User talk:David Eppstein

Hi, and welcome to my User Talk page! For new discussions, I prefer you add your comments at the very bottom and use a section heading (e.g., by using the "New section" tab at the top of this page). I will respond on this page unless specifically requested otherwise. For discussions concerning specific Wikipedia articles, please include a link to the article, and also a link to any specific edits you wish to discuss. (You can find links for edits by using the "compare selected revisions" button on the history tab for any article.)

Question on Dvoretzky's theorem

Hello, I left a question at Talk:Dvoretzky's_theorem#Question, maybe you can take a look? Cheers, AxelBoldt (talk) 03:14, 1 January 2017 (UTC)

Happy New Year, David Eppstein!

Happy New Year!

David Eppstein,
Have a prosperous, productive and enjoyable New Year, and thanks for your contributions to Wikipedia.
Donner60 (talk) 07:04, 2 January 2017 (UTC)

   Send New Year cheer by adding {{subst:Happy New Year fireworks}} to user talk pages.

Nevnihal erdoğan

Dear David,

I had set up the wiki page for Nevnihal Erdoğan, a published scholar in Turkey, and added the relevant source links as was advised by another Wikipedia editor. Could you please fill me in on why it was deleted anyways and what I can do about it.

Regards,

Emre — Preceding unsigned comment added by Emrekaracaoglu (talk • contribs) 17:23, 2 January 2017 (UTC)

All articles here about living people must have references — published sources by other people, about the subject, that can be used to verify the claims made in the article. Your article on Nevnihal Erdoğan had a listing of publications by the subject, but no references about the subject. It was deleted through the WP:BLPPROD process, which placed a prominent notice on the article itself and gave you a week to fix the problem by adding references. At the same time, a notice of all this was left on your talk page. After the week expired with no improvement (indeed no changes) to the article, I deleted it. —David Eppstein (talk) 18:32, 2 January 2017 (UTC)

David Moon

Hi, I saw you added a few cites and new, useful text to the entry. Are there any other references out there? For example, its not clear to me that he's even born or lives in the US, as none of the citations state as much. Right now it looks like there are two journal articles, one listserv email, one webpage about a tangentially related story, and one acknowledgement in a book. Or is there more? Has there been enough written about him to establish an even approximate DOB? Thanks. Bangabandhu (talk) 04:56, 5 January 2017 (UTC)

I found an even better source with a lot more about his accomplishments. But as for names of who he dated, favorite bands, or other celebrity-like personal detail: not so far. I commented out the nationality in the infobox, since as you say it is unsourced. (There is also already a commented-out birthdate there, which looks too early to be right but is not impossible.) —David Eppstein (talk) 06:40, 5 January 2017 (UTC)

Are you suggesting date and place of birth is trivia? It just shows how little is reported about him. While its great that the article has more citations, I'd be surprised if any editor could have written that article from the content of the references alone - especially without using archived listserv email. Is that really a RS? Bangabandhu (talk) 16:43, 5 January 2017 (UTC)

He's known for his accomplishments in software development, not for the circumstances of his birth. Those are now reliably sourced to Steele and Gabriel. The user group message is less clearly reliable but adds some important factual detail (the Symbolics Fellow title and date of departure from Symbolics) which I think should be uncontroversial enough to use such a source. —David Eppstein (talk) 18:42, 5 January 2017 (UTC)

I understand that but it still seems thinly sourced. From the talk page, it looks like there's a lot of confusion about his identity. I'm going to rename the page David A. Moon (which is how he's credited in the journal articles) and make David Moon a disambiguation page. Bangabandhu (talk) 21:32, 5 January 2017 (UTC)

I have no problem with that change. A dab is needed anyway, to list David Moon (historian) along with DAM and the politician, so you're saved from WP:TWODABS. It could also list David Moon, director of Demand Progress, David Moon from the cast of Impractical Jokers UK , and David Moon, one of the minor characters on Frasier. —David Eppstein (talk) 21:33, 5 January 2017 (UTC)

I'm pretty sure David Moon the politician is David Moon the Demand Progress director. How did you find all those names? Just a Google search? Or some other tool? I made the change, maybe you can add those names. Bangabandhu (talk) 22:16, 5 January 2017 (UTC)

Ok, I'll add them. Just a Google search. —David Eppstein (talk) 22:17, 5 January 2017 (UTC)

@Bangabandhu: for future reference, do not ever move articles by copying and pasting into the move target, the way you did. If you can't just do the move directly yourself, request that an administrator perform the move; see WP:MOVE for details. The way you did it left all the edit history for the computer-programmer Moon in the wrong place. —David Eppstein (talk) 22:45, 5 January 2017 (UTC)

I wasn't aware of that. Thanks for fixing and letting me know. Bangabandhu (talk)

DYK for Moon Duchin

On 10 January 2017, Did you know was updated with a fact from the article Moon Duchin, which you recently created, substantially expanded, or brought to good article status. The fact was ... that mathematician Moon Duchin was inspired to break gender barriers in mathematics by a book on baseball player Jackie Robinson's struggles against racism? The nomination discussion and review may be seen at Template:Did you know nominations/Moon Duchin. You are welcome to check how many page hits the article got while on the front page (here's how, Moon Duchin), and it may be added to the statistics page if the total is over 5,000. Finally, if you know of an interesting fact from another recently created article, then please feel free to suggest it on the Did you know talk page.

