Talk:Quantum theory

message: This article arised from a discussion in talk:quantum mechanics where it appeared that wikipedia is not consistent with what is quantum mechanics as opposed to other quantum theories.
An expert is needed to clarify what are all the quantum theories, and define what they are (scope, limitations), and their relations with each other (from a history and scope point of view.  (I'm no such expert).  In particular, he should clarify whether quantum mechanics is relativistic or non-relativistic.  Hopefully, it will then be easier to bring consistency in all the specific articles, and convey a clear picture to an engineer like me.Pcarbonn 05:47, 30 August 2006 (UTC)
replies: text: How about making this a disambiguation page?  --Michael C. Price talk 12:05, 30 August 2006 (UTC)
replies: text: I now see that you have made several edits to this article: they look great ! Thanks for the clarification. Pcarbonn 17:30, 30 August 2006 (UTC)

text: Phonons are a product of a QFT (which may be non-relativistic), not QM -- solid state physics, as mentioned in the article.  --Michael C. Price talk 06:33, 2 October 2006 (UTC)
replies: text:  That makes QFT a sub-field of QM, as I thought, because phonons (and their nuclear equivalent) are predicted by the many body Schrödinger equation.  Since I see no other objection, I am nominating the article for deletion.  There is at least one type of quantum physics:  the Old Quantum Theory, that is not QM, but that is now considered an approximation to QM.  So the central idea of this page is an error.  David R. Ingham 23:34, 19 October 2006 (UTC)
thread_title: expert needed

message: Perhaps we should pull the early history of quantum theory into this article? --Pjacobi 19:59, 24 September 2006 (UTC)
replies: text: Only if we deleted the Quantum_mechanics#History section to remove duplication.  --Michael C. Price talk 20:28, 24 September 2006 (UTC)
replies: text:  Split at 1925, expand the old quantum theory part. --Pjacobi 19:43, 25 September 2006 (UTC)
thread_title:  History section 

message: * con --Pjacobi 19:42, 25 September 2006 (UTC)
replies: text: Comment: That is a big difference, even if true. --Michael C. Price talk 07:24, 30 September 2006 (UTC)

text: I've removed the merge tag: there was only one vote in favour.  --Michael C. Price talk 15:31, 6 October 2006 (UTC)
thread_title:  Merge? 

message: I'm not sure to what, but perhaps "semiclassical theories", "semiclassical approximations" or something? Going from a fictitious classical Dirac equation to the Lagrangian or Hamiltionian for the quantized dirac field is just a heuristic excercise to find the correct quantum mechanical description for electrons. The reverse process can sometimes be physically relevant. I gave the example of the Gross-Pitaevskii equation above. Similarly you can derive the Maxwell equations plus the quantum correction due to electron loops: the Euler-Heisenberg Lagrangian. 
On the more elementary level there you have the various semiclassical approximations like the WKB method etc. Count Iblis 01:03, 21 October 2006 (UTC)
replies: text: I still don't think it's clear what purpose this page is supposed to serve, whether it's a review or a history of early quantum mechanics or what.  I kind of liked the idea of a brief overview/disambiguation of different quantum theories, I simply objected to the way that non-universal terminology was being presented.  Perhaps there should be more discussion on this? -- SCZenz 06:06, 21 October 2006 (UTC)
replies: text: I agree that the page is currently confused and would be better as a straightforward disambiguation page.  --Michael C. Price talk 22:47, 21 October 2006 (UTC)
thread_title:  Rename this page? 

message: I don't think the article should start with an explicit defnition of the word quantum.  This is an encyclopedia, after all.  Perhaps, however, we could put a link to the wiktionary definition of "quantum" at the right of the page in the standard format for such things. -- SCZenz 06:06, 21 October 2006 (UTC)
thread_title:  Start with dicdef? 

message: Disambiguate.  I can't think of anything that could be in this article (history of the quantum, definition, interpretations, etc) that isn't covered elsewhere, so I suggest that this should be a pure disambiguation page, with a (nested?) listing of the various quantum theories (QM, QED, QFT, QG etc) and associated articles.  --Michael C. Price talk 12:42, 22 October 2006 (UTC)
replies: text: The history of this article shows that the current QM article derived from or rivaled an early version of this page. Next somebody redirected Quantum theory to Quantum mechanics. After that someone observed that not all quantum theories are called quantum mechanics so some discussion was necessary to avoid oversimplification.  It seems important to some people, for instance, that "old quantum theory" not be called "quantum physics" or anything that implies that it is currently accepted, "canonical" theory.  It appears to me that not everyone refers to different flavors of quantum physics by the same names.  Is there any single place to which a reader new to this subject could go to get straighted out about all the ins and outs of these terminological changes? P0M 23:05, 22 October 2006 (UTC)
replies: text: It's not just terminology changes.  It's the fact that there isn't any uniform terminology at all.  We need to either aknowledge the multiple ways that terms are used or avoid the issue entirely, but we definitely should not be making our own editorial changes. -- SCZenz 23:21, 22 October 2006 (UTC)
replies: text: I agree. P0M 00:44, 24 October 2006 (UTC)
thread_title: Disambiguation Vote

message: I've turned the page into a plain-vanilla disambiguation page. It removes most details, and hopefully sends all arguments about the precise meanings of terms to articles on those terms.  What do you think? -- SCZenz 01:37, 24 October 2006 (UTC)
replies: text: Looks good. --Michael C. Price talk 08:58, 24 October 2006 (UTC)
thread_title:  Plain-vanilla disambiguation 

message: Why do the particles act the way they do when the are observed? They must think they can do whatever the hell they want. Well not when im watchin. Its obvious that these guys will just mess around unless you force them to behave accordingly. I did a double split experiment today, i used an A4 sheet of paper, taped to the window with two slits cut in it. When observed they acted like expected, but sure enough when i looked away they started acting erratical again. Basically i would like to hear some methods on how to control the particles, i propose building a quantum scarecrow that would trick them into behaving how i want. Would this work? If not why not? Any other ideas?  —Preceding unsigned comment added by 193.120.116.147 (talk) 12:47, 23 May 2009 (UTC)
thread_title:  Quantum problems 

message: Quantum Theory can be a complicated subject and if you didn't get this talk you should look into different areas of it or figure out what it is and then come back and see if you understand it any better.  — Preceding unsigned comment added by 108.205.29.135 (talk) 23:04, 22 December 2012 (UTC)
thread_title:  If You Didn't Understand