanks CSTAR, I'll have to rephrase this.  What I mean is that once the hidden variable has been fixed, that covers all the correlated factors.  Given lambda, this determines the probability of detection at A and the probability at B.  The detections at A and B are conducted independently, i.e. by detectors that have no connection with ("are independent of") each other.  The consequence is that you can apply the usual rule of probability theory and multiply the two singles probabilities to obtain the joint probability.  This is the standard assumption underlying hidden variable theories.  Bell explains very carefully in one of his papers just what assumptions are involved.  I haven't got it to hand but will look it up. Caroline Thompson 22:08, 31 Jan 2005 (UTC)
thread_title:  Re: The CHSH proof 

message: For those that are still watching this show, it is now playing over at my talk page.
However, visitors are requested to send $10 to any Tsunami relief fund per visit.
Thank you!CSTAR 15:09, 8 Feb 2005 (UTC)
thread_title:  More of CT's scurrilous attacks on my talk page 

message: From some reason CT has decided to protest over at my talk page. My latest response to her:
Reply to CT
Why is this discussion taking place here on my talk page and not on the Bell theorem talk page?
:: "They look as if they mean orthogonal settings in your remaining diagram." 
Well in the remaining diagram they refer to the specific quantum mechanical example discussed in that section in which they are orthogonal.  That is clear from the surrounding text.  
::  "I have as yet to see evidence that you understand the whole hidden variable approach."
Whoa, that's a pretty prickly response! Are you now qualified to issue exams?  
:: "You might possibly be interested in the following,"
I've read enough of your theories already.  No thank you.
CSTAR 19:32, 8 Feb 2005 (UTC)
thread_title:  More CT 

message: All the Bell articles should be mentioned, in addition to CHSH, Griffiths, Redhead, Nielsen and Chuang as well as d'Espagnat's classic (it is currently not mentioned).   Am I missing anything?
I see no reason to delete the others, but if you insist, I suppose go ahead and delete them.CSTAR 15:57, 15 Feb 2005 (UTC)
thread_title:  Re: References 

message: The derivation currently presented for the CHSH inequality entirely misses the point and is wrong.  It does not apply either to Bell's original idea or to the actual Bell test experiments! [I had been concentrating my attention on the use of poor notation and have only just got around to looking at the logic.]
The statement that Bell test trials consist of "An infinite sequence of values XAn, YAn, XBn, YBn, where n denotes the trial number" is simply not true, and cannot legitimately be used as a starting point.
Bell's idea was that by assuming hidden variables, with the source being at any one time in a given state and with a fixed probability distribution for those states, one can derive the inequality as a statistical result.  The discussion currently given can at best be regarded as an argument for its plausibility, since in the actual experiments there is no meaning to the index n.  As implied under "Remark 1", the actual Bell tests comprise a set of subexperiments, each investigating one setting for detector A, another for detector B.  It is physically impossible to look at all four combinations of settings at once.  [Even in Aspect's or Weihs'experiments, where the choice between the two settings on each side is random, they cannot physically be observed simultaneously.]  The idea that we can somehow ensure that all the expressions have the "same value when taken on each one of the ... subsequences" is just wishful thinking.  
Valid derivations are given in the CHSH inequality page.  They employ (as far as possible) the standard notation -- that of Bell, Clauser and Horne's original papers -- which differs markedly from that of the current page.
Other faults with the page that urgently require correction include:
#Bell's orginal inequality is not even stated
#The diagrams print poorly
#Some of the Latex expressions over-run the line so the end is not printed
Drastic revision is needed.  My own suggestion remains that we base the new version on the one before CSTAR's intervention.  I don't know where CSTAR got his material from but it is evidently not an authoritative one.  No authoritative version would attempt a derivation based on an index n and not on hidden variables. Caroline Thompson 09:08, 9 Apr 2005 (UTC)
thread_title: Not only bad notation: the derivation of the CHSH inequality is wrong!

