Talk:Quantum indeterminacy

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Contents 1 Measurement 2 Interpretations 3 New Edits 4 Incompleteness 5 Chris Fuchs 6 The ever-changing quotes 7 Heisenberg quotes 8 What logic and flow? 9 Classical theory of measurement 10 Measurement as intervention 11 Einstein's argument for the incompleteness of quantum physics 12 Extensive quotes 13 Dispute claim 14 New dispute claim 15 Further replies 15.1 Replies 16 Measurement requires intervention 17 Dispute status of this article 17.1 What I intend to do 18 Major revert 18.1 RfC 18.2 Time for a truce? 19 What should we do about the quotes? 20 my revert 21 On perspective 22 Dispute 23 Moved disputed content elsewhere 24 Comment (as requested) 25 Please check accuracy of figure 26 Something I need 'cleared up' 27 Semi-protected 28 Grammar

[edit] Measurement

Some comments on quotes from the present article:

[...] a particle with a definitely measured momentum for which there must be a fundamental limit to how precisely its location can be specified

A precise measurement of momentum (of a particle, in reference to a suitable system) simply cannot be obtained at all from observations on reference system locations within a finite distance of each other.

Vice versa, observations at one particular location (or at one particular distance x from the "origin" of the reference system, in one particular direction) don't allow to evaluate its momentum at all; i.e. as proportional to ∂/∂x ().

[...] for exampl,

(Note the typo.)

a particle with a definitely measured energy has a fundamental limit to how precisely one can specify how long it will have that energy

A precise measurement of energy (of a particle, in reference to a suitable system) simply cannot be obtained at all from observations by the reference system within a finite duration of each other.

Vice versa, observations at one particular moment (or at one particular duration t from any selected "reference moment") don't allow to evaluate its energy at all; i.e. as proportional to ∂/∂t (). Also ...

[...] concerned with the predictability of events

... the uncertainty relations (as derived by Robertson and Schrödinger anyways) are concerned with relations between concurrent measurements, from given observational data; not with predictions based on those measurements. The present article on the Uncertainty principle may not express this sufficiently ...

Regards, Frank W ~@) R 02:36 Mar 4, 2003 (UTC).

The last two paragraphs can go, as they have nothing to do with this topic, and seem to just be some crazy guy's theory based on a misunderstanding of what the quantum indeterminacy means. --Havermayer 23:45, 23 Jun 2005 (UTC)

• Moved section on "Indeterminacy in computation" here from Uncertainty principle.--CarlHewitt 2005 July 6 23:03 (UTC)

[edit] Interpretations

Re:Within most interpretations of quantum mechanics, it is fundamentally unavoidable.

Why does indeterminacy depend on the interpretation? I would say, that there can be no interpretation without indeterminacy. I would suggest removing that sentence.--CSTAR 04:18, 8 October 2005 (UTC)

[edit] New Edits

Putting in extensive quotes from Chris Fuchs (or anybody else) is not a good idea.

--CSTAR 05:18, 8 October 2005 (UTC)

Should we paraphrase Fuchs?--Carl Hewitt 05:30, 8 October 2005 (UTC)

I suppose, but this is a lot of work. --CSTAR 05:35, 8 October 2005 (UTC)

The quotation is short so the amount of work is not great. A bigger problem is that the result will undoubtedly be worse than direct quotation. Also there is an issue of intellectual honesty. An alternative would be to gradually expand the article so tha the quotation by Fuchs does not occupy such a large per cent of the article.--Carl Hewitt 05:40, 8 October 2005 (UTC)

Why is there no article? I suppose an article would be a lot more authorative than this discussion.

[edit] Incompleteness

Incompleteness is an old issue in quantum mechanics. Although I think Fuchs is highly quotable, I don;t think it is necessary to rely on anything he says about this topic.

1. There is incompleteness a la EPR.
2. There is Karl Popper's notion of incompleteness, which he discussed in a well known book of essays.
3. Then there is incompleteness as expressed by complementarity.

--CSTAR 05:54, 8 October 2005 (UTC)

We have at least two issues with respect to incompleteness in quantum indeterminacy:

1. Einstein's argument for the incompleteness of quantum physics
2. How quantum physics deals with incompleteness

--Carl Hewitt 07:24, 8 October 2005 (UTC)

[edit] Chris Fuchs

Chris Fuchs did not invent indeterminacy, and moreover his views on QM are too idiosyncratic. I think his view of QM strikes me as being some form of instrumentalism (about which I earlier had an exchange in th einterpretation of quantum mechanics talk page.--CSTAR 02:28, 9 October 2005 (UTC)

I agree that Fuchs is not the only view and that the treatment in the article should bring out other views. Can you see how to do this?--Carl Hewitt 03:11, 9 October 2005 (UTC)

[edit] The ever-changing quotes

Is User:CarlHewitt putting words into Chris Fuchs mouth or is he "channelling" Fuchs? Please could CarlHewitt please decide on what Fuchs said, when did he say it and where?--CSTAR 22:39, 9 October 2005 (UTC)

Do you see any particular inaccuracies in my quotations from the citation?--Carl Hewitt 23:11, 9 October 2005 (UTC)

1. The citation is to Fuchs [2004], but I see no reference with that date on the references list
2. The citation includes extensive editorial additions (which keep changing, which in itself is an annoyance). These editorial additions in my view are unnaceptable and give the impression that Fuchs is actually proposing these as references.
3. Fuchs is a radical source here, because his view of state as "state of information of an observer" (I would say "the state of a principle executing a measurement protocol") though quite reasonable is not widespread. To subject the reader to this interpretation of Einstein is tendentious in my view.

--CSTAR 23:41, 9 October 2005 (UTC)

I have corrected the error; the correct citation is to Fuchs [2002]. Also I have clarified that the references to understanding the notation are not by Fuchs. We should have views in addition to Fuchs.--Carl Hewitt 00:46, 10 October 2005 (UTC)

[edit] Heisenberg quotes

What do these quotes from Heisenberg establish? That measurement is messy, well yeah we know that, but that's not the point of this article. Why did you take out the statement about quantum indeterminacy not being a result of error? Surely outside of crackpot circles that is a commonly held view. This article is not an essay on the history of quantum indterminacty.--CSTAR 02:19, 10 October 2005 (UTC)

The Heisenburg quote attributed to Einstein directly bears on the issue of measurement. Quantum indeterminacy is intrinsically involved with measurement. And measurement involves intervention.--Carl Hewitt 02:45, 10 October 2005 (UTC)

OK, but at the very least the article should say clearly that quantum indeterminacy is not a due to error. There is no controversy about that. --CSTAR 03:37, 10 October 2005 (UTC)

