Talk:Atomic line filter

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Featured article star Atomic line filter is a featured article; it (or a previous version of it) has been identified as one of the best articles produced by the Wikipedia community. Even so, if you can update or improve it, please do.
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Contents

[edit] Banners

To-do list for Atomic line filter: edit · history · watch · refresh

[edit] Almost Definitely

  • New photo from Jonathan Friedman.

[edit] Maybe

  • More on Stark/Zeeman tuning
  • More Faraday filter history

[edit] This is a Good Article

I've been reviewing this article, and have determined that it meets the qualifications for GA status. It is well written, well referenced, and has some very useful infographics. It is a highly technical article about a technical topic, but the author(s) have made a good attempt to clarify terms, and avoid jargon. I've got a few small suggestions for further improvement, beyond continued attempts to expand the article.

  • A very small suggestion... The Chicago Manual of Style (CMS) suggests that inline citations refering to an entire sentence should happen after the full stop of the sentence. Your article places them before the full stop. CMS isn't wikipedia policy, and the guidelines are a bit unclear about what should be used, but in my experience, the CMS style looks a little smoother, and is what is most commonly used in other articles. You can change it, or not change it, but I thought I'd point it out as something I found a little odd looking.
Done -- Rmrfstar 03:45, 28 June 2006 (UTC)
  • Continue to limit the use of jargon, and to include descriptions of terminology inline with the article. You've done a good job of this so far, but as you continue to edit, keep this in mind. Per your user page, the article should be for the curious common man, and parts of this article are borderline specialist.
Roger. I think I've made everything that's already in the article more accessible, and I shall continue to keep it that way. -- Rmrfstar 03:32, 3 July 2006 (UTC)

Keep up the good work. This is an impressive bit of single-editor effort! If you have any questions about my rationale for promotion, don't hesistate to leave me a message. Phidauex 16:36, 27 June 2006 (UTC)

Thanks for the review and for the praise. -- Rmrfstar 03:32, 3 July 2006 (UTC)

[edit] Compliance with WP standards, peerreviewer script output

The following suggestions were generated by a semi-automatic javascript program, and may or may not be accurate for the article in question.

  • Per WP:MOSNUM, there should be a non-breaking space -   between a number and the unit of measurement. For example, instead of 18mm, use 18 mm, which when you are editing the page, should look like: 18 mm.[1]
Done
Done
Done
  • Per WP:MOS#Headings, headings generally do not start with the word "The". For example, ==The Biography== would be changed to ==Biography==.
Done
  • Please reorder/rename the last few sections to follow guidelines at WP:GTL.
Done
  • Watch for redundancies that make the article too wordy instead of being crisp and concise. (You may wish to try Tony1's redundancy exercises.)
    • Vague terms of size often are unnecessary and redundant - “some”, “a variety/number/majority of”, “several”, “a few”, “many”, “any”, and “all”. For example, “All pigs are pink, so we thought of a number of ways to turn them green.”
Am watching...
I've performed a mighty redundancy edit/copyedit. Phidauex 19:35, 22 July 2006 (UTC)
  • As is done in WP:FOOTNOTE, for footnotes, the footnote should be located right after the punctuation mark, such that there is no space inbetween. For example, change blah blah [2]. to blah blah.[2]
Done
Done

You may wish to browse through User:AndyZ/Suggestions for further ideas. Thanks, Wim van Dorst (Talk) 22:30, 21 July 2006 (UTC)

Already have done so. -- Rmrfstar 13:05, 22 July 2006 (UTC)

[edit] Wording of first sentence

There is an atrocious quadruple-"filter" in the first sentence that comes off so puerile, no? And on the front page! 172.162.185.52 07:12, 2 September 2006 (UTC)

I've changed it. I dunno if I like it more though... -- Rmrfstar 00:36, 8 September 2006 (UTC)

[edit] Comments

No special physics background here, but (a) ALFs are cool, and (b) the sections that immediately made the most sense to me were Types, Common components, and Applications (especially LIDAR). A common guy like me needs a clear description of how an ALF works (like the descriptions in Types) before I can understand the historical context or what the special properties of ALFs mean.

Here are more specific ideas that I don't yet know enough to do myself:

