User talk:Srleffler - Misplaced Pages

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Srleffler is busy in real life and may not respond swiftly to queries.

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Hi, feel free to leave me a message. Kindly leave messages on new topics at the bottom of this page. Srleffler

Gordon Gould

If you want them to stay as references convert them to inline references citing a specific fact, they are 100% useless as "references", since no on can tie a specific fact to any of the reference works cited. Their only value is as "further reading" for someone who might want to read each book in it entirety and see if any of the facts cited in the article come from there. Cheers. --Richard Arthur Norton (1958- ) (talk) 18:15, 7 October 2008 (UTC)

Irish Mist (disambiguation)

I have proposed the deletion of this disambiguation page. It no longer seemed necessary as most internal links point to the drink article (as you previously observed), and that article has a hatnote to the book article. Weigh in if you see any issues.--Kubigula (talk) 22:27, 9 October 2008 (UTC)

That's fine with me.--Srleffler (talk) 22:31, 9 October 2008 (UTC)

Myron Evans

Hello. You were concerned in the early stages of this article. It is now up for deletion for a second time here. Cheers, Mathsci (talk) 11:03, 12 October 2008 (UTC)

Solidus?

Hi Srleffler -- you commented on my talk page that multiple solidus in units of measurement is ambiguous. As a oftentimes computer programmer, I have to debate that point. Firstly, which is more ambigous: W/m/K or W/m·K? I think that people will find the first reads better (as in 'feet per second per second') but the second is cleaner on the page. If one observes systematically an operator precedence system '*' > '/' > '·' then there is no ambiguity. I think that many people prefer the exponential form for units because they don't appreciate that units like W/m·K can be perfectly explicit and unambiguous. Add to that the fact that kg/m² can be typed easily on any keyboard and is pure unicode, whereas Wm¯² isn't pure unicode, requires verbose HTML markup and is buggy when sent in emails. I think that engineering communication, at least, is clearer with the solidus! Rebuttal invited (and also interested to know where you got this 'rule' from, too) :-) Jdpipe (talk) 10:35, 21 October 2008 (UTC)

Talk:Optical fiber

I responded to your reply regarding Talk:Optical fiber. I understand that you feel more specific information belongs in the branching main articles, but these articles also lack the exact same examples. Please see for yourself. These articles lack concrete examples, which divorces them from the general readership by: failing to indicate relevance, reduces comprehension, may reduce overall interest. For an encyclopedia, the public is best served with good common examples when possible. Stephen Charles Thompson (talk) 17:10, 25 October 2008 (UTC)

Lens Clock edits accepted, yet missing references

The publishing of the article on lens clock has improved since it's original posting. The study appears to be the personal notes from the University of Houston College of Optometry on the mathematical models of Crown Glass refraction, and the conversion to a Flint Glass power as an example of how the lens clock is calibrated. These notes in particular are from the archives of Dr. R. Weldon Smith, and Optic Researches, Inc. a coorporation involved in the study of lenses, and lens systems. The original equations given are suggested to be from the Royal Society, London opticians historical archives, not well documented, and a rare find indeed. Misplaced Pages is fortunate to have this article put together, in my opinion, because the concept is somewhat ancient, and the practices are learned by few professionals specializing in providing better vision and the engineering that allows us to see better. Other than a verifiable URL that links to another similar article, I would post a reference to Dr. Smith's work at Optic Researches, Inc. This may involve researching his publications at the U.S. Dept. of Commerce. But, I'm sure the explanations were derived from former studies. StationNT5Bmedia (talk) 04:20, 3 November 2008 (UTC)

Thanks. References have to be to published material. Unpublished personal notes are not suitable references for Misplaced Pages articles. It would be useful to know exactly where the material came from, but it sounds like you don't recall exactly.

I'm confused—are you the person who wrote this article, or are there several people sharing a single user account, or was this article written by someone else, and submitted to Misplaced Pages by you on his behalf?

The articles were hard to find topics that were considered unique. Know where else will you find such a complete exhaustion on these topics. The lens clock is a common bench tool for opticians, yet the commercialization of dispensing has made opticianry a little lower than selling shoes. If the shoe fits, wear it.

That isn't quite the case when trying to help someone half blind. Expertise in this field is needed, and can only be aquired with educational material, as is the example provided by the former practicioner and the aged old crafts.

I am quite interested in this article. I have actually used a lens clock many years ago, as a graduate student. Are these instruments no longer in common use? Your comment above seems to imply that. If so, the article should probably mention it.--Srleffler (talk) 04:57, 3 November 2008 (UTC)

Aspheric lens edits

Popularity of the aspheric lens has declined with intra-ocular lens implants. Also, because of their high cost, and limited availability, aspheric lenses were never used widely as a corrective lens. They are, however, rarely available and beneficial in some cases. Please undo your deletion of these sections, as it is counter-productive to the extensive work done to put them together, and I get wary of hearing about the 3-edit rule when we undo each others work. The same goes for material you are editing out of the aspheric lens article opthalmic use section. I understand reversions of the astronomical use section, but not the eyeglasses.StationNT5Bmedia (talk) 11:43, 12 November 2008 (UTC)

That sounds like a good thing to mention in the article. I think the problem with some of your past attempts have been mostly about wording, and partly about lack of sources. --Srleffler (talk) 04:49, 13 November 2008 (UTC)

Finding remarks for the photographs could give some luster. Several comments were made last year about the article's lack of appeal. A little balance might help, but severe critism followed from trying to fit abbreviated text into box space. Once, shortening the word "renowned" would fit, but became a verb transitive. StationNT5Bmedia (talk) 14:26, 12 November 2008 (UTC)

Comments on photographs are good. Photos usually should have a caption attached to them. Longer comments can appear in body text alongside. I shortened the description of the spectacles photo because I had problems with the text, and the resulting shortened text was short enough to be a caption rather than body text. The things that were wrong with the previous description were:

Unencyclopedic tone: articles should not address the reader directly with phrases such as "notice that".
Camera lenses are not afocal. Afocal does not mean the same as "out of focus". In afocal projection it is the telescope that is afocal (if anything is), not the camera.
The phrase "targeting divergence from the concave asphere's centers" is unclear if not meaningless. The test pattern is out of focus because the camera lens is focused somewhere else. The aspheres bring the test pattern (almost) into focus.
It was a bit too wordy. The compressed version is better.

--Srleffler (talk) 04:49, 13 November 2008 (UTC)

We're currently considering working out edits with User:Dicklyon to include links to corrective lens, but not to put references at risk on the world wide web from competition with asphere imports, a trend going on. They get enough junk email already. StationNT5Bmedia (talk) 02:55, 13 November 2008 (UTC)

On Misplaced Pages, references are published sources. Information obtained from private sources simply cannot be used, except in very special circumstances.--Srleffler (talk) 04:49, 13 November 2008 (UTC)

Ask any practitioner

Info box comments about the aspheric bi-convex +15DS lens pertain specifically to this lens for asphakics without IOL implants. This is a health sciences practice going back 100's of years. The dispensing of the lens is declining with newer surgical proceedures. Ask an eye doctor, and you won't have to take my word for it. This info should have been included with the photo in the 1st place. It is an ambiguous diagram to the untrained eye without the clarification. Other diagrams have been removed from this article before for being awfully vague. StationNT5Bmedia (talk) 17:57, 14 November 2008 (UTC)

Visit Ophthalmic Lenses and Dispensing, pg 178, fig. 13.10 found at "Opthalmic Lenses and Dispensing".

Lots of 3rd party published material without diagrams ie. www.aaofoundation.org, and the British Medical Journal relate to dispensing for aphakia. StationNT5Bmedia (talk) 19:21, 14 November 2008 (UTC)

Without more information, I don't think you can tell what the lens in that diagram is. Aspheric lenses are used for many purposes, not just as corrective lenses. To my eye, that lens looks very much like the type of lens used to focus the read laser in a DVD player, or to couple a beam from a laser diode into an optical fiber.. Note that no indication of the diameter of the lens is provided, nor of the radius of curvature. It could be any size from 1 mm diameter up to many inches. Even if this were an ophthalmic lens, how can you be certain it is +15DS and not +14DS, for example?

