User talk:Stevenj/Archive 3

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hi steve from Innab.

About Health Care reform Kenosis change: It is really hard to explain average people without MIT PHD what is health care reform. Most peoples want all in one place, so they do not have to jump all over. I agree that this a little duplication, but it adds value to the article and boost its rating on the search engines. This was a great frustration for me when you removed the text, when I was trying to explain 63 years old woman what it health care reform is. She really not so smart to follow so many links. This is encyclopedia for average peoples, so we need make it undestandable to them. With respect. -- Inna —Preceding unsigned comment added by Innab (talkcontribs) 18:53, 27 March 2010 (UTC)

Standard Wikipedia practice is to not have massively redundant articles, and to merge/split when this occurs. Furthermore, your argument makes no sense; why is it hard for people to click a link for more information? — Steven G. Johnson (talk) 18:56, 27 March 2010 (UTC)

Because this is encyclopedia for average peoples. To have a good rating on serach engines we need average peoples to like it, and make links to it. The more links we get to the article the better it rating on google etc. Also if you have talk to a grandmom that 63 years old you would understand me. This is better to have it all in one place, because it all very relevant to healthcare in America and this is what peoples want to know. If we make whole article a links to other places, then it is no point having it at all. —Preceding unsigned comment added by Innab (talkcontribs) 19:01, 27 March 2010 (UTC)

Such search-engine optimization is counter to WP policy, and makes no sense anyway. I'm not arguing that we shouldn't have a good article summarizing the bill, I'm arguing that we should have one article summarizing the 2010 reforms, and people can link to that. Anyway, discussions about a particular article belong on the talk page for that article, not on my talk page. You clearly don't understand WP practice, so please try to learn a bit more before disruptively creating two redundant articles. — Steven G. Johnson (talk) 19:08, 27 March 2010 (UTC)

Votes are 2:1 - me and Kenosis. Anyway, do what you want, but I still think the article will lose value... —Preceding unsigned comment added by Innab (talkcontribs) 19:13, 27 March 2010 (UTC)

Wikipedia has standard policies and practices; it's not simply a matter of "voting" among 3 editors (an absurdly small number to overturn established practice). Again, however, please discuss this at the article talk page, not here. — Steven G. Johnson (talk) 19:18, 27 March 2010 (UTC)

hi steve from Enrico

you reverted my modification to the aharonov-bohm effect. The current version "a charged particle is affected by electromagnetic fields in regions from which the particle is excluded." is true but says something somehow irrelevant. What is relevant is what is the value of the field where the particle is, and there E=B=0. I agree that B \neq 0 e.g. inside the solenoid, but this is not the astonishing part of the A-Bohm effect. The suprizing property is that along the path followed by the charged particle there E=B=0 and nevertheless the phase of the particle gets modified. —Preceding unsigned comment added by E.pajer (talkcontribs) 12:55, 24 May 2008 (UTC)

Read again what I wrote. The particle is affected by fields in regions where it isn't. That expresses precisely the interesting fact about the A-B effect.
The the point of the A-B effect is that the particle is affected by nonzero fields in regions from which it is excluded. You must have a nonzero field somewhere to have an effect, though, so you do have to talk about where the field is, not just where it isn't.. And the point is that the particle is excluded from these regions. It is more accurate to talk about regions from which the particle is excluded rather than the "path" of the particle, because this is a quantum phenomenon and the particle's wavefunction can be quite spread out.

—Steven G. Johnson (talk) 00:45, 26 May 2008 (UTC)

hi steve from øWaldo.

maybe we should just then delete everything of mine because it's just getting too much trouble around here. I put the things up and then they just get deleted. because it's me, thaty's why it happens. I finally figured out about here, I donated money but it does not matter they just keep deleting all my puctures and all the things that I write. I'm going to eat lunch. thjanks! øWaldo.

All you need to do is to attach an appropriate copyright tag, instead of making up your own license. It's really not that hard. —Steven G. Johnson 23:44, 19 May 2006 (UTC)

PUI

Can you help answer to my posting here? Evrik still doesn't get it *sigh* --Jiang 06:19, 23 May 2006 (UTC)

Peace Offering
Can we set aside our difference and work together? --evrik 19:36, 26 May 2006 (UTC).
Evrik, I have no problem working together, but we should do it within established WP policy. That means, when an image is listed on PUI, you don't unilaterally remove tags or remove its listing while it is still under dispute. Instead, you leave the tags on, and discuss it in a reasonable manner in WP:PUI (or in this case, in the sub-page). As long as you are willing to do this, I have no problems. —Steven G. Johnson 21:05, 26 May 2006 (UTC)

Your revert at Significand

Hey, I noticed you reverted my work at significand. Your edit note says something about the difference between "thinking of the significand as an integer or a fraction". But.. my edit was not meant to address that, and that was a very tiny part of my edit. Can you please explain why you did a fullscale revert of all my work? Fresheneesz 06:46, 26 May 2006 (UTC)

Your edit centered around this supposed distinction, introducing "two" definitions for the significand; I replied in Talk. If you are just learning about a topic for the first time, you should probably be cautious about making major changes in articles that have been around for a while. —Steven G. Johnson 17:42, 26 May 2006 (UTC)

Vandalism

Hello, I have a question. What can I do to stop vandalism on a certain page? There is always someone going in and contributing nothing and just vandalising the page. The page in question is http://en.wikipedia.org/wiki/Sigma_Lambda_Beta ... It has been through a lot and it's not just one IP doing the damage. I always try to counter vandalize and revert edits when I see them on any page and it just seems that this page is targeted a lot. Anything you can do to allow only registered users to edit the page? Nguerrero03 19:36, 30 May 2006 (UTC)

Post a request for help on Wikipedia:Requests for investigation. Realize, however, that many pages receive light vandalism a few times per day, and this is not usually considered serious enough to warrant page protection. Editors are expected to revert as needed. —Steven G. Johnson 00:16, 1 June 2006 (UTC)

Citation for atan formula

Hiya Steve! Er, weren't you the one that suggested that the number of formulas be cut back? P=) As for a citation, that is the typical formula used for geodetic/planetodetic formulation, such as used by Bowring, Sodano and (the current benchmark) Vincenty (Eq.s 14-16). ~Kaimbridge~ 17:37, 3 July 2006 (UTC)

By asking for a citation, I'm not claiming that the formula is wrong. After all, as you say, I advocated including that formula myself. I'm just saying that it needs a source to help readers find more information, etcetera, and also to provide WP:Verifiability for the statements on numerical accuracy. —Steven G. Johnson 17:41, 3 July 2006 (UTC)
Well, all one has to do is try some examples and see that it is verifiable! P=) Serious, though, the concept itself, central angle, here , is well established——this article (Great circle distance) just uses it. Other than a quick heads-up about the possible "small angle error", any in-depth analysis should probably go to the central angle article.
Verifing the numerical accuracy under rounding requires proper numerical analysis to do seriously, and is not just a matter of trying a few examples. Yes, you can write a program to do experiments like I did, but that is verging on original research. It would be better to cite a published source discussing the roundoff error of the different formulae. (Since it is well established, it shouldn't be hard to find a published reference, right?) And I wasn't suggesting that such analysis go into the article...I was just suggesting a citation. I don't understand why you are digging in your heels. —Steven G. Johnson 22:52, 3 July 2006 (UTC)
I'm not (see below).
(Unfortunately, the Vincenty paper is not very useful as a reference here because, first, it is mainly focused on the more general elliptical case; second, it doesn't include any derivations, although it has references thereto; and third, it doesn't seem to discuss purely numerical error.) —Steven G. Johnson 17:45, 3 July 2006 (UTC)
Right, but this paper is well established in geodetic circles (meaning peers) and, while written for the more complicated ellipsoidal case, all one has to do is let a = b and you have the globoidal ("spherical") valuation. ~Kaimbridge~ 18:41, 3 July 2006 (UTC) (BTW, is your linkstale or is just the server down?)
(Nevermind, it's working now! P=)
Obviously the sphere is a special case of the ellipsoid, but the discussions of the latter are rather overly complicated if all you want is the former. And the Vincenty paper still does not discuss rounding error and so it is not a good source for why this particular great-circle formula is better than others. And it doesn't include a derivation. So while it is a reference vouching for the validity of formula in exact arithmetic, it seems far from ideal as a source to point readers to in this context.
Again, I'm not challenging the correctness of the formula, or its numerical accuracy—I've checked its accuracy myself, as you well know. But it's Wikipedia policy, not to mention good scholarly practice, to cite sources for information (especially for formulae like this, and statements that one formula is more accurate than another under rounding, that are neither obvious nor trivial to derive). Why do you have a problem with this? —Steven G. Johnson 22:44, 3 July 2006 (UTC)
Alright, maybe I'm just (mis)reading the request for "citation" as flashing lights and sirens questioning its validity (thus my stressing Vincenty's paper). Isn't there a better template, emphasizing that a citation, featuring background analysis, would help improve the article? Again, I've got no objection to adding more sources, I just interpreted the citation request as, yes, a challenge to the validity of the equation itself (and, since the tangent's denominator equals the well known cosine for sides equation, that would mean the numerator must equal a corresponding sine equivalent).
The best thing is just to find a good source in the literature discussing the rounding error. Why should that be hard? It was easy to find such sources for the haversine formula. —Steven G. Johnson 01:44, 4 July 2006 (UTC)
(I'm not sure why the central angle article is a better place for this stuff. It seems a bit redundant to me.)
Because the central angle is the equation that is the focus of the comparisons and resultant citation request, Great circle distance just uses it. Again, no big objection, it just seems, IMHO, it would be more appropriate to be in central angle~Kaimbridge~ 00:19, 4 July 2006 (UTC)