message: ::: CT's claims have been discussed and refuted in this talk page  and in other forums by other individuals, endlessly. Are you also making the claim that "CSTAR is making statements claiming to be the accepted POV but which are quite inaccurate" or are you simply trying to paraphrase CT? = As I have expressed many times, my presentation closely follows Asher Peres formulation in his standard textbook, which is also essentially the treatment given by Nielsen and Chuang in there now classic book. 
::: Before making any claim , please note that CT has attempted to delete (at 08:56 29 March 2005 to be specific) the past record of this talk page: See 
::: There you can quite clearly she has tried to obliterate an important part of the discussion, including past refutations of her position, contributions of many in the WP community and an explicit statement of my references, which she claims now to ignore. --CSTAR 03:35, 24 Apr 2005 (UTC)
thread_title: Reply to [[User:RayTomes]] 

message: I've looked over some of this talk page change history and found that your problem edit made at 08:56, 29 Mar 2005 almost certainly occurred because you started editing on a very outdated revision of the page, that of 20:28, 9 Feb 2005 rather than the current version of the page (which was 10:09, 20 Mar 2005).  This caused the following 16 edits to be thrown out:
 10:09, 20 Mar Caroline Thompson (→Bell's original inequality - Where is lead to other Bell inequalities?)
 10:13, 19 Mar Caroline Thompson (→Bell's original inequality)
 10:10, 12 Mar Caroline Thompson (→Info on Bell's inequalities has been lost - Perhaps mostly OK now)
 09:55, 12 Mar Caroline Thompson (→Info on Bell's inequalities has been lost)
 18:23, 11 Mar Caroline Thompson (The redirect for both Bell inequalities and Bell's inequalities 
 18:52, 16 Feb Caroline Thompson (→Re: References - Did some deletion and editing; repeated crit
 15:57, 15 Feb CSTAR (→Effect of zero outcomes on formula)
 13:31, 15 Feb CSTAR (→Effect of zero outcomes on formula)
 09:58, 15 Feb Caroline Thompson (→Effect of zero outcomes on formula)
 10:27, 11 Feb Caroline Thompson (→New "Bell inequalities" page - Back to the detection loophole)
 22:24, 10 Feb CSTAR (→New "Bell inequalities" page)
 22:15, 10 Feb Caroline Thompson (→New "Bell inequalities" page)
 22:11, 10 Feb Caroline Thompson (→New "Bell inequalities" page)
 22:00, 10 Feb Caroline Thompson (→New "Bell inequalities" page)
 14:42, 10 Feb Stirling Newberry (Changing header, please do not direct talk page headers at individuals.)
 10:35, 10 Feb Caroline Thompson (→Sorry CSTAR, but you are wrong!)
On the article page itself you have had similar problems (one symptom of which was your "links jinx").  At 18:40, 16 Feb 2005 you made an edit based on the out-of-date revision of 23:10, 9 Feb 2005, thus losing these edits:
 09:56, 11 Feb Caroline Thompson (4th attempt at link to Bell's inequalities page! (My machine glitch?))
 00:34, 11 Feb CSTAR (→Comparison to quantum mechanical prediction - Deleted redundant sentence)
 18:25, 10 Feb CSTAR (→External Links)
 18:25, 10 Feb CSTAR (→References -Format)
 15:40, 10 Feb CSTAR (→Bell test experiments - Removed link. ALready have one link to that page)
The simplest explanation is that you sometimes click to edit while looking at an old revision.  It would be good to be careful in the future, and also to check at the top of the editing page for this message:
:WARNING: You are editing an out-of-date revision of this page. If you save it, any changes made since this revision will be removed.
Yours for more effective wikiing -R. S. Shaw 06:51, 24 Apr 2005 (UTC)
replies: text: Thanks!  I've no idea, though, how I could confuse a really old edition for the current one.  I know my browser sometimes uses one from cache that is not quite up to date, and this can be cured by pressing Ctrl+F5, but it's most strange that I could have accidentally brought back an ancient edition of a talk page.  Ah well, since the article has since been hacked around beyond recognition, most of this talk is now irrelevant.  The problems on the article page were relatively minor and they, too, no longer matter. Caroline Thompson 10:03, 26 Apr 2005 (UTC)
thread_title:  Caroline, about your editing jinx 