This isn't a great diagram. I added it to the article only because I thought it was better to have a poor diagram than none at all. It's basically a place-holder until we come up with a better one.--Srleffler (talk) 23:26, 14 November 2008 (UTC)

It could also be used in the lenticular lens article, a subrogate nomenclature used in older text. StationNT5Bmedia (talk) 02:28, 15 November 2008 (UTC)

You don't seem to have read what I wrote, just above.--Srleffler (talk) 09:38, 15 November 2008 (UTC)

I put my image Image:Fata morgana of the sun glitter.jpg back to reflection

Hi Srleffler, I put my image back. I saw this effect (green upper edge) with my own eyes. I even took off my sunglasses and still saw the same green and blue colors of the upper edge. I then sent the image to the best mirage and green flash specialist Dr. Andrew T. Young Astronomy Dept. San Diego State University and included his response to the image desription page. May I please ask you, if you read it? May I please also ask you, if you believe that all green flash images are caused by Chromatic_aberration? May I please ask you, if you really do not see the difference between the green colors in my image and the color of Chromatic_aberration image? Here's one more difference: Chromatic_aberration artifact are attached to the subject and repeat exact shape of the sybject. My green rim is clearly detached and has its own shape, which was caused by inversion layers. Thanks.--Mbz1 (talk) 20:02, 19 November 2008 (UTC)

OK, I'll accept that you saw it with your own eyes. The colored edges are indeed chromatic aberration, but it appears from your description that it is chromatic aberration in the atmosphere, rather than in your camera. I have now read Dr. Young's comments. There is still a problem here, however. Please read Misplaced Pages's policies on Original research and Verifiability. Your interpretation of your photograph is original research, and you have not provided any citations that back up your claims. No means are provided by which we can verify that your interpretation is correct. Dr. Young's comments are interesting, but are not a reliable source, as required by Misplaced Pages's policies. Furthermore, the text is really off-topic for the reflection article. There are reflections, and there are mirages. It's not surprising that one can have a mirage of a reflection, but this isn't really a distinct effect, and doesn't really merit a section in the reflection article. I understand that you're proud of your photograph. It's pretty neat. That doesn't automatically make it suitable for this article. There is also a technical issue: the green and red edges you describe are extremely difficult to see in the online image. They are not visible in the thumbnail, or in the larger image on the image description page. They are barely visible in the full resolution image on my monitor. Only by zooming in on the full resolution image 4× did the green and red edges become clearly visible. This greatly limits the usefulness of the image for Misplaced Pages. If you're going to use the image (perhaps in the Fata Morgana article), the caption should indicate that the full image must be loaded and zoomed to see these features.--Srleffler (talk) 04:58, 20 November 2008 (UTC)

Well, I do not think I could agree that Dr. Young's comments are not a reliable source. If they are not, it means that there's not a reliable source for any mirage phenomenon at all anywhere in the world, but I believe it is rather something wrong with Misplaced Pages's policies about what is a reliable source.BTW I wonder, if somebody will make a new discovery, let's say a new Albert Einstein will submit to Misplaced Pages a new E = mc2. would it be removed from an article because it had no a reliable source? I am sure that, if Galileo Galilei would have posted the statement that the Earth is rotating to Misplaced Pages it also would have got reverted because there was not a reliable source at the time (of course removing an image or a statement from the article is not nearly as scarry as to get imprisoned for a new idea :=) ) Please notice, in no way I compare my images amd myself to Albert Einstein or/and with Galileo Galilei. Anyway, because Misplaced Pages is not a reliable source itself, IMO nothing wrong will happen, if Misplaced Pages readers would see an image that might prompt them to think
May I please ask you, if you believe that green flash and green and red rims of the sun are also due to chromatic aberration? I'm really interested in learning your opinion about this matter, so may I please ask you to respond this question?
It is not that my image is neat. IMO "neat" is not the right word for it. This image is unique, one-of-a-kind, and IMO nothing wrong would have happened, if Misplaced Pages readers learned something new (maybe even a little bit off-topic) while reading reflection article.
I could agree with you that red lower rim is difficult to see, but upper green is seen good even in thumbnail. --Mbz1 (talk) 14:33, 20 November 2008 (UTC)

It's not a matter of opinion, nor a judgement on Dr. Young himself. Misplaced Pages requires published sources, specifically material that is published by an independent publisher with a reputation for reliability. Dr. Young's professional publications would be reliable sources. A personal comment by him to you is not. If a new Einstein or Galileo submitted their work to Misplaced Pages it would be rejected, and rightly so. We are not a scientific journal or other medium for original research. We are an encyclopedia. We report on work that has been published elsewhere, but do not serve as a primary publisher for new scientific work. In fact, we reject new "science" by people who consider themselves the next Einstein every day. If you want to know more about these policies, and the reasons for them, follow the links above.

Chromatic aberration is an effect in optical systems, in which light of different colors does not come to the same focus since the refractive index varies with wavelength. The green and red edges you describe seem to be due to the same effect occurring in the atmosphere. The green flash requires the addition of a mirage to make it visible. I'm not suggesting anything different from the conventional descriptions you have read—just a different term for the same thing.

I added your image to Sun glitter. It's fine in that article. I just don't feel it is good content for the article on reflection. --Srleffler (talk) 04:38, 21 November 2008 (UTC)

Thank you for responding, Srleffler. You forgot that my green edge was also magnified many times by a mirage. That's why I believe the effect was very similar to green flash. BTW I asked Dr. Young about Chromatic aberration . Here's what he wrote back to me:
"Well, remember that green flashes, and green and red rims on bright objects near the horizon in general, are just due to the dispersion of atmospheric refraction. If you want to call this "chromatic aberration of the atmosphere", fine."
I just read this article on Yahoo news (what a coincidence!): e=mc2: 103 years later, Einstein's proven right Does it mean that Misplaced Pages Albert Einstein article was displaying the formula for so many years without it being corroborated by a reliable source? What a horror!!!How could we possibly do something like this? What kind of encyclopedia we are? Sorry, just kidding.
Srleffler, I'd like to ask you one more question please. May I please add to reflection article a normal sun glitter image. I believe it would be good for the article because many people do not realize tha sun glitter is reflection of the sun in the waves.
I just got a response from another atmospheric optic expert David Lynch. He writes:
"It is gorgeous, I have never seen anything like this. I would like to send your message to a few other people if that is OK with you.Stunning shot, thanks."
Well, I'm glad that there are few people, who understand my image. Thank you.--Mbz1 (talk) 15:28, 21 November 2008 (UTC)

No, Einstein's 1905 paper is a reliable source, because it was accepted and published by a reputable scientific journal, Annalen der Physik. We accept material published in scientific journals, newspapers, books printed by reputable publishers, etc. If a new genius came along with some new theory of relativity, she would need to submit it for publication in a scientific journal before writing about it here. Encyclopedias are tertiary sources. They write about things that have been written about elsewhere, and report what has been said and written. Encyclopedias are not a medium for first publication of new discoveries.

The article you mentioned is a bit misleading. Relativity has been confirmed in very many experiments. What is novel in the new work is that for the first time they have shown that you can accurately determine the mass of an atom from the energies of its constituent subatomic particles. Nobody doubted that this would work, but no one had previously managed to calculate what the energies of the quarks and gluons that compose the atom would be.