Cas Liber (talk · contribs) 12:01, 10 January 2017 (UTC)

DYK for Furstenberg–Sárközy theorem

On 11 January 2017, Did you know was updated with a fact from the article Furstenberg–Sárközy theorem, which you recently created, substantially expanded, or brought to good article status. The fact was ... that the Furstenberg–Sárközy theorem shows that the first player in the game of subtract a square can win from most positions? The nomination discussion and review may be seen at Template:Did you know nominations/Furstenberg–Sárközy theorem. You are welcome to check how many page hits the article got while on the front page (here's how, Furstenberg–Sárközy theorem), and it may be added to the statistics page if the total is over 5,000. Finally, if you know of an interesting fact from another recently created article, then please feel free to suggest it on the Did you know talk page.

Cas Liber (talk · contribs) 12:01, 11 January 2017 (UTC)

Your GA nomination of Clique problem

The article Clique problem you nominated as a good article has passed ; see Talk:Clique problem for comments about the article. Well done! If the article has not already been on the main page as an "In the news" or "Did you know" item, you can nominate it to appear in Did you know. Message delivered by Legobot, on behalf of Spinningspark -- Spinningspark (talk) 14:21, 13 January 2017 (UTC)

FYI

[1]. Is this what is considered to be "an improvement" nowadays? Cassianto^Talk 21:36, 15 January 2017 (UTC)

At least that one's not drawing disinformation from who-knows-where on Wikidata, but I agree that it still fails WP:DIB. I assume you saw my experiment on Talk:Marion Parris Smith. This falls into the same category: making the article longer, but not more informative, by repeating the information on its first line for multiple lines worth of screen real estate. —David Eppstein (talk) 22:20, 15 January 2017 (UTC)

I did. And I agree, the article is all the more worse for including the "info"box here. This user is problematic, something that JamesBWatson seems to be ignoring. Cassianto^Talk 22:47, 15 January 2017 (UTC)

Talk:Nearest-neighbor chain algorithm/GA1

David Eppstein, I posted a note to the reviewer's page a few days ago, notifying them that if they didn't respond within seven days, their review could be closed and the nomination placed back in the reviewing pool. Is this what you would want me to do? Given what was posted to the review so far, and the contradiction of MOS:LEAD, I think this is probably the best course of action.

Absent an objection from you, I plan to close the review when the seven days are up. It seems unlikely that there will be a response before then. Thanks for your patience. BlueMoonset (talk) 15:07, 19 January 2017 (UTC)

Yes, please, a fresh review seems best. —David Eppstein (talk) 17:02, 19 January 2017 (UTC)

I've just closed the review, and this will be available for a new reviewer to take on. I hope a new one shows up soon, and is someone who knows what they're doing. Best of luck. BlueMoonset (talk) 23:17, 22 January 2017 (UTC)

Thanks! —David Eppstein (talk) 01:18, 23 January 2017 (UTC)

Categorising Antimatroid

Hi David!

Thanks for your edit, reverting my addition of three categories to Antimatroid:

Latest revision as of 18:12, 18 January 2017 (edit) (undo) (thank) David Eppstein (talk | contribs) (Undid revision 760650165 by Yahya Abdal-Aziz (talk) formal languages are mathematics, not linguistics)

Yes, I certainly first encountered formal languages in mathematical logic, about 50 years ago. Yet the terminology was always suggestive, and we now find references such as the following one from the article:

• Merchant, Nazarre; Riggle, Jason (2016), "OT grammars, beyond partial orders: ERC sets and antimatroids", Nat Lang Linguist Theory, 34: 241, doi:10.1007/s11049-015-9297-5 .

Optimality Theory (particularly in phonology but also in other disciplines) within linguistics is now at least a quarter-century old (Prince and Smolensky published several relevant works 1991-93), and its dependence on mathematical techniques such as those of order theory continues to increase. The Merchant and Riggle 2016 reference above specifically connects the categories "Linguistics", "Grammar" and "Phonology" to antimatroids, which belong to the category "Matroid theory". So I remain puzzled that you think those categories don't also contain antimatroids.

If you'd objected instead that I added too many categories, including super-categories, I'd have to confess I haven't explored the local region of the category tree very thoroughly, so you could be right. (I also think that WP categorisation has a very ad hoc feel, that maybe, like Topsy, "just growed", and that a disciplined approach to remedying WP categories would be a worthwhile project. But that's another discussion entirely.) yoyo (talk) 13:50, 20 January 2017 (UTC)

Antimatroids definitely do not belong to the category "Matroid theory", either — antimatroids and matroids are two different kinds of mathematical object. If there are applications of antimatroid theory in linguistics, I'd definitely be interested in seeing them added to the applications section of the antimatroid article. But as it is now, there is no linguistics in the article — its use of formal languages is merely to collect orderings of things, not to be any kind of model for any natural language phenomenon. —David Eppstein (talk) 18:00, 20 January 2017 (UTC)

Jacob Barnett

The article is being mostly edited by a near-SPA 67.14.236.50 (talk · contribs · deleted contribs · logs · filter log · block user · block log) who seems rather insistent on the content being presented in a specific manner. Per {{coi}} - Use this tag to alert readers that the article may be biased by a conflict of interest. Do you disagree? Please wp:ping. Cheers Jim1138 (talk) 20:37, 21 January 2017 (UTC)

It's being edited by several editors on a long term basis. Do you have any evidence that the IP has any actual COI? The editor most interested in presenting the subject positively is not that one, but Viewfinder, by the way. —David Eppstein (talk) 22:10, 21 January 2017 (UTC)

Your comment

Hi David, I replied to your comment on my talk page. I've been away from Wikipedia for a while; my apologies that I'm not up to date with all conventions. IMirjamI (talk) 14:59, 23 January 2017 (UTC)

Administrators' newsletter - February 2017

News and updates for administrators from the past month (January 2017). This first issue is being sent out to all administrators, if you wish to keep receiving it please subscribe. Your feedback is welcomed.