  • Say something about why "Only light at the resonant frequency of the vapor is rotated.
To quote Faraday effect:
"This resonance causes waves to be decomposed into two circularly polarized rays which propagate at different speeds, a property known as circular birefringence. The rays can be considered to re-combine upon emergence from the medium, however owing to the difference in propagation speed they do so with a net phase offset, resulting in a rotation of the angle of linear polarization."
If you think a portion of this needs to be in Atomic line filter, I'd be happy to synthesise and add it. -- Rmrfstar 13:45, 2 September 2006 (UTC)
The mysterious thing for me was why light was rotated only around the absorption lines of the gas in the vapor cell. I tried to piece together an explanation from what's available on Wikipedia and the Web. I wouldn't be surprised if this were laughably inaccurate. (Friedman, [1], slide 7 got me started here)
* The Zeeman effect causes each emission line to split into a few lines at nearly identical frequencies, because the magnetic field affects the possible energy states of the atoms. Each line also has different polarization. [2]
* In a vacuum or in air, each of these lines would encounter slightly different indices of refraction, meaning that light at the different wavelengths would travel at slightly different speeds. However, when light is close to an absorption frequency of an atom, its tendency to be scattered and slowed by absorption and reemission depends critically on how close it is to one of the absorption lines of the material it's passing through; this effect is called anomalous dispersion. So the multiple rays of light created by the Zeeman effect travel at significantly different speeds because of their different frequencies. (True? I'm leaving out attenuation and the exact nature of the frequency/dispersion relationship, both discussed at [3]) [4] [5]
* So, incoming light at the atoms' absorption frequency is split by the Zeeman effect into rays with different wavelengths and polarizations. Those rays travel at significantly different speeds due to anomalous dispersion. When those rays leave the medium, they re-combine, and a detectably rotated light beam results. (True? If so, is it the same as the Faraday effect due to ferromagnetic resonance, or is that distinct?)
Thanks for responding to my earlier comments. 67.119.192.12 20:23, 2 September 2006 (UTC)
This really should go in Faraday effect, and I must say I'm fuzzy on the details myself. I don't want to correct any of your guesses, as I may be wrong myself; I'm just sure on what's in the article, and I've not worked too hard on stuff that should be covered in other articles. To elaborate on my previous comment: I think the article is long and dense enough, and material should only be added if really necessary. And you're quite welcome.
  • Bring together in one place the physics of the absorption and flourescence that happens inside the tube. This could help tie together:
Why/how do you want these tied together more? They're all explained once, and I believe, in the appropriate section. -- Rmrfstar 22:48, 7 September 2006 (UTC)
    • The selective drop in frequency that allows absorption re-emission filters to work.
In the section on ARE ALFs.
    • Why particular metal vapors are more commonly used
In "vapor cells"
    • Noise due to thermal radiation
"Sources of noise".
    • Doppler shift
Do you mean Doppler profile or the mechanism of LIDAR?
  • Say something about how radiation trapping happens and what the "state selectivity" in passive ALFs is.
That should be in the radiation trapping article, and I wrote a little more on "state selectivity".

Obviously it's one thing for me to talk a good talk and another thing for someone to be bold in editing pages. Just hope some of this is helpful. —The preceding unsigned comment was added by 67.119.192.12 (talk • contribs).

I think they're fine suggestions and I shall respond to the rest tonight, I hope. -- Rmrfstar 13:45, 2 September 2006 (UTC)
I've posted some more responses... sorry for the delay... -- Rmrfstar 22:48, 7 September 2006 (UTC)

[edit] Spellcheck gone awry?

they may be used for analyzing the earth's thermal libido,

I think this should be albedo. (Presumably an error rather than vandalism as it was posted by the article's main editor: diff.) I tried to look at the Gelbwachs 1988 source to check this, but it requires a subscription. -QuantumEngineer 17:48, 4 September 2006 (UTC)

Sorry-ignore previous comment. Actually, this source refers to filtering out the earth's thermal radiation, not analyzing it. Article now corrected.-QuantumEngineer 13:41, 5 September 2006 (UTC)

[edit] Harvard referencing for patents

The below conversation has been copied from User_talk:GDallimore. Please add further comments here.

--Copied text begins--

Hello. Editing Atomic line filter, you recently replaced all of the patents in the Harvard style with simple links to the patent. You said that Harvard style was "not appropriate" for this application. While I in part agree, I do think that keeping one consistent referencing style is important the article as a whole. Under its current revision (your version), the Harvnb template links in the References section don't work consistently, for instance. And I can't see anything really wrong with calling the author of a patent its "author"; for the sake of internal consistency and simplicity, I feel that your edit should be undone. What say you? -- Rmrfstar 23:55, 26 January 2007 (UTC)

If I may add my two cents, I don't see any real issue with either style of reference. What's nice about the Harvard style (which I hadn't been familiar with before) is that it does list the inventors. On the other hand, what's nice about the direct patent links is that you get to see the patent image. This may be particularly helpful in this technology area. Perhaps it may be possible to combine the two.
As a point of information, there are very different criteria for being listed as an inventor on a patent versus being listed as an author on a refereed publication. Normally, for example, the inventor does not actually write the patent. That's done by a patent agent or patent attorney. Furthermore, inventorship is determined by what the patent is actually granted on. Thus inventors can be added or removed from a patent application depending upon what is claimed. There is also no formal significance to what order inventors are listed on a patent.
That being said, however, I don't see any problem with using the Harvard style for referencing a patent.--Nowa 01:44, 27 January 2007 (UTC)
This is a list of reasons, off the top of my head, as to why a Harvard reference is not suitable for citing patents:
  • The inventors are almost invariably not the authors of a patent spec, and authorship implies copyright ownership. Copyright is a tricky issue when it comes to patent specs, and it would be best to avoid any implication as to who the copyright belongs to.
  • The assignee of a patent is important, especially for non-US patents where the inventors may not even be the first owners of the invention. Harvard referencing doesn't appear to include any sensible way of including an assignee (correct me if I'm wrong).
  • A single field of "date" is confusing/ambiguous. Is this the date of filing, the date of publication of the patent application, or the date of publication of the granted patent? The link generated by Cite patent includes all of those pieces of info in a non-ambiguous manner.
So, as it currently stands, I think Harvard referencing is completely inadequate to cite a patent spec.
As I see it, therefore, there is room for improvement in a number of ways:
  • Harvard referencing template needs improving to include patent specific reference features.
  • Cite patent template needs improving to include (optional) inventor/assignee, publication etc information
(I have not yet read up enough on template creation to be able to do either of these things)
In the absence of improvements in the Harvard referencing template, I think the amendments I made represent the best compromise.
I will copy this discussion to the article Talk page itself. GDallimore 17:32, 28 January 2007 (UTC)
--Copied text ends--

Just went through Harvard NB references to correct non-working double links (which strikes me as being a silly way to reference, by the way). Sadly, the submit button failed, so I'll have to do it again another time.

Noticed while doing this that several of the Harvard NB links weren't working even before my edit, showing how fragile such double links can be. I recommend removing all of them. GDallimore 14:18, 29 January 2007 (UTC)