I added a link to the sun glitter article in the "see also" section of the reflection article. I'm ambivalent about adding a photo of sun glitter to the article. It's not that important an effect. The article doesn't have an excess of photos though, so if you added it it might stick around for a while, as long as it was a good photo that illustrates the concept of reflection well.--Srleffler (talk) 04:32, 22 November 2008 (UTC)

Plane/Plane mirrored lasers

Hi. Responding to your answers in Fabry-Perot Interferometer talk, I understand what you're saying about diffraction and thermal lensing. I can not explain my results of burning a perfectly round spot that measures exactly 5mm. When I got this laser, mirror alignment was poor, and the spot produced was rather bean shaped. I noticed when expanding the beam through a concave lens I was able to image a series of concentric, off center circles onto black carbon paper. The pattern looked remarkably like flatness measurements taken with an optical flat. By focusing the beam through a convex lens I could get a clearer image of a very different pattern, burned into black rubber. Like an interferometer measurement, I was able to use these patterns to align both mirrors perfectly with the rod, and was surprised how very easy it was! (This laser is touted as being "unalignable", because the mirrors rest against solid pegs, but I had no problem inserting thin shims of aluminum foil to achieve alignment). The beam quality improved and output energy went way up. (Before alignment it could put a small nick into the surface of a razor blade, but after alignment it could just put a hole 1/2 millimeter in diameter through a razor blade measuring .008 inch thick.) I have not yet seen a laser with curved mirrors that was that easy to align, especially without the use of an external laser. So, wouldn't a plane/plane mirrored laser better fit the description of an interferometer? Perhaps I am just confused.Zaereth (talk) 20:45, 20 November 2008 (UTC)

Normally, plane-plane resonators are harder to align than curved mirror ones, because the mirrors have to be accurately parallel to get the laser to lase. Stable curved-mirror cavities are simpler because even if a mirror is tilted slightly, some point on it will still be perpendicular to a point on the other mirror. As you noted, though, the beam is much smaller and you get much less gain because the beam does not use all of the rod. I think your laser rod is acting as a negative lens (due to thermal lensing). Combined with the plane mirrors this makes the cavity function as an unstable resonator. Unstable cavities have high loss, but with a gain medium like Nd:YAG they can produce high output power because the beam expands to fill the rod, using all of the gain medium instead of only the center. If I recall correctly, they are also not too hard to align. Anyway, it sounds like an interesting project. You must have been thrilled to figure it out and get it working.

Now that I think about it, not all Fabry-Perot interferometers use plane mirrors. Confocal Fabry-Perot interferometers are very common. The principals are exactly the same as a confocal laser cavity. For interferometers, curved mirrors are beneficial because you can't in practice achieve high finesse with plane mirrors. The usual rule of thumb is that no matter how high the reflectivity of the mirrors is, the actual finesse can't be much more than the ratio of the wavelength to the deviations from flatness of the mirrors. So, an interferometer made with high quality λ/20 mirrors will get you a finesse above 20, but probably not above 100. Confocal F-P interferometers can be made with finesses of a couple thousand.--Srleffler (talk) 05:17, 21 November 2008 (UTC)

Ok, I get it. Thank you very much for taking the time to explain it to me. And, yes, it has been a very fun and interesting project. Tripling the electrical energy to 45 joules did not produce nearly the power increase as aligning the mirrors. Anyway, thanks again! :-D Zaereth (talk) 19:51, 21 November 2008 (UTC)

There is an inherent limitation of curved mirrors. Assuming 1. Increasing light intensity increases stimulation. 2. A SINGLE light wave can shuttle between parallel mirrors (because of coherence). 3. Laser light that shuttles between curved mirrors loses coherence. Therefore, multiple light waves traverse the gain media. A given amount of energy within a single wave is more stimulating than the same amount of energy split into multiple waves. Vze2wgsm1 (talk) 13:30, 27 October 2009 (UTC)

Sorry, but you don't know what you are talking about. There is no problem maintaining coherence in a stable mode between curved mirrors. The wave equation has solutions with perfect spatial and temporal coherence and curved wavefronts. What you are missing is diffraction. A finite-diameter beam of light can't bounce back and forth forever between plane mirrors, because diffraction causes the beam to expand and the wavefronts to curve. To get a stable, fully-coherent beam, you have to either have some lensing in the cavity, or you need curved mirrors.--Srleffler (talk) 04:00, 28 October 2009 (UTC)

There is a problem creating curved surfaces that are as perfect as flat surfaces. Imperfections in curved mirrors can result in differing distances among pairs of reflecting mirror segments. Monochromatic light requires a fixed distance between reflecting segments. The differing distances between reflecting segments can allow a variety of wavelengths (corresponding to distance between mirror segments,) albeit light at each wavelength has coherence. Therefore, curved mirrors normally produce monochromatic light with lower intensity and lower efficiency than parallel flat mirrors.

Does your reference to diffraction apply to both standing waves and similar waves that do not have coherence? See the rules listed in my talk page. Vze2wgsm1 (talk) 23:40, 30 October 2009 (UTC)

Nothing is perfect. There is no such thing as "monochromatic" light, and no laser is perfectly coherent. All have some nonzero bandwidth and a corresponding finite coherence time. What limits the coherence varies—there are factors involved other than accuracy of the mirrors' surface figures.

Yes, diffraction applies to both standing waves and to waves that do not have coherence. A plane-plane cavity cannot by itself support a monochromatic standing wave with finite diameter. A plane-plane cavity could support a standing plane wave, but true plane waves are infinitely wide in the transverse directions. As soon as you make the transverse dimensions of the wave (and your mirrors) finite, diffraction becomes a factor. Lasing in plane-plane resonators generally depends on the gain medium acting as a weak lens due to temperature-dependent variations in the refractive index. The addition of a positive lens inside a plane-plane cavity allows stable standing waves.

Your rules seem to confuse laser pumping with stimulated emission; they are not the same thing. Your rule #1 is not quite true in general. The other two rules are mostly true, with some qualifications and exceptions. Superradiant emission is a lot like lasing, but with travelling waves instead of standing ones. --Srleffler (talk) 06:54, 31 October 2009 (UTC)

To me, diffraction of a standing wave is puzzling. By definition, a standing wave is stationary. There is no impinging wave movement toward molecules or towards a mirror. If a light wave is a particle, perhaps the particle as big as the wave.

I realize that the Desaneis rules (within my workspace) are imperfect and controversial. Based on the Zaereth response, I think they may be helpful to others. Do you have any objection to including them within the laser discussion area? Vze2wgsm1 (talk) 03:26, 4 November 2009 (UTC)

There is more than one way to make a stationary configuration, and the one you are thinking of is not the most useful in practice. It helps to remember that a standing wave is simply two temporally coherent travelling waves, propagating in opposite directions. If the waves are plane waves (which have infinite transverse extent) there is no diffraction, and you get the classic undergraduate physics model of a standing wave. If the waves have a finite transverse extent, however, the waves travelling in each direction expand as they travel, and the wavefronts become curved. If the waves are bouncing back and forth between plane mirrors they don't reproduce their path, and you don't get a stationary configuration. The only way you can get a standing wave between plane mirrors is if there is something between that acts like a positive lens. You can get a decent approximation to a standing wave, however, if the spacing between the mirrors is small compared to the diameter of the beam. Planar Fabry-Perot etalons work this way. (Note that the typical undergrad physics theory of etalons assumes plane waves, and therefore infinite transverse extent.)

So, you can't make a true standing wave with finite diameter using plane mirrors. It turns out, though, that you can make one with curved mirrors. As I mentioned above, diffraction causes the wavefronts to become curved as each travelling wave propagates. If the travelling wave hits a mirror that has the same curvature as its curved wavefront, the wave is exactly reflected back along the path it came from and the diffraction is "undone" as the wave propagates back. It turns out to be easy to choose combinations of curved mirrors and cavity lengths such that the geometry of the wave is stationary, replicating itself on each round trip. One obtains a standing wave with curved wavefronts. The wavelengths the cavity supports are the same as what you would expect for a planar cavity of the same length.

Yes, I do object to you posting your rules on any article talk page. Article talk pages are for discussion related to improving the article. They are not for general discussion of the article topic.--Srleffler (talk) 06:35, 4 November 2009 (UTC)

Hi Srleffler. This conversation has brought me to a question. Can you tell me if I understand this correctly. If an atom absorbs a photon it reaches an excited energy state. After a certain time, the fluorescence lifetime, it will emit a photon but of shorter wavelength. I assume that the energy lost between absorption and emission is due to some form of entropy. Would that be correct? Zaereth (talk) 23:33, 6 November 2009 (UTC)

No. When an atom absorbs a photon, it promotes an electron in the atom to a higher energy state. If nothing else happens, the electron stays in that state for a random time (this turns out to be important), and then decays to a lower state. The average time that the electron will remain in the excited state is the fluorescence lifetime of that state. If the electron decays back to the state it came from, a photon is released that has exactly the same energy (frequency, wavelength) as the photon that was absorbed. If a shorter wavelength photon is emitted, it means that the electron decayed to an excited state between the first and second states. The electron can then decay again by spontaneous emission. If this second decay takes it back to where it started, the total energy of the two photons emitted will equal that of the photon that was originally absorbed.

Now, there are things that can happen to the electron besides decay by spontaneous emission of a photon. Decay by stimulated emission is another, obviously. If the atom is in a solid, the electron can decay by emission of a phonon—a quantum of atomic vibration. Essentially the electron decays but the energy goes into making the atoms in the solid vibrate instead of going into light. This is important in semiconductors.