Administrator changes

NinjaRobotPirate • Schwede66 • K6ka • Ealdgyth • Ferret • Cyberpower678 • Mz7 • Primefac • Dodger67

Briangotts • JeremyA • BU Rob13

Guideline and policy news

• A discussion to workshop proposals to amend the administrator inactivity policy at Wikipedia talk:Administrators has been in process since late December 2016.
• Wikipedia:Pending changes/Request for Comment 2016 closed with no consensus for implementing Pending changes level 2 with new criteria for use.
• Following an RfC, an activity requirement is now in place for bots and bot operators.

Technical news

• When performing some administrative actions the reason field briefly gave suggestions as text was typed. This change has since been reverted so that issues with the implementation can be addressed. (T34950)
• Following the latest RfC concluding that Pending Changes 2 should not be used on the English Wikipedia, an RfC closed with consensus to remove the options for using it from the page protection interface, a change which has now been made. (T156448)
• The Foundation has announced a new community health initiative to combat harassment. This should bring numerous improvements to tools for admins and CheckUsers in 2017.

Arbitration

• The Arbitration Committee released a response to the Wikimedia Foundation's statement on paid editing and outing.

Obituaries

• JohnCD (John Cameron Deas) passed away on 30 December 2016. John began editing Wikipedia seriously during 2007 and became an administrator in November 2009.

---

Discuss this newsletter • Subscribe • Archive

13:38, 1 February 2017 (UTC)

DYK for Pasang Lhamu Sherpa Akita

On 6 February 2017, Did you know was updated with a fact from the article Pasang Lhamu Sherpa Akita, which you recently created, substantially expanded, or brought to good article status. The fact was ... that Pasang Lhamu Sherpa, one of the first Nepali women to climb K2, was named after the first Nepali woman to climb Everest? The nomination discussion and review may be seen at Template:Did you know nominations/Pasang Lhamu Sherpa Akita. You are welcome to check how many page hits the article got while on the front page (here's how, Pasang Lhamu Sherpa Akita), and it may be added to the statistics page if the total is over 5,000. Finally, if you know of an interesting fact from another recently created article, then please feel free to suggest it on the Did you know talk page.

— Maile (talk) 00:24, 6 February 2017 (UTC)

hi, r.e. interaction vertex vertex (physics) etc

I'm just trying to clarify all the jargon here ... in several articles I saw the phrase interaction vertex, in the context of colliders and feynman diagrams. My question is are these things really synonymous, or are these places talking about a vertex in a *diagram*, distinct from a vertex *in space*?

I figure an article vertex (feynman diagram) stating "In a feynman diagram a vertex is..." is overkill, so I'm looking for ways to setup a redirect. (Its so nice with the hover cards feature though, being able to just slide the cursor around and get clarification of what things really mean.)

note:- vertex (physics) redirects to interaction point interaction vertex redirects to something describing the point in a diagram.

Fmadd (talk) 18:19, 7 February 2017 (UTC)

Dual polyhedra

David, we seem to have a profound disagreement here, so I have started a discussion here. — Cheers, Steelpillow (Talk) 21:27, 8 February 2017 (UTC)

RJ Mathar

Not to mention [2] self promotion. Most of RJ Mathar's edits is to insert his own stuff in articles (see [3]). Headbomb {talk / contribs / physics / books} 18:54, 10 February 2017 (UTC)

It's difficult for me to complain about inserting self-citations, since I've done a fair amount of that myself. But they're a small fraction of my edits and when I do, I clearly mark it in my edit summaries (example) and abide by 0RR. —David Eppstein (talk) 19:13, 10 February 2017 (UTC)

Yes, but a difference here is that you're not on a campaign to only add your own work. I've cited myself too (see bouncing ball, Georgallas & Landry 2016), but again that was declared (asked for review at WT:PHYS) and I wouldn't go to war if people felt the reference was not germane and legit. Not something Mathar does. Headbomb {talk / contribs / physics / books} 19:35, 10 February 2017 (UTC)

Etiquette

David, I would be grateful if you could avoid personal attacks or SHOUTING in edit comments, avoid reverting cleanup tags, respect WP:BRD and generally conform to WP:WIKIQUETTE and WP:AVOIDEDITWAR. I would hate this to escalate to WP:AN/EW but your determination to edit ahead of discussion is becoming unacceptable. Thank you. — Cheers, Steelpillow (Talk) 18:32, 11 February 2017 (UTC)

Whatever. Let me know when you start taking other readers' disagreements with your point of view seriously rather than automatically assuming they're more ignorant than you, and when you stop using tea as a substitute for "go away and let me keep editing the article the way I want to". —David Eppstein (talk) 18:36, 11 February 2017 (UTC)

There is currently a discussion at Wikipedia:Administrators' noticeboard/Incidents regarding an issue with which you may have been involved. — Cheers, Steelpillow (Talk) 19:26, 11 February 2017 (UTC)

Tetchy

It's amazing it took you as long to get there as it did. Oy vey. --JBL (talk) 16:38, 12 February 2017 (UTC)

Polyhedron

If you wish to remove properly-cited and relevant content from the polyhedron article, you need to discuss it at Talk:Polyhedron#Proper_citations and not get into a tag-team edit war. — Cheers, Steelpillow (Talk) 17:53, 17 February 2017 (UTC)

"tag-team edit war" is another phrase for a consensus that runs against you. —David Eppstein (talk) 18:17, 17 February 2017 (UTC)

You forgot to say "cheers". EEng 18:55, 17 February 2017 (UTC)

Good point. But at this stage, doing so would probably (correctly) be interpreted as mocking, and therefore uncivil. —David Eppstein (talk) 19:02, 17 February 2017 (UTC)

Hey, you want a change of pace? Having no idea whatsoever what your inclination might be, perhaps you could comment at Talk:Grigori_Rasputin#.21votes_on_reversion. EEng 19:21, 17 February 2017 (UTC)

Notice of Edit warring noticeboard discussion

Hello. This message is being sent to inform you that there is currently a discussion involving you at Wikipedia:Administrators' noticeboard/Edit warring regarding a possible violation of Wikipedia's policy on edit warring. Thank you.