I agree that quantum indeterminacy is not due to error.--Carl Hewitt 04:56, 10 October 2005 (UTC)

As a matter of fact, the Heisenberg quote is irrelevant to this article. Quite apart from that, you are trying to establish that indeterminacy is a result of disturbance which is certainly a non-conventional view. Even Heisenberg himself abandoned that view. Please stop putting in quotes that you are not prepared to paraphrase.--CSTAR 04:16, 10 October 2005 (UTC)

Heisenberg never abandoned the view quoted in the article.--Carl Hewitt 04:37, 10 October 2005 (UTC)

There is an undercurrent in what you added that is clearly not the conventional thinking. You should reorder the sequence of your statements so that the Einstein quote comes first, But one should also clearly say what Fuchs' position on the matter is. His view as I said, is not a common one. (Note that I am not saying he is a crackpot; my personal views are pretty close to his)--CSTAR 05:07, 10 October 2005 (UTC)

Which Einstein quote should come first before what? Thanks,--Carl Hewitt 05:40, 10 October 2005 (UTC)

[edit] What logic and flow?

Your edit summary asserted that my "flow" of my edit was not good and moreover, that it was not logical. This is an entirely unreasonable justification; you'll have to do better than that Flow is entirely subjective and what logic are you talking about. The only things that I changed were

1. the placement of comment about Einstein and EPR, which I argue should be where it is since it is really the motivation for Bell's theorem and other information-theoretic aspects of quantum mechanics.
2. The beginning sentence about uncertainty in the section Argument for incompleteness

--CSTAR 19:09, 10 October 2005 (UTC)

The following logic works

[edit] Classical theory of measurement

Uncertainty in measurement was not an innovation of quantum mechanics, since it had been well established that measurements have a certain variability. However, by the latter half of the 1700s, measurement variability was thought to be well understood and it could be reduced by better equipment and accounted for by statistical error models. That is to say, the general supposition was that there was a "true" value to be measured and that the variation was due to "errors in measurement" explainable by some "error parameter."

[edit] Measurement as intervention

Quantum indeterminacy is intrinsically involved with measurement which itself involves intervention. Measurement in quantum physics has proved to be unexpectedly subtle. How the might the object be affected by the measuring process? This question concerned Werner Heisenberg.

--Carl Hewitt 20:43, 10 October 2005 (UTC)

[edit] Einstein's argument for the incompleteness of quantum physics

Einstein's argument should be in one place, not two.--Carl Hewitt 20:49, 10 October 2005 (UTC)

Einstein is saying something different in the quote from Fuchs, or at least that quote is used by Fuchs to emphasize what he (Fuchs) is trying to say about the information-theoretic nature of quantum state. Apart from that, what's the rule you are applying here to say Einstein's argument should be inb one place not two? --CSTAR 21:37, 10 October 2005 (UTC)

So do you think that Einstein's argument should be made twice?--Carl Hewitt 21:59, 10 October 2005 (UTC)

[edit] Extensive quotes

This article contains a long series of extensive quotes. This is not appropriate for an encyclopedia article. The amount of quoted material should be reduced. --CSTAR 21:46, 10 October 2005 (UTC)

In an area as controversial as this one has been, we probably need all the authority that we can muster from the best sources available. But we can always make improvements;-)--Carl Hewitt 22:05, 10 October 2005 (UTC)

You're making it controversial. This reasonably falls under original research.--CSTAR 00:09, 11 October 2005 (UTC)

Where do you see original research in quoting published work?--Carl Hewitt 00:54, 11 October 2005 (UTC)

I said that the article falls (or comes close to falling) under original research, when most of the article consists of very long quotes, which are not presented to support a well-known and identifiable viewpoint. Do we need to quote extensively Einstein to explain EPR or relativity or Heisenberg and Schrodinger to explain quantum mechanics? Why is this any more controversial than quantum mechanics or the many world interpretation of quantum mechanics? Aside from this, long quotes are not an acceptable form of exposition or research.--CSTAR 02:41, 11 October 2005 (UTC)

The article contains quotes from published material from respected sources with identifiable viewpoints. It is also true that some of these viewpoints are controversial. The longest continuous quote is one with 2 paragraphs with all the rest being 1 paragraph. Presumably additional material will be introduced in the article between the quotations. It is also possible that some of the quotations will be paraphrased--Carl Hewitt 03:21, 11 October 2005 (UTC)

What arethose viewpoints? Heisenberg had identifiable views on a lot of things, but which of those are relevant here? --CSTAR 03:23, 11 October 2005 (UTC)

The quotations in the article from Heisenberg concern his views that bear on quantum indeterminacy.--Carl Hewitt 03:33, 11 October 2005 (UTC)

[edit] Dispute claim

• The purpose and possibly the accuracy and neutrality of this article are disputed.

The article is ostensibly about quantum indeterminacy. Rather than limit the article to the meaning of indeterminacy with a statement about the relations with measurement, the article contains long quotes which are not supportive of any well-known, identifiable claim which would merit its inclusion in Wikipedia.--CSTAR 03:12, 11 October 2005 (UTC)

The article reports published work on quantum indeterminacy.

The longest continuous quote is one with 2 paragraphs with all the rest being 1 paragraph. Presumably additional material will be introduced in the article between the quotes. It is also possible that some of the quotes will be paraphrased.

The quotes will be needed when other editors show up and begin asking for justification and citations.--Carl Hewitt 05:49, 11 October 2005 (UTC)

A list of extensive quotes is not the same as a list of citations supporting a claim. In fact, You are not making any claims in the article!

Your claim about the article stated above that The longest continuous quote is one with 2 paragraphs with all the rest being 1 paragraph. sidesteps my point. The quotes are separated by phrases essentially saying who the quote is from.--CSTAR 14:16, 11 October 2005 (UTC)

I have improved the transitions a bit. More improvements are needed.--Carl Hewitt 19:39, 11 October 2005 (UTC)

[edit] New dispute claim

This article purports to show that measurement is "theory laden". This is not a widely held philosophical position and which in any case does not belong in this article. Either move all sections on this to an article entitled Philosophical issues in the theory of measurement or delete those sections.

The article fails to discuss more standard issues such as von Neumann's theory of measurement and the relation of measurement to other problems and formalisms.

