Talk:Discrete spectrum

Ionized atom

IMHO this expression is an oxymoron. It is namely the Hydrogen atom those energy spectrum is discrete. The thing with a continuous spectrum (i.e. that lies above the Rydberg energy) is a system consisting of one hydrogen nucleus and one electron in vacuum. Incnis Mrsi (talk) 12:05, 27 August 2012 (UTC)

 Fixed. Incnis Mrsi (talk) 21:59, 9 February 2013 (UTC)

The confusion increased

As Sbyrnes321 (talk · contribs) noted a half year ago, the "article" consists of two fragments glued together. This was not improved since, but got even worse after the recent move by Slawekb (talk · contribs) to "… (physics)". This did not solve aforementioned problem and leaved behind a hideous dab page (which I already partially fixed, though), but separated quantum observables (a.k.a operators) from the pure mathematics contrary to objections of several users filed at WT:WikiProject Physics/Archive September 2012 #Discrete spectrum, namely, of TimothyRias and Ymblanter, not counting my opposition to this bold and undiscussed move which was not expressed explicitly because this move was not proposed anywhere. Moreover, the title "Discrete spectrum (physics)" incorrectly suggests that there is one meaning in physics, which is opposed to the meaning from mathematics. So, what will we do now with all this cockup? Incnis Mrsi (talk) 14:20, 2 September 2012 (UTC)

So the issue is that when a physicist refers to the spectrum of an observable, it means the same thing (well, more or less, if one doesn't insist on rigor) as the spectrum of a self-adjoint operator in functional analysis. But there are other meanings of "spectrum" in physics, in the experimental setting, that is different from this, and the current configuration of pages doesn't reflect this, is that the problem? Mct mht (talk) 23:53, 2 September 2012 (UTC)

Certainly, the spectrum of an observable means the same thing as the spectrum of a self-adjoint operator. The additional problem is that this "discrete spectrum" is usually referred to as "[pure] point spectrum" or "discrete point spectrum". But there is no consensus whether discrete wave spectrum and pure point spectrum is the same topic. Ymblanter (talk · contribs) and TimothyRias (talk · contribs) insist that it is, but Steve and me consider these thing distinct. Incnis Mrsi (talk) 08:21, 3 September 2012 (UTC)

Is this discussion going any where? Personally regarding the scope of the page it looks fine to me, there is no confusion as far as I can see. Op47 (talk) 20:40, 9 February 2013 (UTC)

There was a terrible confusion immediately after Slawekb, but the article changed. After Jorge Stolfi dropped

“ In physics, an observable is said to have a discrete spectrum if … ”

from the intro, I do not oppose this article anymore. Incnis Mrsi (talk) 21:59, 9 February 2013 (UTC)

Proposed merge/move with mathematical concept

There is a "split" tag in the article with a pointer to "discuss this on the article page", but there is no such discussion here. I am moving the tag to this page until someone justifies the proposal. (Meanwhile, please note that physics is about the real world, while mathematics is about purely mental constructs that we may use to describe and analyze the real world. Let's not mistake the finger for the moon.) --Jorge Stolfi (talk) 22:08, 5 February 2013 (UTC)

• The tag has been put back in the main article page but there is still no justification for the proposal here. --Jorge Stolfi (talk) 18:44, 7 February 2013 (UTC)
• I must also add that the full machinery of functional analysis and bounded operators in Hilbert spaces are not necessary to explain the appearance of discrete spectra in physics. Perhaps they are needed in quantum mechanics; but there must be a billion people out there who understand perfectly well why vibrating objects and radiation from microwave cavities have discrete spectra, and yet have never heard of Hilbert spaces. --Jorge Stolfi (talk) 19:01, 7 February 2013 (UTC)

  You apparently understand poorly what other peoples say, especially in a conversation which is already written (when there is no person to explain a thing personally to Jorge Stolfi). Nobody cares about your opinion whether the proposal was "justified" or "unjustified". Read relevant discussions (including links given at this talk page above) and formulate your opinion. Should the article to be split? Should the article remained as is? Should the situation before actions of Slawekb be restored? Jorge Stolfi is not the first man who tries to cope with the situation and other participants have absolutely no reason to see the discussion restarted. Incnis Mrsi (talk) 08:19, 8 February 2013 (UTC)

Incnis Mrsi, that is a bit harsh.

To Jorge Stolfi: the point of the proposal, as far as I can tell, was that "spectrum" means several things in physics. Only one of these meanings translates/rigorizes to what a functional analyst means when he says the spectrum of an operator. But other usages has no mathematical counterparts. The split was proposed because the article confuses these. Mct mht (talk) 16:30, 8 February 2013 (UTC)

The problem seems to be dissolved. The article does not stray into Spectrum (functional analysis) anymore. Let us stop here? Incnis Mrsi (talk) 21:59, 9 February 2013 (UTC)

Requested move 27 June 2015

The following is a closed discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. Editors desiring to contest the closing decision should consider a move review. No further edits should be made to this section.

The result of the move request was: moved. Jenks24 (talk) 13:33, 13 July 2015 (UTC)

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Discrete spectrum (physics) → Discrete spectrum – redirect --Relisted. George Ho (talk) 04:41, 4 July 2015 (UTC) – Fgnievinski (talk) 03:51, 27 June 2015 (UTC)

This is a contested technical request (permalink). Anthony Appleyard (talk) 04:25, 27 June 2015 (UTC)

@Fgnievinski: it has other meanings. Anthony Appleyard (talk) 04:25, 27 June 2015 (UTC)

• NOTE the nominator eliminated the disambiguation page [1] and created a redirect here, right before nominating this for a move on top of a "redirect". Clearly this was never to be an "uncontroversial move", as it is a primary topic dispute. -- 70.51.203.69 (talk) 04:33, 27 June 2015 (UTC)

• Apologies, I should have checked the talk page before. But I stand by the proposal, as there is only one additional closely related concept, which is better known by a different name (point spectrum) -- i.e., there's no Discrete spectrum (mathematics). A hatnote of the type {{for|the mathematical concept|Point spectrum}} or even {{distinguish|Point spectrum}} would suffice. Fgnievinski (talk) 04:45, 27 June 2015 (UTC)

• Support and move the disambiguation page currently located at the target page to "XX (disambiguation)" format. Khestwol (talk) 22:13, 5 July 2015 (UTC)

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The above discussion is preserved as an archive of a requested move. Please do not modify it. Subsequent comments should be made in a new section on this talk page or in a move review. No further edits should be made to this section.