Steelpillow, you forgot to say "Cheers" this time. —David Eppstein (talk) 21:52, 17 February 2017 (UTC)

"...where he had to apologize" oh em gee. If this is still going on Monday, I'll try to find time to file a new ANI case. [Later edit: never mind, Steelpillow has been blocked, hopefully things will proceed more sensibly now.] --JBL (talk) 22:24, 17 February 2017 (UTC)

I laughed at that too. EEng 22:30, 17 February 2017 (UTC)

It's not often you see such a one-sided polyhedron dispute. EEng 22:35, 17 February 2017 (UTC)

Curiously, the one-sided polyhedra are not really part of this dispute. —David Eppstein (talk) 23:03, 17 February 2017 (UTC)

I'm shame-faced at the realization I didn't know such things actually exist. EEng 23:42, 17 February 2017 (UTC)

Stevo

You're INVOLVED, but what do you think about my asking at AIV for semiprotection? I think at think point it's well past a content dispute and just plain vandalism. EEng 20:13, 20 February 2017 (UTC)

Involved is the reason I haven't already done it myself. I agree it would be helpful. —David Eppstein (talk) 20:26, 20 February 2017 (UTC)

Requested at WP:RPP. —David Eppstein (talk) 18:53, 21 February 2017 (UTC)

Well, I made the same request and it was declined. Then Mr. Admin Eppstein comes along the same day and makes the same request and lickety-split it's done. Harrumph! EEng 23:32, 21 February 2017 (UTC)

I asked for indef and they only gave me a year, though. —David Eppstein (talk) 00:12, 22 February 2017 (UTC)

Well that's OK then. EEng 19:33, 3 March 2017 (UTC)

Review

Hi

I want to know at the actions of this user are a Canvassing

this and [4]

thank you Modern Sciences (talk) 23:12, 20 February 2017 (UTC)

Asking an admin and another experienced editor to pay attention to an ANI thread seems (1) unnecessary, as lots of people pay attention to that board, and (2) mostly harmless. I don't see a lot of reason for Boaqua to have expected any specific action from those editors, and the thread did not yet have any proposals that needed weight thrown behind them. —David Eppstein (talk) 23:24, 20 February 2017 (UTC)

This user is want to admins block me!!. / He has short time edition history (less than 250) and I guess this user is spare account and is it possible to make request for Sockpuppet investigations for this user. — Preceding unsigned comment added by Modern Sciences (talk • contribs)

Review

Hi Dear Admin.

this is History of some of the disruptive editing or user Boaqua and unfortunately, never receive any warning from Admins. please review them.Modern Sciences (talk) 00:27, 22 February 2017 (UTC)

Rep-tile patterns and original research

|

I understand the Wikipedia rule on original research, but isn't there room for discretion on the part of editors? In history, sociology, and so on, it's difficult to know when something new is valid. But in mathematics some new results can be clearly valid to proper mathematicians (like you, but not me). In any case, can you recommend anywhere that accepts new results from amateurs so that I can get a proper reference for inclusion in the Rep-tile article? MagistraMundi (talk) 09:45, 23 February 2017 (UTC)

DYK for Vojtěch Jarník

On 24 February 2017, Did you know was updated with a fact from the article Vojtěch Jarník, which you recently created, substantially expanded, or brought to good article status. The fact was ... that although mathematician Vojtěch Jarník is known to computer scientists for his minimum spanning tree algorithm, his main work was in number theory? The nomination discussion and review may be seen at Template:Did you know nominations/Vojtěch Jarník. You are welcome to check how many page hits the article got while on the front page (here's how, Vojtěch Jarník), and it may be added to the statistics page if the total is over 5,000. Finally, if you know of an interesting fact from another recently created article, then please feel free to suggest it on the Did you know talk page.

Mifter (talk) 00:02, 24 February 2017 (UTC)

Talk:Jacob Barnett

I didn't ask you to be critical of me. — Preceding unsigned comment added by 2601:197:4400:C1A0:B1:70F0:135D:4144 (talk) 04:37, 26 February 2017 (UTC)

If repeatedly pushing ridiculous and false claims here is not asking for criticism, I don't know what is. —David Eppstein (talk) 05:12, 26 February 2017 (UTC)

mixing up physics with mathematics is not an egregious mistake. Subuey (talk) 02:50, 7 March 2017 (UTC)

"You're not even trying." Is this how you treat everyone? Subuey (talk) 11:29, 3 March 2017 (UTC)

Not everyone. But very-long-term editors (here over ten years) who should know better about what is required about sourcing on a WP:BLP and who I have already and very recently warned about the requirement for adequate sources on a BLP? Why not? —David Eppstein (talk) 19:29, 3 March 2017 (UTC)

I have seen four sources on the internet that all peg the date as May 26th. Do you have some other reason for not including it? Subuey (talk) 07:26, 6 March 2017 (UTC)

All the sources I've seen (and four may be about the right number) do not meet Wikipedia's strict standards for sourcing for a biography of a living person. And in general I'm reluctant to include birthdays unless there's a good reason for it or the sourcing is very clear; it can be a bit of an invasion of privacy. And in this particular case, the talk page makes clear that there has been a problem with wrong birthdays for Barnett here in the past, which may have been copied by other sites, so we need to be extra-careful not to copy it back from them. —David Eppstein (talk) 07:32, 6 March 2017 (UTC)

Well the source you used for the year also includes the date.Subuey (talk) 07:47, 6 March 2017 (UTC)

For values of "you" that may include all editors of the article? I'm pretty sure I'm not the one that added that source to the infobox. —David Eppstein (talk) 07:53, 6 March 2017 (UTC)

Are you going to respond to what I said? You warned someone for not sourcing, and the source was already there.