Based on this, I will add two new dispute claims to the article.--CSTAR 19:54, 11 October 2005 (UTC)

The article no longer mentions "theory laden".--Carl Hewitt 20:16, 11 October 2005 (UTC)

Call it what you will; the article alludes to (mainly in subsection headings) a difficult and philosophically controversial claim about the relationship between physical theory and the nature of measurement. Even if you have identifiable claims that are supported in existing literature which you can paraphrase, the discussion of those claims does not belong in this article. Please start a new article on Philosophical issues in the theory of measurement as I suggested.--CSTAR 21:03, 11 October 2005 (UTC)

The current version appears below. The subject matter of the section reports on published research that is intimately tied to quantum indeterminacy. Also I don't see it as advocating any wild philosophical positions. So it seems to me that the section fits nicely in this article. For example it ties in with Heisenberg's views on indeterminacy that are expressed later in the article. You will see that I added a reference to Measurement in quantum mechanics at the end of the section.--Carl Hewitt 22:06, 11 October 2005 (UTC)

I said difficult and controversial not wild. There is little doubt they are difficult. Controversial means they are not universally accepted. For example, Asher Peres' views aren't wild, but they are not universally accepted.--CSTAR 22:09, 11 October 2005 (UTC)

What specifically do you see as currently controversial?--Carl Hewitt 22:18, 11 October 2005 (UTC)

There are at least two distinct issues. Please do not confuse them. Let me go through this one more time what the problems are:

1) The extensive quotes. Such extensive quotes should not be necessary and are a result of the fact that the article makes unidentifiable claims about the nature of quantum state. An identifiable claim is one which can be explicitly referenced in some way (not by saying these are Heisenberg's views.)

Reply (1) by CarlHewitt. The quotes make identifiable claims about the nature of the quantum state which is part of the subject matter of quantum indeterminacy. This can be verified by reading the quotes. So perhaps your comments are pointing out why the quotes are needed for this article.--Carl Hewitt 03:27, 12 October 2005 (UTC)

2) Speculations about the nature of quantum state ranging from those of Heisenberg to Fuchs. I don't deny the importance of this, but this material belongs in another article about problems in the theory of measurement. Quantum indeterminacy in and of itself is a more straightforward concept which is a result of the physics of measurement. The physics of measurement processes is part of physics not philosophy. It is governed by master equations such as the Langevin or Lindblad equations. I repeat: The speculations which are alluded to in the quotes, about the relations between theory and observation are difficult and controversial and do not belong here.

Reply (2) by CarlHewitt. Explanations of the nature of quantum state by the recognized leaders in physics who are discussing quantum indeterminacy would seem to be a natural part of this article which I see as having a more general subject matter than the article on the uncertainty principle where the equations are discussed.--Carl Hewitt 03:27, 12 October 2005 (UTC)

Please straighten this out. For the record, I would like to point out here that you have repeatedly reverted my edits which were intended to improve this article. --CSTAR 02:27, 12 October 2005 (UTC)

It is true that I reverted your edits in which you inserted material into the article to make Einsten's argument twice. I still think that it is better to make Einstein's argument just once in the article, not twice. This was discussed in the talk page for the article.--Carl Hewitt 03:27, 12 October 2005 (UTC)

[edit] Further replies

1. CSTAR's reply to reply to (1). If the claims are identifiable in the way I proposed, you should be able to identify without quoting

Carl Hewitt's reply. The quotes concerning quantum indeterminacy make their points very eloquently. Paraphrasing the quotes raises some interesting questions:

1. Is the paraphrase better than the quote?
2. What are the issues of intellectual honesty and attribution in paraphrasing the quote?
3. What if a user wants to see the quote and it is not on line or if it is on line and then disappears?

--Carl Hewitt 04:39, 12 October 2005 (UTC)

1. CSTAR's reply to reply to (2). The Heisenberg uncertainty relation article discusses one part of indeterminacy: that which is quantifiable for two complementary observables. The measurement process is a particular example of a physical system interacting with a measuring apparatus.

--CSTAR 03:52, 12 October 2005 (UTC)

Carl Hewitt's reply. We already have an article on Measurement in quantum mechanics--Carl Hewitt 04:39, 12 October 2005 (UTC)

We don't have one on Philosophical problems in the theory of measurement.--CSTAR 13:07, 12 October 2005 (UTC)

[edit] Replies

The issues you are raising are broader and are not specific to Wikipedia; for example Is the paraphrase better than the quote?. This is a general issue about writing (scholarly writing in particular) and referring to already published work. This applies for instance to authors of expository material. Why write a textbook? Just plunk in quotes and you're done.

What if a user wants to see the quote and it is not on line or if it is on line and then disappears? Universal problem. Again, don't try to solve it here or challenge me to solve it.

You are using Wikipedia to make a point (In fact several). Please don't. If you want to play the role of Socrates, start your own blog.

It is assumed that editors know the material they are writing about, unless they are editing for style. The ability to copy somebody else's work and put it in quotation marks is not (normally) considered an indication of knowledge.--CSTAR 16:26, 12 October 2005 (UTC)

It's probably better to keep the discussion here focused on the Quantum indeterminacy article. The quotes in the article are by reputable physicists about physics. It seems to me that the question of whether to quote or to paraphrase is in part a sytlistic one. However, if there are too many objections to paraphrase then it is probably better to quote.

So we have the following questions:

1. For each quote in the article, is it better to paraphrase than to quote?
2. For each quote, what are the issues of intellectual honesty and attribution in paraphrasing that quote?
3. Some of the quotes are not available on line. How should each such quote be provided to enable checking the accuracy of paraphrasing that quote?

Regards,--Carl Hewitt 10:26, 16 October 2005 (UTC)

Reply to Hewitt

1) Is it better to paraphrase than to quote. That's the wrong question. The point I have been trying to make is: Quotes should be presented in support of some point. For example, in the section Measurement requires intervention, the Heisenberg quote is preceded by the sentence

Many years after the fact, Heisenberg recalled how when he was developing the uncertainty principle that Albert Einstein had emphasized the importance of some subtle issues involved in measurement [Heisenberg 1971] (the Heisenberg quote follows)

What's the point you are trying to make? That measurement is subtle? Please say in what way it is subtle! It is subtle for many reasons, (a) because there is a complex interrelation between a theory of physics and how measurement is represented within that theory (b) because there are possible relations between measuring device and object (c) because there might even be a relationship between consciousness and object (I don't take (c) too seriously, by the way, although who knows). Heisenberg alluded to all three. My main point is that As a writer you're supposed to be a guide, not a distributor of travel brochures.

If you are going to write on article on something, you have to add something. It's perfectly fine to tell somebody, Read A,B and C, because it's always better to read the originals. But then don't write an article about it.

2) The issue of intellectual honesty and attribution is a red herring. Is anybody seriously suggesting that you can't summarize what Heisenberg wrote?

3) Some of the quotes are not available on line. Provide a reference to a hard-copy, which should be available in any major university library. Admittedly, this approach puts at a disadvantage readers from poor countries without good libraries that may want to read the entire original article, but that is a different problem. Moreover, putting in part of a quote will not solve that problem either.

Finally, if you post a reply, don't do it within the above piece of textual real-estate.

