Template:Did you know nominations/John Rigby (mathematician)


 * The following is an archived discussion of the DYK nomination of the article below. Please do not modify this page. Subsequent comments should be made on the appropriate discussion page (such as |this nomination's talk page, the article's talk page or Wikipedia talk:Did you know), unless there is consensus to re-open the discussion at this page. No further edits should be made to this page.

The result was: promoted by valereee (talk) 12:35, 8 June 2019 (UTC)

John Rigby (mathematician)

 * ... that Ross Honsberger named John Rigby theorem on the orthopole of the six sides of two triangles "the Rigby point"? Source: Gerry Leversha, Dr John Frankland Rigby, obituary in The Mathematical Gazette, 2015 (see para 6)
 * Reviewed: Hevsel Gardens

Created/expanded by Moonraker (talk). Self-nominated at 09:01, 6 May 2019 (UTC).
 * ALT1 ... that Ross Honsberger named a point in John Rigby theorem to do with the orthopole of the six sides of two triangles "the Rigby point"?
 * ALT2 ... that the mathematician John Rigby was a leading authority on the relationship between maths and ornamental art? Source: Leversha obituary of Rigby linked above


 * Symbol question.svg New enough, long enough, and adequately sourced. QPQ done. But some quotation or close paraphrasing within the article needs to be more carefully marked as a quotation and sourced; for instance we have quote marks around "drawing gasps of admiration from the audience" but the actual copied text starts significantly earlier at "technically correct solutions". Every quote, such as "magnificently accurate diagrams" (again, with the quote marks narrower than the actual quote) needs to have a footnote on that sentence to the source of the quote. Other copied or too-closely-paraphrased text includes "visited universities in Turkey, Canada, Singapore, the Philippines, and Japan" and "the connection between mathematics and ornamental art". Additionally, the hook as worded makes no sense mathematically. The Rigby point is a geometric point that can be defined from any triangle as a triangle center; see . The orthopole is something defined from a triangle and a line, not from two triangles. And a theorem is a mathematical statement with a proof. A theorem can be about a point (although it's not clear whether this one is) but it is not possible for a theorem to be a point, just as an encyclopedia article can be about a mathematician but cannot be a mathematician. —David Eppstein (talk) 05:42, 12 May 2019 (UTC)
 * Many thanks for the thoughtful review, . Yes, in one sentence a quotation mark needed to be moved by several words and I have done it. I have also edited «"magnificently accurate" diagrams» to «"magnificently accurate diagrams"» and added a citation immediately after it, as you suggested. By chance, the other quotations all had one. I have also done some re-wording to deal with your other comments. On the hook, I take your point about a theorem and a point being quite different and stand corrected. Your wolfram.com link is to a different "Rigby point", which is also mentioned by Leversha. The words "the orthopole of the six sides of two triangles" come from Leversha, so does he have it wrong? He is the author of a 541-page book called "The Geometry of the Triangle" (Mathematics Trust, 2013, ISBN 978-1906001179) and I was thinking he could be relied on. I am putting up an ALT1, but in case you believe that is still wrong I am also suggesting an ALT2, on a different topic. Moonraker (talk) 04:16, 14 May 2019 (UTC)
 * I think ALT2 is much more interesting as a hook. But the sentence of the article containing the hook claim must have a footnote. I think the abbreviation "maths" should be spelled out as "mathematics". And the article text "became a leading authority on the interface between mathematics and ornamental art" and the source text "became a world expert in the connection between mathematics and ornamental art" still reads as uncomfortably close paraphrasing to me. —David Eppstein (talk) 06:11, 14 May 2019 (UTC)
 * , I agree that ALT2 might be more interesting. Okay, I have added a footnote straight after the sentence in the article. You have not said if there is now anything wrong with ALT1. There are not many ways to say ALT2. I have changed "...and became" to "He was also..." The obituary says "world expert", and I see no objection to "leading authority", it keeps enough of the meaning. We then need a word for "connection" and I have said "interface". I am not going to try to invent another name for mathematics. The meaning of "ornamental art" is not very clear and I think we should stick to it. If you are not happy, perhaps the answer is to quote the words from the obituary in the article and use them as the hook? Failing that, could you possibly suggest a way to say "world expert in the connection between mathematics and ornamental art" that would not read as uncomfortably close paraphrasing? Moonraker (talk) 17:22, 14 May 2019 (UTC)
 * I am still not convinced that ALT1 makes sense mathematically. Something is missing between the definition of orthopole in our article and the data described in the hook. However, I am increasingly concerned by the close paraphrasing and by your rationalization of it. Copying text from someone else and then replacing words by synonyms is still copying. You need to digest, understand, and write the material in your own words. The failure to do that is in part what has gone wrong with ALT1: The hook is copying some words from Honsberger without understanding the mathematics behind them. —David Eppstein (talk) 17:44, 14 May 2019 (UTC)
 * , on ALT1, I do not doubt that your understanding of the mathematics is better than mine, but Leversha is a top man on the geometry of triangles, which so far as I am aware is not your specialism, and if you say he has this wrong then you should also say what exactly he has wrong. I do not find "something is missing" awfully convincing. If you can say *what* you think is missing, and if it makes sense, then I can defer to you and add it. On ALT2, let me please ask you again, do you have any objection to a quotation being used for the hook, or else can you suggest a wording which conveys the meaning without "replacing words by synonyms"? With a simple statement of this kind there are only those two ways to do it. Moonraker (talk) 04:04, 15 May 2019 (UTC)
 * Re "so far as I am aware is not your specialism": maybe not (I don't tend to specialize in such specific topics), but it is definitely within my expertise and my publication history. Perhaps you didn't notice that my name was dropped in the see-also section of the MathWorld link? —David Eppstein (talk) 16:24, 24 May 2019 (UTC)
 * The Rigby point in the Honsberger book is described in the second part of the MathWorld article. The configuration being considered involves two triangles that have a common circumcircle and that are subject to an additional condition.  This configuration has the property that the three orthopoles of the sides of the second triangle with respect to the first triangle and the three orthopoles of the sides of the first triangle with respect to the second triangle all coincide in a single point—the Rigby point.  The way this configuration is constructed is as follows: start with a triangle and its circumcircle.  Pick any chord of the circumcircle.  Then there is a unique point on the circle whose Simson line with respect to the triangle is perpendicular to this chord.  Joining this point to the endpoints of the chord produces a second triangle with the same circumcircle as the first and with the property described above.  Another property is that the Simson lines of the endpoints of any side of one triangle with respect to the other triangle intersect at the Rigby point.
 * This Rigby point, unlike the ones defined in the first part of the MathWorld article, is not a triangle center since it requires specifying not only the triangle, but also a line intersecting the triangle's circumcircle. I do think that Leversha's formulation, "he named a point in one of John's theorems, concerning the orthopole of the six sides of two triangles, as the Rigby point", is not very informative.  It certainly leaves out key stipulations, in particular that it is the orthopole of a side with respect to the other triangle, and that the two triangles have to be related in a particular way.  Will Orrick (talk) 23:34, 21 May 2019 (UTC)