I'm not sure I see the point of continuing to respond to you. —David Eppstein (talk) 08:36, 6 March 2017 (UTC)

And why is that.Subuey (talk) 08:59, 6 March 2017 (UTC)

Your GA nomination of Nearest-neighbor chain algorithm

The article Nearest-neighbor chain algorithm you nominated as a good article has passed ; see Talk:Nearest-neighbor chain algorithm for comments about the article. Well done! If the article has not already been on the main page as an "In the news" or "Did you know" item, you can nominate it to appear in Did you know. Message delivered by Legobot, on behalf of Tessaract2 -- Tessaract2 (talk) 16:01, 26 February 2017 (UTC)

On the alleged Santanen algorithm

Greetings.

The article on an alleged Santanen algorithm is marked as needing attention from an expert in Mathematics (more precisely, Computer Science). I presume I qualify for that, given that I've been teaching the subject and doing research on algorithms at two universities for well over a decade.

That article does not merely fail to meet notability guidelines, it is outright fake: there is no such algorithm (and apparently no such person as its author either), the contents are clearly meant as a prank or practical joke, and references are misrepresented (they link to unrelated work by entirely different people) and irrelevant to the subject. At first sight the text seemed a heavily vandalized article on the packing problem, but it's really devoid of useful (if any) content.

I wonder why it hasn't been deleted yet; on the contrary, deletion marks have been edited out (first by the presumed article author with a meaningless explanation, now by yourself). — Preceding unsigned comment added by Pbarreto.crypto (talk • contribs) 10:29, 27 February 2017 (UTC)

I removed the second prod because second prods are not allowed. You have to have a full deletion discussion instead. —David Eppstein (talk) 17:14, 27 February 2017 (UTC)

Now at AfD; see Wikipedia:Articles for deletion/Santanen algorithm. —David Eppstein (talk) 21:24, 28 February 2017 (UTC)

Your GA nomination of Nearest-neighbor chain algorithm

Hi there, I'm pleased to inform you that I've begun reviewing the article Nearest-neighbor chain algorithm you nominated for GA-status according to the criteria. This process may take up to 7 days. Feel free to contact me with any questions or comments you might have during this period. Message delivered by Legobot, on behalf of Shearonink -- Shearonink (talk) 20:01, 1 March 2017 (UTC)

DYK for Penny graph

On 2 March 2017, Did you know was updated with a fact from the article Penny graph, which you recently created, substantially expanded, or brought to good article status. The fact was ... that, no matter how n non-overlapping pennies are arranged on a table, at least 0.258n of them will not touch each other? The nomination discussion and review may be seen at Template:Did you know nominations/Penny graph. You are welcome to check how many page hits the article got while on the front page (here's how, Penny graph), and it may be added to the statistics page if the total is over 5,000. Finally, if you know of an interesting fact from another recently created article, then please feel free to suggest it on the Did you know talk page.

Mifter (talk) 00:01, 2 March 2017 (UTC)

Harry Lewis

I have the idea of bringing this to GA in time for a DYK appearance on April 19, when there will be a celebration. I don't think your contributions so far disqualify you from doing a GA review (especially if the article is largely rewritten), and if you agree I'd like to suggest you stay in reserve to do the review. I can get someone familiar with his research to help, and you'd be perfect to act as a fresh set of eyes at the end. Make sense? EEng 05:57, 4 March 2017 (UTC)

Sure. —David Eppstein (talk) 06:35, 4 March 2017 (UTC)

• Since I've got you: WP:Articles for deletion/Delta numerals, WP:Articles_for_deletion/Armands_Strazds_(3rd_nomination). EEng 17:46, 4 March 2017 (UTC)

DYK nomination of Bricard octahedron

Hello! Your submission of Bricard octahedron at the Did You Know nominations page has been reviewed, and some issues with it may need to be clarified. Please review the comment(s) underneath your nomination's entry and respond there as soon as possible. Thank you for contributing to Did You Know! ~ Rob₁₃^Talk 06:10, 4 March 2017 (UTC)

DYK nomination of Plesiohedron

Hello! Your submission of Plesiohedron at the Did You Know nominations page has been reviewed, and some issues with it may need to be clarified. Please review the comment(s) underneath your nomination's entry and respond there as soon as possible. Thank you for contributing to Did You Know! Rlendog (talk) 23:01, 6 March 2017 (UTC)

I think this is a fun article and I think the issue with the hook can be resolved pretty easily. Rlendog (talk) 23:02, 6 March 2017 (UTC)

Nearest-neighbor chain algorithm

	Congratulations, it's a...
	...Wikipedia Good Article!! Shearonink (talk) 07:08, 7 March 2017 (UTC)

I changed the topic/subtopic when I place the article into the List of GAs. Instead of "Computing and engineering" I put it into "Mathematics and mathematicians" where it seemed to fit better. If this is incorrect please feel free to change it. Thanks, Shearonink (talk) 07:20, 7 March 2017 (UTC)

It could go in either, so no problem. Cute ambigram. And thanks for the review! —David Eppstein (talk) 07:48, 7 March 2017 (UTC)

DYK for Kokichi Sugihara

On 9 March 2017, Did you know was updated with a fact from the article Kokichi Sugihara, which you recently created, substantially expanded, or brought to good article status. The fact was ... that Kokichi Sugihara's illusions make marbles appear to roll uphill and circular pipes look rectangular? The nomination discussion and review may be seen at Template:Did you know nominations/Kokichi Sugihara. You are welcome to check how many page hits the article got while on the front page (here's how, Kokichi Sugihara), and it may be added to the statistics page if the total is over 5,000. Finally, if you know of an interesting fact from another recently created article, then please feel free to suggest it on the Did you know talk page.