Venetian chastity belt

The disclaimer at Image:Chastity_belt_in_Hamburg.jpg applies. AnonMoos 11:05, 1 August 2006 (UTC)

FYI

Do you have anything to add here? (It was your warning that tipped me off to the extent of the problem in the first place.) --KSmrqT 09:12, 21 August 2006 (UTC)

Velociraptor-Buitreraptor

Well done on the image - I was just about to upload it to Velociraptor as well, when you had beaten me to it, by a few seconds. - Ballista 05:04, 26 August 2006 (UTC)

Hi & bad luck - this also fooled me but I'm no expert on skeleton identification. Problem is, museum labels can be out of date and fail to keep up with renaming. There is only one sp. of Veloci- now, so your image should probably now carry a new name but I don't know what - I was similarly caught by Velociraptor/Bambiraptor, in the Oxford University Museum of Natural History. I'll ask Dragon Helm (who did the reversion & presumably knows the correct name). We can then alter the Buitreraptor image caption, likewise & upload to the correct article. - Ballista 04:29, 8 September 2006 (UTC)
I note your great image has been dubbed Deinonychus now, instead of Velociraptor. This was going to be the most likely final decision, and the pictures to which Dragon Helm has linked, on his talk page, make compelling evidence. You may want to awit response from the museum or just upload to Deinonychus, now, anyway. That article would benefit greatly. Whatever, the image file should also be altered, once you have sufficient info to satisfy you as to correct name. - Ballista 04:29, 8 September 2006 (UTC)

NOR

Would you be willing to comment, here: [1]Slrubenstein | Talk 15:45, 27 August 2006 (UTC)

Hello. This article is (still) a mess, and I'll be looking at it further in coming days. I've tagged it for cleanup. Thanks for pointing this out. Michael Hardy 01:09, 28 August 2006 (UTC)

PS: Another issue:

"Institute Professor" nominated for deletion

The article titled Institute Professor has been nominated for deletion by user:Kane5187, who says not all of the 10-or-12-or-so Institute Professors are notable. This while many MIT professors who are not Institute Professors have Wikipedia articles and are universally considered notable (and so do most of the Institute Professors). Please opine at Wikipedia:Articles for deletion/Institute Professor. Michael Hardy 01:09, 28 August 2006 (UTC)

US government portraits

Greetings. Back in May, you commented at Wikipedia:Possibly unfree images/US government portraits. The issue has lain dormant for over two months, and is still unresolved. I have attempted to summarize the findings of fact, in the hopes of resolving this debate. Your comments here would be welcome. All the best, – Quadell (talk) (bounties) 17:04, 29 August 2006 (UTC)

up-to-date information

After this edit, I wondered if my information was up to date. Probably you would know. Michael Hardy 22:55, 29 August 2006 (UTC)

Looks okay to me. See here for the current freshman grading policy. —Steven G. Johnson 00:34, 30 August 2006 (UTC)

NOR

You know, you and I do not always agree but I think we handle our disagreements in a civil way and what is more important it is always evident to me that you are tying to be constructive. Thanks to your participation I thought we were making progress in revising one paragraph of the policy into one that more people liked more.

The John Awbrey added this: http://en.wikipedia.org/wiki/Wikipedia_talk:No_original_research#Son_Of_Suggestion Do you see in this the constructive spirit of engagement that I see in your comments? I don´t. On the contrary it seems only to disrupt or undermine the progress we were making, thanks to you and WAS and GBacchus.

Am I off base? Am I out of line? Or is Awbery? Perhaps you can comment on his suggestion. Thanks Slrubenstein | Talk 03:12, 2 September 2006 (UTC)

Radiation Pattern

Hi Steve. Re. Your gave a more general definition...antennas, fiber ends, LEDs, etcetera are all just instances of the same thing (radiation pattern), I couldn't agree more. I would have rewritten this bit myself, but was too timid to obliterate the only pre-existing section before I'd contributed something myself.

Re. Proof - note that this proof is only an approximation for one special case of reciprocity - right again; it should have occurred to me that a reader could stumble into this section when looking for a proof of the reciprocity theorem. But... I reckon the reciprocity result for antennas (i.e. receiving pattern = radiation pattern), is a consequence of the reciprocity theorem rather than a special instance of it. The argument is; for two antennas (far apart or close together), the circuit version of the reciprocity theorem applies exactly. Then if the antennas are far enough apart to be considered independent, then this implies something about a single antenna. Also, although this involves an approximation for finite separation, the radiation pattern is the far field limit (lim r → inf.), so the result isn't really an approximation (I could have made this clearer). --catslash 18:55, 2 September 2006 (UTC)

Yes, it's a consequence. But even the analysis of the consequence, in that section, is limited to the case of far separation in a homogeneous medium. Note that it is perfectly possible to use an antenna in the near field as well and the same theorem applies.
I didn't look closely at the proof in radiation pattern. If the proof there is really taking the reciprocity theorem as a given and just looking at the consequence, I don't understand why it has to be so long. It seems like derivation, starting from Lorentz reciprocity, should only take a couple of lines. —Steven G. Johnson 01:36, 3 September 2006 (UTC)
See my comments in Talk:Radiation pattern. —Steven G. Johnson 01:57, 3 September 2006 (UTC)

Re: Incorrect normalization in Image:Synthesis square.gif

Thanks for pointing that out. It is now fixed :) ☢ Ҡiff 19:46, 3 September 2006 (UTC)

NOR again

I am trying to get things moving - step by step - on the primary/secondary sources issue. Since you had been an active participant in this discussion I think you should check in again, here, [2]. I have broken my own proposed edits into four steps. We pretty much achieved consensus on step one and made an edit, the discussion now is centered on step two. Slrubenstein | Talk 22:19, 11 September 2006 (UTC)

Rodriguez formula

I don't know whether Orthogonal polynomials is on your watchlist -- it probably is. See my recent note on the talk page about Rodriguez formula. While writing it, it occurred to me that you might be able to shed some light on this. Can you? Thanks. William Ackerman 15:52, 12 September 2006 (UTC)

NOR

I don't want the talk page to get too convoluted so I am taking this point here. Do you really believe the probvlem with primary sources has nothing to do with NPOV? I am not saying this is the only problem, but I think it is definitely one problem and one reason for the whole NOR policy, because original research is a way for an editor to get his or her own POV into an article. We should not be surprised that one policy is connected to another. i am not subordinating NOR to NPOV and I repeat I do not think NPOV is the ONLY problem with NOR, but do you really see no connection to NPOV? As to your second point, you are right that anything concerning one kind of source is implictly about the other kinds. i was wrong to suggest otherwise. That said, I think it makes sense to make a claim about the use of primary sources before making any claims about secondary sources (just cause it seems natural to me, primary before secondary). This said, do you think you could craft a middle ground between my points and your initial suggestion? I am not demanding you support what I proposed and if others support your version I will go along, I just wonder (1) if my comments here make sense to you and (2) if you might consider revising your initial proposal in response to my comments. Slrubenstein | Talk 20:12, 12 September 2006 (UTC)

I think the primary problem with primary sources has to do with the fact that they are easily misinterpreted by well-meaning non-specialists, are not accessible to most readers, and are prone to OR. These facts, to me, seem clear and fairly non-controversial and are easily explained.—Steven G. Johnson 20:26, 12 September 2006 (UTC)

I don't really disagree with your claim, but I do think it is a bad foundation for the policy. The consequence of this fact logically could be that expert editors be allowed to use primary sources and non-expert editors can't. Your phrasing invites this interpretation. But really, NOR should not distinguish between expert and non-expert editors and there should be one policy for everyone. The justification for restricting the use of primary sources must apply to expert editors who are capable of interpreting them properly, and not just to non-expert editors. The only justification I can think of (aside from being circular, i.e. saying usiing primary sources violates NOR because it constitutes OR, a tautology) is that even if a specialist is capable of interpreting primary sources properly in so doing s/he would be introducing his or her own interpretation (i.e. POV) into the article, thus violation NPOV. Slrubenstein | Talk 21:06, 12 September 2006 (UTC)

Whether primary source material is more prone to bias ("POV") is much less clear and more controversial---many editors would argue that primary sources are the raw data, whereas secondary sources present interpretations and usually have some specific point of view. It's certainly very easy to find slanted secondary sources. Making such an objection to primary sources on the policy page, therefore, is asking for endless flamewars. It is much better to let editors deal with NPOV issues on a case-by-case basis, I think. —Steven G. Johnson 20:26, 12 September 2006 (UTC)

But this is my point precisely. Because secondary sources DEFINITELY have some POV, we can add them to articles without violating NPOV because when we add the source, we do so in a way that clearly identifies the POV. NPOV does not mean articles must explude POVS, it means (1) editors POV can't go in and (2) POVS that are included (drawn from secondary sources, almost invariably) must be clearly identified. NPOV never prohibits "slanted" secondary sources, it only insists that the slant be properly identified. Slrubenstein | Talk 21:06, 12 September 2006 (UTC)

Regarding whether it should be expressed as a "preference" for secondary sources or a "discouragement" of primary sources, I don't have strong feelings. However, I would suggest that framing things in positive terms is almost always more productive and less prone to offend. —Steven G. Johnson 20:26, 12 September 2006 (UTC)

Okay, I do not object, I just think primary should go begfore secondary Slrubenstein | Talk 21:06, 12 September 2006 (UTC)

Steve, I put in Wjhonson's short form. However, I agree with you that it would be an imporvement to provide the justification. But the more I think about it, the more strongly I believe it has to do with NPOV: when an editor uses primary sources to forward a new synthesis, analysis, interpretation, or explanation he or she is necessarily introducing his or her own POV which is forbidden. When an editor uses secondary sources the editor is not inserting his or her own views (necessarily) and can identify the view of the secondary source and s/he or others can look for secondary sources that reflect other points of view, all complying with NPOV. Please consider this. If you really reject my argument, well, I tried ... but if this makes any sense to you perhaps we can work together to come up with a good rationale to add to the policy. Slrubenstein | Talk 22:05, 14 September 2006 (UTC)

th:DCT

Regarding your comment of DCT on th wiki ThaiDCT

- I made corrections according to your comment of the images.