--CSTAR 16:43, 16 October 2005 (UTC)

I have improved the wording in the article as follows:

Many years after the fact, Heisenberg recalled how when he was developing the uncertainty principle that Albert Einstein had emphasized that it is theory that decides what we can observe [Heisenberg 1971 (the Heisenberg quote follows)

Regards,--Carl Hewitt 12:26, 17 October 2005 (UTC)

That's hardly an improvement. And moreover, it's reverting back to formulating a contentious relation between theory and measurement as though it were more fundamental than the interaction between object and measurement device.--CSTAR 13:17, 17 October 2005 (UTC)

The latest change to the article paraphases slightly the quotation by Heisenberg. Are you saying that it should be limited to quoting instead?--Carl Hewitt 14:18, 17 October 2005 (UTC)

[edit] Measurement requires intervention

Quantum indeterminacy is intrinsically involved with measurement which itself involves intervention. Measurement in quantum physics has proved to be unexpectedly subtle. How the might the system being measured be affected by the measuring process? This question concerned Werner Heisenberg.

Many years after the fact, Heisenberg recalled how when he was developing the uncertainty principle that Albert Einstein had emphasized the importance of some subtle issues involved in measurement [Heisenberg 1971]:

It is quite wrong to try founding a theory on observable magnitudes alone. In reality the very opposite happens. It is the theory which decides what we can observe. You must appreciate that observation is a very complicated process. The phenomenon under observation produces certain events in our measuring apparatus. As a result, further processes take place in the apparatus, which eventually and by complicated paths produce sense impressions and help us to fix the effects in our consciousness. Along this whole path—from the phenomenon to its fixation in our consciousness—we must be able to tell how nature functions, must know the natural laws at least in practical terms, before we can claim to have observed anything at all. Only theory, that is, knowledge of natural laws, enables us to deduce the underlying phenomena from our sense impressions. When we claim that we can observe something new, we ought really to be saying that, although we are about to formulate new natural laws that do not agree with the old ones, we nevertheless assume that the existing laws—covering the whole path from the phenomenon to our consciousness—function in such a way that we can rely upon them and hence speak of “observation.”

Thomas Kuhn emphasized issues in understanding observations in the development of quantum physics including further developing the thesis that it was Einstein who saw the revolutionary implications of the observations of black-body radiation whereas even Max Planck (who had pioneered in the work) initially resisted Einstein's views [Kuhn 1987].

Measurement in quantum mechanics has additional information.

[edit] Dispute status of this article

I have placed two dispute banners on this article:

1. An original research banner.
2. A non-neutral point of view banner.

To explain the reasons for each one of those banners, let me remind the reader that this article is about quantum indeterminacy which is, as the introductory paragraph correctly states, the intrinsic impossibility of assigning to each system state a unique collection of real values to all observables. Indeterminacy has other manifestations, such as the non-determinisic nature of the measurement process, which is fundamental as well, and constitutes one of the main contributions of von Neumann to quantum mechanics. The article is silent on the matter, and moreover Hewitt has reverted my attempts to rectify this, by citing problems of flow and logic with my edit.

Indeterminacy has a long history in quantum mechanics and as the article intimates by a quote from Einstein, is also connected to issues of incompleteness exemplified by the EPR experiment. However, the main historical account of indeterminacy does not belong in this article, nor do fundamental issues in the theory of measurement.

Hewitt is using these quotes to claim a "theory laden" notion of measurement. It's fine to mention that there are complex relations between theory and measurement (this idea is not new with Heisenberg either); in a similar way, there are relations between object and measuring device (which as I mentioned go back at least to von Neumann) and maybe even a relation between consciousness, object and measurement device (that's a view which I don't like, but it has its proponents). It's one thing to mention this. However, to subvert the intent of the article, and use it as a subterfuge to argue for a particular (some would even say "postmodern") view of measurement is definitely a violation of POV. Moreover, I claim it is original research: Careful examination of Hewitt's contribution on wikipedia suggest a clear effort on his part to raise the actor model to the status of a fundamental theory of physics, which it currently does not have. In support of this claim, please see the following articles and/or their discussion pages:

1. Quantum indeterminacy in computation (particularly, see the talk page)
2. Actor model, mathematical logic, and quantum physics. For instance the claims The Actor model is exactly analogous to physics: Quantum theory does not necessarily determine particular physical processes
3. Quantum information and relativity theory. See discussion
4. Actor model early history. Particularly, the claims in the section Relationship to physics, where the quote attributed to Heisenberg appears.

The other contentious issue is the inclusion of long quotes in an article, preceded with little explanation. By that I mean, (as I have repeated at least 3 times in the above discussion), that a quote should be brought in to support an identifiable claim. An identifiable claim is one which already exists in the peer-reviewed scientificliterature, preferably has a name (such as "local realism", "instrumentalism") and can be summarized in a few phrases. I am not sure whether Wikipedia policy is yet clear enough on the matter, but an encyclopedia article should not be a series of quotes. It is particularly irksome to see inclusions of quotes by Chris Fuchs on the matter, as though they somehow support Hewitt's position.

I urge the reader to please consider the History of my comments on this article as well Hewitt's replies.

[edit] What I intend to do

• I will ask a number of individuals on WP to comment on this talk page.
• Failing some change in the content of the article, I will place an RfC.

Thanks. --CSTAR 17:58, 17 October 2005 (UTC)

Remark: I have relocated the following response from Hewitt, which was originally in the middle of my explanatory statement above preceding the subsection what I intend to do. Request to Hewitt: Please answer questions in a separate area.

There is no claim in the Wikipedia articles that you have cited that the Actor model has the "status of a fundamental theory of physics" as you claim above. However, it is true that the Actor model is based on physics (unlike other models of concurrent computation such as the Process calculi which are based on algebra). Thus it is not suprising that there are linkages in the published literature between the Actor model and physics.

It would be good to have other points of view in addition to Einstein, Hawking, Heisenberg, and Fuchs in the article.