— Maile (talk) 00:03, 9 March 2017 (UTC)

Mark_Holcombe

Hey David - I've added sources to this wiki and made a few additional updates as well. I was wondering if you would be willing to offer your thought/feedback? In short, the person was a university professor for 10 years,research assistant with ORI, authored two published papers on the development and impact of RCR training, and finally went on to contribute to the development of training modules for the ORI that are still in use today. The article is benefited, but unfortunately I haven't seen anyone even show interest beyond a 30 second google search, but rather just a lot bickering that the article wasn't insta-deleted. It's quite frustrating to do real research, and see your work arbitrarily marked for deletion without a single attempt at discussion. At this point, I would really appreciate any actionable feedback, as the same nonconstructive approach has been taken on all my my creations in a few days... (never happened in the 2 years or so Ive been here, but I digress) and at this point it appears I need to spend beyond-hobby-amounts-of-time or I'll lose all my creations :/ keen to hear your thoughts. thanks. Trailmixers (talk) 01:26, 9 March 2017 (UTC)

In this particular case my main thoughts are: pay attention to WP:PROF (and to how it is typically interpreted, for instance via the archive of old cases at Wikipedia:WikiProject Deletion sorting/Academics and educators/archive) as part of the process of choosing to create an article about an academic, rather than creating the article for other reasons and then trying to rationalize it. Because in this case, it's very far from the mark. I suspect that the reason for all the off-topic bickering is that all concerned agree on its non-notability, and had to cast around for something else to disagree on to make the conversation more interesting. —David Eppstein (talk) 01:49, 9 March 2017 (UTC)

Since the latest sources were added, at this point does the article meet requirements? How can the article be improved? Looking at archives really isn't helpful though. Due to the subjective nature of guidelines, you'll find articles of equal merit both approved and deleted. There's little rhyme or rhythm to areas like research (and others that people generally find boring and have a short attention span for), other that tt's really easy for people to hit a delete button. As for choosing the "right" article - doesnt that defete the purpose of wikipedia? I mean.. at this point robots would far outperform the capacity of humans to transcribe events and parse text references. Individuals in industries/sectors that are hard to disseminate should have a place too, no? Trailmixers (talk) 02:55, 9 March 2017 (UTC)

Your questions presuppose that the article *should* be improved, and that it is possible to improve it to meet requirements. That shows, to me, that you are still not trying to judge from a neutral point of view *whether* the subject actually merits an article. —David Eppstein (talk) 03:21, 9 March 2017 (UTC)

I don't follow. One has nothing to do with the other. Iteration is a requisite of any collaborative effort. I can be objective and iterative. They aren't mutually exclusive. — Preceding unsigned comment added by Trailmixers (talk • contribs) 03:51, 9 March 2017 (UTC)

DYK for Dehn invariant

On 11 March 2017, Did you know was updated with a fact from the article Dehn invariant, which you recently created, substantially expanded, or brought to good article status. The fact was ... that it is unknown whether the Dehn invariant of a flexible polyhedron stays invariant as it flexes? The nomination discussion and review may be seen at Template:Did you know nominations/Dehn invariant. You are welcome to check how many page hits the article got while on the front page (here's how, Dehn invariant), and it may be added to the statistics page if the total is over 5,000. Finally, if you know of an interesting fact from another recently created article, then please feel free to suggest it on the Did you know talk page.

Mifter (talk) 00:02, 11 March 2017 (UTC)

DYK for Plesiohedron

On 13 March 2017, Did you know was updated with a fact from the article Plesiohedron, which you recently created, substantially expanded, or brought to good article status. The fact was ... that Euclidean space can be completely filled without overlaps by copies of any plesiohedron, a type of convex shape whose known examples have up to 38 sides? The nomination discussion and review may be seen at Template:Did you know nominations/Plesiohedron. You are welcome to check how many page hits the article got while on the front page (here's how, Plesiohedron), and it may be added to the statistics page if the total is over 5,000. Finally, if you know of an interesting fact from another recently created article, then please feel free to suggest it on the Did you know talk page.

Mifter (talk) 00:03, 13 March 2017 (UTC)

Just want to say I found this article very interesting. Thanks! Smurrayinchester 08:39, 13 March 2017 (UTC)

@Smurrayinchester: You're welcome! (And sorry for the slow response, your message got buried in some other ones and I didn't see it until now.) —David Eppstein (talk) 16:16, 16 March 2017 (UTC)

Armands Strazds, retired

Greetings. It seems likely you were conned by Mr. Strazds in the recent exchange. According to the closer, the article was originally written by him, under his name. The closer informed me of this on his Talk page. You can read about Strazds' topic ban and reaction on his Talk page, and final reaction on his User page. Instructive methinks. Tapered (talk) 12:25, 13 March 2017 (UTC)

For values of conned meaning "lied to in a way that did not affect my opinion or actions", maybe. I was aware of the identity of the article creator, though. —David Eppstein (talk) 16:19, 13 March 2017 (UTC)

I was willing to accept the "no" operationally, but thought the embellishments 'doth protest too much.' I'm amazed that someone of his accomplishments, even if not meeting Wikipedia criteria, would be so persistent. Tapered (talk) 17:02, 13 March 2017 (UTC)

One of my favorite quotations is: 'Upon some of Cato's friends expressing their surprise, that while many persons without merit or reputation had statues, he had none, he answered, "I had much rather it should be asked why the people have not erected a statue to Cato, than why they have."' Mr. Contentious 17:11, 13 March 2017 (UTC)

Proof of non existence of a perfect cuboid

Hello David.

