User talk:David Eppstein/2007

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Egyptian fractions, last year and this year's subject

In moving all of your Wikipedia discussions to the old stuff area, there is little that has been resolved between our two points of view. Your view does not commonly or consistently consider the ancient math structures that stressed the FTA, reporting each arithmetical form found within its relatively easy to read historical examples - be it medieval radix info, or whatever. My view tends to take an ancient pattern, like the two medieval radix fragments that you mentioned, a notation that may not be connected to the FTA, and then I work (by well known scholarly references) to connect the medieval fragments back to Egypt, or some other source, commonly documented to have been used prior to that time period.

All math, at any time was built on the shoulders of its giants, a point of view that is consistently, and directly, written into my point of view. Looking forward at any time, taking a strand of info here and there, and building a foundation to discuss one or two modern subjects, seems like an odd way to fairly report ancient mathematics and its foundational arithmetics within its confirmed historical context.

Yes, 2007 will find us again debating Egyptians (like Ahmes), Greeks (Euclid and many others) and medievals (like Fibonacci) scribes and mathematicians that worked very hard in their lifetimes to solve many types of problems using the factoring of rational numbers as its core arithmetic thought.

Your point of view quickly switches to the modern algorithm, or to Babylonian base 60 (a culture that did not use Egyptian fractions as its central form of arithmetic). The medieval algorithmic point of view did alter 3,600 years of Egyptian fraction arithmetic, since Western arithmetic included zero written as an exponential place-holder, defining numbers by algorithm as written up by Stevins in 1585 AD.

Yes, 2007 should be an interesting Wikpedia year.

Best Regards, Milo Gardner 1/2/07 — Preceding unsigned comment added by User:Milogardner (talkcontribs)

Hello Milo and David. My question is for Milo. Is there a reason why you don't sign your comments in the usual way, with the four tildes? It makes you seem like a newbie or a person unfamiliar with Wikipedia. Since you wish to be taken seriously in your mathematical views, adding your signature consistently would improve your credibility. Always logging in to your account before commenting would be another step that would it easier for others to follow the discussions in which you participate, and perhaps grasp your argument more quickly. EdJohnston 21:21, 2 January 2007 (UTC)

I am a newbie on Wikipedia. My focus continues to be on the ancient math. At times I have not properly logged before returning to the issues that motivate by Wikipedia participation. As a New Year's resolution, I'll try to log on and even learn the proper way to sign my name. What is the four tilda method? Best Regards, Milo Gardner 1/3/07. — Preceding unsigned comment added by User:Milogardner (talkcontribs)

Type four tildes ~~~~ at the end of your comment, before pressing 'Save'. The tildes will expand into your signature and a date-time stamp. EdJohnston 15:05, 3 January 2007 (UTC)

David, your suggestion that Fibonacci's 7 methods, distinctions, to find Egyptian fraction series only present a small section of the book is way off base. All the first 6 chapters show in practical and abstract terms how and why Fibonacci was able to factor any number, integer or fraction, using the FTA within several notations. These chapters necessarily lead to the 7th chapter, with the 7th chapter's summary section citing the 7 methods that elegantly and not so elegantly report 3,200 years of Egyptian fraction history, again written in several notations. It should be noted that Fibonacci consistently includes in his practical descriptions the point- if you wish to know why - a clear example then follows that easily allows today's 2007 reader to see the why side of his abstract reasoning. I'd be happy to further detail Fibonacci's abstract reasoning for you - on a separate web page, using the same central abstract methods that Ptolemy, Euclid and Ahmes used (citing remainder arithmetic - quotients and remainders - all the way!)

Again, I will be taking down your Struik reference, oddly placed at the begining of a section, used more as a rhetorical reminder (in my view) that there are many Pro-Babylonian scholars out there. I run into these folks all the time. These people are well know, at least to me. I'd be happy to cite a few of their names (off-line), and their rhetorical styles, just as we are discussing the anti-Egyptian fracion views of Struik, and have misread his point of view. Struik takes a common position, picking up a minor point written in Egyptian fractions, Ptolemy's use of base 60 statements, and then Struik falsely jumps to an incorrect and confusing conclusion that Ptolemy was not pleased to have worked and written in the practical and theoretical form of Egyptian fractions. Ptolemy was pleased with Egyptian fractions, and used it all the way, in all of his work. The base 60 data was not written outside of the traditional Egyptian fraction system! As proof, as you know, from your own description of Fibonacci's Egyptian fractions, Fiboancci wrote several classes data in different number or weights and measres bases. Fibonacci also mixed numeration and weights and masures bases a, b, or c, as needed, a step that Ptolemy also took - though Struik did not grasp the appropriate meaning, as you can discover for yourself by reading the Almagest. Best Regards, Milo Gardner Milogardner 12:11, 4 January 2007 (UTC)

A WP policy that might help in writing about Egyptian fractions

I couldn't help thinking back to last year's debates about Egyptian fractions, when I came across this proposed policy from Wikipedia:Attribution: Unpublished synthesis of published material

Material can often be put together in a way that constitutes original research even if its constituent parts have been published by reliable sources. This includes analyzing sources in a way that produces a new idea or argument. Even if A and B are published by reliable sources, it is inappropriate to combine A and B to conclude a new position C. "A and B, therefore C" is acceptable if and only if a reliable source has published that precise argument in relation to the topic of the article. See the FAQ page for an example.

I won't attempt to draw any conclusions about that here, but I think it could be helpful to think about. EdJohnston 22:03, 3 January 2007 (UTC)

Thanks, but without more specifics it's difficult for me to understand what you see as synthetic in the current article. The part that looks most that way to me, the description of the multiple RMP methods, has different citations in each bullet less because there isn't a single source that covers all these methods (I think Gardner 2002 does cover them all, for instance, although it does so in Milo's idiosyncratic style) and more in an attempt to assign appropriate historical credit for each observation. If you mean that the whole article collects together several loosely related ideas on Egyptian fractions that have not been brought together by a single article elsewhere, I don't really see that as different than most other WP articles; the quote you mention is less about putting A and B together in a single article and more about putting in new inferences that combines material from the two. —David Eppstein 22:25, 3 January 2007 (UTC)

Hi David, It appears that you have not seriously taken to reading and reporting Sigler's comments (footnotes) related to Fibonacci's seven methods to convert vulgar fractions to Egyptian fraction series. The methods were written very close, at times, to the the oldest Egyptian style. At other times a Greek style appeared. Then an Arab style, arguably appears, since it included Hindu-Arabic numerals, with zero being a remainder. It may be best, at least for myself, that a separate web page be developed to cover all seven of Fibonacci's distinctions, and the three notations in which the raw data was written. A blog was posted today per:

citing a brief outline of Fibonacci's Egyptian fraction methods, as translated by Sigler. A great deal more work needs to be put into the blog to improve is readability beyond my usual mangled syntax.

In that way (my spending time on the blog and away from Wikipedia) we may not be arguing (as much) and posting different views. Such a blog may assist in exposing and connecting the interworkings of Fibonacci's set of 7 examples, with sometimes more than one example per method (distinction, to use Sigler's term), to its sometimes older sources (at least that is my goal). At present only a small sample of the examples have been mentioned on Wikipedia, thereby hiding many of the more interesting aspects of Egyptian fractions. Best Regards, Milo Milogardner 23:31, 4 January 2007 (UTC)

Hi David, and Ed: I agree with David on ths topic of A + B + C + ... may equal a visible ancient elephant. To only report A, B per one or two scholars and omitting scholars 3, 4 and 5 (by some undefined process) and parts C, D, and E of a topic, only the trunk, feet or tail of an elephant may be shown. Milo Gardner Milogardner 23:00, 3 January 2007 (UTC)

Milo, now everything is great, you are signing your comments, but can you please create a user page? If you authorize me, I'll create one for you, that is blank. In that way your signature will not show up as a 'red link' for your name, and will not alarm people :-). EdJohnston 23:13, 3 January 2007 (UTC)


Our time together has nearly ended, provided that your odd position concerning Struik, Fibonacci, Ptolemy and many others that wrote base 60 facts and relationships in one of the three Egyptian fraction notations can be modified, considering a few additional facts. For example, Fibonacci's base 60 data was cited to solve a contest problem, while Ptolemy's data was written to solve other irrational number problems, a general statement of latitudes and longitudes. Fibonacci and Ptolemy easily wrote within the Egyptian fraction system, and therefore neither was complaining as Struik oddly concludes in Ptolemy's case. Struik's odd anti-Egyptian fraction position reads more like Neugebauer's Exact Science in Antiquity suggestion, that Egyptian fractions marked intellectual decline in Ahmes' time, and by implication all other time periods. Since Fibonacci's first 127 pages are well defined in LA, and his methods connect to Ahmes's 2/nth table, and its remainder arithmetic, Ahmes's initial Egyptian fraction work should not have been seen as denoting intellectual decline. Hence, Struik and Neugebauer were both incorrect, two errors that we can easily overlook, and move on to other topics. Best Regards, Milogardner 23:50, 12 January 2007 (UTC)


There may be two deeper issues that are effecting your thinking process, at least that is my take on our debate. Let me stress the oldest issue, the documentation of the Horus-Eye numeration system, and its links to the Babylonian numeration system. The Egyptian cursive numeration system was inferior to the Babylonian base 60 cursive way of writing its numbers. Given that Babylonians, through all of their history only used 2, 3 and 5 in their denominators, round off problems severely degraded the accuracy of their everyday and highest theoretical arithmetic, a situtation that was even more troublesome in the binary fraction context.

By contrast, 2,000 BCE Egyptians found a way to solve their "Horus-Eye" problem. It was achieved by allowing any number to appear in their numerators amd denominators within its newly developed Egyptian fraction system. The clearest evidence of this fact is provided by the Akhmim Wooden Tablet where 1/320 was used to down-scale large denominators when partitioning a hekat, thereby allowing scribes to work with small Egyptian fractions.

Aspects of the Egyptian fraction solution have been sent to you in a formal paper that is being published this month. When the journal is released I'll provide the needed reference specifics, if you desire. Prior to that time, remember, Babylonians only used 2,3 and 5 in their denominators - not very accurate, right? Best Regards Milogardner 13:38, 13 January 2007 (UTC)

David, the second issue deals with definitive sources that allowed our modern algorithm to become the context for writing our modern base 10 decimal system. In this area area I may strongly agree with your intuition (I use that phrase advisedly - since you have not made comments on this area) that Hindu-Arabic sources can be attributed as the source for the creation of our modern base 10 decimal system. All the facts found in India and the Arab and Islamic countries, that I have seen, point in your direction. Given a large body of overwhelming, but fragmented, evidence in your favor, I will not confront any of the related Egyptian fractions issues. Therefore our debate is over.

However, as a review, there is great fuzziness in the area of sources that birthed the algorithm that birthed our base 10 decimal system. My sources (Ore and Eves) strongly suggest that al-Karaji may have been Fibonacci's source to convert Diophantine indeterminate equation methods into the Hindu-Arabic numeration system, and so forth. That is, the Islamic algorithm could have reached Europe using several Arab paths. Fibonacci is a likely path, but not the only path.

In conclusion to our two month debate, let up stop pushing our respective sides of very old arguments. We both have reached an area of fuzzy primary sources. The majority of our scholarly debates have fairly identified and fairly concluded that Greek and Arab documents are overly fragmented, and therefore can not be used to reach definitive conclusions in certain areas. Wikipedia standards demand that opinion should not be introduced as a source when fuzzy sources are pointed out. That is, I should not and will not go into any of the fuzzy algorithm and algebra areas, where only personal opinion governs. As a code breaker, I must deal with hard facts connected to more than one text (thereby confirming the existance of an ancient pattern). Thanks again for a stimulating discussion. Your ardent support of your point of view has been very helpful, forcing my long held views to be reconsidered by reviewing 40 year old sources that I had not read for many years. Best Regards, Milo Milogardner 15:05, 13 January 2007 (UTC)

  • David, your view of Egyptian fractions stresses your excellent modern math skills, as a single window to the past. Your method tends to consider information developed from other sources and methods to be improper, it seems. My view is that your single rear view mirror will never fully be able to see the fundamental threads that built the 2,000 BCE Egyptian fraction methods, methods that were very likely created to solve the Horus-Eye problem. Hence, the need for the discussion of proper methods used beyond your singular rear view mirror method is hereby highlited, and will be further discussed, as follows.

That is to say, my view accepts your your singular rear view method, looking backwards in time takinng only the snap shots of particular relationships (i.e. Hultsch-Bruins) that only presents puzzle pieces, leaving the pieces unassembled on a web page, or in incomplete essays written by Peet, Gillings and others, and a confirmational forward viewpoint, slowly accepting new pieces into the larger puzzle.

Stated another way, my forward viewpoint is added to your read view merthod by analyzing each thread of information, parts A, B, D, E. ..., N, ... of a Egyptian fractions, and slowly pieces the ancient puzzle together, unusually by the assistance of at least two texts. Given that every new piece, is confirmed by two or more text, each puzzle piece thoroughly documented using Wikipedia rules. At no time have I every concluded, using all the available pieces, that the puzzle is complete!

Rewording the discussion, your view of finding A, and B (at anytime) does not confirm C is correct. My view requires seeing A and B in two directions, beginning in 2,000 BC, and working toward 1202 AD, as well as working in the reverse direction. Note the confirmal steps involved in isolating the scope and depth of A and B by using the two-directional method. Hultsch-Bruins (A) and the hekat divison method (B) were both indepdendently isolated and confirmed by this bi-directional method. Additional threads C (quotients), D (egyptian fractions as remainders), and E (multiples of EMLR unit fractions to find Egyptian fracions have been found in the RMP and the Liber Abaci), hence there are additional pieces on the table. Oddly, your singular method is relatively with opinions, mostly skeptical ones, directed against C, D and E, (points like the Horus-Eye problem, quotient and remainders, and so forth) because your confirmational methods of A (Hultsch-Bruins) and B (Greedy algorithm in the LA) are weak.

Again, is is important to answer the Horus-Eye problem question, documented from two points of view. What was the most likely reason for Egyptians to have used an exact form of unit fraction notation, and how does anyone confirm or oppose such a hypothesis?. It is easy to deny the hypothesis and a historical ancient Horus-Eye problem, a problem that would exist with any binary fraction system at any time. The problem is shown by excessive round off, a problem that was solved in the AWT, and in other situations and texts. Yet, you take a defensive position that allows a very old outdated fragmented view of Egyptian fractions to continue as the 'proper' and current scholarly view accepted by Wikipedia. I've gone on too long. Best Regards. Milogardner 21:48, 16 January 2007 (UTC)

David, the current Wikipedia version falsely reports that the RMP contains 84 algebra problems. About 18 of the 84 problems can be seen as algebraic, with the total breakdown roughly consisting of: division by 10 (same as the Reisner P.- 6 problems), addition (17 problems), AWT (squaring the circle, the basis for the hekat - 5 problems), MMP (14 problems), business (23 problems) and recreational (3 problems). The total does not add up to 84 since several categories overlap (possibly more than cited above). I'll be summarizing this breakdown into a draft later today. Thanks again for discussing these texts in historical context. Milogardner 17:26, 18 January 2007 (UTC)

David, your latest wikipedia rant - that my suggestion that the greedy algorithm was recreational to Fibonacci is confirmed on three levels. First is the LA itself, wherein Leonardo creates elegant series as his preferred method, and as you state yourself, the awkward series, non-so-elegant using Sigler's term. So why is is not fair to conclude that non-so-elegant series was a form of recreation?

Second, is from India, the source of Fibonacci's numerals. Mahavira was reported in my EMLR paper as using an Egyptian fraction method that many in the history of Indian mathematics have classified as recreational math. To be fair, to report my readins of a 1938 definitive text on the subject, all of Egyptian fraction math reported from India was recreational during the time preceding the arrival of base 10 numerals to Arab sources, the sources that Leonardo read. The question then arises, did Arabs only use Egyptian and Greek sources for its Egyptian fraction methods, and exclude the recreational sources linked to Mahavira and the Hindu numeral system?

Third is the RMP, where 3 of 84 problems were recreational, Robins-Shute is my source, or 1 of 28. That is, from the beginning of Egyptian fractions recreational problems were discussed along the way, the most commonly cited problem is RMP #84.

So what is odd about concluding that one of Leonardo's 7 methods may have been recreational? Well, there were more that 7 methods. Method one was actually three methods. And the 7th method, where your version of the greedy algorithm contains a second fractoring method, much as 2/95 as used by Ahmes to write 1/5 x 2/19, with 2/19 taked from the 2/nth table, the issue of not-so-elegant and elegant arises. I have not counted up all of Leonardo's Egyptian fracion methods, but there are 10 referenced above. One may or may not be recreational. That is, your firm reliance on the first half of method 7 being mainstream, and not recreational, with no question or discussion allowed, is injured by Sigler's use of the 'not-so-elegant' term. At least that is my view.

Of course, you can fairly argue, but not declare (your usual style as you have have unfairly done with respect to decimal notation in the LA) that Leonardo was not-recreational any where in his work. I would not fully argue such a point, since I have not looked at all his problems, except the 'Going to St. Ives' problem, written as 'Going to Rome', that appeared in the RMP as problem #84.

Again, one of my central complaints returns to your usual style, one modern size (of algorithm) fits all, that algorithms were used by Leonardo in ways that directly lead to your work, as noted by Sylvester in 1891. We have not discussed Sylvester's earlier Egyptian fraction paper (Sylvester, J. J. “On a Point in the Theory of Vulgar Fractions”: American Journal Of Mathematics, 3 Baltimore (1880): 332–335, 388–389) one that was contrived, in my eyes, and in the eyes of my friend Noel Brayer (deceased). I suspect that Sylvester's later 1891 paper was also contrived, given that all seven of Fibonacci's methods were not reviewed. Had Sylvester looked beyond the Greedy Algorithm, he would have seen and anticipated F. Hultsch's 1895 discovery, the most likely primary 2/p conversion method used by Ahmes, since Leonardo discussed it!