The electron going through a sequence of decays is important in lasers. Most good lasing media are "four-level" gain media. Electrons are pumped by absorption of photons from the ground state (state 1) to an upper excited state (state 4). The medium is chosen such that state 4 has a very short lifetime for decay to a lower state (state 3—the "upper lasing level"). State 3 has an extremely long lifetime—it is metastable. Finally, there is a state between states 1 and 3, which has a very short lifetime for decay back to the ground state. Initially, the ground state (1) is full in each atom and the other states are empty. When the laser is pumped, electrons are promoted from state 1 to state 4, and then quickly decay to state 3, where they remain. The energy lost going from 4 to 3 might be emitted as photons, or as vibrations in the gain medium, which become heat. We don't care where that energy goes, except that we want there to be as little of it as possible, so we want state 3 and state 4 to be close together. Since state 3 is metastable, electrons leave it only by stimulated emission; you know how that works, I think. When stimulated emission happens, the electrons fall down to state 2, which is empty since it has a very fast decay back to state 1. Again we don't care where the energy lost in going from 2-->1 goes, but prefer it to be small. State 2 is ideally close to state 1, but not so close that it ends up being populated by electrons through random processes.

Some lasing media, such as ruby, are "three-level". In this case there is no state 2. Stimulated emission takes electrons from the upper lasing level all the way back to the ground state. This is bad: the ground state is by default full. In a 3-level laser atoms with an electron in the ground state not only don't participate in stimulated emission, they absorb photons at the lasing wavelength. To get a 3-level laser to lase you have to pump the heck out of it; at least half of the atoms in the beam path have to be in the excited state or the gain medium will absorb more than it emits.

Ok, that makes more sense. Thanks very much for the clear, concise explanation. It's probably the most direct one I've ever read. Zaereth (talk) 00:57, 7 November 2009 (UTC)

Rob Dyrdek

The reason that I removed the info from Rob Dyrdek is because it is not cited, referenced, or have a source. Until it has one of those, I don't think it should be on there. Rollback doesn't allow you to make an edit summary, even if that was a valid edit. Hairy Perry 17:47, 10 December 2008 (UTC)

You're not permitted to use rollback on edits that aren't vandalism. You can lose your rollback priviledge for that (although this isn't likely if you are editing in good faith). When reverting non-vandal edits, you should be doing it the old-fashioned way, and leaving an appropriate edit comment.

You're welcome to challenge the material as uncited. If you remove it again and give that as the reason I won't revert you. Do you actually doubt the statement's veracity, though? It's often best to challenge material under WP:V and WP:RS only if it is actually doubtful.--Srleffler (talk) 17:51, 10 December 2008 (UTC)

Sorry, I will only use it for vandalism from now on, thats the first edit that I have only used it for non-vandalism edit, I'm sorry, but I do want to challenge it as unsourced and verfiability. Thank you, Hairy Perry 17:54, 10 December 2008 (UTC)

Actually now, I'm going to let it stand a little while to see if anybody can come up with a cite for it, most likely not, though as I can't find no reliable sources to say thats when Fantasy Factory is coming out. Hairy Perry 18:01, 10 December 2008 (UTC)

chromatic aberration

Hi, Srleffler. I thought you might be interested to take a look at this. In general I agree that you took the image out of the article. The image is too unique, too one-of-a-kind and too interesting for Misplaced Pages. Best wishes.--Mbz1 (talk) 17:38, 22 December 2008 (UTC)

Good to see the image is getting the attention it deserves. It looks like you have found the right audience for it.--Srleffler (talk) 17:54, 22 December 2008 (UTC)

OptiPedia.org

Hi Srleffler, We, three graduate students working in the area of integrated optics, have launched a website: www.optipedia.org. It is a wiki for optics only, and we are in the process of developing and entering articles. We would very much like to have you a user. Sincerely, Admin (OptiPedia) —Preceding unsigned comment added by 165.91.10.171 (talk) 21:21, 29 January 2009 (UTC)

GAR for Optical fiber

Optical fiber has been nominated for a good article reassessment. Articles are typically reviewed for one week. Please leave your comments and help us to return the article to good article quality. If concerns are not addressed during the review period, the good article status will be removed from the article. Reviewers' concerns are here. --A. di M. (talk) 17:54, 1 February 2009 (UTC)

Perpetual motion

Hi, I think you may have missed the MOS:DABRL and Misplaced Pages:MOSDAB#Exceptions section at MOSDAB. They tell what to do in situations like at free energy where the linked article is not the same title as the DAB title. Also notice that all the examples are of entries which begin with the title of the DAB page. NJGW (talk) 19:49, 14 February 2009 (UTC)

MOS:DABRL is about Red links. That doesn't apply here. Perpetual motion is a blue link. It goes at the beginning of the entry. I'm not sure how you're reading the "exceptions" section. That section is about exceptions to the prohibition on piping and redirects. Neither piping nor redirects was used in the edits I disputed at Free energy.

While the examples at WP:MOSDAB all or mostly seem to be entries with the same name as the page, that is more a flaw in the examples than an a limitation on what can be included. The principals are clear: any article that could be named so as to be ambiguous can be included, and the links are not generally to be piped or redirected because we don't want to obscure the true title of the linked article. If it's possible that someone could search for "free energy" when they want the article on perpetual motion, then that link should be included, and it must appear as Perpetual motion, and it must if possible appear at the beginning of the entry. If it's not possible that someone could search for "free energy" when they want Perpetual motion, then that entry should not appear on the page at all.

The link to Perpetual motion is needed because the "free energy" in Free energy device is ambiguous with Free energy. We can't put Free energy device in the dab page because it is a redirect to Perpetual motion. Therefore, Perpetual motion needs to be linked.--Srleffler (talk) 00:36, 15 February 2009 (UTC)

That's not what I'm proposing. I propose something like "Free energy device, a machine such as a perpetual motion device which is claimed to exist by conspiracy theorists." NJGW (talk) 00:49, 15 February 2009 (UTC)

That's not permitted. If Free energy device were a viable red link, you could use your text but with "Free energy device" linked. This flags the potential for creating an article on the topic. In this case, though Free energy device exists and redirects to Perpetual motion. It's therefore the latter that has to appear as the primary entry on the dab page. See also Talk:Free energy. --Srleffler (talk) 00:59, 15 February 2009 (UTC)

I think I figured out the solution. Have a look at the talk page. NJGW (talk) 02:45, 16 February 2009 (UTC)

Free Energy

Hi, this is the user that was editing the Free Energy page. I thank you for letting me know about the disambiguation page. In addition would I would like to see links to some of these free energy subjects on the disambiguation page. The links are: http://en.wikipedia.org/Geothermal_(geology) http://en.wikipedia.org/Solar_energy http://en.wikipedia.org/Wind_energy http://en.wikipedia.org/Tidal_energy

Since you seem to be the main editor for this page, I will leave it in your hands to do this. If this is a problem, please reply to me so that we can discuss the best outcome. Thank You. —Preceding unsigned comment added by Tkidwell447 (talk • contribs) 01:33, 16 February 2009 (UTC)

There was a big debate on this issue a while back, but I can't find it now. I believe the consensus was that there wasn't any documented use by reliable sources of the term "free energy" to refer to these things. In any event, we wouldn't list the individual types at Free energy, but rather would link to one of the broader articles such as Sustainable energy or Renewable energy. Generally "free energy" is a difficult term to handle in a neutral and encyclopedic manner, because it is used in a number of different ways, some of which are by people pushing a particular ideological agenda. For that reason, use of the term on Misplaced Pages is relatively limited, in favour of terms with broader acceptance.--Srleffler (talk) 02:10, 16 February 2009 (UTC)

If there's no mention of Free energy at the target, there shouldn't be a DAB link. Editors like Reddi have tried to do this in the past and sworn they had refs to support such usage, but these were never furnished. This is an attempt to use Misplaced Pages to popularize a neologism. NJGW (talk) 02:53, 16 February 2009 (UTC)

I think it's not so much a neologism as a distinct ideology. For the people in the so-called "free energy movement" there really isn't a clear distinction between devices that operate on energy drawn from wind or sunlight, and devices that operate on energy drawn from zero-point energy, negative energy states, or whatever. For Misplaced Pages purposes, what matters is that there don't appear to be genuine reliable sources that document this broad usage of the term by other than a tiny minority of people. --Srleffler (talk) 05:28, 16 February 2009 (UTC)--Srleffler (talk) 05:28, 16 February 2009 (UTC)

My bad

Sorry, I should have checked, as I had the nm and THz swapped in my mind. Thanks for fixing. Dicklyon (talk) 18:05, 22 February 2009 (UTC)

Thanks for Rayleigh length

Just dropping this line to thank you for all the corrections and good work on the article about Rayleigh length, and you comments about GaussianBeamWaist.svg. Cheers, Godot (talk) 18:19, 24 February 2009 (UTC)

over-illuminiation on porches and climate change

Hi--

I saw your interesting comments on the wikipedia “over-illumination” article.