I've long been interested in the Perfect Box problem so I am probably not neutral on the question of its existence. I realize that the Randall msg provides some strong confirmation that Wyss's proof is correct. I see that you feel that is sufficient evidence that the proof is indeed correct. I still think we should wait for publishing. It's long been known that none of the parametrizations of a rational cuboid lead to a perfect cuboid, and the crux of Wyss's argument seems to be that he found a parametrization for rational leaning boxes that doesn't lead to a perfect cuboid. I am reading it to see where he establishes that his parametrization is the only one, hence there can be no Perfect Box. I am having to kick my aging brain into a gear that it hasn't used in some 30 years or so (I have a B.S. in mathematics from Cal Poly, SLO and a masters in mathematics from the University of Arizona).

Your thoughts?

TheRingess (talk) 17:58, 13 March 2017 (UTC)

Randall L. Rathbun is an expert on this subject, so if he thinks it's solved, then I think that's pretty strong evidence that it's solved. But you're correct that it's not properly published as a reliable source yet. So I think it's reasonable to go either way on this, but my tendency is to keep it in, at least on the cuboid article itself. —David Eppstein (talk) 18:04, 13 March 2017 (UTC)

I had forgotten about Rathbun, I just found a page detailing his search algo, and funny enough I came up with the same idea, and a similar implementation. As far as the article goes, it can go in as a historical note, that a proof of non-existence has been published, but not yet peer reviewed. I'm thinking of emailing Wyss, for a point of clarification, he seems to be showing that all parametrizations of the perfect cuboid are known and none yield a perfect cuboid. However, I've only skimmed the proof so far, and I may be misreading it. Of course, another way to prove non-existence might be to assume that a parametrization exists and then show that leads to a contradiction. About 15 to 20 years ago, I received a mysterious email from someone who never gave me their real name, claiming that the Perfect Box does exist and the sides are in the Quintrillions (had to look that up). He/she also provided some hints that I investigated for a while but obviously never bore fruit. Was I being played with? Maybe, probably (yes, if Wyss's proof is correct). Perhaps it was wishful thinking that led me to believe that the anonymous emailer was correct, or that the hints contained enough mathematical jargon to sound plausible. I have lost the emails with the hints (silly me, I never backed them up). At best now they would serve as a nostalgic reminder of a mystery I once tried to solve. About the only thing I remember was the emailers anonymous name stuck with me: chazzfinallyfree, which struck me as an anagram. In one email, he/she claimed that we shared the same birthday, October 28th. Anyway thanks for reading this far. TheRingess (talk) 18:42, 13 March 2017 (UTC)

I was assuming the argument went that the parameterizations can be proved to describe all tilted cuboids (not merely that they are all the parameterizations, but also that there are no other sporadic examples), and that none of them produces a right-angled cuboid, so therefore the right-angled cuboid doesn't exist. But I have to admit that I have not read it carefully. —David Eppstein (talk) 18:48, 13 March 2017 (UTC)

And that would do it. I emailed him through his physics department, for clarification, since I didn't see where in his proof he showed that no other independent parametrization exists, which leads me to believe I am not reading his proof correctly. Thanks again for reading.TheRingess (talk) 18:58, 13 March 2017 (UTC)

Hello there again. Not to beat a dead horse.

I'm thinking that Wyss's proof is not what he thinks it is. This is my reasoning. I know of at least 3 parametric formulas for Euler Bricks (see Wolfram's article for reference). All of which have been proven do not result in a Perfect Euler Brick, but all have been shown that they don't generate ALL Euler Bricks. How this is relevant to Wyss's proof, is that he must show that for his parameterization it does generate all Euler Bricks (which would make all the know parametric formulas just special cases of his). Reading through his proof, I did not see where he proved that, unless someone else showed that it produces all Euler Bricks and he provides a reference but it wasn't clear to me where he either cited a proof or did it himself. If he did not, then he has simply shown another parametric formula that does not lead to a Perfect Cuboid, but that by itself is insufficient.

I am still reading the proof, and have emailed him, politely requesting clarification, so this may turn for me into a real face palm moment.

On the plus side, if I am wrong, I think that he should be able to get it published in a mathematics journal rather easily (when I originally looked at the link, I was confused, since I thought the paper had been peer reviewed before inclusion in that archive, but then later read that inclusion in that archive does not necessarily mean that a peer review process has occurred).

Nor am I making any claim that my reasoning above could/should be included anywhere in Wikipedia except in a general discussion like this.

All I'm saying is that either we are 1) Just getting ahead of the curve for a well constructed proof that will see publication or 2) we will eventually retract it or 3) include it as historical reference in the history of a long unsolved problem (am I am assuming that Dr Wyss would not want to be immortalized as another guy who tried and didn't succeed in proving it).

In summary, I am leaning towards not including it until it has gone through the rigorous peer review process that a journal would apply (yes, I am kind of implying that Rathbun's assessment is not rigorous enough since I have the serious concern listed above).

See my sentence above, I expect this might be a very embarrassing moment in my own mathematics career as I may be missing the obvious.

Your thoughts?

Again thank you for reading, I understand that your time is very valuable.