Let me stop here. Best Regards, Milogardner 18:06, 25 January 2007 (UTC)


Your latest Hultsch-Bruins essay seems not to take into consideration the four methods used by Leonardo in the Liber Abaci. The first two used the traditional method that I discuss, one that used subtraction by selecting a unit fraction first partition by some unknown process, creating an elegant Egyptian fraction series. Methods six and seven introduced medieval only concepts. Method six uses a vulgar fraction as a first partition, raising 3/8 to a mod 8 mutiple, or 18/48. Method seven we have discussed several times, so I will not repeat my position at this time. Best Regards, Milogardner 19:06, 5 February 2007 (UTC) Milo Gardner

Fractions in Monty Hall Problem Article

Hello. I undid your last change in the Monty Hall Problem article, and left a note in the discussion page for that article explaining why. Please review and add yor comments there. Thanks. The Glopk 15:22, 1 February 2007 (UTC)

La Rouche link

Could you explain better why you keep removing it. I can see that you are mathematician, and probably your abstract thinking abilities are higher than mine, but when I was learning about this cube problem, the applet from that website helped me understand it as it is 3-D, and I don't need to abstractly imagine 3rd dimension from other links that are there. These applications are helpful in understanding the problem. Honestly, I don't care about larouche and his politics, but that simulation is worthy, and should be in the linked to article. Couldn't find on the whole internet any similar. Lakinekaki 17:08, 17 February 2007 (UTC)

The cube applet itself is fine. If it were by itself on a standalone page I would keep it, regardless of the name of the url. But surrounded by so much other irrelevant stuff, with the political links at the top of the page, it doesn't come across as a useful mathematical description: it looks instead like a collection of vaguely useful stuff thrown together in the hope that people will link to it and by so doing garner more attention to LaRouche. You know, like the spammers who copy Wikipedia content so that Google will index their spam. —David Eppstein 17:15, 17 February 2007 (UTC)
I don't know. I mean, I was learning about doubling the cube with the help of that simulation, and I didn't even pay attention to other stuff as it didn't seem interesting to me (as I can see, it talks about KKepler's law, and some other stuff, that I don't know how are related to the cube, but certainly don't have negative effect on the page). I think that people do have ability to filter out noise, and just because something comes from bad guy, it should not be dismissed. I would really appreciate if you put the link back, as I don't like revert wars, and also, simulation was helpful to me, and I believe, it will be helpful to others too. Lakinekaki 18:06, 17 February 2007 (UTC)

re: Penrose tiling

Hi, you said:

rv. Replacing svg by png seems like the wrong direction to me

but I want to point out that I replaced Image:Penrose tiling3.jpg with Image:Penrose tiling 3 iterations.png; I replaced JPEG, not SVG, with PNG.

I would have replaced the JPEG file with an SVG file, but Image:Penrose tiling 3 iterations.svg doesn't look very nice when rendered by MediaWiki, so I made the PNG manually. (MediaWiki usually converts SVG files into PNG files for Wikipedia.) --Kjoonlee 19:54, 24 February 2007 (UTC)

Ok, I misread, sorry. The png does have somewhat more consistent looking strokes than MediaWiki's rendering of the svg but I don't see a big difference there. —David Eppstein 20:36, 24 February 2007 (UTC)
MediaWiki uses librsvg (probably version 2.14.0) to render SVG files at present, despite its known limitations. Having looked at the source for the tiling example, which is quite simple, the ugly rendering is a surprising disappointment. The default thumbnail size is 180 pixels wide; perhaps an image width that is an integer multiple of that will work better. My hunch is, the inconsistent widths are an aliasing problem in the renderer, though I wouldn't expect that from the cairo backend. --KSmrqT 21:44, 24 February 2007 (UTC)

Indian Mathematics

Hi David, Thanks for your comments. I've replied to them on the Indian Mathematics page. Will fix the Taylor series remarks. Fowler&fowler«Talk» 22:07, 24 February 2007 (UTC)

Thanks for your participation in the ongoing discussion. Sir, I'm not making any claims at all; everyone who has entered the discussion seems to assume that I am an Indian nationalist intent on inflaing India's contributions. All I have done is provided citations for the already existing statements, removed the glowing praise for Indian mathematics from the intro (including words of Laplace and Einstein), removed the Indian charge of "Eurocentrism" and the very oddly written "Assesment of Vedic mathematics" section which provided a series of quotations. Sir, I have been removing flamebait material not adding it and suddenly people are lablling me as an insignificant troublemaker which is devastating to my credibility.

I have carfted a version for Indian mathematics. The version can be accessed here.

Kindly compare the version with the present Indian mathematics article, the version which to which I edited earlier and the version prior to my involvement

Judge me on my intentions and the effort I'm willing to make for this article through my examinations, sir; and not what a group of users has to say about me. I have yet to actually "make claims" and "inflate India's contribs\utions" as people automatically seem to have judged of my edits. Many regards,

Freedom skies| talk  06:41, 25 February 2007 (UTC)


Hi David, I e-mailed you several days ago about some fractal sequence I was trying to re-create in flash, I found you on here just by chance as I was browsing a reference desk page and saw you sign on there (small world!?). I havent heard back from you and was wondering if it got caught in the hole that is spam prevention, or if you're just busy? I'm still struggling with it. Capubadger 07:55, 26 February 2007 (UTC)

I can't tell your email from the name you're using here, but if it was the message with subject line "Indra's Pearls?" then it was me being busy; if it was a different subject then the spam filter got it while letting through a lot of spam. On the assumption that the Indra one was you, though: if I remember correctly, that image was generated by starting with four mutually tangent circles then repeatedly inverting the configuration through its circles. There's a web site for the Indra's Pearls book. And for more on circle inversion you might also look here. —David Eppstein 08:10, 26 February 2007 (UTC)
Yes that's the one. I had a look at the indra's perals site and saw things that were similar to the picture I linked to, but not quite similar enough for me to work out what's going on. I'm having a hard enough time working out the coordinates and radii of 4 mutally tangent circles :p, I'll have to look at inversion a little more closely. Capubadger 08:56, 26 February 2007 (UTC)

Indian mathematics

Greetings, I was involved in the RfC in Indian mathematics. My efforts were directed towards creating a version such as this one, as compared to the this, this and this version. My efforts initially began with removing misrepresentation of quotaions and then I tried providing some of the "citations needed" tags with actual citations. The situation resulted into an RfC, timed during my examinations, to which I could admittedly, not work on adequately. Fowler&fowler has asked me to work with him but since I am sitting my examinations and the article has been edited extensively since the RfC by other editors I no longer can keep up the pace. My exams will continue and after that I will be leaving, taking a few days off WP. I have reviewed my future with the Indian mathematics article, and have come to the conclusion that since I am under time constraints and am under such pressure in real life that adequate responses or editing actions on "Indian mathematics" are just not possible for me right now. I can't contribute to it in the manner that I usually would; it would be unethical to the extreme to ask the other editors, who have wished me well during my examination, to wait. The article is under the watch of many good editors and I see and hope that it's quality benefits from the present situation. Many regards, Freedom skies| talk  02:03, 27 February 2007 (UTC)

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you know...

Probably the struck out "yaoi" was removed because of yaoi. So I'm curious. Did you really mean to allude to yaoi? --C S (Talk) 08:18, 5 March 2007 (UTC)

Mostly I meant "thoughts on yaoi" as a catchphrase to mean going on at length about stuff very few people are likely to care about. My actual thoughts on yaoi are that I don't care to read it but don't care that it's out there either. —David Eppstein 15:58, 5 March 2007 (UTC)
Heh, ok. That went completely over my head. --C S (Talk) 16:07, 5 March 2007 (UTC)
Yeah, I mostly wrote it that way for my own amusement rather than in the expectation that most readers would get it. —David Eppstein 16:08, 5 March 2007 (UTC)

PlanetMath bio

Just thought you might want to know there's a bio of you at PlanetMath (link: Though I think having a Wikipedia bio is the higher honor. CompositeFan 18:08, 5 March 2007 (UTC)

Thanks for the heads up. Since it doesn't seem to be on the WP entry and the PlanetMath page guesses wrong: I was born in 1963. If you have IEEE subscription access there's some documentation here. —David Eppstein 18:36, 5 March 2007 (UTC)
I guessed wrong. It was the NSF Young Investigator Award that made me think of the 1970s. Hopefully that was the worst of the mistakes, right? Anton Mravcek 20:51, 5 March 2007 (UTC)
The only other inaccuracy that I saw was that the paper from which I first got the Erdos number was earlier, via Frances Yao: Horizon theorems for lines and polygons. M. Bern, D. Eppstein, P. Plassman, and F. Yao. Discrete and Computational Geometry: Papers from the DIMACS Special Year, J. Goodman, R. Pollack, and W. Steiger, eds., DIMACS Series in Discrete Mathematics and Theoretical Computer Science 6, Amer. Math. Soc., 1991, 45-66. You could also see Google scholar for a better idea of which of my papers are considered important.
I used the AMS MR Collaboration Distance Web site provided by our WP article Erdős number. Like the Bacon Oracle provided by the equivalent article, the AMS oracle tends to favor newer work (a lot of actors get linked through the 2005 film Where The Truth Lies). But I will change the PM bio to use the earlier path. Anton Mravcek 22:54, 5 March 2007 (UTC)


Thanks for your patience with me AlfPhotoman 01:32, 6 March 2007 (UTC)

And the same to you. This sort of thing would be a lot easier if the people writing these bios had been through a few such debates themselves and written with the expectation that their article would undergo this sort of review, rather than making us find the sources after the debate starts... —David Eppstein 02:07, 6 March 2007 (UTC)
I have suggested a few times that we don't really need debates for deletion but debates for inclusion. That way all the fluff and unsourced material would never get to the view of the public. AlfPhotoman 12:42, 6 March 2007 (UTC)

Divisor function stuff

Howdy, professor. I see you edited the template I created at Template:Divisor classes and also Highly abundant number. Maybe then you are enough a mathematician or you know a math professor who can help out here. As I said at Template_talk:Divisor_classes#Heading, I had a box to create and a concept I could describe, but no name for it. The heading "Divisor class" should be changed. (The underlying template name can remain, since readers don't see it.) Also, at Talk:Divisor_function#What_is_.27.27the.27.27_divisor_function.3F I point out that "the divisor function" is used inconsistently. — Randall Bart 05:25, 7 March 2007 (UTC)

I'm not sure of a good name either, so I tried making it more of a description and less something that sounds like a name for something else. —David Eppstein 05:44, 7 March 2007 (UTC)

Good. I like the categorization scheme, too. I was just trying to logically bunch them, but you've done better. That was the first box that I created from scratch, and I spent a lot of time learning not to fight the tool. Once I got a box that looked decent I stopped. — Randall Bart 16:51, 7 March 2007 (UTC)

Split graph

Hi, David!

I just read your new article. It's great! I'm not even an algebra guy, and it made sense to me. I'm glad you're able to tear free from Egyptian fractions long enough to add such excellent new content to Wikipedia.  ;^> DavidCBryant 22:37, 8 March 2007 (UTC)

Thanks, I'm glad you found it helpful! Though I think I would call it combinatorics more than algebra... —David Eppstein 02:04, 9 March 2007 (UTC)

more graphs, enjoy

Series-parallel graph Cactus graph Operations on graphs, Hamiltonian completion. `'mikka 01:38, 9 March 2007 (UTC)

Thanks for the pointer. I don't promise to do a lot of editing on these, but I'll take a look. —David Eppstein 02:10, 9 March 2007 (UTC)
Well, that was the idea. I merely wanted to show you "Series-parallel graph" with your name inside. `'mikka 18:20, 9 March 2007 (UTC)
I did see that. It's good to see a few articles here related to my actual research rather than my recreational math web sites. So, thanks again. —David Eppstein 18:26, 9 March 2007 (UTC)

Wikipedia:Requests for arbitration#Freedom skies


I've requested an arbitration regarding the conduct of Freedom skies and listed you as a party because of your involvement at Talk:Indian mathematics.

Can I trouble you to write a brief statement at Wikipedia:Requests for arbitration#Freedom skies about what you think of Freedom skies' edits?

A summary of your comments at Talk:Indian mathematics will suffice.

Thank you.

JFD 21:00, 15 March 2007 (UTC)

Wikipedia:Requests for arbitration/Freedom skies


An Arbitration case involving you has been opened: Wikipedia:Requests for arbitration/Freedom skies. Please add any evidence you may wish the arbitrators to consider to the evidence sub-page, Wikipedia:Requests for arbitration/Freedom skies/Evidence. You may also contribute to the case on the workshop sub-page, Wikipedia:Requests for arbitration/Freedom skies/Workshop.

On behalf of the Arbitration Committee, - Penwhale | Blast him / Follow his steps 02:51, 20 March 2007 (UTC)

Would you be willing to fully support the proposition "Freedom skies cites sources which do not support his claims as well as sources which are highly suspect" under the title "Freedom skies' citations are suspect"?
CiteCop 03:48, 23 March 2007 (UTC)
Yes. —David Eppstein 03:51, 23 March 2007 (UTC)
DoneCiteCop 10:13, 23 March 2007 (UTC)

Rafel Gely

I notice your colleague at Laval has about 10 published peer-reviewed articles (smile) DGG 06:13, 25 March 2007 (UTC)

Fast catch on Heppel!

Cheers, Pete.Hurd 04:11, 30 March 2007 (UTC)

WikiProject Cellular automata

Any thoughts about creating a WikiProject for the CA articles? If you think it's a good idea, let me know at my discussion page, along with ideas for tasks, potential members &c. Alpha Omicron 23:12, 10 April 2007 (UTC)

Robert Ira Lewy

David - Am I putting this in the place you requested? I am writing about your comments about non-documented statements about Lewy. You are right; I cannot document that he had no medical privileges for the last ten years or so of his career, as it is almost impossible to document that someone DIDN'T have those privileges, only that he lost them. But there is a host of material on Lewy and the Burzynski Clinic, available by Googling Burzynski and Lewy. some of which directly or in a cached form show that he was the "Medical Director." I just don't know how to incorporate that into the text and its references. As to the credentials of the Burzynski Clinic, quackwatch is a good place to start, but again, I don't know how to connect that up to the article. There are many other references to Burzynski and his clinic by respected oncologists. My only interest here was in seeing that the original biography, with its many omissions, not be used for malevolent purposes. I am not the one, by the way, who has removed references from the bibliography and reference section. Thank you for your comments and your help in this matter. MarciamariaMarciamaria 03:40, 13 April 2007 (UTC)

Close enough to the right place, thanks! I can find plenty of web pages showing some connection between Lewy and Burzynski, but sadly nothing in Google news, which would be more likely for something usable as a source in an article. It doesn't just have to be true, it also has to be documentable to go in. As for the Burzynski clinic, WP's current coverage in Stanisław Burzyński and Antineoplastons makes it look respectable; if you believe otherwise, again, you need reliable documentation. I did add a critical link to the Antineoplaston page; we'll see whether this leads to an edit war. —David Eppstein 03:53, 13 April 2007 (UTC)

Dr Eppstein: Dr Lewy appreciates your thoughtful comments and certainly would like the original complete set of references, including the Circulation article,restored. The article was never intended as a global review of his life, merely a dry rendition of his various publications and philanthropies.At this, it has not succeeded. Best. Kingseasn.

I don't think a complete bibliography is appropriate. This is not a curriculum vitae. If there are a small number of articles that can be documented as particularly well-cited, or necessary to support the claim that Lewy has worked in some general area, it's reasonable to include them, but I don't think this is the place for a "complete set of references". —David Eppstein 21:20, 13 April 2007 (UTC)

Notability template at PROF

David, I would support a better paragraph following the prime notability tmeplate at PROF. Please read the template. We have been successful in introducing some broader inclusion language in the template through compromise. I would support a following paragraph which acknowledges the special cases as exceptions rather than "likely" to have coverage examples. The consensus to use the template is at WP:N and it is inevitable, why not work together to make the inclusion more palatable? --Kevin Murray 20:39, 14 April 2007 (UTC)

As I wrote on the talk page for WP:PROF, I view the template and WP:PROF as serving completely different purposes. I think having the template there unnecessarily confuses the issue. —David Eppstein 21:06, 14 April 2007 (UTC)

Is there room for compromise such that inclusion of the template could be acceptable? --Kevin Murray 21:41, 14 April 2007 (UTC)

I suppose I'd find it acceptable to include a compromise that mentions or includes the template, states that in general most academics will meet the minimum threshhold stated in the template due to their publication and citation records, and goes on to state that standards that more directly address importance are needed for academics and here they are. Is that the sort of thing you mean? I would not want to see a compromise that weakens the language of WP:PROF and directs readers to WP:N to resolve any ambiguities, though, because I see WP:N as inadequate to resolve discussions of academic notability. —David Eppstein 22:01, 14 April 2007 (UTC)
I could agree to that. My concern is lack of continuity. I would rather that PROF could be covered under the creative professionals section at BIO, which has evolved in that direction, but as a compromise I can go with your concerns. I less oppose PROF than I oppose a plethora of special pages by profession. MAybe we could work together on some wording and build some consensus. Thank you for discussing this with me. --Kevin Murray 22:13, 14 April 2007 (UTC)

User talk:

Hey I'm just letting you know that I removed the warning you placed on this user's talkpage and replaced it with a vandalism warning rather than a "no OR" warning. The edit was pure vandalism, nothing else. Hope you don't mind. LibLord 17:51, 16 April 2007 (UTC)

No problem. —David Eppstein 21:08, 16 April 2007 (UTC)

Template:pnc nominated for deletion

See Wikipedia:Templates for deletion/Template:pnc for the discussion, which will certainly spill over into larger issues. Your thoughts would be appreciated. --Kevin Murray 23:04, 16 April 2007 (UTC)


Hi, I was thinking of nominating Pseudotriangle for Wikipedia:Did you know, but I'm not a mathematician, so it's a little difficult for me to write a "hook". Would you be interested in trying? If so, please add it to Template talk:Did you know in the "Articles created on April 12" section. Today is the last day that it's eligible, so if you'd like to see the article on the Main Page, try and get something soon. Thanks. howcheng {chat} 16:05, 17 April 2007 (UTC)

Thanks, I added a suggestion there. —David Eppstein 16:47, 17 April 2007 (UTC)
Updated DYK query On 17 April, 2007, Did you know? was updated with a fact from the article Pseudotriangle, which you created or substantially expanded. If you know of another interesting fact from a recently created article, then please suggest it on the "Did you know?" talk page.