I’m a climate change activist. I’m exploring the idea of a grass-roots, door-to-door campaign focused on illumination. The idea is to go door-to-door evenings, and grab people’s attention by offering to change their porch light to a compact fluorescent bulb that is half as bright (or less ) than the current one. This would have some benefit on its own, but more important, it would be an entre to talking about everything from motion sensors to insulation to converting to a high-efficiency furnace.

To do this, we’d have to be very well prepared (presumably with a written hand-out as well) to explain what is the proper range for illumination on a front porch. It would be nice to be able to measure current illumination, change the bulb, and re-measure to convince people they can live with less light, but I suspect the cost of the instruments would be prohibitive if we do this on any sort of large scale.

A better approach might be simply to carry a tape measure and a chart to hand people that shows lumens for typical incandescent watt bulbs, lux depending on height of the bulb above the porch floor, and the more appropriate lux range, together with the size compact fluorescent bulb that would serve. Our town has a pretty high average education level, so we’d very much want to be able to cite to sources.

Do you have any thoughts about where I might go to start putting together information like this?

Thanks very much.

--Werner

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Werner Lohe
Brookline, MA  USA
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

p.s. - I'm a newbie, so if I'm violating some protocol by posting here, forgive me. For the life of me, when you say at the top of your talk page "feel free to leave me a message. Kindly leave messages on new topics at the bottom of this page," and I go to the bottom I don't see what I'm suppossed to do to leave a message.......

WLohe (talk) 20:37, 26 February 2009 (UTC)

You posted in the right place. You click "edit", and then go to the bottom of the page in the edit window. Alternatively, if you're starting a new conversation, there's a button at the top of the page that says "new section" that will do the same thing.

Why focus on making the lights dimmer? It seems to me that a better approach is to focus on encouraging people to switch to compact fluorescents that produce the same level of light output. This is a win-win-win: It saves 75% on the energy usage, saves money, and has no down-side because the illumination level is the same. Going door-to-door trying to convince people to replace their bulbs with dimmer ones seems like a less viable idea.

Personally, I use the brightest porch lights I can get, but they are compact fluorescent and they are on timers. One is about 900 lm and consumes ~15 W, the other is about 1200 lm and consumes ~18 W. I would have used bigger CFLs, but they wouldn't fit in the fixtures.--Srleffler (talk) 04:52, 27 February 2009 (UTC)

Well, you make a very good point--I should probably focus on what I really care about--reducing energy use. But I can't help but comment that when you say "I use the brightest porch lights I can get," I shudder a bit. :-) At least in my neighborhood--pretty nice houses on smaller than quarter-acre lots--a little, 250 lm, 5 W CFL (like a 25 W incandescent) provides plenty of light and really adds to the architectural ambience. It would seem quite dim to you, probably, but when I walk past neighbors who have a big 150 W or three 100's or whatever on their porches, to me it's the visual equivalent of walking past a house where there's the sound of at TV quiz show blaring out the windows!

Anyway, you haven't heard of anyone looking into or any source for ideal illumination levels on porches, I take it.......?WLohe (talk) 20:00, 5 March 2009 (UTC)

I'll keep this in mind the next time I replace the bulbs. No, I'm not aware of any source for info on ideal illumination, but I would think it would depend a lot on the layout of the porch, and what you use it for. If the goal is just to keep visitors from tripping on the steps, you don't need nearly as much light as if you have a large porch and enjoy sitting outside in the evening.--Srleffler (talk) 00:24, 6 March 2009 (UTC)

WP:PHYS

Hey there, I noticed you're interested in optics/lasers etc... Can I interest you in joining WikiProject Physics? We'll take all the help you're willing to give. Headbomb {_{κοντριβς} – WP Physics} 04:33, 1 March 2009 (UTC)

Maybe. I'm not too interested in the whole WP1.0 thing, nor in efforts to rate articles by quality or importance. Nothing wrong with it, it just doesn't interest me. What else is the Wikiproject doing?--Srleffler (talk) 05:07, 1 March 2009 (UTC)

Well that's the behind the scenes stuff, I have the feeling that most participants don't do "assessment runs", but simply bother to fill class/importance when they happen to go on a talk page, so if your not interested in that, just do something else. The main thing is that the talk pages serves as a "discussion central" for all things physics on wikipedia. For example when you want to have another pair of eyes looking at some of your edits, or to ask for a second opinion about a recent addition of material by an IP. There's also the bot-automated article alerts, which is sort of a "news ticker" of the current activity (articles nominated for deletion, peer reviews that opened, good articles nomination, etc...). There are other smalls things here and there, but joining WP:PHYS helps up build a list of "go to people" on certain topics. For example if exciton laser is going under a peer review, then the nominator know "alright, this guy and this guy seem to know something about lasers, so their opinion should prove insightful". Stuff like that. Some people get involved on doing peer/featured/good reviews, other people simply use the physics talk page when they need it. Headbomb {_{κοντριβς} – WP Physics} 23:44, 2 March 2009 (UTC)

Could you help, please?

Hi Srleffler, May I please ask you to take a look here and help us to understand how soap bubble worked? Thank you for your time.--mbz1 (talk) 15:08, 2 March 2009 (UTC)

WP:GLASS

Thank you for helping with tagging acticles for the taskforce glass, as you did with Crown glass. I would like to encourage you to continue helping the new taskforce in any way that seems appropriate to you. In the optics field, there are editors needed. I am planning to give more details in the near future on the taskforce page.-- Afluegel (talk) 20:28, 30 March 2009 (UTC)

Date autoformatting poll

Hi there, I noticed that like me, you are opposed to any form of dates autoformatting. I have created some userboxes which you might like to add to your userspace to indicate your position. You will find the boxes here. Ohconfucius (talk) 06:42, 1 April 2009 (UTC)

Note

@Jaakobou:

-- Jaakobou 17:40, 29 April 2009 (UTC)

Another reply posted, Jaakobou 09:09, 30 April 2009 (UTC)

Cheers/polarization intro

Very nice work on the Polarization intro.
Cheers! Jaakobou 01:43, 5 May 2009 (UTC)

Hi, I was excited to read the first comment in my discussion page, hope to have archives of my own one day :-) I think the intro is excellent, yet I'm still unsure about the transversality issue, this time in free space. As you know EM modes can be spaned in a plane wave basis, for plane waves the polarization is inherently transverse as evident from Gauss's law for magnetism, but for a more realistic EM field it is not necceserally true, such as raidally polarized beams.. I'm not even sure whether Gaussians modes must be purely transverese? Will be glad to hear your thoughts on the issue. Eranus (talk) 07:12, 15 May 2009 (UTC) Hello again, I've made some changes to the polarization page, probably improved the correctness but ruined the simplicity (which I agree with you is very important). I would appreciate to get feedback from you on the changes. I also included a link to transverse modes which is very related to the subject of polarization. I did npt change it but I don't like calling longitudinal fields as fields with no polarization. They have well defined polarization it is just 1 dimentional rather than two. Any thoughts? Eranus (talk) 07:45, 19 May 2009 (UTC)

Template:F/

I've unprotected this, thanks for the note. — xaosflux 18:55, 2 May 2009 (UTC)

intro to QM article has been radically altered

Hi,

A new editor has unilaterally many drastic changes to the article Introduction_to_quantum_mechanics to which you have made contributions. I do not think that the changes are desirable. I do not want to start an edit war. Could you please have a look at it? Thanks. P0M (talk)

A study on how to cover scientific uncertainties/controversies

Hi. I have emailed you to ask whether you would agree to participate in a short survey on how to cover scientific uncertainties/controversies in articles pertaining to global warming and climate change. If interested, please email me Encyclopaedia21 (talk) 19:05, 31 May 2009 (UTC)

Newton vs Goethe: Resolved?