TheRingess (talk) 11:31, 14 March 2017 (UTC)

DYK for Bricard octahedron

On 15 March 2017, Did you know was updated with a fact from the article Bricard octahedron, which you recently created, substantially expanded, or brought to good article status. The fact was ... that a Bricard octahedron (pictured) can change its shape without changing the shapes of its faces? The nomination discussion and review may be seen at Template:Did you know nominations/Bricard octahedron. You are welcome to check how many page hits the article got while on the front page (here's how, Bricard octahedron), and it may be added to the statistics page if the total is over 5,000. Finally, if you know of an interesting fact from another recently created article, then please feel free to suggest it on the Did you know talk page.

Mifter (talk) 00:01, 15 March 2017 (UTC)

Stone space

Hello.

Can you explain the meaning of this edit? Michael Hardy (talk) 01:44, 15 March 2017 (UTC)

If you're saying [5] that, in general, "Every member of X is isomorphic to some member of Y" implies that "Every member of Y is isomorphic to some member of X", that's obviously wrong. EEng 02:14, 15 March 2017 (UTC)

The meaning is that, not only is every Boolean algebra isomorphic to the algebra of clopen sets of a Stone space, but also every algebra of clopen sets of a Stone space is a Boolean algebra. I don't think that would be obvious to most people without saying it explicitly. —David Eppstein (talk) 03:15, 15 March 2017 (UTC)

It currently reads like this: "A form of Stone's representation theorem for Boolean algebras states that every Boolean algebra is isomorphic to the Boolean algebra of clopen sets of a Stone space." That the clopen subsets form a Boolean algebra does seem obvious to me.

If a set of subsets of a set is a Boolean algebra in which the order is inclusion, then the join of two sets is not always their union, since the family of sets may not be closed under union, but the union is always a subset of the join, and a similar thing applies to meet. But the set of all clopen subsets of any topological space is closed under union, intersection, and complement, so it's a Boolean algebra with meet and join coinciding with intersection and union. Michael Hardy (talk) 18:46, 15 March 2017 (UTC)

I don't think you qualify as "most people" for the purposes of testing whether reasoning like that is obvious. For that matter, I think most mathematicians would be somewhat unfamiliar with the definition of clopen (which was not and should not be given at that point of the article) and with the closure properties of open and closed sets in point set topologies (is it the closed sets that are closed under arbitrary unions and the open that are closed under intersections or vice versa? and does a clopen set inherit the closure properties of both closed and open or the intersection of the properties?) I think any mathematician could work this out with five minutes thought, but that's more than I would call obvious. —David Eppstein (talk) 20:26, 15 March 2017 (UTC)

DYK nomination of Thomas North Whitehead

Hello! Your submission of Thomas North Whitehead at the Did You Know nominations page has been reviewed, and some issues with it may need to be clarified. Please review the comment(s) underneath your nomination's entry and respond there as soon as possible. Thank you for contributing to Did You Know! MB 16:56, 18 March 2017 (UTC)

Check yr gmail

EEng 00:01, 19 March 2017 (UTC)

Thanks. I can send you a similar collection of photos from the Lowe book, if you care to look at them. —David Eppstein (talk) 00:03, 19 March 2017 (UTC)

Sure. Odd nothing except the ANW letter mentions Harvard. Maybe he was embarrassed about it. Or maybe it wasn't Harvard after all. Believe it or not I'm beginning to think the Field item Dicklyon found is from this [6] or [7]-- these kinds of gents' mags often had pop science and math. Harvard seems to lack the right volume (not positive because I'm not sure of the volume 3 -- if you figure that out let me know) and if so I'd have to get it on microfilm, which is a bit of a pain but I'll get it (and other Field items mentioned in Cook) if you think it will help. So the outstanding sources I think we have are:

• Field per above (I'll wait to hear from you)
• "Lifetime" Who's Who instead of Who Was Who -- also a pain if we don't know in what year(s) he appeared
• Index at Harvard archives -- this I can do in the next week or so.

Given that IEE mentions Barr was an erection engineer, and Who's Who mentions his work on screws, if you want I can put together one of my patented crude DYK hooks. Certainly after Talk:Edwin_Stevens_(missionary) there's nowhere to go but up. Might be good for April 1. EEng 00:44, 19 March 2017 (UTC)

Sure, there's lots of material in the article now for a hook. If I come up with one it will probably be more boring. Checking whether he actually had some kind of Harvard affiliation temporarily around 1927 would definitely be helpful; maybe also the Field. I'm not sure the lifetime Who's Who is worthwhile but I do at least need the full publication data for the Who Was Who version. —David Eppstein (talk) 00:52, 19 March 2017 (UTC)

OK, you asked for it. Like shooting fish in a barrel.

... that Mark Barr was an erection engineer and expert on screwing?

... that erection engineer Mark Barr possessed spherical balls [8], had a business making rubbers, and was elected to the Screw Committee?

Honestly, I don't know how I keep getting away with this. For Field, can you look around for any indication of the volumne numbers? That would help. EEng 02:07, 19 March 2017 (UTC)

I'm not sure the second hook is accurate. Weren't the balls in the hands of his employer at that time? —David Eppstein (talk) 21:02, 19 March 2017 (UTC)

May we assume you have tenure? EEng 21:25, 19 March 2017 (UTC)

Long since. —David Eppstein (talk) 04:42, 20 March 2017 (UTC)

it's sad that CS prof don't know the definition of APX-Hardness

Do not undo my edits in the FAS article 109.64.70.151 (talk) 08:02, 21 March 2017 (UTC)

Your edits have been consistently wrong. I will keep undoing them until they stop being wrong. —David Eppstein (talk) 15:58, 21 March 2017 (UTC)

So you'll halt when you recognize a good edit? EEng 16:15, 21 March 2017 (UTC)

Heh. Fortunately the undecidability of that problem rarely comes up in practice. —David Eppstein (talk) 16:19, 21 March 2017 (UTC)