Just as a matter of curiosity, does Chris Fuchs view have a name or short descriptive phrase in the literature?--Carl Hewitt 19:23, 17 October 2005 (UTC)

He calls it "interpretation without interpretation". I would call it instrumentalism.--CSTAR 19:42, 17 October 2005 (UTC)

I have removed the quotation by Heisenberg on measurement as it is somewhat tangential.--Carl Hewitt 19:00, 17 October 2005 (UTC)

• • I have read this article several times and as it stands it is an absolute disgrace, and in my opinion should be rewritten in its entirety. I have also followed the debate here in comments which has become sterile, as Carl Hewitt will not directly address the fundamental issues that CSTAR among others, has raised. I firmly believe that the only possible resolution is to put the page on RfC sooner than later or a start from scratch with an editor with a NPOV. DV8 2XL 18:29, 17 October 2005 (UTC)
  • Only a first comment: A collection of quotes doesn't make an encyclopedic article. Also note the overlap with Measurement in quantum mechanics and Interpretation of quantum mechanics. It seems to me, that the entire topic of quantum mechanics suffers from fragmentation and lack of red line guiding the reader. --Pjacobi 18:54, 17 October 2005 (UTC)

I agree that there is a stylistic issue in the use of extensive quotation. However, it seems that we have an extremely controversial topic here. I could fairly easily paraphrase the material in the quotations that report what highly reputable physicists have published on quantum indeterminacy. However, if I do so, then what do we do about editors that claim that the paraphrased material violates NPOV? As it stands now, at least it is clear that the quotation is the point of view of the physicist quoted.--Carl Hewitt 19:06, 17 October 2005 (UTC)

Quantum indeterminacy is not controversial.--CSTAR 19:11, 17 October 2005 (UTC)

Is there another reputable physicist whose views we might add to the article to balance the views of Fuchs and Peres?--Carl Hewitt 20:30, 17 October 2005 (UTC)

Far too much of the article (CH version) depends on quotes by Fuchs about words by Einstein. This is not good. Einstein was much cleverer than me, but he was out on a limb as far as QM is concerned, and the article (CH version) misrepresents his contributions anyway. As C* says, QI is not controversial. I would encourage people to support EMS's proposal. William M. Connolley 20:30, 17 October 2005 (UTC).

The article quotes Fuchs about how Einstein had a good argument for incompleteness and then quotes Hawking about where Einstein went wrong and why.--Carl Hewitt 20:56, 17 October 2005 (UTC)

[edit] Major revert

I have restored the 6/23/05 version of this page as a way of getting around the issues raised by Carl's edits. Part of my reason for doing this is to show that it can be done. I won't say that the old version is all that great, but it at least it is a foundation on which one can create a better article.

I leave it up to other editors to enforce this reversion if they share my preference for the June version of this article. I am willing to assist in maintaining this version as the current one, but will not repeat this stunt if I am the only one interested in doing so. --EMS | Talk 20:19, 17 October 2005 (UTC)

I've read the article. I agree with EMS. We can do all kinds of RFC stuff if needed, but the simplest first thing to try is to see if the weight of opinion supports the old version. Other comments above. William M. Connolley 20:27, 17 October 2005 (UTC).

Second EMS' action.--CSTAR 21:18, 17 October 2005 (UTC)

Support EMS' action. linas 03:05, 18 October 2005 (UTC)

---

Well, it took Carl no time to undo the reversion. I encourage others to go to the history and look and what I did. This is an easier "out" than debating how to further modify the article, but without others enforcing this all that my efforts will become are a meaningless edit war. With support, Carl will be left on the short end of the 3RR stick very quickly.

I will admit that major reversions do have a downside in the loss of much effort on the part of others, but when an article has truly gone off in the "wrong" direction that becomes the best course of action. In the previous times that I have done this the affected editor(s) have not contested it, but it is no surprise that the situation is different this time. --EMS | Talk 20:30, 17 October 2005 (UTC)

Quantum indeterminacy is a phenomenon that can be experimentally observed. What is not clear is if it is a fundamental property of the universe or if it is an artifact of our status as observers within the universe. That discussion belongs elsewhere. I fully support the revert by EMS. There seems to be no other recourse at this point than RfC. DV8 2XL 20:36, 17 October 2005 (UTC)

The article quotes the published work of highly reputable physicists (e.g. Einstein, Hawking, Heisenberg, and Fuchs) on quantum indeterminacy. Should the article be suppressed because their views are controversial?--Carl Hewitt 21:03, 17 October 2005 (UTC)

The article should present, first and foremost, the accepted standard viewpoint. Einsteins view is definitely not that - his view is now, as I understand it, a very small minority view. But there is nothing wrong with mentioning hidden variables stuff. William M. Connolley 21:09, 17 October 2005 (UTC).

Actually, the article presents a fairly standard viewpoint. This not to say that the area is uncontroversial! The article distinguishes between Einstein's argument for incompleteness which is very strong and pretty much accepted from the conclusions which he drew from that argument which as the Hawking quote ponts out are definitely not accepted and have been controverted by experiment.--Carl Hewitt 21:21, 17 October 2005 (UTC)

Quantum indeterminacy is not controversial. That's one of the points I've been trying to make. As mentioned in my statement explaining the dispute, the introductory paragraph of the previous version (that is, prior to EMS' reversion which I support) was largely correct. In that article, however, after the ToC, Hewitt began inserting quotes which were not directly related to indeterminacy. He inserted these quotes under various headings such as

• theory laden,
• Measurement requires intervention,
• According to Einstein, a "real state of affairs" should not depend upon measurements that can be made on other causally unconnected systems

and other titles. Philosophy has an important place in science, and it is worthwhile bringing up these issues, but not with extensive quotes here. Most of these quotes were out of context anyway.

What could a reader take away from reading this article? Some quotes out of context. Perhaps the following (a) That there is a relation between theory and measurement? (b) That measurement causes disturbance? We could agree on both these points and the article would not be objectionable if it merely stated that such is (or might be) the case. Indeed (a) seems plausible, and in some form is undoubedtly true. But the quotes disguise a vast field of philosophical difficulties. This is not the place to bring them up, unless the intent is to mislead the reader into believing the most naive form of (a) (philosophical idealism). As far as (b) goes, again we know measurement involves entanglement and "interaction" of measurement device and system. But given Hewitt's reluctance on my adding edits about this interpretation and his particular phrasing of disturbance, I believe Hewitt is suggesting a local-realist notion of disturbance.

--CSTAR 22:10, 17 October 2005 (UTC)

I studied quantum mechanics in college, and can assure you that for most people who deal with quantum mechanics, Einstein's view is not in the least the "standard view". It certainly is a significant view, and as you note even has adherents to this day. However, your article gives readers the impression that it is by far the dominant view, and it tilted to the point where it all but announces the hidden variables view as truth. To make matters worse, you harping on Einstein and his hidden variables results in an article where the reader learns very little about quantum indeterminacy itself. That is why I feel that reader are better off with the June version: At least what is there deals with the issue at hand. --EMS | Talk 22:30, 17 October 2005 (UTC)

I don't think it does present a std viewpoint. I think it misrepresents and oversells Einsteins views. But I suspect that others may have better knowledge of the details.

Also, adding Reverted so that the issues can be discussed. to your reverts isn't helpful. We can discuss it whichever version is there.

William M. Connolley 21:51, 17 October 2005 (UTC).