--howcheng {chat} 19:02, 17 April 2007 (UTC)

Joe Sanchez article

In late March and early April, I added comments to the Joe Sanchez page in an effort to improve it. After weeks of inactivity I marked the article for deletion and after the time limit no changes were made and the page was deleted. Yesterday the article reappeared and the user Brentwood said it was brand new. I am at a loss of what to do. I would love to see the article stay if it is improved. —The preceding unsigned comment was added by Typewriter (talkcontribs) 14:29, 25 April 2007 (UTC).

I keep forgetting to sign. Typewriter 14:38, 25 April 2007 (UTC)

Cyclic cellular automaton

Updated DYK query On 26 April, 2007, Did you know? was updated with a fact from the article Cyclic cellular automaton, which you created or substantially expanded. If you know of another interesting fact from a recently created article, then please suggest it on the "Did you know?" talk page.

--howcheng {chat} 19:59, 26 April 2007 (UTC)

Thanks for including this! —David Eppstein 20:53, 26 April 2007 (UTC)

Wikipedia:Requests for arbitration/Freedom skies

This case is now closed and the results have been published at the link above.

  • Freedom skies is placed on standard revert parole for one year. He is limited to one revert per page per week, excepting obvious vandalism. Further, he is required to discuss any content reversions on the page's talk page.
  • Freedom skies shall select one account and use only that account. Any other account used may be indefinitely banned. Pending selection of an account Freedom skies may not edit Wikipedia.
  • Violations of paroles and probations imposed on parties of this case shall be enforced by blocks for an appropriate period of time. Blocks and bans are to be logged at Wikipedia:Requests for arbitration/Freedom skies#Log of blocks and bans.

For the Arbitration Committee --Srikeit 18:39, 3 May 2007 (UTC)

Julius König

Thank you for improving my article. Regards, WM 07:49, 4 May 2007 (UTC)

You're welcome! —David Eppstein 14:28, 4 May 2007 (UTC)


Hi David. You've been here for eight months now, and I think by now you have a good experience with what Wikipedia is about. Would you consider candidating for administrator? If so, I'd be very happy to nominate you. I wonder what you think. You can reply here. Thanks. Oleg Alexandrov (talk) 03:30, 5 May 2007 (UTC)

Sure, go ahead. It looks like the extra tools admins have could be useful for some of the patterns of editing I've been doing. Thanks for the suggestion and the vote of confidence. —David Eppstein 21:07, 5 May 2007 (UTC)

Cool, here it is: Wikipedia:Requests for adminship/David Eppstein. You would need to

  • Answer the questions
  • Accept the nomination
  • Change the time on top to one week from the time you accepted the nomination
  • Transclude the nomination at WP:RfA

From past experience, I would suggest you take great care in answering the questions. (If you wish, you could take a look at other people's nominations first, e.g., at some mathematicians' past nominations, like CMummert, Paul August, Arthur Rubin, etc.) That because the adminship process is rather political, and people like to vote silly and pick at things sometimes. (But don't worry too much, I am sure you will pass, and with a solid amount of support.)

Good luck! Oleg Alexandrov (talk) 01:20, 6 May 2007 (UTC)

By the way, note that you may get grilled in the RfA by the "bitch about" comment mentioned below. I happen to agree with fbb_fan that it can leave one seriously pissed off (even though, both you and him meant well, of course). Just to let you know. :) If you'd prefer us to delay this adminship business for a while, I would understand, although my guess would be the resulting pile-on oppose votes won't be enough to derail the nomination. Oleg Alexandrov (talk) 01:28, 6 May 2007 (UTC)
I'm happy to delay, if you think that best. I'm quite comfortable contributing at the level I have been already, so if the timing seems strange, to make this request just as this minor kerfuffle erupts, I have no problem waiting. —David Eppstein 02:04, 6 May 2007 (UTC)
Yeah, I think it's better to delay a bit. You'll pass either way, but given how susceptible to drama RfA can be, there's no need to actively create more of it over there. I'll bug you again in a short while. In the meantime, keep on doing the good work, I've been very impressed with your picture gallery by the way, and that as a tenured professor you have the enthusiasm to contribute to Wikipedia. Cheers, Oleg Alexandrov (talk) 02:42, 6 May 2007 (UTC)
I would be happy to support; far be it from me to bitch about a little helpful kibitzing. But Oleg, you know those UC schools in southern California are party schools where the students spend most of their time surfing and working on their tans. ;-)
A suggestion about the images: Consider placing them in Commons. Also, if you use freely available tools (e.g., Graphviz), it might be nice to mention that on an image's description page, to guide others. --KSmrqT 04:10, 6 May 2007 (UTC)
You're thinking of UCSB, I think... as for the commons, that is something I have yet to figure out, but it doesn't look too difficult...maybe I will try that the next time I upload some images. The tools I use (mostly Adobe Illustrator) are not free, sadly. —David Eppstein 04:12, 6 May 2007 (UTC)
Did you notice where Oleg chose to do his post-doc? ;-) --KSmrqT 05:24, 6 May 2007 (UTC)
Uploading things at commons is as easy at visiting and doing the same thing as you do on Wikipedia. Images from there are automatically available on the English Wikipedia and any other Wikipedias, they behave exactly as local images. David, you could also upload some of the existing images to commons, that way they may be used by other projects too. Oleg Alexandrov (talk) 04:35, 6 May 2007 (UTC)
I have a bunch of older .png format images that should be vectorized anyway (I kept the vector versions on my local disk, so it is mostly just a matter of opening and resaving). I just tried uploading the vector version of one of them (no-three-in-line problem) to the commons and updating both the en and th wikipedia pages to use the new image. It was, as you say, easy. Thanks for the tip. —David Eppstein 04:38, 6 May 2007 (UTC)
I prefer SVG over PNG as well; but Wikipedia has chosen a rasterizer (librsvg) with limitations, and font support is also a consideration. Many of your images have no text, which makes them excellent as contributions to Commons. (And if you can use SVG, the text is usually easy to replace with a translation.) --KSmrqT 05:24, 6 May 2007 (UTC)

Wikipedia:Articles for deletion/Friedrich Stephan

It looks like you ought to become familiar with WP:AFD#AfD_etiquette and WP:CIVIL. fbb_fan 22:01, 5 May 2007 (UTC)

  • It was not intended as incivility, merely constructive criticism. I attempted to suggest a course of action that would, I think, lead to a greater amount of improvement to WP than the (inherently destructive although necessary) AfD process: edit, when an edit is obvious and easy, instead of using someone else's failure to make that edit as an argument against an article. It was not intended as an insult against you, merely a disagreement with your course of action, and if the way I worded it led you to interpret it in any other way I apologize. —David Eppstein 22:28, 5 May 2007 (UTC)


Updated DYK query On 9 May, 2007, Did you know? was updated with a fact from the article Rule 184, which you created or substantially expanded. If you know of another interesting fact from a recently created article, then please suggest it on the "Did you know?" talk page.

--ALoan (Talk) 14:21, 9 May 2007 (UTC)

Wow, what an amazing article! Great work! Thanks for providing an enjoyable break from revision... Verisimilus T 17:28, 9 May 2007 (UTC)
Thanks! I'm glad to hear you found it interesting. —David Eppstein 20:22, 9 May 2007 (UTC)

Mathematics CotW

Hey David, I am writing you to let you know that the Mathematics Collaboration of the week(soon to "of the month") is getting an overhaul of sorts and I would encourage you to participate in whatever way you can, i.e. nominate an article, contribute to an article, or sign up to be part of the project. Any help would be greatly appreciated, thanks--Cronholm144 20:59, 13 May 2007 (UTC)

Re: Prodding me

Please see WP:AGF. Your suggestion that my edit was in "bad faith" is laughable. Yours was not the only article I tagged; I know you are aware of this, since you have subsequently edited a few of the tagged articles. I've become aware recently that there are numerous articles on college professors that do little more than indicate where the person has taught and what their research interests are. I don't see where there is any bad faith in adding notability tags to such articles. fbb_fan 23:39, 13 May 2007 (UTC)

Read more carefully. I did not suggest that your edit actually was in bad faith — that would require knowledge of your state of mind that I do not possess. What I said was that it had the appearance of being in bad faith. And I don't see how tagging my article and then those of another half-dozen faculty at the same university is evidence either way, especially in light of all the bad-faith accusations (not from me!) when another single institution (Florida State) was targeted in a sequence of AfDs that we both commented on. Look, I can easily find good-faith explanations for your behavior: our interaction led you to my user page, which led you to the article on me, which you then tagged as you often do other articles, and followed links from there to the other UCI faculty to tag some more. But it's not the only explanation that comes to mind. I think WP:AGF has a corollary, that you should act in a way that makes it easy for others to assume good faith.
I don't want to argue about your individual edits, anyway. You'll notice that I didn't just undo all your tags — many of them did point out genuine weaknesses in articles that were worth fixing. I do take exception to your apparent attitude that tagging things as a default is a good way to improve Wikipedia. A tagged badly-written article is just an uglier badly-written article, until someone else does the actual work required to remove the tags. My preferred approach is that if I see something easily fixable, I fix it. It doesn't take much more time than tagging and it leaves WP in a more usable state for everyone else. I do leave tags, sometimes, but only in situations where my searches failed to find the information needed to improve the article. Here's a recent example — maybe a prod or an AfD would have been better but for that article I'd rather see it improved to the point of being worth keeping than just dumped.
As for the "do little more than indicate where the person has taught and what their research interests are": these are articles about university faculty. What else do you expect the articles to describe? It is unlikely for academics to be notable solely for their teaching, but statements of research interests can often be read as meaning that the academics are considered by their peers to be important experts on that subject. Such statements, of course, would be much more believable if backed up by sources rather than just unsourced assertions, but it is rare to find publically-available documents that say "so-and-so is the world's leading expert on such-and-such" — usually such statements are reserved for the confidential recommendation letters that go into all academics' hiring, tenure and promotion cases. Instead one must make inferences e.g. from citation counts on Google scholar and similar databases, membership on editorial boards and program committees, awards and honors, or exalted academic ranks such as named chairs and distinguished professorships. Which is a long-winded way of saying that, for those with eyes to see, the notability assertions are already there.
David Eppstein 00:34, 14 May 2007 (UTC)

AFL operations redirect

Thanx for the redirect. I am working through the missing math articles lists, and I have yet to try to redirect from one-sentence articles that I find now are better suited to the dictionary. As I go through the lists, I find many topics that may end up being redirect pages. I'm going to read up on redirects right now! Hotfeba 19:36, 16 May 2007 (UTC)

Indian Mathematics

Hi David, I finally have some time to start doing a major revision of the page, which I had originally planned to do much earlier (after the RfC in March). I hope you'll have some time to look in every now and then and offer criticism. Regards, Fowler&fowler«Talk» 01:09, 17 May 2007 (UTC)

Thanks, I've been seeing some of your changes on my watchlist. It'll take a while to get through it all, I'm sure, but what you've done so far looks good. —David Eppstein 01:37, 17 May 2007 (UTC)

Star -- possible misunderstanding

Sorry about the possible misunderstanding of the "star" comment on the AfD for Andrew Gordus. I know from your other AfDs that you don't require star status, and I think that's why I rushed in with the disagreement comment (which I was pretty sure wasn't a disagreement at all). I was concerned that someone might take your comment as a precedent (e.g. "As Eppstein himself has said, researchers need to be stars to be notable.") for future AfDs. I appreciate the reply.

Thanks for all your great work on the Academics AfD sorting. Best, -- Myke Cuthbert (talk) 21:27, 19 May 2007 (UTC)

No need to apologize, I think — thanks for giving me the opportunity to clarify what I meant. —David Eppstein 21:28, 19 May 2007 (UTC)


Hey, David, nice to see you here. In case you don't remember, I emailed you in the past about my circular infinity image. I've learned more about it since then and it has led me to more esoteric research as of late. Anyway, just wanted to say hi. See you around. -Єερ² (τ|c) 21:51, 19 May 2007 (UTC)

Vertex Dab page.

From Wikipedia:Disambiguation#What_not_to_include


Lists of articles of which the disambiguated term forms only a part of the article title don't belong here. Disambiguation pages are not search indices. Do not add links that merely contain part of the page title (where there is no significant risk of confusion).

Can 'Vertex' really refer to the vertex cover problem? etc.

Taemyr 20:21, 20 May 2007 (UTC)

Thanks for the clarification. I'll check through more carefully and move some of these to the main "vertex" articles for those topics, if possible. I have found some links to vertex that should go to some of these part-of-the-title pages: particularly, surface vertex, vertex shader, and vertex pipeline, so I think just blindly removing all articles not titled "vertex" would be a mistake. —David Eppstein 20:26, 20 May 2007 (UTC)


Hi David. It's been more than a couple of weeks, it appears that your exchange with User:Fbb fan did not escalate beyond the original discussion, and back then you promptly apologized for any possible offense caused by your remark. So, we can put that behind us. How about giving adminship a try? :) Oleg Alexandrov (talk) 02:51, 24 May 2007 (UTC)

I second that.--Cronholm144 02:53, 24 May 2007 (UTC)

Ok, I'll work some more on the questionaire and let you know when i am ready with it. —David Eppstein 05:13, 26 May 2007 (UTC)
Great! The nomination is at Wikipedia:Requests for adminship/David Eppstein (now reverted from the redirect). I wrote above a few suggestions on what to do as far as I can can tell. Good luck! Oleg Alexandrov (talk) 05:36, 26 May 2007 (UTC)

Indian math

Hey Dave, although it doesn't really matter, but it would be good to know the reason behind your edit summary here. All I did in that edit (excluding the Kerala part) was the following:

Deleted line: This period is often known as the golden age of Indian Mathematics.

This is unreferenced, and quite likely to be plain wrong.

Deleted phrase: Although earlier Indian mathematics was also very significant,

This is a judgement on earlier Indian mathematics that need not really be made, and certainly does represent a viewpoint.

Deleted phrase: Though its authorship is unknown,

Though is used to express contradiction. There is no contradiction between the unknown authorship and the fact that it contains the roots of modern trigonometry.

Replaced :

It also contains the earliest uses of:


It also contains the earliest uses of Tangent and Secant.

Please let me know which part of these edits, that I was aiming to remove judgements and improve sentence structure was "too loaded with pov". Thanks, deeptrivia (talk) 19:59, 25 May 2007 (UTC)

I think if you look at the edit history a couple lines up, you'll see a later edit from me where I realized that the pov I was complaining about wasn't inserted by you, it was just made more prominent by your edit. It was much more blatant than the quotes you've included here, but I don't have time to look it up right now. —David Eppstein 20:01, 25 May 2007 (UTC)
(Later): here it is. The sentence I didn't think appropriate was the unsourced, hyperbolic, and not especially informative claim that "the system of Indian mathematics used in this period was far superior to Hellenistic mathematics, in everything except geometry," which your edit moved around but left unchanged. —David Eppstein 23:00, 25 May 2007 (UTC)


Hi, i just wanted to make sure that my accounting wasn't flawed somewhere, because i found what seems to be a missing edge in that image, compared to Image:Koenigs-theorem-graph.png. The way i see it, there is a (hidden?) edge between the leftmost vertex on S1 and the leftmost vertex on S4, corresponding to the edge between leftmost vertex on top line and second vertex from right on bottom line. Would you agree with that statement? And is there a way to make it bypass the other edges and vertices that might show up above it? (Like an arc on the left exterior or something...) Thanks. -- Jokes Free4Me 21:02, 30 May 2007 (UTC)

Yes, looks like you're right. I should replace those images with vector versions anyway; I'll do so later today, and add the missing edge when I do. —David Eppstein 21:12, 30 May 2007 (UTC)


I replied on my talk page. Oleg Alexandrov (talk) 15:48, 31 May 2007 (UTC)

How about signing you acceptance, just for the sake of clarity? :) Oleg Alexandrov (talk) 16:04, 31 May 2007 (UTC)

Image:Groetzsch-graph.png on Commons?

hello there David, that's a really cool graphic of yours. Have you thought about using the Wikimedia Commons as well? That would greatly increase the usage of such images for the other language Wikipedias and help interlink your images. I would be very happy to see you there, take a look if you can. sincerely Gryffindor 14:47, 1 June 2007 (UTC)

Thanks, I've been slowly converting my images to svg instead of png (as the original vector information still exists on my hard drive) and uploading them to commons, but hadn't gotten to that one yet. Will do. —David Eppstein 15:52, 1 June 2007 (UTC)

Significant loss of relevance of MathSciNet for applied fields

I appreciate your interest and contribution. Please respond on the talk page there if you wish. Jmath666 16:31, 1 June 2007 (UTC)

A semi-random question about your article

First off, congrats on your soon-to-be adminship. I, for one, feel it is well-deserved.
Second, the image on your article (which you uploaded yourself) is fair use. Why not just take a picture of yourself and release it for free use? I know that's an incredibly random question, and it's not as if this has a bearing on anything, but I was simply wondering. -- Kicking222 13:51, 2 June 2007 (UTC)


Thanks for uploading Image:Eppstein-UC03.jpg. I notice the 'image' page specifies that the image is being used under fair use, but its use in Wikipedia articles fails our first fair use criterion in that it illustrates a subject for which a freely licensed image could reasonably be found or created that provides substantially the same information. If you believe this image is not replaceable, please:

  1. Go to the image description page and edit it to add {{Replaceable fair use disputed}}, without deleting the original Replaceable fair use template.
  2. On the image discussion page, write the reason why this image is not replaceable at all.