- It's a bit misleading using odd/even length transformation. It was not to mean the length of the data itself, but the length of the data + virtual extension. I added an explanation about the length in the content.

Thanks for the commments. Please let me know if there is any other correction or suggestion. BTW: Do you read Thai? :) ไร้สติ

Thanks for your quick response! The figures look great now. I would suggest uploading them (correctly named) to the Wikimedia commons so that the other Wikipedias can use them. Ideally, upload them in SVG format instead of as PNG, since they are vector graphics. (I must confess that I don't read Thai; in this case the math and the figures were clear enough that I didn't have to.) —Steven G. Johnson 15:10, 15 September 2006 (UTC)

Hi there. You commented extensively on this page here during its review period. It's at decision time regarding whether its FA status should be removed. If you'd like to post a comment on its present condition, please do so soon. Cheers, Marskell 18:57, 17 September 2006 (UTC)

Asymptotic notations

I find your recent redirections at asymptotic notation and Landau notation to be over-confident. For one thing, I have been trying to check whether the Big O notation article contains everything in the redirected pages. It seems not to define f ~ g, which therefore means your statement on the content is wrong.

For another, the choice of page title is not the best. 'Big O' is just one of several notations used. It would be more in accordance with the way pages are named to make 'asymptotic analysis', the more general term, the title of a combined page. You in any case seem to have missed the point that asymptotic analysis is a subject with a few branches, which was clearly set out on the page you redirected.

Charles Matthews 10:09, 26 September 2006 (UTC)

You're right, I missed the f ~ g; I've added it back. I'm not sure why you think I've "missed the point that asymptotic analysis is a subject with a few branches". The merged page clearly describes the application to several areas besides computational complexity. I'm glad you pointed out that I missed two sentences, but this is an exception that proves the rule—there was almost total overlap between the articles prior to merge.
Regarding whether the main page title should be "Big O notation" or "Asymptotic notation", this can be debated now that it is merged. I agree that "Asymptotic notation" seems a more general title. On the other hand, in practice "Big O notation" seems to be used to refer to all five asymptotic notations in addition to O(...), and seems a more popular term. The Big O notation page certainly received far more attention on Wikipedia than either asymptotic notation or Landau notation, which is why I merged in the direction I did.
But, if people want to rename to asymptotic notation, I won't oppose. The main point is that we shouldn't have three pages on Wikipedia that are almost entirely redundant, which was the situation previously.
—Steven G. Johnson 15:27, 26 September 2006 (UTC)
If you want to rename, please comment on Talk:Big O notation. —Steven G. Johnson 15:52, 26 September 2006 (UTC)

GNU/Linux

I saw that you reverted the GNU/Linux disambiguation page back to the redirect to Linux.

  • Why do you think that the correct place to discuss an edit of a redirect is the target page rather than the edited page? I think it would be best to discuss it at GNU/Linux. Please tell me what you think.
Because most people editing this topic (or any topic) watch the target page; hardly anyone watches the redirect pages. Discussing at the redirect page means that you are omitting most of the interested editors. —Steven G. Johnson 18:44, 2 November 2006 (UTC)
I will put a note on talk:Linux directing anyone with an interest in the GNU/Linux page to talk:GNU/Linux. That way, (a) anyone who wants to track this particular issue can put it on the watchlist, and (b) all discussion actually relating to the page being edited can be found on its own talk page. I hope that resolves your concern. -- Alan McBeth 19:19, 2 November 2006 (UTC)
  • Procedurally, I think it would be best to adopt the 22:26, 26 December 2005 version of GNU/Linux during discussion, since it was the last version with broad support (see Talk:Gnu/linux). If you agree, please revert it or let me know and I will.

-- Alan McBeth 05:24, 2 November 2006 (UTC)

You only think it has broad support because you're looking at a small self-selected group of editors who are watching a Talk page on a redirect. —Steven G. Johnson 18:44, 2 November 2006 (UTC)
This is the way Wikipedia always works--all editors of a given page are self-selected. I meant "broad support" only in the context of those editors who discussed the issue on the page in question. Any theory that they weren't representative of a hypothetical larger group may be best tested by a larger group discussion. Until then, I think their consensus should carry more weight than subsequent unilateral actions. Which do you think should carry more weight? -- Alan McBeth 19:19, 2 November 2006 (UTC)
The consensus that should carry more weight is the one on Talk:Linux, which is watched by all editors who are interested in editing the article on Linux-based operating systems. A Talk page on a redirect is a backwater. —Steven G. Johnson 23:16, 2 November 2006 (UTC)
Could you point out which consensus you're referring to? Thanks. -- Alan McBeth 23:46, 2 November 2006 (UTC)

Hi Steve from Andy Pratt The quickness of your pounce reminds me of my cat. If you are interested my memoir is now available at www.xlibris.com - go to bookstore and search for Andy Pratt. No problem Andy Pratt

Photonic Crystals

Your reversion was not a minor edit. So I reverted it. Dtneilson 06:49, 18 November 2006 (UTC)

Adding "Britney Spear's guide to photonic crystals" as a reference for the photonic crystal page is not a useful contribution as a reputable source to direct readers to. I removed it again. —Steven G. Johnson 16:31, 18 November 2006 (UTC)
Have you looked at the site? You say it's not reputable but if you look at the about [3] you will that the creator who is a doctoral student at a reputable university intends it to be an educational site. I hope you don't disregard it just because it has Britney's name in it and that it's not your style. Dtneilson 06:43, 19 November 2006 (UTC)
Oh, I'm familiar with the site, ever since it was just "Britney Spears guide to semiconductor physics", and I know that it attempts to convey serious information despite the goofy name. However, the creator obviously has no special expertise in photonic crystals; that section of the site reads like a review by a well-meaning doctoral student who has read a few papers on the subject but hasn't completely comprehended it. —Steven G. Johnson 20:14, 19 November 2006 (UTC)

GNU/Linux IPA Pronunciation

Heya. I can change it if you like but the article shows it both ways, in the top line of that section it shows it pronounced as (I'm Australian if you can imagine this without IPA as you've said you can't view it) "noo linucks" and the last line says stallman pronounces it "gah-noo" making it "gah-noo slash linucks" or "gah-noo linucks". Would you like me to change the top line or change "Given that Stallman pronounces GNU as gəˈnu" to "Given that Stallman uses the standard American English pronunciation of GNU (IPA for gah-noo)"? •Elomis• 06:31, 7 December 2006 (UTC)

Since the GNU project, since 1985 [4], has explicitly defined its name as being pronounced with a hard "g" ("guh-noo"), I think we should give priority to this pronunciation. And in any case, the particular article we're discussing is talking specifically about Stallman's suggested pronunciation. This has nothing to do with how the animal's name is pronounced in American English (Americans use "noo" or "nyoo" for the animal, although there is a famous Muppet skit pronouncing it with a hard "g" as a joke). GNU is a specific organization, and has some authority to define its own name. —Steven G. Johnson 06:55, 7 December 2006 (UTC)
Ok, I've updated the IPA. Nice catch. •Elomis• 21:04, 7 December 2006 (UTC)

Images

I apologize for the inadequate source tags on some of my images. I will try to bring these images within Wikipedia guidelines. My user name is a bit of a misnomer in regards to Wikipedia; I devote countless hours to writing well-referenced articles, fighting vandalism and generally trying to be part of the solution rather than part of the problem. Its only in regards to these photos that I’ve been sloppy. I have updated the tag for “Image:Eldridge.jpg”. Have I met minimum standards? HouseOfScandal 05:04, 14 December 2006 (UTC)