message: Although I don't agree with Caroline Thompson's cranky ideas, I do whole-heartedly agree with her on one point.  This page is AWFUL.  In fact, out of every page I've ever seen on wikipedia, the Bell's Theorem page is the worst, by at least an order of magnitude.  Was this page supposed to be a practical joke?
First of all, you've lost all your readers who aren't physicists by paragraph 5.  This is a shame.  It's certainly possible to do a very respectable job describing Bell's Theorem that is both factual and accessible to the general public.  Whoever wrote this nonsense has completely and utterly jettisoned the non-technical audience.  No regard has been made for them.
Second of all, I have to say, even for a technical audience, it's really not well written.  It's dry, mechanical, and uses godawful notation.  Even I find it abstruse.  You can pick up a copy of "Quantum [Un]speakables From Bell to Quantum Information", open it to any random page, and you'll find text easier to consume than this page.  And those guys are world experts!
If you REALLY want to help wikipedia out, and benefit the internet community, toss the whole thing out.  Contact Professor Shankar, Professor Griffiths, Professor Liboff, or Professor O'Hanian and ask them to donate a treatment for Bell's Theorem.  Not only do those guys know how to write, but they know how to write TO AN AUDIENCE, which is completely lacking here.
If anybody wants THIS level of detail in Bell's Theorem, they either know the subject already, have a suitable book on their shelves, or can go to any number of excellent resources on the web that can be found via Google.
Please -- instead of arguing over the merits of Caroline Thompson's wierd ideas, why don't you:
1. Spend a LOT of time discussing who you want to write for.  Who is your audience?
2. Make a draft of precisely which aspects of Bell's Theorem you want to cover, being mindful that this needs to be a general treatment for a wide audience.
3. Go ahead and write.
=== Reply ===
Hello. That's pretty strong criticism!  Here are some comments in reply to your points, presented in no particular order:
:#Well I wrote much of the page, not I must say, with any great enthusiasm, as should be evident from the copious comments on this and related pages.
:#No, this page is not a joke. 
:#Referring to something is nonsense is clearly not helpful; indeed if you think it is nonsense, delete it or shorten it to one or two sentences.  I agree Wikipedia should not contain nonsense, but it would be more helpful if you supplied a more substantive replacement (at least in the near future-- see my suggestion in (7) below).
:#If anybody else wants to write the article, fine by me.  But it appears that aside form Caroline Thompson, there haven't been may takers. I doubt Griffiths or any of the others you mentioned are salivating at the prospect of replacing this article, but who knows?
:#Re: Your comment Even I find it abstruse. Not knowing who I refers to in this case, or more to the point the backgound of I is hardly any help.
:#Re: Your comment out of every page I've ever seen on wikipedia, the Bell's Theorem page is the worst, by at least an order of magnitude. . Either you haven't seen many pages in Wikipedia, or you're exaggerating.
:#Re:You can pick up a copy of "Quantum [Un]speakables From Bell to Quantum Information", open it to any random page, That may indeed be the case. You could write a useable summary based on your reading to (eventually) replace the current article which I assume you will feel the urge to delete or drastically reduce as quickly as possible. I assure you I will not revert any reductions.
Cheers.--CSTAR 00:32, 14 July 2005 (UTC)
replies: text: Greetings and congratulations on your dissertation, may it go smoothly. This is a situation that often is reached in Wikipedia - namely, a subject that has a great deal more information than a basic article would have. What we may need is, in essence, an overview which would be the first section on the page, targetted, as you suggest, at someone who wants to grasp the idea and why it is important, and then the more technical presentation in the rest of the article. I'm sure that your efforts will be warmly supported in providing the "layman's introduction" that the topic desperately needs. Stirling Newberry 17:51, 14 July 2005 (UTC)

text: Apology accepted (to the extent that your remarks were directed at me). I look forward to your contributions in this article.  Thanks .. and welcome to Wikipedia! --CSTAR 19:28, 14 July 2005 (UTC)
replies: text: A major problem with any article on Bell's theorem is that the content does depend so much on the intended audience.  One can write something that will help students with their essays at school level or something that will help them with essays at university or something that will enable them to make a reasonable stab at understanding the physics of the actual experiments.  The latter is what I attempted, based on study of many experimental reports, including Aspect's PhD thesis coverage of his three famous Bell tests.  If you want the first option, you can take something such as Nick Herbert's book.  I haven't read this myself but gather that it makes the subject sound fairly straightforward.  Unfortunately, though, it seems to be a poor introduction for anyone trying to understand what goes on in the actual experiments.  For this, it would be better to stick to John Bell's own papers, and give a ref a comprehensible one on the detection loophole.  For the latter, I would (of course!) recommend my own.  See my user page for refs.  Caroline Thompson 10:15, 15 July 2005 (UTC)