Alternatively, you can also choose to replace the fair use image by finding a freely licensed image of its subject, requesting that the copyright holder release this (or a similar) image under a free license, or by taking a picture of it yourself.

If you have uploaded other fair use media, consider checking that you have specified how these images fully satisfy our fair use criteria. You can find a list of 'image' pages you have edited by clicking on this link. Note that any fair use images which are replaceable by free-licensed alternatives will be deleted one week after they have been uploaded, as described on criteria for speedy deletion. If you have any questions please ask them at the Media copyright questions page. Thank you. ··coelacan 14:59, 2 June 2007 (UTC)

Copied from Image talk:Eppstein-UC03.jpg

User:Coelacan tagged this as questionable for WP's fair use policy. I don't really care whether you keep this image or not (I don't feel that maintenance of the article David Eppstein should be my responsibility, and I only uploaded this at the request of User:NerdyNSK, as can be seen in a discussion on my talk page dated 5 Nov 2006), but as for "replaceable fair use": I do not believe there exists a public domain or freely licenced portrait of me that would be suitable; there exist some snapshots of me that are less appropriate for this use (mentioned in the referenced discussion) but they have not been granted any kind of copyright release, are less encyclopedic, and I am very reluctant to request any of the photographers who have taken those snapshots to release them freely. Does it really matter whether there could exist a replacement if only some Wikipedian were generous enough to pay a professional photographer to take a portrait of me and release it more freely?

This photo was taken with the intent that it be used for publicity purposes such as this, and has been granted explicit permission for use on Wikipedia by the copyright owner (the Regents of the UC, via the proxy of my school's external relations office); I realize that that's not as acceptable for WP purposes as something that has been placed in public domain or freely licensed, but it's a lot less questionable than merely "fair use of copyrighted material" and it was and remains the most free shot I have that would be suitable. The external relations office has told me that they have some plans for doing a new series of photos of this type that would be, I think, licensed via Creative Commons in a way that would work better for Wikipedia, but it hasn't happened yet. —David Eppstein 15:28, 2 June 2007 (UTC)

Hi David. Under a directive from the Wikimedia Foundation (at Foundation:Resolution:Licensing policy), we do not allow fair use images of living people. See Wikipedia:Non-free content#Examples of unacceptable use: "8. An image of a living person that merely shows what s/he looks like. The rationale is that this is potentially replaceable with a freshly produced free photograph." That's the policy side of it. For practical purposes, as to getting a good photo for the current article, perhaps you have a friend who's handy with a camera? Then there could be a good image in the meantime, until your employer comes up with something properly licensed. ··coelacan 18:39, 2 June 2007 (UTC)
I know plenty of people who can press the shutter button on a camera. I know nobody who is a professionally skilled portraitist willing to give his or her work away for free. And I do have a little pride: I'm not especially interested in supplying you with or helping to produce an unprofessional snapshot for this sort of purpose. So if the one that's already here does not count as an acceptably-licenced image, I think the result of your policy will be no image at all. You guys have a strange definition of "replaceable". —David Eppstein 18:41, 2 June 2007 (UTC)
Well... I didn't write the policy and I wasn't happy with it when it first went into effect. So I do empathize with your dissatisfaction. But speaking from my new perspective: the primary goal of is to produce a libre-licensed encyclopedia, so we only use US fair use law when we believe we could never get a libre alternative in the future. Some projects, like, don't allow fair use at all. Since you're alive and walking around, we think we can probably get a photo of you somehow. If you're not careful, someone will get a snapshot of you with your mouth open. =D Or, if you get eaten by a grizzly, we can keep this fair use image. But you're right; the result of the current policy will be no image at all until/unless something GFDL-compatible comes along. ··coelacan 22:44, 2 June 2007 (UTC)
I think the line in the policy that "The rationale is that this is potentially replaceable with a freshly produced free photograph" is missing a very important detail, that the replacement photograph should be of encyclopedic quality. But the policy itself is clear. So I'll remove the "disputed" tag and copy this discussion to my talk page, since here it seems in imminent danger of being deleted with the image. —David Eppstein 22:52, 2 June 2007 (UTC)
We do get rid of some very bad pictures on grounds of being unencyclopedic, though for our purposes, "encyclopedic" just means "providing information that would visually identify the article subject". It's a perennial discussion, which is why Wikipedia talk:Non-free content carries the {{calm talk}} banner, but the result has consistently been that we require GFDL-compatible images except where impossible, without regard for professional photography. Does your removal of the disputed tag mean I can go ahead and delete the image, or would you prefer to wait for another admin to review the talk page discussion and come to an independent conclusion? ··coelacan 00:02, 3 June 2007 (UTC)
I'd prefer to wait until Wikipedia:Requests for adminship/David Eppstein closes in a few more days, since there's some related discussion going on there that will become unlinked if the picture gets deleted. But as for whether you want to remove it yourself or get another admin to review, it's your decision; my removal of the disputed tag means that I agree with your interpretation of the current policy, though. —David Eppstein 00:07, 3 June 2007 (UTC)
Okay, if you think that's best. I thought it might be better to go ahead and redlink the image: "old mistake, all cleared up now, no reason to oppose." But I won't hurry, if you'd rather now. ··coelacan 00:16, 3 June 2007 (UTC)
I'm still not convinced it was a mistake, though under the current version of policy it likely would be. In any case, I'd prefer old mistakes to remain visible for now rather than trying to cover them up. —David Eppstein 00:18, 3 June 2007 (UTC)
This was the status of the page when you made the upload. That version had essentially the current doctrine but there had been a recent edit war about it. It's quite possible that when you familiarized yourself with it, the page might have been in a different state. As near as I can tell, the doctrine went into effect with this edit and the slow revert war continued into late October. The dispute was over whether replaceable fair use images would be allowed to remain until free images became available. ··coelacan 01:03, 3 June 2007 (UTC)

You're an Admin!

It is my pleasure to inform you that you are now an admin. Congratulations. You can feel free to do everything you're supposed to do and nothing you're not supposed to do. If you haven't already, now is the time look through the Wikipedia:Administrators' how-to guide and Wikipedia:Administrators' reading list. If you have any questions, feel free to ask me, or at the Wikipedia:Administrators' noticeboard. Best wishes and good luck, -- Cecropia 15:13, 7 June 2007 (UTC)

Congrats! :) Oleg Alexandrov (talk) 15:15, 7 June 2007 (UTC)
Wow, 87/0/0; congratulations indeed. I almost opposed on the grounds that you would inevitably be sucked in to doing admin stuff rather than fine editing, but I had already committed to support. ;-) Enjoy the mop. --KSmrqT 16:25, 7 June 2007 (UTC)
Congratulations, David. —Anas talk? 16:23, 7 June 2007 (UTC)
Congratulations. Here are what pass for words of wisdom from the puppy:
  1. Remember you will always protect the wrong version.
  2. Remember you must always follow the rules, except for when you ignore them. You will always pick the wrong one to do. (See #5)
  3. Remember to assume good faith and not bite. Remember that when you are applying these principles most diligently, you are probably dealing with a troll.
  4. Use the block ability sparingly. Enjoy the insults you receive when you do block.
  5. Remember when you make these errors, someone will be more than happy to point them out to you in dazzling clarity and descriptive terminology.
  6. and finally, Remember to contact me if you ever need assistance, and I will do what I am able.
DISCLAIMER: This humor does not reflect the official humor of Wikipedia, the Wikimedia Foundation, or Jimbo Wales. All rights released under GFDL.
Many contratulations from me too. I just read your "fix it rather than add tags (if possible)" comment above. I couldn't agree more with your wiki-philosophy. Geometry guy 21:11, 12 June 2007 (UTC)

Thanks, all, for the overwhelming support (and too for the words of wisdom)!
David Eppstein 21:30, 12 June 2007 (UTC)

Lowest Common Ancestor

Hi there,

The binary tree in my implemetation doesn't have to be balanced (I know that pictures suggest that), as long as nodes have proper numbering. (This isn't big problem, since the depth of BT can be remembered while building BT and BT depth can be used to easily calculate node number, if there are missing nodes).

(replied on Talk:Lowest common ancestor) —David Eppstein 19:51, 13 June 2007 (UTC)



thanks a lot for pointing out that my links to CGAL packages might be considered as a COI. Also, you might have a look at my contributions page, as there are more external links than those you fixed.

Finally, in case you don't watch the CGAL page, I added two suggestions on the discussion page.

Andreas Fabri 20:43, 16 June 2007 (UTC)

I have no ties to the CGAL project, and would be happy to vouch for links should the need arise. It's a valuable package with generous dual licensing. Robust computational geometry is commercially important, and coding is far more work than the uninitiated might imagine. Yet CGAL is open source and free for open-source use.
Wikipedia has ongoing problems with individual (vanity) self-promotion and commercial promotion, especially since its pages have become so prominent in web search results. So, we try to avoid even the impression of COI. Large numbers of links created by an individual connected with a site tend to arouse the "immune system". :-) --KSmrqT 21:22, 16 June 2007 (UTC)

Please help me.

Could you help me rollback the history on Talk:White Latin American. Thank You. Etherroyal 22:00, 18 June 2007 (UTC)

I'm not sure I understand this request. What part of the history do you want rolled back, and why? —David Eppstein 22:32, 18 June 2007 (UTC)

Welcome to the wonderful world of adminship David :)--Cronholm144 22:41, 18 June 2007 (UTC)

Heh, thanks. But did someone forget to include telepathy among the amazing powers granted to admins? —David Eppstein 22:45, 18 June 2007 (UTC)

They had to throw out the telepathy so they could fit in the giant troll magnet, the smaller but equally fun crank and vandal magnet, and the automatic assumption bad faith.--Cronholm144 22:53, 18 June 2007 (UTC)


Thanks for fixing Template:Autoblock, much appreciated! -Ravedave 06:21, 24 June 2007 (UTC)

You're welcome, glad to be of service. —David Eppstein 08:26, 24 June 2007 (UTC)

Sprague Grundy Theorem

Hi there,

You reverted my edit "proof omitted." on the Sprague Grundy page. Now there may be other reasons not to put that there, but "it's a definition, not a result" is not one of them. The paper at for instance, spends just over a page (roughly, page 7) getting from "equivalence is defined as both games having the same outcome no matter what game is added to it" to "in impartial games this reduces to the sum of the games being a P position." It's not a hard result to get, but it's by no means a trivial one. Now, I'll stand by your edit if you still think no mention of the work required to get from one to the other is necessary, I'm just wondering what your thoughts are.

— Preceding unsigned comment added by Helopticor (talkcontribs)

I was misinterpreting the part you were omitting the proof for to be "Two games G and G' are equivalent if for every game H, the game G+H is in the same outcome class as G'+H," a definition. I agree that it makes more sense to have a proof for the second sentence, "For impartial games, this is the same as the condition that G+G' is a P-position," and that the proof of this statement is important for the proof of the Sprague-Grundy theorem as presented. Maybe the "proof omitted" statement would work better as a full sentence somewhere in the proof section, but I thought it seemed out of place where you put it. —David Eppstein 19:45, 26 June 2007 (UTC)

A request re: review of some game theory articles

Hi David, I was wondering if you could spare some time to look at some game theory articles WRT to good article criteria. An editor has suggested that none of them meet the conditions. The concern seems mostly to do with the quality of the lead sections. Of these articles, I'm most motivated to improve Best response and Evolutionarily stable strategy (editor's concerns about this article are presented on Talk:Best response#GA review & Talk:Evolutionarily stable strategy#GA review). I trust your opinions on this, and would be very keen to hear if you have any suggestions to make the lead to Best response a better summary of the article, and/or more accessible. Best regards, Pete.Hurd 03:38, 13 July 2007 (UTC)

Sorry for the nonresponse, I was traveling and largely away from the internet. Back now, but I still have a lot of catching up to do. In the meantime, it looks like Geometry Guy (an active and competent member of Wikiproject Math) has delisted them, so a full good article renomination would be needed to restore their GA status, I guess. —David Eppstein 14:23, 16 July 2007 (UTC)

Wikipedia:Articles for deletion/Detleff Neumann-Neurode

In closing Wikipedia:Articles for deletion/Detleff Neumann-Neurode, it appears you forgot to remove the AfD notice from the article itself. I have done so. — Swpb talk contribs 16:31, 13 July 2007 (UTC)

Oops. Thanks for the cleanup. —David Eppstein 14:18, 16 July 2007 (UTC)

Knowledge space

I've suggested that the page be deleted. Banno 22:03, 13 July 2007 (UTC)

Barton Myers

re: Barton Myers post - Appreciate your comment and yes, he is the grandson of the Barton Myers you mentioned. If you are interested, here is a blurb from the exhibition mounted at the Chrysler Museum of Art in Norfolk: "One of Norfolk’s most prominent citizens of the early 20th century, Barton Myers (1853-1927) dedicated his life’s work to the betterment of his community and fellow citizens. He involved himself in numerous projects, including political reform, economic development, and public improvements. These projects molded Norfolk into the modern, prosperous port that it is today. Despite his accomplishments, Barton Myers remains little known today in a city that still enjoys the fruits of his labor." (seems to be a family curse) re: the debate on Barton Myers the architect being noteable, frankly I'm shocked by the ignorance of some. Do they not realize what the Canadian Governor General Award is or what an elite honor it is for a Canadian to receive one? If someone asked Robert Ivy, the editor-in-chief of Architectural Record, if Barton deserved a place among the most import American architects of the past 50 years, he would certainly agree. As for his status in Canada, he is certainly considered one of the most important figures and is responsible for ushering moderism and changing ideas about urban infill (perhaps boring to some but fascinating to the architecture and urban design community). His design for the Wolf House was cited as the Canadian design "that most anticipated the 21st century" by Canadian Architect Magazine. Canadian encyclopedias (print and online) have been publishing a Barton Myers entry since the early 80s. I choose to let the cards fall where they may because aguing with the "Quiznos" scholar just insn't worth the effort. I sense a real bias against professional entires in Wikipedia. Perhaps this is why the researchers, scholars, designers and artisits are increasingly ignoring this wonderful opportunity to build a knowledge base. An interesting bio can also be read here (trivia: the "noteable" Edmund Bacon mentioned was a wonderful urban planner and the father of Kevin Bacon): Bmyersinc 17:55, 19 July 2007 (UTC)

Re: the username change: in case you were interested, the reason I changed the username was that it was upsetting some users (see very first postin the debate). I'm trying not to take comments personally but words like "lackluster" and "crummy" are just plain mean, aren't they? I continue to let the community decide of the fate of this entry although I could point to numerous peer and less accomplished architects with their own pages. I'm such a novice at this that I'm not even sure if I'm allowed to join the debate. Seems to me that anything I would say in defence would already be in the entry itself. BTW, Bmyersinc and blueberryman are the same user with a request for a username change. Thanks for your "objective" support of this entry. The full reason and documentation of the username change can be found here: Blueberryman 00:31, 25 July 2007 (UTC)

John Buscema

'Skyelarke: given your direct involvement in the ongoing RFM, an extensive set of edits of this type from you seems premature, and contradictory to the reason for imposing a block on editing this page'.

Thanks for taking a look at my request - I can see how it appears to seem premature and contradictory to the block rationale - allow me to clarify a bit, if I may -

The footnote corrections that I did were in fact the final step in a process begun by myself (and I thought with the other editor's agreement) i.e. 'So I'll start going through my notes and and gather up the proper references. Skyelarke 15:30, 15 December 2006 (UTC)

Cool. Let's ref it up... --Tenebrae 15:31, 17 December 2006 (UTC)

also: 'I plan on going over the footnotes once they're done and make the necessary corrections. -Skyelarke 00:38, 11 May 2007 (UTC)

The only reason that I was unable to finish before the block was due to the other editor's rather peremptory and impulsive implementing of adminstrative procedures i.e.

- Feb. 26 - RfC
- April 27 -' Several editors, and heaven knows you can see them at Talk:John Buscema, have tried to work with a fanatic fan, User:Skyelarke, who is a single-purpose account... He has continually added POV and irrelevant, fan-page trivia,...'

- June 11 - RfM
-June 12 - Page Protection Request - 'Severe, longstanding edit is requested to stop edit war...'

In all cases, theses were implemented without prior discussion of particular obstacles or notification and without any indication of relunctance on my part to continue with rational, civil discussion.

The description of the page protection request as 'severe, long-standing edit war...' being misleading as the lenghty, discursive nature of the dispute being due to my conscious efforts to implement verifiability, discussion, and slowing down as prelimary dispute resolution steps.

