Talk:Spectral line shape

Incomprehensible

In the section "Lifetime broadening" is written: "As the excited state decays exponentially in time ..." What exactly disintegrates? The electron? The entire atom? The energy? What is the decay product? — Preceding unsigned comment added by 2A02:810D:AF3F:EC88:599C:9DD6:F9D5:170C (talk) 14:18, 19 January 2018 (UTC)

Natural lifetime broadening?

Suggestion: For Origins and instances, mention natural lifetime broadening before pressure broadening. Both are Lorentzian but the natural lifetime is for an unperturbed atom or molecule so should be first. Dirac66 (talk) 01:28, 1 May 2013 (UTC)

Organization

I think reordering the sections was a good move. Now, the chicken-and-egg problem can be fixed by removing references to the line shape models in Spectroscopic line shape#Origins. The following section could be renamed "Models for line shape", and the discussion of each line shape could begin with a physical process, move to the statistical model for it, and then finally describe the line shape. For example, the Lorentzian could start with atoms radiating with equal probability and then describe the statistical models for the time domain and frequency domain. Similarly, the Gaussian could start with a discussion of thermal processes and continue with normal distributions. Finally, there could be a general description of how different contributions can be combined by convolution, leading to the specific example of the Voigt line shape. RockMagnetist (talk) 18:14, 13 May 2013 (UTC)

These are interesting suggestions. They indicate the importance of the subject. Unfortunately I don't have the expertise to implement them. I wrote this article to fill a glaring hole in WP coverage which became apparent when working on Vibronic spectroscopy, Rotational-vibrational spectroscopy, and Rotational spectroscopy. It had to be a broad-brushh approach as I am not familiar with the physics, having been concerned, in my research, only with applications in chemistry. Petergans (talk) 08:18, 14 May 2013 (UTC)

DYK nomination

Accept hook

• ... that gadolinium-based pharmaceuticals alter spectral line shapes in magnetic resonance imaging allowing better visualisation of some brain tumours?

Lead and content modified. Petergans (talk) 08:52, 23 June 2013 (UTC)

• I cannot pass the proposed hook about gadolinium. I looked at the Google Books online preview of the book that's cited. I can't actually read the chapter ("Relaxation") that is identified in the citation, but neither the table of contents nor the search results that I can see (for "gadolinium", "spectral line shape", "spectral line", and "brain") nor the book's index so much as hints that the chapter might contain the kind of content that would include this hook fact. Gadolinium-based contrast agents are discussed much later in the book; in those later sections I do see extensive discussion of the value of this kind of imaging for investigation of several kinds of tumors, but I don't see mention of brain tumors.

Also, I noted that the hook fact was added to the article lead section. I removed it, but edited the article body to include the substance that I had removed from the lead. This is a detail that is not sufficiently important to the topic to belong in the article lead section, which is supposed to summarize the rest of the article. There is no requirement that a DYK hook appear in the article lead. --Orlady (talk) 02:32, 26 June 2013 (UTC)

How about

• .. that spectral line shapes are needed in many types of spectroscopy for curve fitting of spectra containing overlapping lines.

Unfortunately, reference 6 (Maddams) is in a journal that does not give DOI, but the abstract (https://www.s-a-s.org/journal/viewer/abstract/1256/) explicitly mentions "shape". Petergans (talk) 08:03, 26 June 2013 (UTC)

There seems to be a good deal of confusion in this submsission over what the requirements for DYK actually are. Firstly, the hook fact must be in the article. It is not enough that it could be synthesised from the article text, it must actually be there saying more or less the same thing as the hook. There are three places that the Maddams source is cited, but at none of those places in the article are "many types" or "overlapping lines" mentioned. Secondly, there must be an inline citation where the hook fact appears in the article that directly verifies the fact. In most cases we would expect the cite to include a specific page number where the verification could be found. Citing entire journal articles or book chapters is not usually considered sufficient (unless the entire article/chapter/book/webpage is about the hook fact).

It is not necessary that the source cited be freely available online. We normally assume good faith for offline and behind paywall sources unless there is evidence to the contrary. However, given that several hook submissions in this submission have failed verification already, it would be wise to post the exact quote from the source which verifies the hook, either on this page or in the footnotes for the article. SpinningSpark 10:27, 26 June 2013 (UTC)

• Regardless of whether a suitably cited hook is found in the discussion above, I cannot support this article going to the front page after the proposer's refusal to clarify in-article the relationship of spectral line and spectral line shape. The argument that spectral line is not mentioned because it is not a broad enough article speaks for the need to expand that article, not create another one. The broadest article should be at the broadest title, not a more specific title. That's not to say that I believe this article should not exist, but it needs to be placed in proper context with the rest of the encyclopaedia. Deliberately wanting to isolate from other articles raises suspicions of WP:content forks and WP:walled gardens. SpinningSpark 10:27, 26 June 2013 (UTC)

Proximity broadening?

Does anyone have a good reference for proximity broadening? It would be nice to add which line shape is the correct one. — Preceding unsigned comment added by 130.133.8.114 (talk) 09:58, 15 April 2015