If it is impossible to write "your version" of the article without having a huge quote to content ration, then "your version" seems to be a dead end. --Pjacobi 21:51, 17 October 2005 (UTC)

[edit] RfC

I've added an entry at Wikipedia:Requests for comment/Maths, natural science, and technology but don't hold your breath, waiting for a mass of editors coming over to help. --Pjacobi 21:37, 17 October 2005 (UTC)

I rather suspect that everyone is already here... William M. Connolley 21:51, 17 October 2005 (UTC).

No, not quite. I've posted an RfC notice at Wikipedia talk:WikiProject Physics, which is a better place to find physicists than the RfC page. Also, I am reading through the debate now, and will comment shortly. Also, some of us aren't logged onto WP 24 hours a day (despite appearences). linas 00:34, 18 October 2005 (UTC)

[edit] Time for a truce?

I notice that Appleboy has joined the fray on the side of Carl. So amongst those of us who are willing to fight over this, we are now 2 to 2. As-is, this is the formula for a useless edit war. Therefore:

• To William Connelly: PLEASE DO NOT REVERT AGAIN TODAY. I also will not revert again today.
• To the others: If any of you wish to see this page reverted to the June version, then go ahead and do it. However, I want each person doing so to revert this only ONCE today.
• TO ALL: Note that my reversion cannot hold unles there is a general consensus to do so. Carl and Appleboy together cannot overcome a dozen editors who want this the other way.
  • Note however, that if anyone else joins in on Carl's side then it must be assummed that the consensus does not exist, and we all should respect that.

I will assume that (for the editors other then Carl Hewitt) this is a fight over technique instead of substance. In any case, I emphasize to everyone that a major revert has no busines standing without the consensus (either explicit or impled) of the editors to support it. I am glad to have tried it, but if the result is an unwinnable edit war then we must let Carl's version remain until a consensus is obtained on what to do instead. --EMS | Talk 22:08, 17 October 2005 (UTC)

STATUS [as of 23:19, 17 October 2005 (UTC)]:

Appleboy has apologized and CSTAR has done the latest reversion. So this looks like at this the support for the major reversion is running (literally) 3 to 1. This is enough to make the major reversion stick, so there is no need for a truce at this time. (That is not to say that more support would not be appreciated.) --EMS | Talk 23:21, 17 October 2005 (UTC)

[edit] What should we do about the quotes?

This article has proven to be extremely controversial in practice (although there has been a claim that the subject matter of the article may not be controversial). This poses the dilemma that an attempt to paraphrase a quote by a Wikipedia editor opens them to the charge of NPOV. At least the quotations currently in the article are the point of view of extremely reputable physicists published works that represent a mainstream of current physics.

1. For each quote in the article, is it better to paraphrase than to quote?
2. For each quote, what are the issues of intellectual honesty and attribution in paraphrasing that quote?
3. Some of the quotes are not available on line. How should each such quote be provided to enable checking the accuracy of paraphrasing that quote?

--Carl Hewitt 22:30, 17 October 2005 (UTC) (signed later; sorry for the mistake)

Long quotes are illustrative. An article should already be fine, without all the quotes. --Pjacobi 22:18, 17 October 2005 (UTC)

So do you think that the material in all the quotes should be paraphrased?--Carl Hewitt 22:31, 17 October 2005 (UTC)

I have discussed the quotes and believe that I have given reasonable specific answers to all these questions (Please see above). To repeat once more a general remark: these questions are not Wikipedia specific. A request to Hewitt: Do not use wikipedia to make a point.--CSTAR 22:33, 17 October 2005 (UTC)

[edit] my revert

sorry about that guys, when I followed the link from the vandalism channel it just showed a chunk of the page missing without any explenation and it looked like vandalism, please forgive me.
--AppleBoy ^Talk 22:21, 17 October 2005 (UTC)

If you no longer support that action, then please undo it (or rather revert from Carl's latest reversion). You are within your rights to do so, even under the 3RR. --EMS | Talk 22:42, 17 October 2005 (UTC)

[edit] On perspective

I am first and foremost, in the context of this community, an encyclopediaist. That I interpret to mean: it is my role to collect ideas and report them, in a condensed form and in such a way that the broadest cross-section of the general public may understand. This is the standard that I will hold any other editor to as well.

The disputed version of this article fails to meet that standard. QM and QT are complex enough for those of us that have studied it for years - filling the page with this sort of obscure, biased, and minority-view opinions will not do anything for the high school student with an interest in this field, or professional whose expertise lies far from physics.

Never forget that those are the people we are writing for. DV8 2XL 23:37, 17 October 2005 (UTC)

[edit] Dispute

Lest the content of the dispute gets lost in the tempest of a revert war, let me reiterate what the dispute is about (at least the way I formulated it). There are two issues

• Content: The article, should have an introduction saying what quantum indeterminacy is, how it's related to fundamental problems of quantum mechanics. Insofar as philosophical issues are involved, the article might briefly mention them but referring to other articles. Quantum indeterminacy is not a mystery any more say than the Heisenberg uncertainty relation (which I might refresh Hewitt's memory on that, was quite contentious also. See the talk page of that).
• Style: The article shouldn't have long quotes. References are fine, short quotes are fine, but not extensive quotes which are not required to support a point. As Pjacobi put it, the ratio of quotes to content should be small.

The other issues Hewitt raises (intellectual honesty, accessibility) I think are red herrings.

In my explanatory statement, I also conjectured why Hewitt seemed to be so intent on reverting my edits. That is not part of the dispute, only insofar as it bears on my claim that the article violated the no original research policy.

At this point, we might consider reverting to Hewitt's form, with all of the sections that currently include quotes deleted. But I don't think we should agree that the appropriate course of action is discussing the relevance of each quote.--CSTAR 01:52, 18 October 2005 (UTC)

I agree with CSTAR on the whole. The starting point should be an article without any quotes. I also do not want to debate the quotes, one by one, for the resons I'll state below. The Hewitt version without the quotes might be acceptable, but only after some major editing. Even without the quotes, its pretty stilted. I propose the following structure:

• The article should first explain what indeterminacy is (which none of the versions did well.) Then it should explain that the interpretation and meaning of this indeterminacy has been historically controversial, and continues to be controversial. It might even include a few paragraphs (but certainly no more, and even that may be too much) outlining some of that history. It should then point to the articles that we already have that review the various different types of interpretations of QM.

• Somewhere in WP there should be an article reviewing either the history of the debate. I don't think this is the correct article to report that history.

The reason I'd want a distinct article dealing with the history of the debate is because we've already got a fairly large number of quantum articles pushing various flavors of QM POV. The POV is already leaking out in all sorts of articles, and it shouldn't be. I'd rather see it contained and corralled to articles that are explicitly intended to describe and document the debate. We could have 50 articles on these topics, sprinkled with lots of quotes, for all I care, as long as they are well written.