Finally, my failure to finalize footnote revisions was in part due to the other editor's unexplained withdrawal from editing and abrupt return on June 7th and his subsequent arguments with two new unexpected contributing editors on June 11.

All this to say that I'd appreciate it if you could at least upload the version onto the article and revert back to the current version - as I feel having an accurate, clearly referenced version on record, with the dating and comparison functions, will help with the mediation process. In any case, it's the version I'd like to work with in mediation rather than the 12:48, 12 June 2007 version; it would also free up space on my user page.

--Skyelarke 00:22, 21 July 2007 (UTC)

In attempting to continue the discussion here as well as in the article talk page and in the RFD, you deleted some old conversations that were already here. I've restored them, but in future please don't do that. —David Eppstein 00:25, 21 July 2007 (UTC)


Wikipedia wants to avoid legal exposure to copyright violations. I expect the lack of compliance in this case was due to ignorance, but that is often the case. There can be little argument that we were dealing with a copy (derivative work), and that it would have been trivial to comply with the license by including attribution and using the same license. People need to learn to pay attention to copyright if it is to mean anything. Ignoring it can be costly; intellectual property is taken very seriously by some.

Improper integral, two ways

There were several creative choices involved in making an image to illustrate this aspect of Boolean algebras; I know, because I made those choices. One of those choices, note, was to use graphviz, something most graphic artists would know nothing about. Copying the image is much simpler than designing and creating the original.

Consider Image:Improper integral.svg (shown right), which seems to be trivial. I spent quite some time hunting for a good function to illustrate both kinds of improper integral simultaneously; that included a discussion on Talk:Integral, where this particular one was suggested. The very idea to include both kinds of impropriety was not obvious. (Challenge: look for precedent.) I experimented to find an appropriate domain and range. I learned to use gnuplot, including various details I wished to control. I had to do some tinkering with the font, and choose one supported by Wikipedia. (How many people would be aware of the issue, and know of this listing?) And, the curve itself is not the piecewise-linear one produced by gnuplot, but a G1-continuous piecewise-Bézier-curve approximation produced by optimization involving the lengths of tangent vectors. (Thus it really will scale to huge sizes without visible kinks.) And that pretty blue color? That is not merely an "artistic choice"; it is based on a long interest in human vision and a search of the research literature to find reliable data to reproduce the "unique blue" of the opponent process and Berlin and Kay, using the sRGB color space.

I feel fairly sure the depth of work behind this image, and others I have created, is somewhat unusual. No casual reader or copier would be likely to suspect that depth. They may think it's pretty, or effective, if they think at all. That's fine; a good design does its job without calling attention to itself, except to an expert. (Like sleight-of-hand, if the audiences notices it, it's a mistake.) But that is no excuse for ignoring the fine print.

The license gives permission to use the image and to create derivative works, even works for profit. Is it really so much to ask for attribution? --KSmrqT 19:42, 24 July 2007 (UTC)

It's more than I care to ask for my own diagrams, even this one where the artistic choices involved rather more than coloring or whether to fill the arrowheads. But obviously, if you choose that kind of license for your own images, it should be respected, and I wasn't asking that it not be. The dispute arose not because of any difference over how copyright and licensing should be interpreted and applied, but because the edit descriptions removing the image didn't make it clear to me what was wrong with its licensing. As for whether "there can be little argument" that this was an improperly credited derivative work: the discussion convinces me that it was, but I think there is room for argument, since the image in question is so close to the default output of a standard graph drawing package, as we already discussed. —David Eppstein 20:04, 24 July 2007 (UTC) (For future reference: this conversation involves this sequence of edits and the ensuing discussion.)
P.S. I hope that this doesn't mean you will require a credit line whenever anyone uses something close to that blue in a diagram, or whenever anyone draws a Hasse diagram of a Boolean algebra that draws the vertices as ovals with an expression for the set inside them. —David Eppstein 20:06, 24 July 2007 (UTC)
I think the human visual system holds the rights to unique blue. However, it would surprise me if I saw that particular RGB triple and there was not a path back to me; vision research typically uses Munsell chips, or CIE chromaticity coordinates, or other such standards. One of these days I'm going to fill in the rest of the basic colors: orange, purple, pink, brown. They don't fall into the unique hues theory, so it's harder to pin them down precisely.
As for Hasse diagrams, if I were filing for a patent, it would, of course, claim rights to the {x,y,z} example, and to any three-element example, and to any n-element example, and to any Hasse diagram, and to a diagram with ovals of any eccentricity. Poor companies would pay to license the patent because they couldn't afford court costs. If the patent were challenged in court, the judge would rule that prior art goes to Arlo Guthrie, whose epic talking blues, Alice's Restaurant refers to pictures with "circles and arrows and a paragraph on the back". He might be correct; but I could sell the rights to Microsoft, and thus be guaranteed a win on appeal (and an early retirement). :-D --KSmrqT 21:01, 24 July 2007 (UTC)

encountering bad speedies

Most speedies put on during an afd discussion (except for copyvio) are bad speedies, and if you think one is, the simplest thing to do is to simply take it off immediately. It doesnt have to be an admin. There are two or three of my esteemed colleagues who seem to delete anything they happen to see nominated as speedy without further inquiry, so it's safer not to wait. (this is re Takashi Hikino). Thanks for spotting it. Between me & the orig. author, we found 8 books or so. DGG (talk) 07:36, 25 July 2007 (UTC)

Comment at AfD

Dear Prof. Eppstein, I have responded to your comment on the Wikipedia:Articles for deletion/Thomas A. Romberg about including the professors together. I hadn't made the connection clear between their biographies before, and I was interested in getting further input. Thanks! Eliz81(talk)(contribs) 17:28, 26 July 2007 (UTC)

Thanks for the heads-up. I saw your response there but hadn't formulated a reply yet (and may not, it may be time for others to weigh in). —David Eppstein 17:48, 26 July 2007 (UTC)
Thanks for your help with all of this!! I really appreciate it. Every article nomination/lack of nomination should now be in order. Just let me know if there's anything else I need to do. Eliz81(talk)(contribs) 20:01, 26 July 2007 (UTC)

Prof Camburn

The article as deleted was a copyvio of this page, and no version existed without the copied text, so it should not be restored in any event. Often multiple speedy criteria apply and I won't wikilawyer to try to cite each to cover all bases; suffice to say, if assertion of notability there was it was marginal. Feel free to recreate an article for the guy - whether there was an assertion of notability based on a prize given apparently once per quarter in a fairly limited genre - and then re-take it to Afd. Carlossuarez46 20:27, 26 July 2007 (UTC)

  • Thanks for closing the afd, by the way. Usually multiple speedy criteria apply (for example, most attack pages are about non-notable people and usually have little context, often little content, and probably fit a reasonable definition of "patent nonsense"; similarly most spam/blatant advertising is about non-notable products, firms, websites, bands, etc.), my preference where both copyvio and non-notable both (appear to) apply, is to speedy on notability grounds to prevent re-creation with a more difficult to detect cut and paste job. Clever people who really want an article about their favorite thing and cut and paste something off the web only to find shortly thereafter that it's been deleted due to copyvio will do a better montage next time and it may not be caught so readily again, usually copyvio deletions only induce people to look for a repeat copyvio - and different RC patrolers focus on different things to catch - and so it gets through even though there are notability concerns. If someone sees that copyvio has been a past issue - that's easily curable - whereas if notability has been a past issue, unless something has changed regardless of how new and original the presentation of the material is, it's probably still an issue. Just my philosophy on this, other admins will differ, and I may realize over time that discretion isn't the better part of valor. Carlossuarez46 20:41, 26 July 2007 (UTC)

Image:Phaeoceros spores.jpg

The creator and source of this image are clearly stated in the documentation. The image came from the pt:esporos page (see [1]). When the image was later uploaded to Commons (by incorrect procedure), the Portuguese wikipedia deleted its copy and the source information. --EncycloPetey 16:22, 31 July 2007 (UTC)

Thanks for the correction. I did look at that page on pt, but what I found was that not only was the image deleted but also it was removed from the esporos article. And I did not see anything there about it being replaced by anything on commons at that time. So my impression was that the Portuguese wikipedians might have found some licensing problem with that image leading to its removal. In any case, saying "I got it from the Portuguese Wikipedia" is not I think an adequate source trail — where did they get it from? —David Eppstein 17:26, 31 July 2007 (UTC)
No idea. I copied all the information about the image that pt WP had. At the time I did so, I was new to WP and did not even know about Commons, or I would have gone through them directly. My assumption at the time was that it had been loaded onto the pt WP by the creator of the image; I seem to recall a number of liverwort-related images all added by the same person and all credited to the same "J. Ziffer" of Brazil. I do find another of his images on Commons for Image:Dendroceros.jpg, which does contain additional source information. It was transferred from the pt WP to Commons by the same person who transferred the spores image, but it seems to have preserved more of the source info. The history for the pt:Dendroceros article indicates that pt:User:Bonás linked that image into their article, but I don't know whether he/she was the originator for all the images by "J. Ziffer". --EncycloPetey 03:54, 1 August 2007 (UTC)
The Dendroceros image gives credit to pt:User:1978. I've left a message on his talk page in hopes that he can shed light on this issue. —David Eppstein 04:09, 1 August 2007 (UTC)


Updated DYK query On August 2, 2007, Did you know? was updated with a fact from the article John Hooper (sculptor), which you created or substantially expanded. If you know of another interesting fact from a recently created article, then please suggest it on the Did you know? talk page.

Blnguyen (bananabucket) 01:31, 2 August 2007 (UTC)

Planar triangulated graphs

Hi David, I noticed you undid my change. I thought I saw this usage of 'triangulated', meaning chordal, in some books just a couple of hours ago. I'll check (though not today).

I wasn't aware of the other usage (maximal planar), though a quick look at the planar graph article calls these graphs triangular, not triangulated, though triangulation (disambiguation) does. Even if triangulated graph has a different meaning for planar graphs, wouldn't a link from chordal graph to planar graph to explain this usage, though phrased differently than I did of course, be justified?

Cheers, Phaunt 15:16, 2 August 2007 (UTC)

Re "wouldn't a link be justified" — yes, I think so, in both directions. —David Eppstein 15:20, 2 August 2007 (UTC)
I didn't check the graph theory literature, but I'd like to react to a statement from your edit summary:
Planar triangulated graphs are maximal planar, not necessarily chordal planar.
This would imply that there are maximal planar graphs that aren't chordal, right?
If what I think is true, which is that every chordless cycle in a planar graph corresponds one-on-one to a face, then every chordless cycle in a maximal planar graph has 3 edges, by definition, and the graph is chordal.
I can't see (at this moment) how a planar graph could have a larger chordless cycle that doesn't correspond to a face, but tell me if that's the case, and I will believe you and look up the relevant literature myself.
All this is not to accuse you of lying or point out mistakes or anything—I'm just good-faithedly trying to learn :-)
Thanks for your time, cheers, Phaunt 23:03, 2 August 2007 (UTC)

Examples of a maximal planar graph that is not chordal: the skeletons of the regular octahedron and icosahedron. Note e.g. that the equator of an octahedron is chordless but not a face. —David Eppstein 23:11, 2 August 2007 (UTC)

Of course. Thanks again for pointing this out to me. Phaunt 23:31, 2 August 2007 (UTC)

Internet Servers Section for Phutball

Hi, many games pages like those for Connect6, Pente, Oware, etc have either an Internet Servers subsection or links to game sites directly under External Links. Admittedly many do not, but do you suggest it's inappropriate for wikipedia to link to places where people can actually play the game (whether against the computer or other players)? Should all such links be removed?

I'm not sure, but the link I remember removing had nothing in the link itself about phutball, it was just a generic link to a computer game server. Such links are inappropriate, I think. And certainly long lists of many different internet game servers aren't approproate. WP:EL describes several other reasons why it may be inappropriate to include such links: if the site contains excessive advertising, is a for-pay service, etc. —David Eppstein 16:19, 4 August 2007 (UTC)
When posting the link I used the Connect6 page as an example and basically setup the link in the same manner. The link could easily refer to the Phutball specific page at Vying Games, if that would be preferred. Vying Games is, from what I can tell, the only game server offering Phutball. While Phutball is a new addition, players seem to be responding well to it. For example, I currently have games going with 5 different players. (As an aside, given your knowledge of the game, I'd love to be able to play you sometime...) The site is free and has no advertising. Being somewhat new to Wikipedia, I will accept your judgment on whether the link is inappropriate. Thanks. (from 4 August 2007)

Hi again, David, a simple "I'm too busy to look into this" or "I still think the link's inappropriate" would be fine. I don't really care whether there's a link or not, but it'd be nice to resolve this one way or another (or to know it's going to be on the back burner for a while). Thanks again. --Lockeness 23:01, 9 August 2007 (UTC)

Spelling of names.

Hi. Well, what you said is not true for Spanish in Hispanic countries, at least. This language has certain rules of pronunciation that inforce the fact that, if you don't use acute accents, the word has to be said in a different way. Therefore, an Hispanic person's name has to be spelled as that person says it, not neccesarily as he/she writes it (ignorant people could be writing it in the wrong way). My doubt is only when it comes to people with Hispanic-origin names living in countries with languages where accents are not used.

Regarding your reversion, it may be right. I was following instructions from a Puerto Rico Project member.


--Damifb 21:17, 5 August 2007 (UTC)


WikiDefender Barnstar.png The Mighty Defender of the Wiki Barnstar
Thanks for all your work in taking care of the Humboldt University "professors"! Nyttend 20:32, 6 August 2007 (UTC)
Wow, my first barnstar! Thanks! —David Eppstein 20:43, 6 August 2007 (UTC)

+ Barnstar

GDBarnstar1.png The Graphic Designer's Barnstar
Dear me, you hadn't gotten any barnstars yet?? Well you certainly deserve this one. Keep up the good work. Cronholm144 03:29, 7 August 2007 (UTC)
Thanks thanks! —David Eppstein 03:55, 7 August 2007 (UTC)

Mathematics abilities (3RR)

"I did block him. You were both violating the 3RR rule, both on Heron's formula and on Qin Jiushao. As WP:3RR states, "In the cases where multiple editors violate the rule, administrators should treat all sides equally." —David Eppstein 06:33, 8 August 2007 (UTC)"

It seems that you're incapable of counting revert counts. As I had shown: [2][3][4] at Heron's formula, no more than three. [5][6][7] at Qin Jiushao on moving, no more than three. Nowhere I could find the revert counts that had exceed three, and those are just simple calculation. Either you're incapable of counting, or failed to understand the different between more than three and three and above. That's is just about my comprehend. While I was under block, this guy had already been back from your block 10 hours later[8][9], just how does what happened. Eiorgiomugini 14:42, 9 August 2007 (UTC)

I suppose getting into arguments on user talk pages is a step up from getting locked into a revert cycle, so to that extent my block seems to have succeeded. But it's still not being a constructive Wikipedia editor. For what it's worth, I think your edits to the Heron's formula article were good, it's just your choice of how to deal with an edit-warring anon that's in question. —David Eppstein 16:18, 9 August 2007 (UTC)

On "Vertex (Graph Theory)" Article

Your justification for removal of the words "a pictorial representation of a" I added to the explanation of the graph is unconvincing. As far as it is written in the "graph theory" article a "graph" is an abstract concept that differs from the graphs of functions. Therefore the graph in the article is a pictorial representation. Similarly a game tree is only a representation in game theory that does not show us the underlying objective functions of the players. It is also my belief that while writing on (at least non-applied) mathematics or similar non-empirical disciplines one should try to distinguish between concepts and representations (What is a point?). Anyway, since your knowledge on mathematics is much greater than mine I will respect your final say. However you should then edit the "graph theory" article as well for consistency. Best regards. Evren Güldoğan 16:56, 9 August 2007 (UTC)

I considered having it say "a drawing of a graph with...", and linking drwaing to graph drawing. That would be a bit off-topic on the vertex article, but it would probably make more sense for the main graph theory article. I'll go take a look. —David Eppstein 17:00, 9 August 2007 (UTC)


I redid your AfD result banner on this article because you said, "closed as delete" in the edit history. KP Botany 07:34, 12 August 2007 (UTC)

Oops. Thanks for the fix. —David Eppstein 07:36, 12 August 2007 (UTC)


Updated DYK query On 17 August, 2007, Did you know? was updated with a fact from the article permutohedron, which you created or substantially expanded. If you know of another interesting fact from a recently created article, then please suggest it on the Did you know? talk page.