Thanks. You should, however, give the exact URL of the page where you found the image, not just the page for the whole web site. It's possible to find the image link via Google, but as a general principle you shouldn't make other editors search to find the original image. I've edited the page to reflect this.
However, now that we have a proper source, I'm going to list the image on WP:PUI, since the claim of "fair use" seems rather dubious. This is an image that a Boston-area Wikipedian could easily take themselves. (Note that one of the items in the fair-use rationale you quoted is, "Where no free equivalent is available or could be created that would adequately give the same information.") And furthermore, the argument about economic interest seems weak; by copying the information from the historical-society web site, we lessen the motivation of anyone to go to that web site, which lessens their publicity and possibly their ability to sustain themselves as a non-profit organization.
Unfortunately, "fair use" does not mean "we can use any image at all if we really really want to." It's an extremely narrow exemption to copyright law (and, I'm afraid, getting narrower all the time). —Steven G. Johnson 16:04, 14 December 2006 (UTC)

I understand. Qué será, será. Thanks for your time. HouseOfScandal 16:56, 14 December 2006 (UTC)

Images

Wow, cool images. Love the trig stuff. Great contributions! Tparameter 22:23, 22 January 2007 (UTC)

Stubs

Recently, I noticed the addition of the page The Price is Right Sets. The page is definetly a stub and it does not make any sort of point. I'm not sure how to make it a stub or where I have to talk about making it a stub. Secondly, the page may even be worth deleting because it really is of no value to Wikipedia. If you could please clear up my confusion. Thank you much.Scottydude 00:32, 26 December 2006 (UTC)

Thanks for pointing out that article. In this case, any useful information in the article (not much, it seems), should be merged into The Price is Right, so I added a {{mergeto|The Price is Right}} tag. The images were also problematic (no source was given), so they have been tagged for possible deletion. (If they are deleted then most likely the page should be deleted as well.) —Steven G. Johnson 01:08, 26 December 2006 (UTC)
Thank you, I wasn't sure.Scottydude 04:15, 30 December 2006 (UTC)

Identification of Image:Pseudoras-niger.jpg

Hi Steven. I noticed the fish in this picture is not Pseudoras niger of the Doradidae family, but is actually the redtail catfish of the Pimelodidae family. I'm removing the picture from the Doradidae article if you don't mind. --Melanochromis 08:45, 12 January 2007 (UTC)

Thanks for the correction; I wrote down the label from the tank at the New England Aquarium where I took the picture, but either the label was out of date or perhaps I got confused (there are several fish in each tank, and it's not always clear which label goes with which fish). —Steven G. Johnson 01:36, 8 July 2007 (UTC)

A long time ago, you worked on the Exponentiation article to resolve problems introduced by User:Bo Jacoby. I have recently made significant changes to the article. If you have the time to look over the article again, I would be glad to hear any comments you have. CMummert · talk 04:12, 16 January 2007 (UTC)

Direction dipole

Please see discussion dipole where I answered your question of a month ago. --P.wormer 12:13, 28 January 2007 (UTC)

New topic

Hello. I have posted a new article Fast Cosine Transform. I want to have your opinion.

My intention was to define practical description of one choosen Fast Cosine Transform algorithm. For people interesting in wider picture I have links to other Wiki pages.

The problem I am trying to solve: It is not easy at all to implement FCT given only articles in this Wikipedia. And yes, I have seen Cooley-Tukey FFT algorithm and Fast Fourier Transform articles.
Arkadi

Is the competitiveness of a university necessarily relavent to future success?

I am presently a student at a California community college pursuing a major in computer science. I have been planning to attend a campus within the California State University system, but I have heard recently that my prospects would be much better if I attended UCSD. I wouldn't mind going to UCSD at all (in fact, it seems really interesting), but it would be much more expensive. My grade point averages for high school and college are 3.9 and 4.0 respectively (on a 4.0 scale, though I haven't taken many college courses yet), so I might have a chance to be admitted. My friends, family, professors, and counselors have all presented different viewpoints on this subject. As an assistant professor at MIT, I would like to know what you believe would be best for me to do as well. — H.7004.Vx (talk) 02:50, 17 April 2007 (UTC)

Contributions on May 11, 2007

I wanted to stop by and say that I have seen a lot of crap today during my new pages patrolling, but your new article on matrices made my day because it was high qaulity. Good job, and keep up the good work! --Nenyedi TalkDeeds@ 17:29, 11 May 2007 (UTC)

Thanks! I assume you're referring to in-place matrix transposition, which is still somewhat stubby but at least has the relevant references. —Steven G. Johnson 17:35, 11 May 2007 (UTC)

Hello, this is a message from an automated bot. A tag has been placed on Seth Finklestein, by Mordicai (talk · contribs), another Wikipedia user, requesting that it be speedily deleted from Wikipedia. The tag claims that it should be speedily deleted because Seth Finklestein fits the criteria for speedy deletion for the following reason:

redirect to deleted article


To contest the tagging and request that administrators wait before possibly deleting Seth Finklestein, please affix the template {{hangon}} to the page, and put a note on its talk page. If the article has already been deleted, see the advice and instructions at WP:WMD. Please note, this bot is only informing you of the nomination for speedy deletion, it did not nominate Seth Finklestein itself. Feel free to leave a message on the bot operator's talk page if you have any questions about this or any problems with this bot. --Android Mouse Bot 2 21:18, 14 June 2007 (UTC)

Newland transform

Hello. The users who created the page titled Newland transform did not say what the Newland transform is, even after being asked. Perhaps you know something about this? Michael Hardy 19:34, 28 June 2007 (UTC)

I don't know a lot about it, but I do have access to the seminal paper and wrote up a short summary. From a literature search, it seems to be called the "harmonic wavelet transform" rather than the "Newland transform" (although it was introduced by Newland). —Steven G. Johnson 20:54, 28 June 2007 (UTC)

um...

Relations among the continuous Fourier transform, the Fourier series, the discrete-time Fourier transform and the discrete Fourier transform could doubtless benefit from your advice. Michael Hardy 22:39, 10 July 2007 (UTC)

I saw your comments from long ago (Aug. 2005, if you happen to recall) about the Black Hawk War, thought I would just let you know that I have been working on the article and its related articles of late, they are rapidly improving. : ) IvoShandor 14:39, 1 August 2007 (UTC)

The Barnstar of Diligence
Bestowed upon Stevenj for extraordinary scrutiny in ensuring that information crucial to the understanding of the 1832 Black Hawk War did not slip through the proverbial crack. Thank you for digging up, composing and referencing the information which has since been added to the "Background" section of the article. Happy editing. IvoShandor 18:21, 1 August 2007 (UTC)
Thanks for the note. I posted a comment on Talk:Black Hawk War. —Steven G. Johnson 18:35, 1 August 2007 (UTC)
Indeed, thus, the barnstar. You don't happen to know where the section "Final confrontation," which is currently in residence on the talk page could be sourced to do you? It would go great in Battle of Bad Axe. IvoShandor 18:38, 1 August 2007 (UTC)
Not offhand; I never edited that section.
Your edits are most helpful. If you don't mind dropping by the article and taking a look every once in awhile as it develops that would be great. Sometimes when you are or become the main contributor it is easy to gloss over simple errors that others catch right away. Anyway, your input is a valued contribution to its developments. As a note I am awaiting the arrival of Kerry Trask's 2006 book on the Black Hawk War (ISBN 0805077588), which should arrive in my mailbox around August 8. : ) That should help clarify some of the facts and events. IvoShandor 15:35, 3 August 2007 (UTC)

Thanks!

Hey, my name is Aaron-James, or AJ. Thanks so much for editing that MathML mistake I made. I should have known that, since I programmed LaTeX for the Japan Journal of Applied Physics way back in 1996.

You have very interesting reeearch, from the immediate glance I took on your User page. Do you study Emergence? You see, I am in neurobiology, and I see much emergence in our field, but I still lack the mathematical tools to describe them. Perhaps if you would ingratiate me with dialogue? Aschoeff 19:12, 17 August 2007 (UTC)

Black Hawk - again

Hey Steven. I have a problem, rather large in the world of Wikipedia. This is kind of a lengthy explanation, sorry.

I have a friend that works at a local newspaper, he was talking to the President of Northern Illinois University and somehow the Black Hawk War came upon, I guess he is quite the Black Hawk War buff. In this conversation he called the Wikipedia article on the war "blatantly wrong." This is really bothering me, as I strive for accuracy because I think the dissemination of knowledge is only useful if it is correct, with history (and math I am sure) especially. I have poured over hundreds upon hundreds of pages of text on the internet, in books, on microfiche etc, to make this article move toward shining. I don't know if this person read an older version weeks ago or came upon yesterday, I just don't and can't know that, but the fact that he pointed out an article that I have put so much energy into has really discouraged me. What I am wondering is, can you take a look at the article, maybe together we can flesh out any inaccuracy. It doesn't seem to me that the article is in any way "blatantly wrong." At least not based on everything I have read and studied thus far. If this article is truly inaccurate then I give up, my days on Wikipedia are over. The only reason I am posting this to you is because you seem interested in the topic, and I don't know any historians on the Wiki, which would be a great thing if I did and had a professional with knowledge on the topic help flesh it out, but we make do around here with what we have. I am no stranger to historical research and don't think I have made any missteps along the way, I am very careful to consult multiple sources before writing, sometimes they disagree but I almost always note this unless I think it's just too trivial or the source too biased to be useful. Basically disregard the stray point on the graph, you know? Anyway, if you're not interested and these messages have been an annoyance I do apologize but hopefully, if you have time, you can take my request into consideration. Thanks. IvoShandor 07:34, 23 August 2007 (UTC)