, that's most helpful, many thanks. I also took this up with Dr Leversha, who has said this: "My actual reference is ‘one of John’s theorems, concerning the orthopole of the six sides of two triangles’. This was paraphrased from the phrase in Honsberger ‘the orthopole of six sides of triangles ABC and PQR’, and even this is inadequate, since the actual result takes two paragraphs to describe and a further four pages to prove.  Clearly I could not go into any such detail in an obituary for popular consumption, and so I adapted Honsberger’s own contraction of the result omitting the names of the two triangles. Very few readers would even have heard of an orthopole." So clearly this hook is best abandoned. , you were right that something was missing. Can we please focus on ALT2? A reply to the above would be appreciated, or you may prefer someone else to take over? Moonraker (talk) 15:27, 24 May 2019 (UTC)
 * ALT1 might be salvageable. For example, ... that in triangle geometry two different kinds of Rigby point have been named after the geometer John Rigby?  That, of course, would entail adding the information about the second kind of Rigby point to the article. Will Orrick (talk) 18:28, 24 May 2019 (UTC)

A good suggestion,, many thanks. The only thing is, if does not reappear, another reviewer is needed. Moonraker (talk) 23:57, 3 June 2019 (UTC)
 * ALT3 ... that in triangle geometry two different kinds of Rigby point have been named after the geometer John Rigby? Source: http://mathworld.wolfram.com/RigbyPoints.html
 * Symbol confirmed.svg Reappear? I was waiting for you to respond to Will Orrick's comment. The new version of the paragraph on which the hook is based, "With Branko Grünbaum, Rigby elaborated the Grünbaum–Rigby configuration,[5] and Ross Honsberger named a point in a theorem by Rigby "the Rigby point".[2] Adrian Oldknow named inner and outer Rigby points in connection with Soddy triangles, with the Rigby points lying on the Soddy line.[6]" is now almost completely content-free (one learns nothing mathematical except that one should go to the sources to find out what those things all are), but at least it's no longer wrong. I think "realized" is probably a more accurate word than "elaborated" (he didn't make it more complicated; rather, he showed that it didn't have to be complex and could be merely real), but that's a minor point. Anyway, being uninformative is not actually against the DYK rules, the new hook is properly sourced, and the rest of the article is still ok. So I suppose I have to pass this. —David Eppstein (talk) 00:15, 4 June 2019 (UTC)
 * Thank you, . I think it's best only to touch the surface in the article, which after all is about Rigby. Moonraker (talk) 12:51, 4 June 2019 (UTC)
 * Symbol question.svg Hi, I came by to promote this. Can I promote ALT2 without stepping on any mathematical-minded toes? Yoninah (talk) 19:41, 6 June 2019 (UTC)
 * Hello, . I like ALT2, but I believe only meant to approve ALT3, as for ALT2 he dislikes my paraphrasing of the source. But he did not reply (see above) when I asked if he would prefer a quotation. If you think it is okay, I can still see no problem with it. Moonraker (talk) 23:56, 7 June 2019 (UTC)
 * Sorry for being unclear — I have no objection to the meaning behind hook ALT2, so as long as you think the difference between the hook's "leading authority on the relationship between maths and ornamental art" and the source's "world expert in the connection between mathematics and ornamental art" is not too-close paraphrasing, go ahead and use it. —David Eppstein (talk) 00:06, 8 June 2019 (UTC)