--Carabinieri 00:59, 17 August 2007 (UTC)

Wow what a smart guy. I bet youd put my IQ to shame - Yours must be in the 150+ range!! Thanks for the great work -it really is good to known we have professionals on this site. All the best ♦ Sir Blofeld ♦ "Expecting you?" Contribs 08:56, 17 August 2007 (UTC)

P.S. I added an image to Alfréd Rényi which I noticed you edited ♦ Sir Blofeld ♦ "Expecting you?" Contribs 09:03, 17 August 2007 (UTC)

Could you help cleanup and reference and expand Video coding if this is within your field. Regards ♦ Sir Blofeld ♦ "Expecting you?" Contribs 09:09, 17 August 2007 (UTC)

Thanks! I know little more than the article on video coding, sadly. —David Eppstein 13:56, 17 August 2007 (UTC)

Glen Dettman

Hello. I was wondering why you removed Detman's vanity awards? Surely if Detman wished to hide them, he never would have bought them in the first place? Further, many of his claimed memberships in this list are just as dubious. A while back I planned to go through them all and expose them for what they were but I haven't yet got around to it. In the meantime, I reckon his vanity awards should remain. Aren't you pushing a POV by removing them?  : ) Cheers, Gillyweed 07:34, 20 August 2007 (UTC)

Short answer: because an award one buys isn't an award at all, and shouldn't be presented here as anything noteworthy. It creates a false impression that he is being recognized for his merit, when really all that he is being recognized for is his wallet. —David Eppstein 14:40, 20 August 2007 (UTC)

People known as the founder, father, or mother of something

If you are going to make up your own "personal" reference rules and make "mass deletions" of references, could you please paste all the references you deleted to the said talk page so I better see what your issues are. --Sadi Carnot 23:39, 20 August 2007 (UTC)

My "personal" rules are in WP:RS. Please go read that guideline. —David Eppstein 23:40, 20 August 2007 (UTC)


selfwormTalk) 04:28, 21 August 2007 (UTC)

Macbeath surface


Thanks for the changes to the page, it made it considerably better. It is not altogether precise to say that the Macbeath curve can be obtained from a non-congruence subgroup of the modular group. Tesseran and I had a detailed parallel discussion in the context of the Klein quartic recently. The reason is that the modular group is not co-compact, and therefore none of its subgroups will be, either. The math review of Wolfart's paper does not make this clear unfortunately. I have not looked at the article yet, but I assume the article makes this clear. What Wolfart presumably proves is that an affine neighborhood of the Macbeath curve admits a modular group construction. Incidentally, are you aware of anyone actually referring to this object as Fricke-Macbeath? It principle this sounds like a good idea, but wikipedia's role is not to set norms in general. Katzmik 08:10, 21 August 2007 (UTC)

Furthermore, the claim about the symmetries is incorrect. What the 1994 paper calls "symmetries" are the orientation-reversing ones, not present in the automorphism group. Orientation-preserving automorphisms of surfaces cannot fix circles. Katzmik 13:29, 21 August 2007 (UTC)

Thanks for the corrections. As for Fricke-Macbeath, Elkies does in two papers, and searching Google for the phrase will find more. —David Eppstein 14:14, 21 August 2007 (UTC)

Diophantus II.VIII

Hi Dave

In the Pythagorean Triple page, sub article Platonic sequence there is a sentence which runs as follows:

"The Platonic sequence itself may be derived by following the steps described in Diophantus II.VII"

Since this sentence was included following submissions I made on the associated talk page, I felt it needed a link to the relevant "steps" which I have detailed in another article on the talk page. However when I put in the link the edit was reverted with the following comment:

"Inappropriate to link to a talk page from the main namespace, revert"

I have no problem with the reason given so have now created a separate page entitled Diophantus II.VIII. Would it be appropriate to include that as a link to provide the necessary detail?

Neil Parker 08:42, 23 August 2007 (UTC)

I'm not sure how well the new page works as a Wikipedia article, but given that it's there it's quite appopriate to link to it. My objection to linking to talk pages doesn't apply in this case. —David Eppstein 14:07, 23 August 2007 (UTC)

Article W. Kuperberg

Thanks for the article on my dad. I am not sure that my family is really so prominent as to merit this many Wikipedia articles (three so far), but if nothing else it's a nice compliment.

It's an anachronism to say that he was born in Belarus. He was born in Senno/Sienno, Byelorussia. Google Maps lists two of them, and I am not sure which one it was. Maybe "escape World War II" is a better phrase than "avoid the war". Also, Szczecin was not their prior home. It couldn't have been because it was expropriated from Germany; it used to be Stettin. They were from the Warsaw area. When they returned to Poland, they were either assigned to Szczecin or they selected it, or something in between.

I have the feeling that the bound due to me and my dad on packing densities has been improved by a hair by someone that my dad knows. It's clear from our paper that sqrt(3)/2 cannot be optimal. Using basically the same ideas it was improved slightly, I think.

The bound was inspired by a double-lattice packing of regular pentagons that has been discovered several times by both mathematicians and physicists. We were not the first ones; it was mentioned in a paper from 1982 (I think) by Subir Sachdev. My dad even laid it in tile in my downstairs bathroom, and there is a photo of that on Dror Bar-Natan's page.

There is an interesting Wikipedia page on the March 1968 crisis in Poland. It may or may not be worth mentioning that my family left Poland because of that crisis.

Greg Kuperberg 01:07, 24 August 2007 (UTC)

I should also mention that my parents and I don't set any records for mathematician relatives. There is also the Neumanns! Greg Kuperberg 01:19, 24 August 2007 (UTC)

Thanks for the corrections. My general feeling is that Wikipedia could use a lot more coverage of good mathematicians; its coverage is haphazard and arbitrary. The festschrift we both contributed to provided enough ammunition to make an article that I felt could be defended, but (unique or no) I do think your family history of multi-generation mathematical work is also interesting. —David Eppstein 01:27, 24 August 2007 (UTC)

Reliable sources

Hi David,

A week ago, you removed two in-line citations on People known as the father or mother of something, citations which came from the Society of Television Engineers and the DuMont Television Network Historic Website. I restored these today, with an additional source for verification, but you have removed two of the sources. My understanding is that you have been attempting a massive clean-up of this article, and you do not want to see it junked up again with unreliable sources.

However, while we know that WP:RS states "Anyone can create a website or pay to have a book published, then claim to be an expert in a certain field. For that reason, self-published books, personal websites, and blogs are largely not acceptable as sources." it also states "Self-published material may, in some circumstances, be acceptable when produced by an established expert on the topic of the article whose work in the relevant field has previously been published by reliable third-party publications."

In the case of the DuMont Television Network Historical Website, the author is Clarke Ingram, who has been in the broadcast business for more than 20 years. Mr. Ingram is a subject-matter expert in early broadcasting. Ted Bergmann, who wrote The DuMont Television Network: What Happened? (ISBN 0-8108-4270-X) states Ingram's material is "exactly right", and David Weinstein, author of The Forgotten Network, wrote "No other broadcaster has been rewarded with a historical web site as informative and thorough as Clarke Ingram's" (The Forgotten Network, page 186, ISBN 1-59213-499-8).

When Wikipedia is rejecting sources that multiple print publications are citing (and recommending), I feel the WP:RS guideline is being over-enforced, or enforced without regard to the proviso on self-published sources laid out in the guideline itself. Will you restore the citation, David? Firsfron of Ronchester 18:50, 26 August 2007 (UTC)

Sci American Article - Cellular Automaton

Hi David, I just saw your graphic Image:2dCCA-n16.png and read Cyclic_cellular_automaton, cool stuff. I'm looking for the following reference: "Computer Recreations: A cellular universe of debris, droplets, defects, and demons". Scientific American (Aug 1989), pages 102–105, by A.K. Dewdney. Do you know where I could get a copy? thnx much, Bob.lanahan 19:17, 26 August 2007 (UTC)

I looked pretty hard for a copy online and didn't find one. I think you'll have to go to a library. —David Eppstein 19:48, 26 August 2007 (UTC)

Prime number

Yes, all! Please go ahead and revert all his/her edits. Sorry about my error and thanks for pointing it out. Please also see my message on his/her talk page. Thanks again. --Mathsci 21:21, 26 August 2007 (UTC)

I did it myself (I hope). --Mathsci 21:34, 26 August 2007 (UTC)

Adam Greves AfD

Hi David, I suspect that the Adam Greves article is a hoax from the sockpuppet family of users: Curious Gregor, R:, Iconoclast4ever, A.J.1.5.2., Tim.Boyle, etc. In comparing the edits of Mark1mark2,, & to Curious Gregor etc contributions I came to notice that the AfD page Wikipedia:Articles for deletion/Timothy Boye has been deleted. Is there some admin power you can use to find out who did this etc? If you are too busy for this, let me know & I'll see if DGG is up for it. Best Regards, Pete.Hurd 16:36, 6 September 2007 (UTC)

Whups, nevermind. I forgot that they vandalized the spelling in the closed SSP I was looking at, Wikipedia:Articles for deletion/Timothy Boyle is right where it ought to be. My apologies. Pete.Hurd 16:42, 6 September 2007 (UTC)

A new version of Image:Graph-tensor-product.svg

The tensor product of graphs.
The tensor product of graphs with colors.

I noticed you made the illustration for the article on Tensor product of graphs. I think it could be clearer if it would use colours, so it's more easy to see ‘which node goes where’ in the product graph. I made a quick version of this, as you can see too.

This new one could use some more improvements though. It now uses the same colours for the left and the right graph which might suggest some connection where there is none. Also, maybe one could give the left graph circular nodes, and the right one square nodes, and the product graph nodes which are formed by the left half of a circle and the right half of a square.

The colours which I choose are not optimal, green and cyan are too close, as are red and purple. This could be improved upon, and would it be useful to number the nodes (1-5 for the left graph, and a-d for the right one) too, for those who are colour blind? This might be a bit crowded though.

Other suggestions are welcome too, I would be willing to make the final image and update some other graph product pictures too. --Berteun 13:42, 9 September 2007 (UTC)

Ok, I've recolored it. Better? —David Eppstein 17:32, 9 September 2007 (UTC)

Top Financial Economics Honors

Even though you describe yourself as a computer science person, you talk as if you understand financial economics publications very well. I would like to produce pages like I have produced for Smith Breeden Prize and Brattle Prize for most major journal prizes without opening the door wide for the Southwestern Missouri Journal of Financial Intermediation Management Best paper. Basically, what I think would be consistent with rules on WP:N would be to include only lists for journals that count towards tenure at most top research institutions (Journal of Finance, Journal of Financial Economics, Review of Financial Studies, Journal of Political Economy, Econometrica, American Economic Review, and Journal of Financial and Quantitative Analysis). Once such lists are created, then a template could be created with major Financial Economics awards Starting with Nobel Prize in Economics, including Fischer Black Prize and the Morgan Stanley American Finance Association Award as career awards and including the research paper awards. Such a template could be placed at the bottom of all winners articles to give the winners some heft. Then we could also produce lists for annual conference Presidents such as the AFA, WFA, EFA Presidents and add these honors to the template. However, the problem is that we need a reliable source distinguishing major journals and associations from minor ones. I.e., we need to quickly be able to draw a line as a tertiary source based on a reliable secondary source. Do you have any ideas where I can find a source of which financial economics journals and associations are important to top tier research institutions.--TonyTheTiger (t/c/bio/tcfkaWCDbwincowtchatlotpsoplrttaDCLaM) 04:49, 11 September 2007 (UTC)

If you have to quantify something like this, I'd try something like impact factor. But it might be better to stick to the more general Wikipedia notability standards: if you can find reliable third parties noting the award, it's notable, otherwise not. As for financial economics specifically, I don't think I have any special expertise or understanding there. Is there really such a binary distinction between good and bad journals for tenure in that field? I'd expect, especially at the better research institutions, more of a focus on how good the applicant's research itself is or how much impact it's had and less on how good the other papers around it are. —David Eppstein 05:48, 11 September 2007 (UTC)
Actually most top 25 or 30 research institutions go by publications in the top journals listed above (except Harvard which has its own system which counts case studies and other factors). You basically need to average one/year at the time of tenure.--TonyTheTiger (t/c/bio/tcfkaWCDbwincowtchatlotpsoplrttaDCLaM) 17:14, 22 September 2007 (UTC)

Lauren Cohen (economist)

New information making Lauren Cohen (economist) a notable athlete, I believe. Please reconsider.--TonyTheTiger (t/c/bio/tcfkaWCDbwincowtchatlotpsoplrttaDCLaM) 15:15, 12 September 2007 (UTC)

Numbers books

Just wanted to tell you about a book by David Wells, the Dictionary of Curious and Interesting Numbers. It is one of the books which cemented my interest in number theory, and I suspect it has similarly inspired others to take math up as a hobby. It covers all the integers from 1 to 100, a few important irrational numbers and some largish numbers pertaining to combinatorics. There's also one by Bryan Bunch, called The Kingdom of Number, if I recall correctly. It doesn't cover all the integers from 1 to 100, but it does talk a little bit about complex and transfinite numbers. Quaknin's Mystery of Numbers hardly impressed me, but it could be a useful support to Wells and Bunch. PrimeFan 22:26, 14 September 2007 (UTC)

Thanks, I do have a copy of Wells. But its range of coverage doesn't exactly overlap with Wikipedia's and I wonder whether its coverage might be considered trivial in some cases. I don't have the Bunch and Quaknin books, though. —David Eppstein 22:40, 14 September 2007 (UTC)
I got my copy of the 1987 back now, and now I have to agree with what you say about its coverage being "considered trivial in some cases." All it says about 1 million is that it's 10 to the sixth. PrimeFan 21:57, 20 September 2007 (UTC)
Mm, yes. For a lot of 4-digit numbers there's nothing besides some base-dependent property. I still like that book, and, it seems, so does my friend who is delaying in returning me my copy. PrimeFan 20:18, 19 September 2007 (UTC)

whups, thanks!

Whups, I knew nothing of the wubbot (but often thought the task could've been automated, hats off to whoever), thanks for the tip. Cheers, Pete.Hurd 06:27, 16 September 2007 (UTC)


Please could you explain why you made this revert on the talk page of the article. --Philip Baird Shearer 17:13, 20 September 2007 (UTC)

Brad M. Barber

I noticed that you are quite active at WP:ACADEMICS and have commented at Brad M. Barber. I am contemplating either DRVing or recreating this article. According to his media page he is a widely cited expert. According to his research log] he is a widely published expert. If we concentrate on the Top 3 journals in financial economics (Journal of Finance, Journal of Financial Economics, & Review of Financial Studies) he is a well published expert. It seems you were unsure whether his research is notable. I do not know impact factors for his work but these two things seem to make him notable to me. Is either of these two facts new information to you.--TonyTheTiger (t/c/bio/tcfkaWCDbwincowtchatlotpsoplrttaDCLaM) 17:10, 22 September 2007 (UTC)

Thanks so much!!!

I appreciate your helpfulness, and educating me on finer points of Wikipedianism.

By the way, there's a problen with your User:Boxs on your Homepage - cut of at edge & one is chapped off[sic].
As a mathematician you solve that easily too, I'm sure.
All the best, --Ludvikus 20:54, 22 September 2007 (UTC)

Why don't you just do this:

E-to-the-i-pi.svg This user is a member of WikiProject Mathematics.
Admin mop.PNG This user is an administrator on the English Wikipedia. (verify)
Yours truly, --Ludvikus 20:59, 22 September 2007 (UTC)
Sorry - typo

Good job at your repair. Now I believe that you really are a Computer Scientist!!! --Ludvikus 21:06, 22 September 2007 (UTC)

By the way, I've just gotten a new HP PC ( HP Pavilion Slimline to be exact) with OS Vista. One of the problems is that it's got a CRAMPED keyboard which makes me hit all these extra (adjacent) characters - and I'm essentially a one or two key typist at that. So I'm wondering now if I've got a complaint for Product Defect.

You don't need to answer this. I just needed an ear to voice that frustration. And your relationship with Computer Science seemed to me like you are an appropriate person to express that to - while I'm wondering what's the best way, short of returning the PC, of addressing my frustration. Best to you. --Ludvikus 21:17, 22 September 2007 (UTC)
No problem. I use Apple machines myself, though. —David Eppstein 21:54, 22 September 2007 (UTC)

DYK - Möbius–Kantor graph question

I rewrote your hook because it did not conform to the DYK rules. Would you check it out? I am not at all sure that my rewrite is correct. --Mattisse 18:05, 23 September 2007 (UTC)

Thanks, I replied there. —David Eppstein 18:28, 23 September 2007 (UTC)

Random Smile!

-WarthogDemon 04:53, 25 September 2007 (UTC)

Did you know

Updated DYK query On 27 September, 2007, Did you know? was updated with a fact from the article Möbius–Kantor graph, which you created or substantially expanded. If you know of another interesting fact from a recently created article, then please suggest it on the Did you know? talk page.