I am copying part of this message to the Black Hawk War talk page, so everyone can see the problem. IvoShandor 07:35, 23 August 2007 (UTC)

Continuity condition for characterization of exponential function

Hi,

I'm replying to the comment you left on my user page. In the only proof that I know of (which implies taking the limit of the function of a sequence), you need the continuity condition to state that

The proof that is first done on positive integers, then on all integers, then on rational numbers and then on real numbers. The step that requires the continuity is from rational to real numbers. If you managed to prove that for all rational numbers , then as is dense in , for any real number , there exists a sequence of rational numbers which converges to . You can then use the continuity argument:

Deimos 28 11:40, 26 August 2007 (UTC)


Suppose you've proved that the exponential function is the only continuous function satisfying

f(x + y) = f(x)f(y).        (*)
and
f(1) = e.        (**)

What do you mean by saying continuity is "necessary"---i.e. necesary for what? Necessary for it to be an isomorphism from the reals with addition to the positive reals with multiplication? It's not necessary for that, if you allow the axiom of choice. You can use the seemingly weaker hypothesis of monotonicity. That might superficially appear to mean you don't need continuity, but since it's enough to narrow it down to just one function, and since that function can be shown to be continuous, in that sense continuity is necessary. Now you could ask: How do you show that the unique monotonic function satisfying the identities (*) and (**) is in fact continuous? That could be what is meant by "How do you show continuity is necessary?" But that can't be what you meant since you were assuming continuity. Since Lebesgue measurability and the identities (*) and (**) are also sufficient to narrow it down to just one function. Generally, Lebesgue measurability is a weaker condition than continuity, so you could say in that sense continuity is not necessary, but on the other hand, Lebesgue measurability and the two identities (*) and (**) are enough to entail continuity (since the unique function satisfying those conditions can be shown to be continuous), so in that sense, continuity is necessary. Michael Hardy 13:04, 26 August 2007 (UTC)

There is one particular context within which continuity is not sufficient but differentiability is: when the domain is the complex field, rather than the reals. I just added a counterexample to the talk page; maybe I'll add it to the article next. This is "OR" except that until now it never occurred to me that it might not be universally known, and besides, you can check it in a few seconds. Michael Hardy 13:30, 26 August 2007 (UTC)
Well the point is not to show that continuity is necessary if you already suppose the function is continuous. What I was trying to show is that implies if and only if is continuous. The problem is the meaning to give to without using exponentials. If you define it saying it is the limit of a rational sequence, then you will have trouble proving is continuous. I have not proven the above equivalence. I was just saying that the only proof I know that needs the continuity of at some point.
Another problem is differentiability: I do not know whether it is sufficient to suppose and continuous to prove that and thus define e as for .
-- Deimos 28 15:28, 26 August 2007 (UTC)

Assuming only monotonicity and the functional equation (*) above, you can conclude that f(x) = ax for some a > 0, and then that entails continuity. So it's not necessary to assume continuity in advance. But continuity is necessary in the sense that it necessarily follows from the assumptions; you cannot have a monotonic solution that satisfies the functional equation without continuity. Michael Hardy 23:28, 26 August 2007 (UTC)

...oh, and as for your power-series question: if you're working only with real numbers then continuity plus that functional equation together are enough to entail that that power series. If your'e working with complex numbers, then continuity is not enough, as shown by the example I added to the article about nine or ten hours ago. Michael Hardy 23:31, 26 August 2007 (UTC)

Amazing that in this discussion no one's linked to the actual article: characterizations of the exponential function. But now I have. Also, user:Stevenj seems blissfully unaware that this exchange has taken place on his talk page. Michael Hardy 20:04, 27 August 2007 (UTC)

NOR

If you are around, could you review and comment on the current discussion at Wikipedia talk:No original research? Thanks, Slrubenstein | Talk 10:58, 23 September 2007 (UTC)

An award for you

Chief Black Hawk Certificate of Alliance
I IvoShandor bestow upon thee, Stevenj, this certificate of alliance in the name of Sauk Chief Black Hawk. Thank you for your occasional helpful commentary on the Black Hawk War. This article and its daughters are well on their way, in part, thanks to you. Both I, and history, owe you a thanks. Thank you. IvoShandor 11:23, 27 September 2007 (UTC)

IvoShandor 11:23, 27 September 2007 (UTC)

Boston meetups

Are there actually Boston meetups every month or does this page just automatically schedule a new one whether people attend or not? It's hard to tell from our project pages. Either way, it would be great if the Wikipedia:Meetup/Boston page was updated. Thanks.--Pharos 23:33, 5 November 2007 (UTC)

dct image

Steven, I see that you're involved in the DCT page, and have uploaded this image: DCT-symmetries.svg. I think there's a discrepancy: the DCT article says the following about the Type II DCT:

This transform is exactly equivalent (up to an overall scale factor of 2) to a DFT of 4N real inputs of even symmetry where the even-indexed elements are zero.

In the image you uploaded (which, BTW, I like a lot), the DCT-III has this property, but the DCT-II does not.

-- Stephen Lavaka (talk) 00:20, 25 January 2008 (UTC)

Nope, the image and the text are correct. DCT-II has the property described. For DCT-III, the transform is equivalent to a DFT of length 4N, but there are no interleaved zeros. —Steven G. Johnson (talk) 20:16, 26 January 2008 (UTC)
I agree now -- I read the phrase "even symmetry where the even-indexed elements are zero" too quickly and it looked like it meant zero elements at the symmetry points, but it should mean interleaved zeros. Lavaka (talk) 15:40, 29 January 2008 (UTC)


Free space vs. Empty space in permittivity article

Both these terms were adequately introduced in the "Terminology" section in the earlier version on a par with each other. I see absolutely no basis for putting "free space" in the intro and putting "empty space" in a later section. They should be treated alike. The Sears and Zemansky reference, for example, has been a standard reference for decades and used "empty space". Jackson uses "free space". So I'd say: your different treatment of these two terms cannot be supported. Brews ohare (talk) 03:06, 13 February 2008 (UTC)

"permittivity of free space" is far more common than "permittivity of empty space". e.g. google turns up more than 60 times as many references for the former term. Google Scholar turns up more than 100 times as many references for the former phrase. The INSPEC and Factiva literature databases (which only index abstracts and titles for the most part) turn up no references at all for the latter phrase, and a number of references for the former. There's no comparison in frequency of usage. —Steven G. Johnson (talk) 04:41, 13 February 2008 (UTC)

Steven: How can you claim that the statement "By definition, the linear relative permittivity of vacuum, where ε = ε0, is equal to 1" is "original research?? You have made an issue out of exactly this point. Brews ohare (talk) 14:37, 19 February 2008 (UTC)

I was reverting because of the other edit you made: Contrariwise, departure of a measured εr from 1 is evidence that the measured medium is not "vacuum". This implies that it is possible to measure the relative permittivity of a putative vacuum, which is original research (since you cannot provide sources) as explained to you ad nauseam on Talk:Vacuum permittivity.

Some recent changes

Steve: I think you should take a look at these articles: vacuum permittivity footnote 17 and free space. I hope you won't find them inflammatory. I've taken User:Arthur_Rubin's remarks on Wikipedia_talk:Naming_conventions as a green light to change the lead-in phrasing on vacuum permittivity. I also added a few sentences to exhibit the nondimensionalized Maxwell's equations to demonstrate the unobservability of the speed of light in SI units. Also is used in ISO 31-11. Finally, I also discovered that ISO 31-5 has adopted the use of c0 for the speed of light in vacuum, and that NIST and BIPM documents use this convention.[1] So I have changed to this notation where I have found it.

The point I was missing, and I hope you will agree, is that free space plays the same role for the SI units as the absolute zero of temperature does for thermodynamics: it is a reference state that is in principle unattainable, but nonetheless serves as a baseline.

It is my hope that the present articles meets your standards as well as my own. If that turns out to be so, I'd say that this evolution was difficult, but has led to much better articles. Brews ohare (talk) 20:23, 22 February 2008 (UTC)

  1. ^ Current practice is to use c0 to denote the speed of light in vacuum according to ISO 31. In the original Recommendation of 1983, the symbol c was used for this purpose. See NIST Special Publication 330, Appendix 2, p. 45
After some second thoughts, I split up footnote 17 and put part of it into the text Brews ohare (talk) 20:29, 25 February 2008 (UTC)

Luke Ford photos

The photos on Commons that you tagged as copyvios are no such thing. The limitation of "photos present before 08 August 2001" applies only to images taken from lukeford.com. All images taken from lukeisback.com and lukeford.net are fair game irregardless of when they were taken. Tabercil (talk) 01:08, 27 February 2008 (UTC)

That's why I removed the copyvio tags a few minutes later, when I noticed my mistake. —Steven G. Johnson (talk) 04:23, 27 February 2008 (UTC)

Vacuum permittivity

Hi Steve: Has vacuum permittivity settled down? I apologize for becoming excited about this topic. It blind-sided me, and I had some learning to do. Brews ohare (talk) 16:03, 27 February 2008 (UTC)

I've been busy for the last week and haven't had a chance to look at it; I'll look into it this weekend, I hope. —Steven G. Johnson (talk) 00:29, 28 February 2008 (UTC)

Fractal Compression

Hi Steve, we are having a dispute on Fractal Compression, your input would be appreciated. Best, Spot (talk) 00:20, 1 March 2008 (UTC)