I would also like to ask Carl to develop better table manners. There have been numerous substantive comments and criticisms made not only in this article, but in many others that Carl has edited. The pattern of brushing off and ignoring these criticisms results in a lot of friction. I have trouble seeing Carl's edits as being in good faith. As with previous encounters, I view the proceedings with consternation. linas 03:49, 18 October 2005 (UTC)

If you want to see a better article here, then kindly draft it. You can do it either here or in your user space, but if you want to move beyond this reversion, then you (or someone) now needs to provide something better. My goals in doing the major reversion were to bring the article back to its last "good" state, and to pull the rug out from under Carl. With Carl's edits no longer counting, it should be much easier to produce a better article. Do note that getting a better article really is my goal here. Sometimes you have to go backwards in order to go forwards. I have done something audacious and it seems to be holding. Now we need to make what I have done actually count for being something more than a slap in Carl's face.

To Linas: Please, please assume some good faith on Carl's part. That does not mean that his edits are acceptable, but I do not believe that he is trying to get our goats. I hope that my major reversion tactic makes it clear to Carl that he needs to respect us if he wants us to respect him. However, I have noticed that once he gats an idea into his head, he will push it as hard as he can and damn whoever chooses to get in his way. There are some places where that kind of bull-headedness is a plus, but Wikipeidia is not one of them. --EMS | Talk 05:21, 18 October 2005 (UTC)

I started a first draft with an earlier version which simply says what indeterminacy is and has a reference to incompleteness. Missing is a short section on the relation between indeterminacy and measurement. Once that's done, I don't see that there's a need for anything more.--CSTAR 06:09, 18 October 2005 (UTC)

---

This may be influenced by the fact that I am to some extent a minimalist, but here goes. My opinion is that in cases where there is a dispute on some subject it is a good idea for both sides (or however many there are) to step back, remove the contraversial sections, and leave only what everyone agrees on - yes, leave a minimum of content. The subtelties (really!) about QM we are discussing are not entirely resolved in the scientific community, so how can we imagine to clarify them in an online encyclopedia article? If one side wins, then we shall have one POV. I know, there's alot of POV on this "leaking out" in other articles and that is bad. That is not a reason, however, to continue it here, and for a Wikipedia article it suffices to state the problem and not try to solve it (which is original research by the way). After all, this is not a scientific journal. Karol 08:22, 18 October 2005 (UTC)

[edit] Moved disputed content elsewhere

I moved the disputed content to Actor model, mathematical logic, and quantum physics where it is used in reporting published work that relied on the results of quantum indeterminacy that used to appear in this article. In this way, work can continue there while decisions are made what to do here.--Carl Hewitt 08:53, 18 October 2005 (UTC)

This is totally inacceptable. Whatever lemma you choose, you cannot get your personal space on Wikipedia, trying to prevent consensual editing. --Pjacobi 09:05, 18 October 2005 (UTC)

I am simply trying to contribute to an encyclopedia reporting on published scientific work.--Carl Hewitt 09:16, 18 October 2005 (UTC)

If I can clarify. There is of course no objection to your contributing, as such. You seem to have aroused some feeling that what you post is POV. That is, the slant goes against our NPOV policy. I haven't fathomed what the precise issue is, yet. Needless to say, in the longer term such criticisms have to be addressed, or the page won't stand (I'm not talking about reverts, which are purposely made very easy, but a working-out amongst interested parties of forms of words on any controversial points). Now, it is only to compound the troubles to treat pages on a Wikipedia:Walled garden basis. Charles Matthews 09:34, 18 October 2005 (UTC)

Reporting on the published work on Actor model, mathematical logic, and quantum physics actually needs to report on the published work of Einstein, Hawking, Heisenberg, Fuchs, etc. that used to appear here. The argument has been made on this talk page that reporting their work is not appropriate in this article. So I moved the reporting there where it seemed more appropriate.

Also I am being NPOV by quoting published work of Einstein, Hawking, Heisenberg, Fuchs, etc. that is in a mainstream of physics. However, the published work by these authors is not without controversy. So it seems that any editor who paraphrased may be opening themselves up to the charge of POV because then they could be accused of promoting a POV instead of reporting on published work. What is the best way out of this conundrum?

Thanks for your help,--Carl Hewitt 09:59, 18 October 2005 (UTC)

It is amazing how an author in trouble for violating policy will often invoke the names of prominent scientists and hold up those names like a shield. Yes. The writings of Einstein, etc. have been reported on. So what? The complaint is that you have created an article that

1. fails to focus on the issue of quantum indeterminacy, and
2. is totally dominated by text supportive of Einstein's hidden variables view, which has always been a minority view amongst those who study quantum mechanics.

What the text (now moved) actually says is the opposite of what you have said above. The text says that Einstein had a good argument for the incompleteness of quantum physics but that according to Hawking, Einstein was wrong in proposing a hidden variables view. Just because Einstein was wrong about hidden variables doesn't mean that he was wrong about everything;-)--Carl Hewitt 15:54, 18 October 2005 (UTC)

In the end what you have written about is not quantum indeterminacy itself but instead why Carl Hewitt thinks that it is explained by the hidden variables theory. However, Wikipedia is not Carl Hewitt's soapbox. That is why your edits have been removed, and why the other editors support that decision. --EMS | Talk 14:39, 18 October 2005 (UTC)

Unfortunately you have gotten what the text of the article says exactly backwards (see comment above). The article is in a mainstream of modern physics. This is not to say that the views of the highly reputable physicists quoted in the article are without controversy.--Carl Hewitt 15:54, 18 October 2005 (UTC)

This response impeaches your writing all the more. You so much quote Einstein that it is his opinion that dominates the article as you wrote it. Hawking's comments seemed to almost be an aside. A naive reader would conclude that Einstein's hidden variables view is the one that dominates the field, whether or not you intended that.

The text of the article actually quotes Fuchs on Einstein's argument for the incompleteness of quantum physics. Note that: Einstein is actually correct in his argument about the incompleteness of quantum physics. The only mention of hidden variables in the article is the quotation by Hawking that hidden variables is incorrect.--Carl Hewitt 16:39, 18 October 2005 (UTC)

It is proper to mention the hidden variables view. It is not proper to discuss it at great length while barely mentioning the other interpretations, or how the other interpretations view quantum indeterminacy. This article needs to be clear, balanced, and focussed on quantum indeterminacy; not dominated by Einstein's views on QM in general. --EMS | Talk 16:25, 18 October 2005 (UTC)

The article mentions hidden variables only once and then only to the effect that Hawking says that it has been disproved. In fact the article is almost entirely about views of quantum mechanics other than hidden variables.--Carl Hewitt 16:39, 18 October 2005 (UTC)

Please understand that selective quotation can raise hackles. I think it is fair to say that WP has now collective experience on handling controversial matters. The way through is always by a process of engagement; which is why simply hiving off material to another article page is not really the answer. If you want to draft without others, it is much better for example to do so as a subpage of your user page, and link to that for comment. Charles Matthews 11:09, 18 October 2005 (UTC)

There is no selective quotation going on in the text of the article in the following sense: The quotes in the article honestly represent the views of those quoted.