--Allen3 talk 21:23, 27 September 2007 (UTC)

Ronald A. Carson

David: I noticed that you had hand in deleting Ronald A. Carson from wikipedia...I was hoping that you could assist me with its re-creation. The newspaper that was cited pertained to specific articles about Ronald A. Carson. Therefore, they were specific to him and spoke to his notability? I do not understand why/how wikipedia will not let his page remain, please tell me what I can do to have his page stand--thanks — Preceding unsigned comment added by Alinob77 (talkcontribs)

See Wikipedia:Notability (people) and Wikipedia:Biographies of living persons. Basically, Wikipedia articles need to include some citations to published sources by people independent of the subject that speak to the subject's significance, and the facts in the article similarly need to be sourced. (I'm copying the answer here and in your talk page.) —David Eppstein 15:45, 2 October 2007 (UTC)

David: Thanks for getting back to me--also, apologies for editing your user page. Also, the articles in the advocate speak to the facts of the Ronald A. Carson page. Do you suggest that I take some information out of the page to make it acceptable? This page is important to thousands upon thousands of African-Americans who see this page as a beacon of hope. Carson's story needs to be told, please help. Alinob77 15:57, 2 October 2007 (UTC)

From what I could see in the article, Carson has worked on (but not taken a major role such as campaign chair in) some political campaigns, and hopes to do more in politics in the future. That is not significance, and documenting that he's done that much isn't going to help. I suggest waiting to make an article about him for a few years, until he's achieved something for himself. If the "story needs to be told" now, then perhaps Wikipedia isn't the best medium for that. —David Eppstein 16:44, 2 October 2007 (UTC)

Thanks again for getting back to me. Your advice is appreciated. I have been able to contact the editor of The Aurora Advocate and have retrieved a couple of newspaper articles featuring Carson. I have also been informed that they are in the process of putting these articles online, which would give them a url that can be used on a Ronald A. Carson page. Once that is done, this would satisfy the third party source that is lacking. Also, Carson has been the point person/strategist in cities across the country for President Clinton, Vice-President Gore, Senators Lieberman, Edwards, Kerry and now Clinton. He is a political strategist in the mold of a James Carville, or a Paul Begala. This is what makes him notable, becasue he is so young, a wonderkid if you will. Also, it should not go without notice that he is African-American and let's be frank, this is an accomplishment that not many African-American's can boast of. This is why this "story needs to be told" it serves as inspiration for the throngs of African-Ameican youth who feel that if Carson can do these things, why not them. So, I will find the url's to the sources and then I hope that, after this, you will assist me in making Ronald A. Carson a permanent page on wikipedia--thanks again. Alinob77 22:47, 2 October 2007 (UTC)

Along with the notability guidelines I mentioned earlier, please also keep in mind that Wikipedia is not a soapbox. Our task is not to promote people who are deserving but not really known yet, or who would make good role models: it is to collect the stories that have already been made prominent through other media. So, if instead of two articles covering him in the Aurora Advocate (a weekly newspaper serving a town of less than 15000 people), you had a similar amount of coverage in, say, Time Magazine, it would be a lot easier to make the case that he is already notable and therefore an appropriate subject for a Wikipedia article. But in any case, the interests of Wikipedia would be better served if you would devote less energy to trying to squeak past the notability requirements for this one subject and more energy on improving the Wikipedia articles on the many other subjects that are unquestionably notable and yet have inadequate coverage here. —David Eppstein 00:16, 3 October 2007 (UTC)

Ronald A. Carson

An editor has asked for a deletion review of Ronald A. Carson. Since you deleted and/or restored this article at one point in time, you might want to participate in the deletion review if you have not already done so. -- Jreferee t/c 23:20, 3 October 2007 (UTC)

Math Desk Situation

I want to express my apologies to you for what I said on the math reference desk seeral days back to you. I was kind of desperate and about the questions I did't know how to do and, like I said, my participation in extracurricular activities was riding on that test. It turns out I got an 88 on the test and my average for the class is now a C+. Anyway, I took thigns too far and took out my own anger at myself for not studying earlier in the trimaester on soemoen else. schyler 00:30, 4 October 2007 (UTC)

Andres Mignucci

Hi David. An article I wrote about Andres Mignucci has been put forward by Krakatoa Katie for deletion. I agree with your comments in September as why it should remain in Wikipedia. Could you please restate them as part of the current discussion regarding deletion? Thanks Maribel Ortiz Here are some of the arguments I put forward which are in line with yours.

Keep. Andres Mignucci was elected as a FELLOW of the American Institute of Architects in 2005. There are currently 74,000 architect members of the AIA of which, in the history of the AIA, only 2,500 have been elected as Fellows of the Institute. In he year 2005, alongside Mignucci, Santiago Calatrava - AIA Gold Medalist; Thom Mayne - Pritzker Award Winner; and Toshiko Mori - Head of Harvard’s Graduate School of Design were also elected. You cannot be in such company without being notable. See below from the AIA's press statement on the induction: Washington, D.C., February 25, 2005 --The American Institute of Architects (AIA) elevated 66 architects to its prestigious College of Fellows, an honor awarded to members who have made contributions of national significance to the profession. Andrés Mignucci, FAIA, of San Juan, Puerto Rico, was elected to receive this honor because of his contributions to the field of design. Mr. Mignucci has enriched the profession by integrating the disciplines of architecture, urban design and landscape architecture in the creation of urban environments with a sense of place, human scale, and environmental responsibility. His work reflects a commitment to the role of public space as an integral part of people’s lives, as a setting for social and cultural exchange, and as a vital component in the structure of our cities and towns. In addition, his leadership through public service and teaching has made significant contributions in extending knowledge of the profession to a larger public. Out of a membership of more than 74,000, there are fewer than 2,500 AIA members distinguished with the honor of fellowship. It is conferred on architects with at least 10 years of membership in the AIA who have made significant contributions in the following areas: the aesthetic, scientific, and practical efficiency of the profession; the standards of architectural education, training, and practice; the building industry through leadership in the AIA and other related professional organizations; advancement of living standards of people through an improved environment; and to society through significant public service.

In two recent books on Iberoamerican Architecture one in Madrid and one in Mexico, (Iberoamerica Arquitectura. Rispa, Raul; Tanais Editores, Madrid, 2004 and Arquitectos Iberoamericanos del Siglo 21. Noelle, Louise Fondo Cultural Banamex, Mexico DF 2006), Andrés Mignucci’s work has been highlighted as exemplary in the discourse of current architecture in Latin America.

Mignucci, as one of seven members of the Governor’s Council on Planning and Urbanism, is also one of the authors of the Economic Development and Government Transformation Plan for Puerto Rico. See below. (ECONOMIC DEVELOPMENT AND GOVERNMENT TRANSFORMATION PLAN FOR PUERTO RICO (PDF) Economic Development and Government Transformation Plan for Puerto ... Architect Andrés Mignucci, Dr. Gabriel Moreno, Atty. Omar Jiménez, Architect Liz ... - 658k - View as html).

Mignucci is also the author/editor of Arquitectura Contemporanea en Puerto Rico 1976-1992, one of the latest books on Puerto Rican architectural history.

His articles can be found in Italian (Spazio Societá Milan Italy) or in English (University of California Berkeley) showing relevance beyond Puerto Rico’s local architectural mileu. see below. planum - spazio e società / space & society - summariesTranslate this page Spazio e Società / Space & Society 84, Ottobre-Dicembre 1998 ... Andrés Mignucci Giannoni. Costruire nei tropici. 98. Luciano Barbero. La fontana e il pino ... - 4k - Cached Places - 33k - Cached Andres Mignucci Giannoni Inhabiting Shadows: Observations on the Tropics as Place [Forming Place, Informing Practice]38. Maribel ortiz 15:34, 5 October 2007 (UTC)Maribel ortiz 12:33, 4 October 2007 (UTC) Maribel ortiz 15:34, 5 October 2007 (UTC)

Did you know

Updated DYK query On 6 October, 2007, Did you know? was updated with a fact from the article pseudoforest , which you created or substantially expanded. If you know of another interesting fact from a recently created article, then please suggest it on the Did you know? talk page.

--Allen3 talk 17:40, 6 October 2007 (UTC)

Synchronizing word

Attn, because of Eppstein, David (1990). "Reset Sequences for Monotonic Automata". SIAM Journal of Computing 19: 500-510. `'Míkka 21:21, 10 October 2007 (UTC)

Thanks, I've added a little more. There are still more papers on the subject (e.g. Google scholar search) several of which are I think at least as deserving as mine to be cited. Probably the article should also mention something about the road coloring conjecture. —David Eppstein 21:43, 10 October 2007 (UTC)

ACM Multimedia

You may want to challenge my reponse to your AfD vote. I ask that you consider my argument and change your vote to merge. Robert K S 05:44, 20 October 2007 (UTC)

No, you're not obligated to change your vote, even when the rationale behind it is demolished. But accusing me of canvasing is out of line. The AfD process is based on discussion. I was alerting you to my response to your vote. Robert K S 07:26, 20 October 2007 (UTC)
I believe the usual mechanism is to trust that everyone who cares enough to respond will put it on their watchlist. But it's not just one message in a talk page: it's the fact that you've responded to every non-merge comment saying "please change your vote to merge". —David Eppstein 14:53, 20 October 2007 (UTC)
What a bunch of libel. I said no such thing. Robert K S 11:22, 23 October 2007 (UTC)

Graph isomorphism: answer my questions

Dear Prof Eppstein,

Please, read Talk:Graph isomorphism#IMHO and answer my questions.

--Tim32 06:18, 25 October 2007 (UTC)

Please, see my reply: Talk:Graph isomorphism#IMHO...

--Tim32 16:20, 25 October 2007 (UTC)

You did not reply me. Seems you have no valid argument :-(

--Tim32 10:54, 3 November 2007 (UTC)

Sometimes that means I'm just not interested in continuing the discussion. —David Eppstein 15:10, 3 November 2007 (UTC)

Yes, I see... But a discussion is only way to improve Wiki. Or, perhaps, you prefer edit war? Please, " remember that it is still a communal article and communal shared collaboration". I also spent a lot of time to wait for your replies. Didn't you think that somebody (except you) also has plans for productive work? Didn't you think that you spent MY TIME, when I have been waiting for your answer during a week or more? Is it right communal shared collaboration?

--Tim32 10:48, 4 November 2007 (UTC)


Updated DYK query On 25 October, 2007, Did you know? was updated with a fact from the article cycle detection, which you created or substantially expanded. If you know of another interesting fact from a recently created article, then please suggest it on the Did you know? talk page.

--Carabinieri 15:57, 25 October 2007 (UTC)

Thanks! I hadn't realized it had been nominated, and didn't consider nominating it myself since it was more than a stub before I expanded it, but I'm pleased it was selected. —David Eppstein 16:59, 25 October 2007 (UTC)

Gary Chester

Thanks for standing up for a Legend, drummer great, Gary Chester. Rharrykelly 21:42, 27 October 2007 (UTC)


Sorry, I've had flu. i'm.. not entirely sure if it's as good as it could be yet. It's a lot better, but the subject seems like it should be simple enough for any layman to understand the basics, and yet is still quite difficult. Mybe I'm holding it to too high of standard. Adam Cuerden talk 20:05, 28 October 2007 (UTC)

Wolfram's (2,3) controversy

Hi David. Gee, you might want to archive some of this talk page :-) I wrote up a synopsis of the Wolfram (2,3) controversy, as I understand it, in my user space here; I'd appreciate comments, suggestions, rebuttals, etc. Thanks, Pete St.John 17:35, 1 November 2007 (UTC)

Godel's IT

You rolled back the changes on Godel's IT and I subsequently removed your roll back. This is because there is an ongoing discussion about those topics on the talk page (Talk:Gödel's incompleteness theorems#"Modern proof") that I think you should refer to and discuss on before making such drastic changes. Thanks --DFRussia 02:36, 2 November 2007 (UTC)

Russell A. Alder

This one made me curious, so I checked out the name on Google, found the company website, and discovered that the "Russ Alder" described (born 1973) is the grandson of the founder and the son of the "Russell A. Alder" who built the global market for glass bending.I still think it is all spam, but it is too late at night to get too involved. We've each made a judgement, and so it goes. Bielle 06:12, 3 November 2007 (UTC)

Comment at Wikipedia_talk:Categories_for_discussion/Log/2007_October_28#Erdos_numbers_reasoning

I apologize, my comment was actually directed at SparsityProblem, not you. I have amended it but I should have been more careful. Quale 15:48, 4 November 2007 (UTC)


The "fluff" that you deleted from Godel's incompleteness theorems is the shortest existing complete proof of the theorem. I would ask that you read it and think about it before deleting it. If you have any questions, I will be happy to answer them.Likebox 20:04, 5 November 2007 (UTC)

Basically, I have a difficult time calling it a proof, because it is so vague and handwavy about important details (like what language are the programs coded in, how are the desired program transformations coded, and is that language capable of addressing unbounded amounts of memory). —David Eppstein 20:12, 5 November 2007 (UTC)
Read and understand the proof first, please. It is identical to Godel's. There is nothing in the least bit handwavy about it.Likebox 22:54, 5 November 2007 (UTC)
As far as languages which can adress an unlimited memory, there are well known examples in CS, and I was assuming you were familiar with them. If you are not, please read about them before deleting things.Likebox 22:55, 5 November 2007 (UTC)
It is not an issue of what I'm familiar with. It is an issue of what you need to put in writing before calling something a proof. —David Eppstein 22:56, 5 November 2007 (UTC)
That is a political question, that you should not be judging alone.Likebox 23:00, 5 November 2007 (UTC)

I will violate the three revert rule, if I have to. I will get myself banned from Wiki for life if I have to. This is completely ridiculous. I give you a gift of a perfect proof of Godel's incompleteness theorem and instead of thank you, I get idiotic bickering for weeks. That is unbelievable.Likebox 06:32, 6 November 2007 (UTC)

Please calm down. I'm sure you're capable of making very constructive improvements to Wikipedia, and I'd much rather see that than see us lose a knowledgeable editor because of the difficulty of conforming to the procedures here, but edit warring and original research are not the way to get your contributions accepted here. —David Eppstein 06:42, 6 November 2007 (UTC)

Deletion of the Erdos Number categories

Recently (as you know) the categories related to Erdos Number were deleted. There are discussions and debates across several article talk pages, e.g. the Mathematics WikiProject Talk page. I've formally requested a deletion review at this deletion review log item. Pete St.John 18:39, 7 November 2007 (UTC)

Thanks regarding the project to Ban me

Thanks for your remarks at the ANI. My own rhetoric (and where I can post) is restricted by the threat to ban me (at my talk page; it would only be temporary, during the resolution of the Deletion Review). So, uncharacteristically, I'm not able to speak freely for myself. Actually it probably would be a good thing if I just took a wikivacataion for a few days, anyeay. This on the heels of the (2,3) thing is nuts to me. Anway thanks. Pete St.John 23:18, 9 November 2007 (UTC)


Hello. I am somewhat concerned that User:Wlod has been adding articles on his own not particularly notable work to the WP. He has also been contaminating other articles, where he has made no appreciable contribution, with copious references to himself in the text and bibliography. His additions are extremely poorly written and often trivial. You might have seen his rude remarks about User:Arthur Rubin and myself on the talk page of Prime number over a completely irrelevant and pedantic point. I find his unjustified self-promotion somewhat strange and fear that it might be getting out of control. Cheers, Mathsci 03:47, 11 November 2007 (UTC)

I don't have the expertise to be able to determine if this user is engaging in self promotion or just has some trouble with the concept of encyclopedic writing, so could you also look at User talk:Oleg Alexandrov#Metric space aimed at its subspace. —Ruud 17:02, 11 November 2007 (UTC)

Hello! RS-ness

Hello! I would really appreciate your opinion here. Could you please check the site indicated in this link and give your opinion about its reliability. It's very important to me. Best regards, ShahidTalk2me 00:27, 13 November 2007 (UTC)

About Sam Vandervelde

He has actually done more stuff. And plus, saying that Sam Vandervelde isn't notable enough is almost like saying Richard Ruscyzk or Sandor Lehoczky aren't notable enough.

Please read the part in the notability tag about "the best way to address this concern". And the articles as they exist now on Wikipedia do not at all convince me that the other two people you name are notable either. —David Eppstein 02:24, 16 November 2007 (UTC)
So people who own a mathematics company and co-founded a math competition and co-wrote a well-used math textbook aren't notable? Wow, the standards are REALLY HIGH nowadays. Are you sure most of the people on Wikipedia make the cut, then? That's sarcasm, just to tell you. --Heero Kirashami (talk) 06:40, 29 November 2007 (UTC)
Please calm down and find some sources, as I already hinted at above. Preferably, published third-party sources. I am not saying that any of those types of people can't be notable, but notability needs to be documented not merely asserted. —David Eppstein (talk) 06:44, 29 November 2007 (UTC)
With many math competitions, the most significant resource is the competition site, though. --Heero Kirashami (talk) 06:47, 29 November 2007 (UTC)
I guess I'll just try to prove my point, then, so just check up on the page in one week and if it's not any better just delete it or something or redirect it to Mandelbrot. --Heero Kirashami (talk) 06:49, 29 November 2007 (UTC)
Source. Source. Source. Source. Source. Source. I'll add these to the articles when I have time. Temperalxy 02:42, 30 November 2007 (UTC)

International Journal of Health Science

Hello David. Is this a candidate for WP:PROD? A journal which has yet to appear and has not attracted any published comments would have a hard job showing notability. There is a sister publication called International Journal of Medicine that is also yet to appear, which I think could also be proposed for deletion. If you think either of these should be kept, please let me know. EdJohnston 04:14, 16 November 2007 (UTC)

I'd support prodding it. —David Eppstein 04:15, 16 November 2007 (UTC)

Multi- vs. simple graphs in pseudoforests

David, I won't have an edit war with you. However, there are some issues of terminology. In general, you come from computer science and I come from matroid and graph theory. The conventions between these two sides differ. The Wikipedia articles on graphs and graph theory set up some guidelines for terminology; the article on pseudoforests does not adhere to them in regard to "simple cycle"; in graph theory this is called "cycle" (most often). A "spanning" subgraph is a subgraph that contains all the vertices; it is not defined by edge criteria. Other terminological questions arise, as you may have noted. The best decision is not obvious to me.

The greatest concern to me is the question of simple vs. multigraphs. I do not see why the article on pseudoforests should exclude multigraphs. Is there a reason connected with computer science? I know that in optimization over graphs there is sometimes reason to exclude loops and sometimes not; and the same is true in graph theory. Thus, which is most appropriate has to be decided case by case.

For the bicircular matroid there is good reason to allow loops. I would like to be able to say in that article that the independent sets are pseudoforests, but that works better if pseudoforests may have double edges or loops.