Free space

Hi Steve: Please take a look at free space. Brews ohare (talk) 17:37, 2 March 2008 (UTC)

Capitalization in book titles

By clicking on the isbn number of a cited reference one can elect to find the book using Worldcat. That accomplished, one can click on "cite this item". Then half a dozen or so standard citation formats are listed. Only the first letter in a title is captilized, not the the subsequent words. Doesn't WIkipedia intend to follow this practice? Brews ohare (talk) 16:24, 6 March 2008 (UTC) As a follow up on this, I found that this particular book is cited by Worldcat with capitalization. That surprised me because my earlier experience does not follow this convention at all: look at the reference to Serway, for example. Brews ohare (talk) 19:33, 6 March 2008 (UTC)

The Lorentz Force

Could you please have a look at the Lorentz force dispute and the Faraday's law dispute. 202.69.172.152 (talk) 00:39, 7 March 2008 (UTC)

Format Books

Steve: I looked at the link you suggested: Williams College Libraries. They list pretty much the same formats as Worldcat. The ACS version and the Chicago (note) uses capitalization. The Chicago (Author-date) the APA reference list do not. Worldcat lists in addition the Harvard and Turabian forms of citation that do not use captialization. So it appears there is choice in the matter, but the majority of forms do not captilize. Any reasons for your preference? Does Wiki have an ennunciation? Brews ohare (talk) 19:41, 8 March 2008 (UTC)

First, ones you are citing that do not capitalize the title words are for (Author, Year) in-text citations, which are not being used in the article in question—like most of Wikipedia, it uses numbered endnotes. Second, in the physical sciences MLA and APA per se are not common as far as I can tell. See the American Chemical Society example on the page I mentioned; similar capitalization for book titles is used by the American Institute of Physics and by the American Physical Society (e.g. for Physical Review) and the IEEE. —Steven G. Johnson (talk) 00:10, 9 March 2008 (UTC)

Maxwell's Original Works

Steve, I wasn't trying to introduce archaic terminologies on the main page. However, I had been reading Maxwell's original works and found them to clarify alot of the existing confusion surrounding the fact that the Faraday's law in the modern (Heaviside) Maxwell's equations does not cater for all aspects of electromagnetic induction.

I accept the fact that Maxwell used EMF as a force whereas modern textbooks use it as a voltage (energy/work done per unit charge).

The important thing is to get the readers to understand the relationship between the Lorentz force, the partial time derivative Faraday's law and the full Faraday's law.

Equation (D) in Maxwell's 1865 paper is in effect both the Lorentz force and the full Faraday's law. Every aspect of electromagnetic induction that is covered by Faraday's law is also covered by the Lorentz Force and vica-versa.George Smyth XI (talk) 01:51, 27 March 2008 (UTC)

I'm familiar with Maxwell's paper, and the fact that he combined the Lorentz force with what most people now call Faraday's law (formulated in terms of the vector potential with a particular gauge choice). Nowadays, however, it's considered mathematically more convenient to separate the two equations for most purposes. I'm not sure why you think there is a lot of confusion here (at least in terms of the application of the equations, rather than their history). —Steven G. Johnson (talk) 02:06, 27 March 2008 (UTC)

GNU/Linux naming controversy

Thanks for reverting that unexplained tagging on GNU/Linux naming controversy by that IP address. He re-inserted the same tags again without explanation and I removed them. He was also very rude and insulting, so I have left him a note on his talk page. I would appreciate it if you continued to keep an eye on the article as I suspect there will be more traffic on this issue! - Ahunt (talk) 11:42, 18 April 2008 (UTC)

Thanks for your note. I have actually been having a conversation with him at User talk:62.106.48.52. I am not entirely sure it is the same person - the IP addresses are very different and the tone is not quite as rude. I am watching it all! - Ahunt (talk) 16:07, 22 April 2008 (UTC)

Leibniz rule

Hi Steven: I wonder if you could be persuaded to take a look at the Leibniz integration rule. This integration rule in three dimensions crops up in several physical discussions, for example Faraday's law of induction and Lorentz foce. The article on Leibniz rule has a very restricted proof for this rule that does not appear to include rotation nor a time-dependent deformation of the region of integration. Do you have some references where a better discussion can be found, or maybe you could provide a more complete discussion yourself? Thant would be very helpful. There is a (to me) cryptic discussion in this article, and a possibly useful discussion at Kholmetskii & Missevitch The Faraday induction law in relativity theory. Brews ohare (talk) 17:54, 24 April 2008 (UTC)

A successful wikipedia article

I am doing a project for class and need to write a wikipedia article I was wondering if you could describe to me what goes into an article to make it successful on wikipedia.

Thanks Hochy15 —Preceding unsigned comment added by Hochy15 (talkcontribs) 18:26, 24 April 2008 (UTC)

Proposed deletion of off-topic section in Extended precision

As a possible interested editor, please see Talk:Extended precision#Hyperprecision. -- Tcncv (talk) 02:38, 19 May 2008 (UTC)

FAR Trigonometric functions

Trigonometric functions has been nominated for a featured article review. Articles are typically reviewed for two weeks. Please leave your comments and help us to return the article to featured quality. If concerns are not addressed during the review period, articles are moved onto the Featured Article Removal Candidates list for a further period, where editors may declare "Keep" or "Remove" the article from featured status. The instructions for the review process are here. Reviewers' concerns are here.--Ioannes Pragensis (talk) 12:36, 12 June 2008 (UTC)

Great-circle distance

When you deleted a section from great-circle distance, you did not only delete a section. You left three blank lines between sections where one is usual. A single blank line before or after a section heading has no effect on what the reader sees and makes things easier for people editing the article, since then they can see where the sections begin. Additional blank lines beyond that have the effect of moving the sections farther apart than the standard distance. Michael Hardy (talk) 17:50, 16 July 2008 (UTC)

..... a further comment: one way to avoid this problem is to edit the article as a whole rather than just the section you're deleting. Alternatively, if, after editing the section you're deleting, you edit the previous section, deleting ALL line-breaks and blank space after the last non-blank character, then the software automatically puts in a single blank line after that and before the next section heading. That's the one blank line that doesn't affect the appearance except when you're editing, in which case it enables you to find the section heading easily. Michael Hardy (talk) 18:12, 16 July 2008 (UTC)

Vector (spatial)

Please see Talk:Vector (spatial). Thanks. Paolo.dL (talk) 10:49, 20 August 2008 (UTC)

Contour

Steve, thanks for so quickly fixing the contour references. Would you mind scanning Special:WhatLinksHere/Contour to see if any other math/physics usages should be converted to "curve". Like I said on the Maxwell's Equations talk page, I'm a cartographer, not a mathemetician... Thanks!--Natcase (talk) 01:00, 2 September 2008 (UTC)

FFT looks much better now

Hi!

Thanks for compromising on the FFT article. I suspect you think it's gravely over-simplified while I worry that it's not simplified enough, but if you can live with the current intro then so can I. LouScheffer (talk) 22:28, 9 October 2008 (UTC)

Hi Lou, I think the current form is reasonable and I agree that it is an improvement; sorry I got a bit grumpy. —Steven G. Johnson (talk) 22:37, 9 October 2008 (UTC)

Speedy deletion of Image:FigJ.png

A tag has been placed on Image:FigJ.png requesting that it be speedily deleted from Wikipedia. This has been done under section I8 of the criteria for speedy deletion, because it is available as a bit-for-bit identical copy on the Wikimedia Commons under the same name, or all references to the image on Wikipedia have been updated to point to the title used at Commons.

If you think that this notice was placed here in error, you may contest the deletion by adding {{hangon}} to the top of the page that has been nominated for deletion (just below the existing speedy deletion or "db" tag), coupled with adding a note on [[ Talk:Image:FigJ.png|the talk page]] explaining your position, but be aware that once tagged for speedy deletion, if the article meets the criterion it may be deleted without delay. Please do not remove the speedy deletion tag yourself, but don't hesitate to add information to the article that would would render it more in conformance with Wikipedia's policies and guidelines. Lastly, please note that if the article does get deleted, you can contact one of these admins to request that a copy be emailed to you. This, that and the other [talk] 09:56, 24 October 2008 (UTC)

Boston Meetups

When is the next intended Boston Meetup? The page hasn't been updated in a while. JoshuaZ (talk) 04:32, 5 December 2008 (UTC)

Thanks for your work FFTW

Hi, sorry bothering you, but I just could not resist. I am a fftw3 user, which you have aided developing (at least you share the authoring of the corresponding scholar article), correct? It was such a surprise to see your comments in the discussion about the Banach-Starski paradox that I felt compelled to add this section here.