Hey, I just wanted to say I liked your explanation on the discussion page of Goethe's Theory. And then I went to your user page and found out why. You work in lasers and optics. I have a degree in photonics, and worked at Edmund Scientific many, many years ago. I was recently accepted as an Alumni Council Member for OP-TEC, and was trying to refresh my memory with some background before I dive back into the textbooks and trade journals. Now that I think back, that's almost exactly how I felt when confronted with Newton vs Goethe back in college. Light is simply E-M radiation that our eyes are sensitive to. How our brain, and eyes, perceive those colors, is something totally different. Thanks Mikem3307 (talk) 03:37, 10 June 2009 (UTC)

Earth pronunciation

Regarding your edit to remove the pronunciation of the Earth in the lead, I just wanted to say that I completely agree with you on this point (and I have a similar concern about the relevance of etymology sections). To me the pronunciation entry disrupts the flow of the lead, and often causes layout congestion. Unfortunately the editors who insert and maintain those pronunciation entries are pretty determined to keep them in the articles. It's probably going to take some type of wikipedia policy change to get that reversed. Thanks.—RJH (talk) 16:05, 11 June 2009 (UTC)

User:Igfmnbo

Just wanted to thank you for cleaning up after that user (he crossed "my" area on liquid crystal). I myself have 10+ years of professional experience in optical spectroscopy and will be glad to collaborate. Regards. Materialscientist (talk) 01:40, 19 June 2009 (UTC)

Wavelength

Hi Srleffler: It seems to me that somehow my text has been taken to say that in general waveforms can propagate unchanged, while in fact that can happen only in linear media or in certain cases in non-linear media. That was not the purpose of the text.

The connection between dispersion and failure to propagate rigidly has been explained using a Fourier decomposition, but that approach has been taken to be contrary to this purpose.

It seems to me that some rewording should patch up all these disagreements. What do you think? Got some suggestions for rewording rather than deletion? Brews ohare (talk) 15:03, 19 June 2009 (UTC)

That is certainly part of the problem: while your text didn't explicitly say that waveforms propagating unchanged is a typical case, it was written in a way that would tend to mislead the reader into thinking that. This type of propagation happens only in dispersionless linear media, and for special wave shapes in certain nonlinear systems. I tweaked the wording a bit last night, to try and make the limitation of the model more explicit. More rewording is probably needed but I didn't want to change it too much until we see what kind of comments the RFC produces.

This isn't the only issue, though, and I'm not sure how best to address the other issues. There are probably possibilities for compromise that we haven't yet explored. I think the approach you are taking, with some rephrasing, would be fine for an introductory article on waves. This article, though, is specific to the concept of wavelength. This derivation is long, and only peripherally relevant to wavelength itself. The article definitely needs to explain that general waveforms can be decomposed into sinusoids and that when a general waveform has a well-defined wavelength it will be the wavelength of the lowest-order sine wave in the expansion. I'm not sure it is necessary to present a mathematical derivation of this. A simple referral to other articles on Fourier analysis is sufficient. I think the long derivation is more distracting than useful in this article.--Srleffler (talk) 18:00, 19 June 2009 (UTC)

Adding pronounce to TNO articles

Since there's a vast number of solar system object articles with the pronounciation right after the name in the first line of the article, and I see that you've started rolling out changes to move that to the new field in the infobox (which does seem a good idea), do you want to put a note up at Wikipedia_talk:WikiProject_Solar_System that you're doing this? It shouldn't be too controversial, but one never knows. Iridia (talk) 04:20, 25 June 2009 (UTC)

See Misplaced Pages talk:WikiProject Astronomical objects#Pronunciation.--Srleffler (talk) 04:53, 25 June 2009 (UTC)

Cheers; thanks for that. Iridia (talk) 05:18, 25 June 2009 (UTC)

trouble with Logger9

Hi. I saw that you tried unsuccessfully to clear glassy state. I have looked more in depth into the doings of User:Logger9, and concluded that massive counteraction is necessary. Could you please have a look at Misplaced Pages:Wikiquette_alerts#User:Logger9_dumping_off-topic_material_in_various_solid-state-physics_articles ? Regards -- Paula Pilcher (talk) 15:22, 27 June 2009 (UTC)

I did not in fact try to clear the article. I just proposed a merge. I'm not concerned with the content one way or another, but rather with the fact that there must not be two articles on a single subject. The proper solution to this problem is to merge the two articles. How much material gets kept or cut in the merge would be a decision for someone else to make. I'm not planning to wade through logger9's text.

I haven't carefully evaluated logger9's contributions, but I understand your concern. I think, though, that you need to try to stay calm and patient. I've seen this kind of dispute before. Sometimes it turns out that the troublesome editor really can be turned around and make good contributions. Some people just have lots of information that they are eager to share, but don't take naturally to the collaborative editing environment on Misplaced Pages, nor to the requirements and constraints of encyclopedic style. Hostile confrontation is not usually the best way to deal with such editors. Get help from other editors, so that the material you question can be evaluated by several people, who can achieve consensus on whether it is suitable for inclusion, or needs to be modified or deleted.

You seem to be getting frustrated with Misplaced Pages's procedures for handling problems like this. I think the trouble you are having there comes from not knowing what to do. Misplaced Pages can and does deal with content problems (and problem editors). The key is to start by building consensus. Explain what you see going on on the talk pages of the articles, and/or at Misplaced Pages talk:WikiProject Physics/Taskforces/Glass. Remain civil, and focus on the content, not the editor. If you are right, other editors will agree with you. Major changes such as deleting blocks of content can be done quickly when a group of editors agree.--Srleffler (talk) 05:02, 28 June 2009 (UTC)

Hi (response)

Hi , thanks a lot for your remark. I'm aware of what you say and I completely agree with you on that. I really wish terminological issue were given a satisfactory solution in Misplaced Pages; in fact, I think this solution is relatively easy, and the question about it, is more a problem of application, practice and convention, than a problem of investigating and finding the terminological solution itself. Even more: I'm sure most of us actually know what terminological principles would be desirable for something like Misplaced Pages. I guess most of us just wonder: "ok, but how can you set all this process in motion? I get a strong opposition even for introducing a small change within an article... ". In this sense, I must admit lately I've been a bit guilty about how I've edited categories. Bests. --Faustnh (talk) 23:45, 11 July 2009 (UTC)

Eponychium

In your March 9 edit of Eponychium, you deleted a large mass of text as a copyvio. Please, next time, in addition to noting why you did it on the discussion page, take a few seconds and at least put in a stub-like section to take the place of the material you removed. A reader coming to the page will have no idea that it has a use in veterinary medicine. In ten seconds, you could have changed the section to "In veterinary medicine, the eponychium is the deciduous hoof capsule." —Preceding unsigned comment added by CruiserBob (talk • contribs) 16:18, 17 July 2009 (UTC)

Thanks for your comment. I didn't understand that material well enough to summarize it properly, and I wasn't sure that it belonged in the article at all. Despite sharing the same name, it appeared to be a distinct thing being described. Misplaced Pages articles cover a single subject, divided conceptually rather than by name. Distinct things that happen to have the same name are covered in separate articles. In this case, the lead paragraph of the article is explicit that the topic is human anatomy. If the article is also going to cover related structures in animals, the lead needs to be adjusted to include this, and the material you added needs to be rephrased to focus on the thing, not the term.