I agree with the process of engagement. The problem that we have here is that one area of science, i.e. Actor model, mathematical logic, and quantum physics depends on another area of science quantum indeterminacy. So the intent is not to draft without others. For example User:CSTAR has contributed to developing the text that has now been moved. Others are welcome to continue the work at the new location.

Thanks for your help,--Carl Hewitt 16:17, 18 October 2005 (UTC)

You really don't get it. This article is about quantum indeterminacy, not the truth or fallacy of the hidden variables view. With your edits gone, we can now focus on the core issue here, and not deal with a bunch of quotes that fail to bear directly on that which is supposed to be the subject of this article. --EMS | Talk 16:43, 18 October 2005 (UTC)

So do I take it that you agree that it is good that I moved the material to the other article where it is more appropriate?--Carl Hewitt 17:16, 18 October 2005 (UTC)

It does not belong in Actor model, mathematical logic, and quantum physics either, assuming that that article should even exist. You could create an article entitled "Einstin's views on quantum mechanics" out of it and have a not-too-bad beginning for that. It would still need to be do less in the way of quoting and more in the way of describing the points that the quotes are supporting, but at least you would have an article that reflects the subject matter of its title.

Since Einstein originated the argument for the incompleteness of quantum physics, out of intellectual honesty we need to acknowledge his contribution. But of course the substance of the argument is what is most important for the purposes of Actor model, mathematical logic, and quantum physics and the quotation by Chris Fuchs states the argument eloquently.

I am still working on better describing the points in the quotes like the ones by Chris Fuchs. The challenge is to do this without violating the strictures against presenting a POV since there are controversies involved.

Regards,--Carl Hewitt 19:08, 18 October 2005 (UTC)

You keep coming at subjects like this with no sense of perspective as to what is being discussed and how it relates to other things. This makes you a very disruptive editor. I for one regret that you did not get suspended for your 3RR violation of yesterday. You need to learn how to work with this medium instead of trying to run roughshod all over it. --EMS | Talk 18:15, 18 October 2005 (UTC)

If I can have another try at clarifying. The Wikipedia style differs in an important respect from proper academic paper writing. That is, one does not here try (as in essentially any academic subject) to make a reasoned and supported case, properly qualified, for something. The style to aim at here is that of the good survey article, written as those tend to be, somewhat after the event. That is, our vision of the encyclopedia is as a collection of reports on areas, content to be a little behind the leading edge of research, a little understated, and dealing with controversies in an even-handed way. That, at least, is the ideal. In pursuit of that, we regard as important certain factors on style and presentation, and ways of integrating disparate views in an article. It becomes important to take great care not to be tendentious, and to represent an area in a broadly comprehensive fashion (without needing 'equal time' for all views, though). Charles Matthews 19:44, 18 October 2005 (UTC)

I completely agreee. And in fact that is what Actor model, mathematical logic, and quantum physics is supposed to be; reporting on published work of well over a decade ago with additional reporting on some more recent published work as an aid to understanding the older work. For example it reports differing views on Prolog-like concurrent programming languages. I apologize for any way in which I have been tendentious and will try to do better.--Carl Hewitt 20:15, 18 October 2005 (UTC)

[edit] Comment (as requested)

The aim of this article seems to be explaining quantum indeterminacy in a non-technical way as much as is possible.

My suggestions are:

Keep only the first and third paragraph of the introduction. Write in the first paragraph that QM only makes predictions in the form of a probability distribution over possible experimental outcomes.

The second paragraph starts with: "Quantum indeterminacy can be quantitatively characterized by a probability distribution on the set of outcomes of measurements of an observable." Change this sentence to make it clear that "a probability distribution" is in fact the probability distribution as predicted by QM.

Don't mention complementarity for noncommuting observables, uncertainty principle etc. in the introduction.

The third paragraph is ok.

The rest of the article should go to the dust bin. If you want to mention Einstein and von Neuman etc. do that in the intro.

This is what I would prefer for the rest of the article:

The second section should make the qualitative notions about quantum indeterminacy mentioned in the introductions more precise. Here you can mention complementarity and uncertainty principle etc. Then explain that the uncertainty principle implies the EPR paradox and refer to the EPR page for more details.

Then write about Bell's theorem, Aspect's experiment etc. Mention the accepted view of physicists that local realistic hidden variable models are ruled out.

Some of the interpretations of QM such as Kopenhagen, Many Worlds etc. should be mentioned. Mention that in Kopenhagen the wavefunction collapses while in MWI you end up with two parallel worlds after a measurement.

It would also be interesting to mention quantum noise. E.g. in any electrical circuit involving resistors at finite temperature there is Nyquist noise, but at zero temperature you have quantum noise. So, you cannot make an infinitely accurate voltmeter even at absolute zero.

Count Iblis 13:41, 18 October 2005 (UTC)

If we were to vote, I would support this rough outline. Karol 20:28, 18 October 2005 (UTC)

[edit] Please check accuracy of figure

Another pair of eyes needs to check my figure in the article. Remember this is a collabortaive effort I don't want to be responsible for all the dumb mistakes.--CSTAR 22:49, 18 October 2005 (UTC)

CSTAR has done a fantactic job of putting this page back on track. No dumb mistakes; none at all. DV8 2XL 18:06, 20 October 2005 (UTC)

Just very clever mistakes? :-) William M. Connolley 19:33, 20 October 2005 (UTC).

He shoots...He scores!! DV8 2XL 19:35, 20 October 2005 (UTC)

• I removed the RfC DV8 2XL 22:50, 30 October 2005 (UTC)

[edit] Something I need 'cleared up'

Err - I started reading this and I stopped when i got to the part where the calculations take into account "complex numbers"; i've always understood complex numbers as 'un-natural' and so why are they being used to describe interations within nature. I have no doubts that this indeterminism can exist in 'theory' but in practice is this really true? It would seem not to me - can someone explain this for me please :( mookid 12 Feb 2006

[edit] Semi-protected

I've semi-protected the article for awhile, until Daniel Arbatsky gets tired of his unimaginative sockpuppet vandalism. --Fastfission 23:52, 11 June 2006 (UTC)

[edit] Grammar

When this gets unprotected again, will someone remember to put the missing "been" in the first sentence of pargraph 3?