Thanks for you and Matteo Frigo. —Preceding unsigned comment added by Eshneto (talkcontribs) 00:35, 14 January 2009 (UTC)

You're welcome; we're always pleased to hear from happy users. —Steven G. Johnson (talk) 17:19, 16 January 2009 (UTC)
Your Featured picture candidate has been promoted
Your nomination for featured picture status, File:Bananaquits.jpg, gained a consensus of support, and has been promoted. If you would like to nominate another image, please do so at Wikipedia:Featured picture candidates. MER-C 07:06, 6 February 2009 (UTC)

Delist nomination

An image that you uploaded, and is Featured, is currently nominated to be delisted from Featured Picture status. Please see nom for more information. ~ ωαdεstεr16♣TC♣ 17:21, 10 March 2009 (UTC)

File:Kaiser-window-spectra.png listed for deletion

An image or media file that you uploaded or altered, File:Kaiser-window-spectra.png, has been listed at Wikipedia:Files for deletion. Please see the discussion to see why this is (you may have to search for the title of the image to find its entry), if you are interested in it not being deleted. File:Kaiser-window-spectra.png Bob K (talk) 11:27, 3 May 2009 (UTC) --Bob K (talk) 11:27, 3 May 2009 (UTC)

This user contacted me on IRC and asked me to request that you allow him to edit his talk page. While I don't fully agree with the policy, users are generally allowed to blank their talk pages, except for declined unblock requests and ISP headers for IP talk pages.

Thanks for your time, J.delanoygabsadds 18:09, 1 July 2009 (UTC)

Hmm, I'm actually not sure how to unblock; never done that before. If you want to unblock him from his Talk page, go ahead. —Steven G. Johnson (talk) 20:56, 1 July 2009 (UTC)

hey

I think there is a very dangerous section in the NPOV policy, which I deleted and discussed on the talk page here. Now there is an RfC, I hope you will comment. Slrubenstein | Talk 06:47, 5 August 2009 (UTC)


What is a contribution?

Your last 'contributions' are doubtful indeed. To consequently delete contributions of other persons I would not call contribution at all. In contrary.

It would be appreciated if you would simply add citations, in case you thinkt that's necessary. This brings much more progress to Wikipedia than deleting correct statements. I belive you'll understand.

Thank you, A. Pichler (talk) 19:57, 10 September 2009 (UTC)

When you add information, you need to include citations of your sources. This is Wikipedia policy (WP:CITE and WP:V). This is not hard to do, and you have received repeated polite requests for sources. Since you persist in adding unreferenced information, it is likely to be deleted, as unreferenced information is next to useless for an encyclopedia, as there is no reasonable way to check it. Nor is it the job of other editors to clean up the messes you leave.
If you are working from a source, how hard is it to cite it? And if you are an expert in the field, you should know where to find published references. And if you don't know of published references in reliable sources, the information has no place in Wikipedia. — Steven G. Johnson (talk) 20:07, 10 September 2009 (UTC)

Legendre polynomials

I'm just alerting you that I responded to your post at Talk:Legendre polynomials, and started a new discussion thread there as well. Best, Sławomir Biały (talk) 15:08, 29 December 2009 (UTC)

List of permutation topics

I've just added bit-reversal permutation to the list of permutation topics. If you know of others that should be there and are not, could you add those too? Michael Hardy (talk) 04:00, 6 January 2010 (UTC)

I don't know of any offhand, but thanks for the note. — Steven G. Johnson (talk) 05:36, 6 January 2010 (UTC)

Regressive discrete Fourier series

Since you seem to be active in Fourier-analysis topics on Wikipedia, maybe you can help improve this article: Regressive discrete Fourier series.

Besides the content of the article, it may be that more other articles should link to it. Michael Hardy (talk) 20:24, 28 February 2010 (UTC)

notations for sine series

I saw this. While you're at it, could you comment briefly at Talk:Trigonometric_functions#Pros_and_cons_of_notations_for_series, where a discussion is in progress? Thanks. Michael Hardy (talk) 21:28, 8 March 2010 (UTC)

DYK for Pairwise summation

Updated DYK query On March 21, 2010, Did you know? was updated with a fact from the article Pairwise summation, 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, quick check ) 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.

Materialscientist (talk) 06:06, 21 March 2010 (UTC)

0^0=0

Why do you revert without reading what you revert? The formula 0^0=0 assumes no continuity; It only assumes the very original definition:

a^(x+1)=(a^x)*a

of exponentiation with whole numbers, as well explained in footnote no.16. Please read this footnote. Eliko (talk) 17:39, 27 March 2010 (UTC)

You're right, I looked at it too hastily, I saw 0^x and thought it was using a continuity argument on 0^x for x>0. In fact, it is even more goofy than that, it is using the assumption that 0^x is defined for every integer x, including negative x! Basically, it is saying that (1/0) * 0 = 0, which is total nonsense.
The fact of the matter is, any claim that 0^0 = 0 is consistent with all rules of exponenentiation is guaranteed to be nonsense and original research (the whole reason for the controversy is that no single definition works for all purposes, although the one that works for the biggest number of purposes is probably 0^0 = 1), so the precise details of the nonsense don't actually matter much. — Steven G. Johnson (talk) 17:44, 27 March 2010 (UTC)
No, you haven't read the whole footnote. Who says that (1/0) * 0 = 0? you can't prove that 0^(-1)=1/0, just as you can't prove the formula a^(-1)=1/a when a is zero, just as you can't prove that the formula a^(x-y)=(a^x)/(a^y) is applicable for all whole numbers! It obviously can't be applied when the base is zero and x<y, because such application entails a contradiction! I'm sure you haven't read the whole footnote no. 16: It explains the difference between the formula a^(x+1)=(a^x)*a and the formula a^(x-y)=(a^x)/(a^y): The first formula is the very definition of exponentiation, so there is no ground for discriminating between various cases in which a given definition can be applied (unless applying the definition for all cases entails a contradiction). Why do you afford to use this defintion when a=7 and x=2? Why don't you say that 7^2 = 49 is nonsense? What's the difference between 7^2 and 0^0? Eliko (talk) 18:03, 27 March 2010 (UTC)
Sorry, you don't understand exponentiation if you think that 0^x is necessarily defined for all integers x (including negative x), or that powers of negative x (if they are defined at all) aren't necessarily equivalent to multiplicative inverses (modulo branch cuts for fractional x). If you feel that I'm wrong, feel free to provide a reputable source that 0^0 = 0, that 0^{-1} is defined and is not equivalent to 1/0, etcetera. Or feel free to publish your insights in a reputable mathematical journal, in which case we can cite it. The nice thing about Wikipedia policy is that I don't have to argue with you if you don't give a source; I and other editors can simply continue to revert your additions, and block you if you continue to insist on adding unsourced material. — Steven G. Johnson (talk) 18:18, 27 March 2010 (UTC)
The nice thing about Wikipedia policy is that I don't have to argue with the editor Arnold Reinhold who doesn't give a source for his claim (in the chapter: powers of zero) that the powers of the base zero with a negative exponent is necessarily equivalent to a multiplicative inverse; Can you prove the formula 0^(-1)= 1/0? Can you prove the formula 0^(x-y)=(0^x)/(0^y) when x<y? Can you prove your implicit claim that the definition a^(x+1)=(a^x)*a is not universal and can't be applied when a=0? I and other editors can simply continue to revert your additions, and block you if you continue to insist on deleting necessary conclusions provable mathematically from a common definition, which is also indicated in the article for all integers - without any restriction.
No source is needed when the claim is a necessary conclusion derived mathematically from a definition; Note that the definition a^(x+y)=(a^x)*(a^y) for integers - is also indicated in the article for all integers - without any restriction. Don't you agree that the formula 0^0=0 is provable from the definition a^(x+y)=(a^x)*(a^y) ? The formula 0^0=0 can only be denied by denying the universality of the definition a^(x+1)=(a^x)*a or by denying the definability of the function 0^x for a non-positive x. If anybody claims that the definition a^(x+1)=(a^x)*a is not universal, or that the function 0^x is not defined for any non-positive x, then they must prove that, or give a source for that. I don't have to prove that the definition a^(x+1)=(a^x)*a is universal, nor do I have to prove that the function 0^x is defined for every integer x, because the default requires to apply every mathematical definition and every arithmetical operation - to every number, unless such an application entails a contradiction.
To sum up:
1. The difference between the formula a^(x+1)=(a^x)*a (which proves that 00=0), and the other formulas mentioned above (which prove that 00 can't be 0), is that the former is a definition: Nobody have to prove a definition, while they do have to prove formulas which are not definitions.
2. The formula 00=0 is well founded, whereas denying it needs a proof/source, but no such a proof/source exists.
Eliko (talk) 01:17, 28 March 2010 (UTC)

Sorry, I stopped reading at "no source is needed". Go peddle your nonsense about 0^0=0 someplace else; I'm sure there are circle squarers you will get along splendidly with. — Steven G. Johnson (talk) 01:22, 28 March 2010 (UTC)

re: Witricity

The witricity scheme is just a resonant transformer. At the heart of the 1902 TC is a resonant transformer also (Tesla invented it)- it's used there to give a large air gap because that permits high voltages to be generated on the secondary. The Witricity scheme just uses the air gap to give wireless power transmission, it's the same kind of thing just laid out differently. The high voltages on TCs is a bit of a red herring, Tesla mostly used to make them do that for fun and for demonstrations, his primary aim of wireless power wouldn't have caused any arcing, because arcing is lossy.