I hope to hear your thoughts on this. If I bothered you by editing without consulting, I apologize. Zaslav 09:56, 16 November 2007 (UTC)

See my response over on the pseudoforest talk page. I think there is room in the article for both simple graphs and multigraphs (and don't see a reason to classify one as CS and the other as math). I agree that multigraphs make sense in the context of matroids but am less convinced for the context of graph minors. —David Eppstein (talk) 05:05, 17 November 2007 (UTC)
Let's use this as a basis for discussion. For instance, we seem to agree that both simple-graph minors and multigraph minors are independently interesting. (I got overexcited in my initial edit! Again, sorry.) Zaslav (talk) 01:49, 19 November 2007 (UTC)

Giving 366-degree geometry a fair chance

Dear Sir, I think deleting the whole thing would be sad, and a huge loss for human knowledge and research in the field of historical mathematics. (I think it would be fair to leave at least one page on the topic, but that's only my opinion of course). Personally I discovered 366-degree geoemtry 6 years ago and (incredibly, perhaps) the more I investigate on the subject, the more evidence I find. Here is a copy of my 3 letters to Dr Rubin, with his 2 replies (so far he hasn't replied the 3rd one) so you can catch up with the debate. I'd love to have your real, objective opinion on the problem because you're a mathenmatician. I'm not trying to convince you, force you thinking anything, I'd just like you to have a quick look at the matter to make yourself an unbiased opinion. You may be surprised but this 366-geometry is not the hokum some uninformed people can think it is. You can delete this copy once read for it takes a lot of space (sorry) and is already existing in Arthur Rubin's talk page. Many thanks for giving the topic just a few minutes of your time.)--Snicoulaud (talk) 20:16, 18 November 2007 (UTC)

Dear Dr Rubin
What do you mean "the article should fail on its own merit". May I ask you if you have taken the time to consider just a bit Alan Butler's theory. As a mathematician, don't you find it fascinating the Megalithic people could have been cognizant with a geometry which could have preceded ours (360-degree geometry)?
To sum things up: 360-degree geometry is known to have been "invented" in Sumer. Now Babylon, Assur and Nineveh are all located on Salt Lines locations, which means: if you trace Salt Lines all round the globe, you will find that Assur and Niniveh both are on 366-degree geometry parallels. What is more, they are located on the 36th and 37th parallels respectively (i.e. on each side of latitude 36.6 Megalithic degrees). Babylon is on a longitudinal line (just like Stonehenge), which means their respective longitudes are spaced by an integral number of degrees.
Isn't it tempting to think Babylon has been founded on its location AFTER the invention of the 366-degree geometry? 360-degree would then be a simplification of a geometry (366-degree geometry), itself ultimately based on a 366-day calendar.
The biggest Megalithic sites of Britain (Stonehenge, Avebury, Silbury and West Kenneth Long Barrow) are all located along the same Salt Line. So is the biggest site in Scotland, the Ring of Brodgar. It is precisely located on the 60th 366-degree geometry parallel, and it was made of... exactly 60 standing stones!
If Butler is still not widely known it doesn't mean he hasn't hit on one of the greatest mathematical and historical discoveries of modern times.
I'd love to have your informed opinion on that. --Snicoulaud 21:15, 15 November 2007 (UTC)
Have you (by whom I mean all those you have supported either set of "Salt Lines") done analysis as to whether the 366-degree "salt lines" pick up more ancient cities than 360-degree or 354-degree lines. If not, the "results" are virtually worthless, and we can consider them discredited per se, because no one else would have done that analysis. Also, have you allowed for the ellipsoidal earth in your calculations? I think that latitude lines can be offset up to about 10 arc minutes from where you might think they are. Consider the difference between "geodetic", "geodesic", and "geocentric" latitude. (Yes, I've worked on geodesy projects before.) — Arthur Rubin | (talk) 22:15, 15 November 2007 (UTC)
The amazing thing is that these Salt Lines virtually pick up most ancient capitals before Rome (at least the greatest), as well as related key sites, in the Old World, including Stonehenge, Avebury, Silbury, West Kennet Long Barrow (Britain), the Ring of Brodgar and the Stones of Stenness in Orkney (Scotland), Babylon (and Baghdad, maybe coincidentally), Assur and Niniveh (Mesopotamia), Thebes (Valley of the Kings) and Abu Simbel (Egypt), Harappa (Indius Civilization), Mycenae, Argos, Tiryns, Dodona and Athens (Mycenian Greece), Hattusa (Hittite civ.) and Alesia (Gaul). As for the New World, Salt Lines also pick up THE MOST ANCIENT capitals of the first great civilizations, including San Lorenzo, Teotihuacan, Cuicuilco and even Chichen Itza (more recent, so it might just be coincidental) in Mexico, and Caral and Tiwanaku in Southern America! So what I just quoted are virtually all of the world's most ancient capitals of GREAT civilizations between the period 3100 BC-1200 BC (Old World), and c.2630 BC-400 BC (New World).
Let's follow your logic and see how many of these cities fall on the (Greenwich-based) modern 360-degree lines (with the same degree of accuracy, that is, with a margin of + or - 3 minutes of arc max.) and compare: the Ring of Brodgar, the Stenness Stones, Hattusa and Caral. The result is quite simple: 4 instead of 26. That is, 6.5 times less! Please explain me that! Add the funny "coincidence" mentioned last time that Brodgar doesn't stand on any line but precisely on the 60th parallel North (with 60 stones in the circle!), that Assur and Nineveh are located on the 36th and 37th parallels North (on each side of latitude 36.6 degrees) and that Teotihuacan is not on any line but on the 20th parallel North (!), it is starting to make a lot of "coincidences", isn't it?
The remark about the Earth being ellipsoidal, although apt, doesn't seem to be relevant in our case (the modern lines obviously take it into account and the 366-degree system has just been "modernly" established by extrapolating from them). Using the GPS positions of the sites and the new system of reference, the resulting errors are very small, if not tiny or existant at all.
The adjective "geocentric" doesn't seem to be relevant in our case. And as far as I know, "geodesic distances" are not relevant either. So the right answer would be geodetic latitudes and longitudes, that is, meridians and parallels in the same way as we have them today on Earth, except that in 366-degree geometry, the interval between lines is slightly shorter.-- 16:28, 16 November 2007 (UTC)--Snicoulaud 16:30, 16 November 2007 (UTC)
As was pointed out in our latitude article, the difference between different definitions of latitude can be as large as 11 arc minutes (modern; 360) in temperate latitudes, so it's important which definition is used. "geocentric", "geodesic", and "geodetic" are my terms as used in my last geodesy project, "geocentric" is the angle between the line from the point to the center of the earth and the equatorial plane; "geodetic" is the angle between the normal to the ellipsoid (or, perhaps, the local vertical) and the equatorial plane (which is more likely if astronomical observations were used), and "geodesic" divides equally the distance along lines of longitude (more likely if "conventional" mapping was used). As they differ by a number of minutes of arc, and the accuracy you were asserting above is ±3 minutes of arc, it makes a difference which system is used. So — which system IS used. — Arthur Rubin | (talk) 16:50, 16 November 2007 (UTC)
Dear Dr
I've just read the article on latitude and, although it doesn't refer to "geodesic" latitude, it is clear from both your explanation and the article that Salt Lines must probably been understood as "geodetic" latitudes or "common" latitudes (in the sense that these "common" latitudes refer to something similar as today but with 366 lines instead of 360). What is more it seems clear that, if Salt Lines are to be validated someday by historical science, they're very likely to have been developed from astronomical observations.
This being said, the definition of latitude is not particularly relevant for most of the locations I pointed out earlier, for the majority of them is located on longitudinal lines or meridians (which if I understand well are not affected by the rotundity of the Earth).
A little additional experiment I've just done. This time I "shoved" modern meridians 30 minutes east of Greenwich, just to see if I would pick up more of the 26 locations referred to earlier. I didn't. The parallels not moving by definition, I picked up a total of 4 cities (on parallels).
I tried again the experiment by shoving modern meridians 15 minutes east of Greenwich. This time I picked up 3 more locations (Assur, San Lorenzo and Tiwanako), which makes a total of 3 + 4 = 7 locations, i.e. still 3.7 times less than with 366-degree geometry. And I again tried, this time by shoving modern meridians 15 minutes west of Greenwich. That time I picked up 5 more locations (Mycenae, Argos, Tiryns, Athens and Dodona), which makes a total of 5 + 4 = 9 locations, i.e. 2.8 times less than with 366-degree geometry. But please note that all these locations are in Greece. These locations are located on 3 neighbouring Salt Lines so it is "normal" that in this case (in a small country like Greece) they adjust to the modern meridians, the distance between them being not very different from 366-degree geometry meridians when you consider a small interval of 3 or 4 lines. So the result of picking up so many cities in Greece in this case might be the consequence, if Butler is right, of these cities having been placed along Salt Lines in the first place.
So again, my question is: if not compelling to you, isn't the evidence starting to make you think a bit? Think of the primary importance of all the locations I pointed out earlier, and the mysterious fact that all of them are "picked up" by a single system of reference. Doesn't it seem mathematically unlikely, or even highly unlikely, that this be the mere result of chance? I'm not trying to convince you. On the opposite, I need to have the objective view of a mathematician on that.---- Snicoulaud (talk) 20:50, 16 November 2007 (UTC)
And your answer would be?--Snicoulaud (talk) 22:54, 22 November 2007 (UTC)

Is there any point in continuing to discuss this now that they've all been deleted? —David Eppstein (talk) 23:46, 22 November 2007 (UTC)

I appealed the decision, and now some people consider that after all, the topic was notable. —Preceding unsigned comment added by (talk) 06:58, 23 November 2007 (UTC)


Thanks. Septentrionalis PMAnderson 05:57, 23 November 2007 (UTC)

Clean up SEFI

David, Thanks very much for your help in cleaning the SEFI page. Now I see much better what was meant by the comments. Erik de Graaff —Preceding unsigned comment added by GraaffErik (talkcontribs) 13:29, 25 November 2007 (UTC)

Pseudoforest GA review

Hi there. As you probably realized, the article was in fact "reviewed" twice; once by Adam Cuerden, who didn't pass it or list it, and then by ScienceApologist, who passed it. As {{ArticleHistory}} is meant to list all assessment processes an article has undergone, I thought someone might find it strange that only one GA review was listed, so I tried (obviously unsuccessfully :) to clarify that with the edit summary. In short, I meant to say there was no result from the first review, only from the second, and I was therefore listing the second review alone. I apologize for any misunderstanding, and will cross-post this to Talk:Pseudoforest if you wish. Best, Fvasconcellos (t·c) 01:11, 28 November 2007 (UTC)

No, that wasn't my intent at all; I simply replaced {{GA}} with the more complete {{ArticleHistory}}. As the template clearly states, Pseudoforest has been listed as a Mathematics good article under the good-article criteria :) Here, "Mathematics" is the GA topic—that is, the category under which the article can be found at Wikipedia:Good articles; "Mathematics good articles" are simply Good articles concerning mathematics. Best wishes, Fvasconcellos (t·c) 01:24, 28 November 2007 (UTC)
You're welcome; again, I apologize for the misunderstanding. Best, Fvasconcellos (t·c) 01:29, 28 November 2007 (UTC)

Deletion removals

Ah, ta. I didn't realise the system had changed. Tyrenius (talk) 04:18, 28 November 2007 (UTC)

Kahun Papyrus

David, the Kahun Papyrus. and other ancient texts. confirm that improper (vulgar) fractions were easily converted to optimal Egyptian fraction series by ancient scribes. Your avoidance of the wide ranging arithmetical contents of the ancient texts, be it the Kahun Papyrus writing about arithmetic progression, as confirmed in two RMP problems, is non-scholarly. Let's consider to end this year with a truce? My proposal is: Let the ancient texts speak for themselves, without 'gatekeeping' from other later points of view. Best Regards. Milogardner (talk) Milo Gardner 11/28/07

Deletion of Tim Phillips (Businessman)

Sir, I am a bit unclear regarding your deletion of this page. Before I create a deletion review I kindly wanted to discuss it with you. Obviously I am the creator of the page and feel that it should be included in Wikipedia. According to your reason for deletion you noted that only one article was added. I actually added two or three others to the bottom of the links section since the deletion discussion began. My main point of concern however is this; browsing the uncomprehensive United_States_chief_executive_stubs category as well as the general Chief_executives category I find a very small number of CEOs that have even done anything as notable as have a congressional run. I would assume that Wikipedia, if it wants to keep those categories, would want to add to them. If the length of the page I created is the issue, I would be happy to shorten it. I just felt that the more information the better. Hopefully you can look at this from my perspective and not only clarify it for me but also possibly give me some direction to successfully add someone to Wikipedia who I, and others, see to be a notable figure due to his contributions to business and his community. Sturatt (talk) 20:06, 28 November 2007 (UTC)

My understanding is that failed candidates for public office are generally regarded as not sufficiently notable. And the diff I did was of the references added since near the start of the discussion, since those would have been the ones that earlier discussants wouldn't have known about; the ones added very early in the discussion wouldn't have shown up in my comparison. But you're welcome to take it to WP:DRV; I won't take it personally. I'll copy this to your talk page as well. —David Eppstein (talk) 21:01, 28 November 2007 (UTC)
Thank you, I have added this to the deletion review. Sturatt (talk) 22:54, 29 November 2007 (UTC)

An editor has asked for a deletion review of Tim_Phillips_(businessman). Since you closed the deletion discussion for this article or speedy-deleted it, you might want to participate in the deletion review. Sturatt (talk) 22:54, 29 November 2007 (UTC)

Hey, with the article on you

Shouldn't it be put under Wikipedians with articles? Also, find some third-party sources to verify some of these things. I mean, sure, a person could always just look up your name on Google Scholar, but then what about lazy people? Cite your third-party sources, please. — Preceding unsigned comment added by Heero Kirashami (talkcontribs)

Due to the obvious conflict of interest, work on the article about me is someone else's problem, I think. I'll interfere when there are serious problems with the article, but uncited facts and missing categorizations don't rise to that level. —David Eppstein 22:37, 1 December 2007 (UTC)
But what about Wikipedians with articles? Put yourself on there! Obviously, you are a Wikipedian who also has an article! So put yourself on there. Unless you want me to. --Heero Kirashami 01:42, 2 December 2007 (UTC)
Ok, fine, I'm there. —David Eppstein 03:50, 2 December 2007 (UTC)


When you merged lstat (Unix), and fstat (Unix) to stat (Unix), you didn't even to copy the content ZyMOS (talk) 10:42, 7 December 2007 (UTC)

As the synopsis already included full information on lstat and fstat I didn't see the need to copy more. —David Eppstein (talk) 02:51, 9 December 2007 (UTC)

related Afd

FWIW Wikipedia:Articles for deletion/Ray O. Wyland. Pete.Hurd (talk) 02:11, 9 December 2007 (UTC)

Thanks, I knew I'd seen another one but couldn't remember where it was. —David Eppstein (talk) 02:50, 9 December 2007 (UTC)

Kitia, BHG and supercentarians

David, yes I saw that. Hence why I brought it to attention. It appeared to be a canvassing attempt. Guroadrunner (talk) 06:42, 9 December 2007 (UTC)

Yes, I just didn't know whether BHG had seen it, and thought she should if she hadn't already. —David Eppstein (talk) 08:04, 9 December 2007 (UTC)
Cool beans. Guroadrunner (talk) 09:40, 9 December 2007 (UTC)


Regards this, is it worth an AFD for Bacchus-F? Essentially the same entry... WLU (talk) 16:34, 12 December 2007 (UTC)

True, and I wondered about that myself, but it is better referenced than the other article was. I don't plan to put it up for AfD myself, but you're welcome to. —David Eppstein (talk) 16:36, 12 December 2007 (UTC)
It's not really better referenced in my mind - the first ref link is dead, the others are to lists of ingredients at a grocery store and the company website. I'm checking out what wayback has to say, and depending on that I may try deletion. Should I go full AFD or is prod just as good? Note, webarchive is to the company's own website [10], so no independent sources, and the source that's there is just an ingred list. Google turns up little also. AFD's a pain in the ass, so I'd rather prod it 'cause it saves me time, but I don't want to bypass if it's frowned upon. WLU (talk) 17:33, 12 December 2007 (UTC)
It already went through one AfD, so it's ineligible for prodding — you'd have to go the full AfD route. —David Eppstein (talk) 18:02, 12 December 2007 (UTC)

B. Rusty Lang

Hi David, I noticed you were trying to locate info 'bout who I am from Google, etc. I placed a partial CV on my User page FYI. I'll include some web links and references soon. I'm a novice Wikipedia contributor, and I appreciate your input, advise, critique, editing help, and any questions. Thanks! Dr. B. R. Lang (talk) 06:33, 15 December 2007 (UTC)

Dense graph

Hi. I was the editor who had removed the section from Dense graph detailing the work by Streinu and Theran. Beginning an edit war is the last thing I'd intend to do, so I won't revert your reversion, but I find it peculiar to detail a result contained in an unpublished paper: it seems to me that it goes against the criteria of notability. I did not even think it to be a CoI, but we have just your word that "it's a legit paper by a known expert" and that "it will eventually be properly published"... Happy editing, Goochelaar (talk) 20:57, 26 December 2007 (UTC)

Hi David, not long ago you deleted a link, because "arxiv is not peer-reviewed", today I see, you added another link to arxiv. Sorry, but it seems that your criteria of notability is too original ;)--Tim32 (talk) 08:47, 27 December 2007 (UTC)
I was relying on this clause: Self-published material may, in some circumstances, be acceptable when produced by an established expert on the topic of the article whose work in the relevant field has previously been published by reliable third-party publications. But maybe I should look around to see whether the same material can be supported by published papers. —David Eppstein (talk) 16:53, 27 December 2007 (UTC)

LiveJournal List

I added you to List of LiveJournal users as requested here. Temperaltalk and matrix? 01:49, 27 December 2007 (UTC)

Thanks! —David Eppstein (talk) 04:50, 27 December 2007 (UTC)

Sava Grozdev

Thanks for cleaning that up. --Alfadog (talk) 13:33, 29 December 2007 (UTC)

You're welcome. —David Eppstein (talk) 17:08, 29 December 2007 (UTC)