I don't see a need to have made a note on the talk page. My edit summary covered the reason for deleting the material.--Srleffler (talk) 03:38, 18 July 2009 (UTC)

List of duo and trio cocktails

Nice work improving such an important article--thanks! Drmies (talk) 05:02, 6 August 2009 (UTC)

Links to wiki articles

The wiki links that I placed for "Stealth technology as a pliable electromagnetic envelope" are relevant. I mean the article discusses all this stuff - microwave, polarization, wave propogation, diffraction, etc., etc. So, what's up? It looks like you read the article, so I am thinking you can see my point. Ti-30X (talk) 05:57, 7 August 2009 (UTC)

Relevance is not a two-way relationship. For example, Stealth technology as a pliable electromagnetic envelope talks about prisms. That makes prisms relevant to the article on stealth technology, but does not automatically make stealth technology relevant to prisms. The stealth article should link to Prism (optics), but not the other way around. Stealth technology is, at present, not an important application of prisms.--Srleffler (talk) 15:18, 7 August 2009 (UTC)

Sorry, I didn't get back to you sooner over here. I was busy for a good part of the day. Anyway, I do see your point, on this, and it makes sense. And I thought that might be the reason behind it, but I wasn't sure. It is true that relevance is the control in this situation. OK thanks. (I should have asked you to respond over at my talk page, I would have seen your response sooner. Certainly not your fault.) Ti-30X (talk) 00:52, 8 August 2009 (UTC)

Negative index metamaterials

I have a few responses for you over at Talk:Negative index metamaterials. Hopefully these responses are seen as positive, mends fences, and allows work on the article to begin. Ti-30X (talk) 18:48, 8 August 2009 (UTC)

I would like to put this in the article talk page, but you might not be able to find it :). I am certainly not adverse to working on a stealth article. However, I don't know any topic that we could choose, that hasn't already been done, at Misplaced Pages. Well, there is one - an in depth article on the limitations of current stealth. But, that might create an adverse reaction from the stealth community. Other than that the other topics seem to have been done already. However, people being naturally creative - you might come with a topic that hasn't been done. Ok you see you back at the article talk page. Ti-30X (talk) 20:33, 8 August 2009 (UTC)

I apologize for the count of the word "cloak". That was very sloppy of me. I didn't count it myself, and thought it was true. I was on edge when I wrote that, but it is still very sloppy. This has definitely been a good learning experince.Ti-30X (talk) 12:58, 9 August 2009 (UTC)

Blockquotes

Hi Srleffler. thanks for your note. I have replied on my Talk page. Skinsmoke (talk) 19:19, 8 August 2009 (UTC)

DYK for Negative index metamaterials

On August 15, 2009, Did you know? was updated with a fact from the article Negative index metamaterials, which you created or substantially expanded. You are welcome to check how many hits your article got while on the front page _{(here's how)} and add it to DYKSTATS if it got over 5,000. If you know of another interesting fact from a recently created article, then please suggest it on the Did you know? talk page.

King of ♥ ♦ ♣ ♠ 14:14, 15 August 2009 (UTC)

Look of scientific notation template

Hi,

Back in 21 March 2008, as memorialized here on WT:MOS Archive 97, you, Tony, and SamBC had differing opinions on the best looking format for scientific notation. Some thought no spaces on each side of the times (×) symbol worked and/or looked best (see examples, below), and others thought a space worked and/or looked best. At that time, I suggested a compromise using thinspaces and all agreed that was a workable solution.

The template that eventually came out of all that originally used thinspaces but was later tweaked to use non-printing, non-selectable, Cascading Style Sheet-based visual gaps (using <span>‑based gaps. It appeared to me that the CSS gaps were exceedingly close to the full-width regular space and this might displease those who prefer no spaces at all. So I want to run the proposed tweak by you and see if you are at peace with what I think best achieves the spirit of that compromise.

Here is the proposal (bottom) with comparative examples:

6.0221412579×10 kg (no spaces)
6.0221412579 × 10 kg (full-width, non-breaking spaces)
6.0221412579 × 10 kg (Original compromise: thin spaces)
6.0221412579×10 kg (Proposed: The tweak of the CSS version of thinspaces)

If you are satisfied with the appearance of the proposed tweak, please advise here on WT:MOSNUM.

Greg L (talk) 22:31, 24 August 2009 (UTC)

Diamond Turning Photo

I think that the two licenses you pointed out are the best idea, I am just not sure how to edit the image to include that. Could you help me out with that? 17:11, 25 August 2009 (UTC) —Preceding unsigned comment added by David Casale (talk • contribs)

Sheela mugshot

With respect there has already been a lot of discussion regarding this mugshot, please take your case for inclusion to the talkpage, regards. Off2riorob (talk) 22:31, 15 September 2009 (UTC)

Feel free to ask me if you need the links. Off2riorob (talk) 22:34, 15 September 2009 (UTC)

Laser pumping additions

Hi Srleffler!

I've been working out some revisions and additions for the laser pumping article. I'm not finished yet, but if you'd like to review what I have so far you can see it at User:Zaereth/Laser pumping. Thanks.

Also, I did provide some new photos to the article, as promised. Zaereth (talk) 21:15, 24 September 2009 (UTC)

Spectralon

I've been reading up on Spectralon, as it seems to me that your article meets the criteria for notability. From my own original research, this material seems to be used extensively in laser construction. After looking at the manufacturer's specs, it turns out that my ruby laser has spetralon inserts in the cavity, which can be seen in the laser pumping article. I can pull these out and try to provide some decent photos for the article in your user space.

In my research I'm finding information that may be useful, and may be able to provide some inline sources and such. Would you mind if I do this? Zaereth (talk) 22:50, 28 September 2009 (UTC)

I wondered if the cavity in your photo was spectralon. It wasn't so much the appearance of the material as the design. A reflective cavity has an elliptical cross-section. Yours is much narrower.

I'm certain that spectralon meets the requirements for notability. I did a Google Scholar search, and found many scientific papers specifically about spectralon and its properties. My intent was to add some of those as references, which is sufficient to establish notability. Once that is done, I can get the article undeleted. (Important, so the original edit history is preserved.) I just haven't had time to work on it.

Feel free to edit the article in my userspace. --Srleffler (talk) 03:35, 29 September 2009 (UTC)

Spectralon has been restored. Watch the superlatives and promotional tone, and try to fix some of the redlinks in your userspace version. --Orange Mike | Talk 15:42, 29 September 2009 (UTC)

Wow, I wasn't expecting it to be restored so fast. I'll begin gathering up information and see what I can do to help. I know what it's like to be short on time, as I'm just coming out of my busy season. Thank you both for your help. Zaereth (talk) 16:28, 29 September 2009 (UTC)

Hi Srleffler, I had a chance to take apart my laser this weekend, and am sorry to report that the inserts are not spectralon, but rather ceramic, (as I'd originally suspected). I began to wonder after finding the energy threshold for spectralon, which is fairly low. This particular laser can take up to 600 joules per lamp. I guess Kentek must've gave me the wrong spec sheet, but I am sorry to say that I won't be able to provide a photo. I will, however, add more info and refs as I find them. Zaereth (talk) 18:22, 19 October 2009 (UTC)

Focal length refs

I tried to fix up and simplify inline refs in focal length, but it wasn't clear what to do with Hecht, which you added here. Can you find something in the article to cite it for, and put it back in this simpler easy-to-maintain style? Dicklyon (talk) 18:27, 29 September 2009 (UTC)

Irene Craigmile Bolam refs

External links

Hello Srleffler, many thanks for your attention re: the Irene Bolam article links. The first one was really obsolate and broken; so i found a new one (to the same material)and restored it. About the second link, it was not actually "broken"; possibly (I just guess), you could be confused by the text "Sorry, your time to enter the code has expired. Please try again" - that appears first if to click on the link. This text however doesn't mean that the link is broken; if you would go down to the bottom of the page, you would see that the actual download link is still there, and works normally (i just checked from my computer); so, i restored it too. Anyway, thank you again for your attention to these questions. Alex V Mandel (talk) 18:03, 12 October 2009 (UTC)

Thanks for your message. I removed the second link again. It does not comply with Misplaced Pages's policy on external links. The actual content (a tiny link) is buried under way too much advertising, and is not sufficiently accessible. The download link didn't work on my first two tries, and then made me wait half a minute, as an incentive to register on the site. This kind of behaviour is clearly not in compliance with Misplaced Pages's policy. I didn't actually download the document. There is absolutely no way I would download a Word doc from a site this flaky, and open it. It is too easy to get viruses that way.--Srleffler (talk) 02:09, 13 October 2009 (UTC)

Hi Srleffler,

Understood. What if i will send it to you in a WORD or PDF format, and you would download it and make it somehow accessible on Misplaced Pages in some other way? I'm just not sure about how to do it "technically". This report, i think, is worth to be made available from the Irene Bolam page on Misplaced Pages... as it presents, in my opinion, a most detailed and scrupulous way, the results of quite extensive historic research that debunks the theory that Bolam was Earhart... it is much more detailed then the TIGHAR report, and touches more aspects of the story. Kind regards - sincerely, Alex V Mandel (talk) 12:53, 13 October 2009 (UTC)