text: There's no conflict between having a layman's introduction, followed by a full presentation. Stirling Newberry 04:16, 16 July 2005 (UTC)
replies: text: Good idea!  Let's hope the introduction makes it quite clear that Bell's inequality is something that really, in itself, has nothing to do with quantum mechanics at all.  It is simply a mathematical consequence of a few "local realist" assumptions.  Bell's theorem states that this inequality can be violated under QM, but the casual reader does not, I think, need to know why.  What he may well be interested in, though, is whether or not the experiments really do support QM, given that it conflicts with local realism.  I trust the improved page will not play down the doubts on this score. Caroline Thompson 08:32, 17 July 2005 (UTC)
replies: text:  OK good point for has nothing to do with quantum mechanics at all. --CSTAR 17:28, 17 July 2005 (UTC)
thread_title: This Page Is Awful

message: Hello. That's pretty strong criticism!  Here are some comments in reply to your points, presented in no particular order:
:#Well I wrote much of the page, not I must say, with any great enthusiasm, as should be evident from the copious comments on this and related pages.
:#No, this page is not a joke. 
:#Referring to something is nonsense is clearly not helpful; indeed if you think it is nonsense, delete it or shorten it to one or two sentences.  I agree Wikipedia should not contain nonsense, but it would be more helpful if you supplied a more substantive replacement (at least in the near future-- see my suggestion in (7) below).
:#If anybody else wants to write the article, fine by me.  But it appears that aside form Caroline Thompson, there haven't been may takers. I doubt Griffiths or any of the others you mentioned are salivating at the prospect of replacing this article, but who knows?
:#Re: Your comment Even I find it abstruse. Not knowing who I refers to in this case, or more to the point the backgound of I is hardly any help.
:#Re: Your comment out of every page I've ever seen on wikipedia, the Bell's Theorem page is the worst, by at least an order of magnitude. . Either you haven't seen many pages in Wikipedia, or you're exaggerating.
:#Re:You can pick up a copy of "Quantum [Un]speakables From Bell to Quantum Information", open it to any random page, That may indeed be the case. You could write a useable summary based on your reading to (eventually) replace the current article which I assume you will feel the urge to delete or drastically reduce as quickly as possible. I assure you I will not revert any reductions.
Cheers.--CSTAR 00:32, 14 July 2005 (UTC)
replies: text: Greetings and congratulations on your dissertation, may it go smoothly. This is a situation that often is reached in Wikipedia - namely, a subject that has a great deal more information than a basic article would have. What we may need is, in essence, an overview which would be the first section on the page, targetted, as you suggest, at someone who wants to grasp the idea and why it is important, and then the more technical presentation in the rest of the article. I'm sure that your efforts will be warmly supported in providing the "layman's introduction" that the topic desperately needs. Stirling Newberry 17:51, 14 July 2005 (UTC)

text: Apology accepted (to the extent that your remarks were directed at me). I look forward to your contributions in this article.  Thanks .. and welcome to Wikipedia! --CSTAR 19:28, 14 July 2005 (UTC)
replies: text: A major problem with any article on Bell's theorem is that the content does depend so much on the intended audience.  One can write something that will help students with their essays at school level or something that will help them with essays at university or something that will enable them to make a reasonable stab at understanding the physics of the actual experiments.  The latter is what I attempted, based on study of many experimental reports, including Aspect's PhD thesis coverage of his three famous Bell tests.  If you want the first option, you can take something such as Nick Herbert's book.  I haven't read this myself but gather that it makes the subject sound fairly straightforward.  Unfortunately, though, it seems to be a poor introduction for anyone trying to understand what goes on in the actual experiments.  For this, it would be better to stick to John Bell's own papers, and give a ref a comprehensible one on the detection loophole.  For the latter, I would (of course!) recommend my own.  See my user page for refs.  Caroline Thompson 10:15, 15 July 2005 (UTC)
thread_title:  Reply 