The guy that worked out how to do witricity, he comes from the same neck of the woods as Tesla did, I'm 99+% sure he knew how Tesla coils worked already and just applied the same principle for charging cell phones. ;-)

Incidentally, the same principle has actually been in use for ages; wireless smart cards use it (like on the London underground), and some forms of pacemakers use it as well. I think a lot of the tags you see in shops to avoid theft are also powered the same way, those barriers you go between have coils that resonantly send power to the tags.- Wolfkeeper 23:55, 28 March 2010 (UTC)

They specifically cited the Tesla-coil work in their paper and explained how they differ. Sure, you can operate Tesla coils at lower voltages, but the key point is that the coupling in Tesla coils includes a large fraction of the electric field energy outside the device; in the WiTricity case almost all of the electric-field energy is inside the device in a capacitor. — Steven G. Johnson (talk) 00:02, 29 March 2010 (UTC)
Sure, the capacitor is laid out differently from most TCs, but people have been doing exactly this kind of thing for decades; that's how the pacemaker recharger worked; they didn't have a great big tesla coil arcing away- I saw footage of this back in the 70s or 80s; it was just a coil they held it against the guys chest.- Wolfkeeper 00:10, 29 March 2010 (UTC)
The only clever bit is suggesting using it for cell phones, and tuning it to get (fairly) good distances; oh and hyping it up a bit 8-) - Wolfkeeper 00:10, 29 March 2010 (UTC)

Um... given you work at MIT, I have to ask whether you know Marin Soljačić personally or have any other involvement. The problem is that you're editing a page that is related to an MIT project, so I'm not sure whether you should be editing these pages.- Wolfkeeper 01:27, 29 March 2010 (UTC)

I know him personally, but I'm not directly involved in WiTricity or in Marin's wireless-power work, so I don't think that a conflict of interest arises here. Also, my edits are supported by reputable sources in the literature; where are your sources explaining how this work is identical to previous technology? — Steven G. Johnson (talk) 16:31, 29 March 2010 (UTC)
For example check out this RFID patent from 1999: [5] if you notice in the diagrams the power supply/antenna structure consists of a capacitor and inductor in parallel. There's a picture of the coil in one of these cards at: proximity card. The power transfer there is magnetic mode resonant transformer, just as the power transfer between the primary and secondary in a single Tesla coil is, or the Witricity system. The basic tech really is donkey's years old.- Wolfkeeper 02:45, 3 April 2010 (UTC)
I mean Tesla certainly knew all about this stuff, he invented it as one of the tricks for his later Tesla coils. As I understand it, he wasn't very impressed with it though for power transmission, because the range is pretty shitty. Even with the Witricity stuff, their best case is about 3 coil diameters, and in cases where one of the coils is smaller, (like a cell phone) you probably are looking at more like 1-2 coil diameters range.- Wolfkeeper 02:45, 3 April 2010 (UTC)
So I've a horrible suspicion that the tech, while it will work and will be safe, may not be as commercially viable as you would hope. But we'll see.- Wolfkeeper 02:45, 3 April 2010 (UTC)
Every resonant circuit diagram has an inductor and a capacitor in it; abstract circuit diagrams tell you nothing whatsoever about how the field energy is spatially distributed. And the RFID system is excited with propagating waves from a broadcast signal via a resonant antenna, so it is totally different from an evanescently coupled transfer between two matched resonances. Also, there is no such thing as a "magnetic mode": every harmonic mode has equal EM energy in the electric and magnetic fields, although they can be located in different spatial regions. The rest of your comment is simply argument by assertion (Tesla "certainly knew" about it, not responding to the distinction made in published works with Tesla coils). As for the short range, the point that WiTricity is making is that the "last meter" problem is much more important now than it was in the past, which is why this problem received relatively little attention previously; time will tell if they are right about the current market needs. (There is also some fairly tricky distance-dependent impedance/Q matching involved in the case of charging nonstationary items.) — Steven G. Johnson (talk) 23:46, 10 April 2010 (UTC)
No, you're not right, the RFID tags are powered by resonant magnetic fields picked up by the tuned coils, as are the wireless smart cards on the London underground, the patents are over a decade old now.- Wolfkeeper 01:03, 11 April 2010 (UTC)
The coupling is done by magnetic fields or electric field. Teslas short-range power system was done by electric fields, but there's magnetic field transfer within the Tesla coil as well.- Wolfkeeper 01:03, 11 April 2010 (UTC)
I mean check out this: [6], it's exactly the same, it's just laid out slightly differently; there's no physical connection there between the primary and secondary at all; it's exactly the same thing. This is really, really old hat.- Wolfkeeper 01:03, 11 April 2010 (UTC)
Doing the coupling almost exclusively via magnetic fields is the whole point of the WiTricity approach (external electric fields are problematic because they can couple strongly with other matter); I don't understand how you can admit that the transfer in Tesla's case was done mostly by electric fields and then turn around and say that it's "exactly" the same thing. — Steven G. Johnson (talk) 01:06, 11 April 2010 (UTC)
That electric field is generated by resonance that is driven wirelessly and magnetically from the primary coil which is a few inches away with an air gap. The magnetic field that forms is a near-field evanescent field around the resonant primary coil, which is designed to resonate at the same frequency as the secondary. The magnetic field that cuts the secondary generates an oscillating potential on the secondary; the large number of turns means the potential step-up is considerable and this can cause arcing. The system gets ~85% efficient power transfer from the primary to the secondary with a coupling coefficient of about ~0.2 or so. It's exactly the same principle.- Wolfkeeper 05:21, 14 April 2010 (UTC)
Incidentally, an evanescent wave is nothing special, all inductors have evanescent waves around them. It's just the standard near-field pattern.- Wolfkeeper 05:21, 14 April 2010 (UTC)
(I never said that evanescent waves are "special"; they are certainly familiar concepts in any wave-propagation context. The point is that evanescently coupled systems work totally differently than systems coupled by propagating waves. And if you use evanescent coupling without resonance, as in standard inductive coupling, then you get low efficiency except at very short separations. Nor did Soljacic's group claim to have invented the idea of resonant energy transfer; they take great pains in their papers to point out that this by itself is an old idea. The difference is that they came up with a practical system to do this at ~meter separations using primarily magnetic coupling. I'm sorry that you can't grasp this; you might as well say that it's all Maxwell's equations, so there is has been nothing new to be found in classical electromagnetism since 1865.)
PS. Saying something is powered by "resonant magnetic fields" is nonsense. Fields are not resonant or non-resonant, structures are resonant. The question is, how do the fields get to the RFID device; if it is through propagating waves, then it is totally different from evanescent coupling. — Steven G. Johnson (talk) 01:08, 11 April 2010 (UTC)
Oh, ok here's a technical note on that from 1998, check out: [7]. The key bit is on the first page where they clearly point out it's all near-field and it's a non propagating field, and you'll note that there's tuning caps on the transmitter and receiver. That system is running at 125Khz.- Wolfkeeper 05:21, 14 April 2010 (UTC)
This is non-resonant inductive coupling. — Steven G. Johnson (talk) 01:21, 5 May 2010 (UTC)
Oh it so isn't. That only works at a fraction of a coil diameter.- Wolfkeeper 02:15, 5 May 2010 (UTC)
You're right, I read it too quickly. On the other hand, it is in the 'extreme near field where 1/r^3 near fields can be used, which is the case here because the wavelength is so large (kilometers). (What is the power-transfer efficiency of these devices, BTW? I'm guessing it is low because to get good efficiency you have to adaptively alter the quality factor/impedance of the resonators as the distance between source and receiver varies.) In Witricity's proposal, they are operating at mid-range distances that are not so small compared to the wavelength, compensated by large, matched quality factors of the resonances to achieve decent power-transfer efficiency, using designs that avoid strong stray electric near fields anywhere outside their device. If you actually read their papers, you'll find that they actually discuss a number of previous works on both resonant and nonresonant wireless power transfer (see e.g. this paper, p. 40) and explain what distinguishes the different regimes. Again, they clearly explain that resonant power transfer is an old idea, but argue that their devices bring it into a different regime than what was previously achieved. You keep bringing up "counterexamples" that are operating in totally different regimes than what Witricity is doing, and in several cases seem to have been explicitly discussed in their papers, and I get the sense that you are arguing with a straw man. — Steven G. Johnson (talk) 17:39, 5 May 2010 (UTC)

Uncertainty principle for the short-time Fourier transform

Maybe you can shed some light on the article titled Uncertainty principle for the short-time Fourier transform? Michael Hardy (talk) 02:26, 16 April 2010 (UTC)


The Anti-Vandalism Barnstar
For your judicious efforts to invigilate the time-frequency bogs. Cuzkatzimhut (talk) 15:17, 8 July 2010 (UTC)


Could you perhaps, at some slow time in future, bring some order and organization to the reduplicative rants and non-sequiturs in these wetlands? The "cross talk problem" in the physics Wigner quasi-distribution is not a problem: It is a crucial and salutary reflection of "beats" in the time domain, symmetric and quite analogous to frequency beats. They are there, and are necessary for faithful marginal distributions, and they are kept in check by the uncertainty principle; and obscuring them by invertible transforms to other equivalent distributions merely hides their function and importance. Quantum physics exorcised these demons of confusion successfully decades ago, but evidently the signal processing community, after adapting the Wigner distribution, no longer draws insights from the solutions of its problems in physics. Cuzkatzimhut (talk) 15:17, 8 July 2010 (UTC)

Discrete Fourier merger

Should the nearly orphaned discrete Fourier series get merged into discrete Fourier transform? Michael Hardy (talk) 13:43, 20 April 2010 (UTC)

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