Did you write this essay? Unless it has been published somewhere, there is probably no way to host it on Wikimedia's servers. If you did write it, the right way to include the material is to use it to improve the article.--Srleffler (talk) 05:41, 14 October 2009 (UTC)

Hello Srleffler. This essay was written in co-authorship by several Earhart researhers, including me, as a "free informational release" for any interested party. It was first time publicly presented as a self-published booklet during the Amelia Earhart Festival 2005; since then, it was published already twice - as "Appendix" to two Earhart-related books, "Lost Flight of Amelia Earhart" by Carol L.Dow and "Legerdemain" by David K. Bowman. Does this answer the question about possibility to refer to it on Misplaced Pages? Kind regards - sincerely, Alex V Mandel (talk) 12:30, 14 October 2009 (UTC)

The best way to use the essay is still to incorporate any new information it contains directly into the Misplaced Pages article, as long as there are references that support it. If the essay were hosted online somewhere in an accessible form without excessive advertising, I would not object to an "external link" to it. I checked both of the books you mentioned on Google Books; neither has an online preview. If the authors have released the essay under a suitable license (or are willing to do so now), it might be suitable for submission to Wikisource as an "analytical work". Their inclusion requirement is:

Analytical works are publications that compile information from other sources and analyze this information. Any non-fiction work which is written about a topic after the main events have occurred generally fits in this category. These as well as any artistic works must have been published in a medium that includes peer review or editorial controls; this excludes self-publication.

Note that the Legerdemain book doesn't meet Wikisource's publication requirement, since it is self-published. I'm not sure whether the book by Dow is self-published, but the fact that it is a historical novel might be a problem. You would have to ask someone over at Wikisource about that. I'm not very familiar with their project.--Srleffler (talk) 16:54, 14 October 2009 (UTC)

Hi Srleffler, you wrote: "If the essay were hosted online somewhere in an accessible form without excessive advertising, I would not object to an "external link" to it" - that's exactly what i asked you about, - and asked for some advice, if possible, how to do this... The problem is that i just don't have my own website (as i'm not involved in any advertising/commercial activity and just don't need it); otherwise i would just host it there. It is now hosted on Filefactory, but you said that website was not good for linking to... can you propose some better solution maybe? You wrote: "If the authors have released the essay under a suitable license (or are willing to do so now), it might be suitable for submission to Wikisource as an "analytical work"." - the answer is positive. When we wrote and presented this work publicly for the first time, in 2005, we specially announced it as "free informational release - that is prepared purely for the interests of historical truth and accuracy, without any commercial goal, and can be copied, re-published and quoted, for free, completely or in parts - by any interested author, publisher or researcher". Such were conditions on which Dow and Bowman re-published it as an "Appendix" in their books; and these conditions, announced by us the authors, are still actual. You wrote: "the fact that it is a historical novel might be a problem" - "yes and no"... not fully. The "main body" of the book is really a novel; it is having, however, a big "Appendix" section - in which many real documents, actual researchers' reports and statements and references are provided. Kind regards - sincerely, Alex V Mandel (talk) 10:47, 15 October 2009 (UTC)

Try posting the text at Wikisource. It may get rejected, but it is worth a try. --Srleffler (talk) 16:53, 15 October 2009 (UTC)

Hello Srleffler, thanks for your kind advice: did this today, the link is: http://en.wikisource.org/AMELIA_EARHART’S_SURVIVAL_AND_REPATRIATION:_MYTH_OR_REALITY%3F Does it look OK? Sincerely - Alex V Mandel (talk) 14:13, 16 October 2009 (UTC)

References

As to the refs, it looks like your edits removed perfectly good written out citations with templates that had errors in them. When the referencing style is already in place, it is contingent on new editors to either follow the proscribed style or explain clearly why changes are to be made. FWiW Bzuk (talk) 05:12, 14 October 2009 (UTC).

Citation templates are neither mandated, nor recommended. They are available for use, but do not necessarily supersede any other form of citation style. FWiW Bzuk (talk) 05:19, 14 October 2009 (UTC).

Fair enough. Personally, though, I strongly prefer the templates for their preservation of data in machine-readable form, and the fact that they open up references to automatic updating by utilities such as the citation bot. Converting template-formatted references to straight wikicode is harmful and disruptive. I left it your way, but fixed some small errors that were reintroduced in your reversion.--Srleffler (talk) 05:41, 14 October 2009 (UTC)

See extensive discussion on citations in the layout forum. Many editors do not use the citation templates since they are still "buggy" and introduce the "garbage in, garbage out" syndrome. FWiW, the bots have yet to make any use of the templates which were introduced to facilitate referencing for the newcomer. The metadata canard along with the "harmful and disruptive" comment is a hoot. Bzuk (talk) 07:29, 14 October 2009 (UTC)

See Citation bot. This very useful bot reads references that use the templates, checks for and fixes common errors, queries external databases of journal articles and books, and adds missing bibliographic information and external links. --Srleffler (talk) 16:33, 14 October 2009 (UTC)

Read the appropriate page carefully, even this bot is now officially "paused" in order to sort out problems. BTW, some bots work perfectly well within the < ref > section and do not need the template format at all. FWiW Bzuk (talk) 18:06, 14 October 2009 (UTC).

Both of those points are irrelevant.--Srleffler (talk) 22:16, 14 October 2009 (UTC)

Bokeh

S, your edits followed on this diff, an uncommented change of meaning and removal of reference, repeated after I had asked him for a source. Did you mean to endorse that change? Dicklyon (talk) 17:17, 26 October 2009 (UTC)

No, I copyedited the text as I found it and did not review the recent edit history. If you undo the other editor's change, I would appreciate it if you would merge my changes in your edit. Alternatively, I can merge the edits tonight. (No more time for editing now.)--Srleffler (talk) 17:21, 26 October 2009 (UTC)

I can't work on it right now either... Dicklyon (talk) 17:26, 26 October 2009 (UTC)

Thanks for the good fixes to my attempt. Dicklyon (talk) 04:31, 27 October 2009 (UTC)

Plasma lamp

Done. — Malik Shabazz /_Stalk 07:08, 7 November 2009 (UTC)

Thanks.--Srleffler (talk) 07:09, 7 November 2009 (UTC)

Dioptre

I can't figure this introduction out.

I studied physics decades ago, and I went through the lens equations, but I've forgotten them, and I went to Misplaced Pages to try to get the basics again. I'm trying to figure out how the dioptres are related to the focal lengths. For example, how do you calculate how changing the diopter power of a lens changes the focal length in a pair of eyeglasses?

A Misplaced Pages entry is supposed to be written for the non-specialist, ordinary reader, and the introduction is especially supposed to be written for the ordinary reader. I thought I understood it, and I wrote the summary as I understood it, but you say it's not accurate.

Could you rewrite that introduction so that an ordinary, non-specialist reader can understand how dioptres are added together? --Nbauman (talk) 05:40, 12 November 2009 (UTC)

I tried. Take another look. The issue is that dioptres are not actually additive in general. In the special case where you have relatively thin lenses close together, adding the powers of the lenses is a good approximation to the actual optical power of the lens combination. If the lenses are not thin and close together, adding the powers will give you a completely wrong answer. The optical power of a telescope is not the sum of the powers of the elements within it, for example.

Regarding your broader uncertainty: the optical power and focal length are always reciprocals of one another by definition, whether you are talking about a single surface, a single lens, or a complicated multi-element optical system. Accurately calculating the optical power (or focal length) of a complicated system is not easy. The fact that in certain circumstances one can get close enough just by adding up powers is a significant benefit.

Let me know if you think the intro still needs work.--Srleffler (talk) 05:53, 12 November 2009 (UTC)

@ARTICLE{2003PhRvL..91w3901D, author = {{Dorn}, R. and {Quabis}, S. and {Leuchs}, G.}, title = "{Sharper Focus for a Radially Polarized Light Beam}", journal = {Physical Review Letters}, year = 2003, month = dec, volume = 91, number = 23, pages = {233901-+}, doi = {10.1103/PhysRevLett.91.233901}, adsurl = {http://adsabs.harvard.edu/abs/2003PhRvL..91w3901D}, adsnote = {Provided by the SAO/NASA Astrophysics Data System} }