message: # This level of presentation is fine. The inequality page is far too much of a summary.
# Very detailed articles, such as this one, are very often the result of edit wars. Clearly, if there was enough dispute to cause the edit wars, there is cause for this level of detail.
# It's extremely rude to speak in a condescending fashion and to attack a page with hyperbole. Please refrain from personal attacks.
Stirling Newberry 01:03, 14 July 2005 (UTC)
thread_title:  Support CSTARS efforts 

message: Yes, you are right.  My criticism should've been more constructive, and not contain hyperbole, which is completely inappropriate. I do apologize. But honestly, this IS one of the more technically "out there" pages I've seen on Wikipedia.
Ideally, we should strive to write an article that would be of benefit to a high school student doing a report on quantum mechanics can understand.  I'm not advocating free of detail, but the notice at the top of the page should really be changed.  Some of the technical details _need_ to go.
I'll put my money where my mouth is.  I'm handing in my dissertation Monday, and will probably spend (no more than) a month dealing with edits.  When I'm done, I'll try edit this (off line because I don't know the protocol of changing the main page yet) and send a RFC.
Again, please accept my sincere apologies.  Sometimes it's difficult to remember there are human beings on the other side of this monitor, and my dissertation has been one of the biggest emotional roller coasters I've ever seen.  If I knew back then what a PITA it would be, I never would've done it in the first place.
:Greetings and congratulations on your dissertation, may it go smoothly. This is a situation that often is reached in Wikipedia - namely, a subject that has a great deal more information than a basic article would have. What we may need is, in essence, an overview which would be the first section on the page, targetted, as you suggest, at someone who wants to grasp the idea and why it is important, and then the more technical presentation in the rest of the article. I'm sure that your efforts will be warmly supported in providing the "layman's introduction" that the topic desperately needs. Stirling Newberry 17:51, 14 July 2005 (UTC)
replies: text: Apology accepted (to the extent that your remarks were directed at me). I look forward to your contributions in this article.  Thanks .. and welcome to Wikipedia! --CSTAR 19:28, 14 July 2005 (UTC)
replies: text: A major problem with any article on Bell's theorem is that the content does depend so much on the intended audience.  One can write something that will help students with their essays at school level or something that will help them with essays at university or something that will enable them to make a reasonable stab at understanding the physics of the actual experiments.  The latter is what I attempted, based on study of many experimental reports, including Aspect's PhD thesis coverage of his three famous Bell tests.  If you want the first option, you can take something such as Nick Herbert's book.  I haven't read this myself but gather that it makes the subject sound fairly straightforward.  Unfortunately, though, it seems to be a poor introduction for anyone trying to understand what goes on in the actual experiments.  For this, it would be better to stick to John Bell's own papers, and give a ref a comprehensible one on the detection loophole.  For the latter, I would (of course!) recommend my own.  See my user page for refs.  Caroline Thompson 10:15, 15 July 2005 (UTC)
thread_title:  Yes, you are right.  I apologize 

message: Hate to agree with Caroline, but Bell's theorem is one of those topics that is of interest to both college students with no background in QM and also to PhD's who have years of experience.  The technical content should not be gutted just so that some casual reader who hasn't a clue about quantum mechanics can read this.  As to its being "too technical", that's unadulterated bunkum. There are many thousands of far far far more technical articles on WP; try BRST formalism on for size; any article under :Category:Quantum field theory, or, for that matter, almost each and every article under :Category:Mathematics, with few exceptions. linas 00:35, 16 July 2005 (UTC)
replies: text: There's no conflict between having a layman's introduction, followed by a full presentation. Stirling Newberry 04:16, 16 July 2005 (UTC)
replies: text: Good idea!  Let's hope the introduction makes it quite clear that Bell's inequality is something that really, in itself, has nothing to do with quantum mechanics at all.  It is simply a mathematical consequence of a few "local realist" assumptions.  Bell's theorem states that this inequality can be violated under QM, but the casual reader does not, I think, need to know why.  What he may well be interested in, though, is whether or not the experiments really do support QM, given that it conflicts with local realism.  I trust the improved page will not play down the doubts on this score. Caroline Thompson 08:32, 17 July 2005 (UTC)
replies: text:  OK good point for has nothing to do with quantum mechanics at all. --CSTAR 17:28, 17 July 2005 (UTC)
thread_title: Dumbed down vs technical version