Talk:Sundial

message: reference number 12 is not a pointer to a reliable source - it is "content" which is better suited in the main article - i was going to mark the "content" contained in reference number 12 with a "citation needed" but don't seem able to do that - this looks like a way to insert content without any source reference - if you know how to deal with this issue - let me know 
Johnmahorney (talk) 19:54, 22 August 2012 (UTC)
replies: text: A lot of articles have the title "References and footnotes" instead of just "References". This allows users to click on the numbers and see footnotes, where applicable, with no confusion. This article had just "references", so I've made the change. Incidentally, number 12 is not the only footnote in the list. DOwenWilliams (talk) 20:26, 22 August 2012 (UTC)
thread_title:  content in reference section 

message: IMO the article is being swamped again with pretty but uninformative images. More so because they all have huge captions trying to explain and justify their inclusion, and many are far too tall. This is making the article unreadable, and the rendering abyssmal. Has anyone any suggestions other than some wholesale zapping. --ClemRutter (talk) 21:13, 21 April 2009 (UTC)
replies: text: I've moved 8 images (which didn't need to be locked to a section) to a Gallery at the end, also floted the TOC, to allow more text at the top of the page, hope that looks a bit better  Ronhjones  (Talk) 22:14, 21 April 2009 (UTC)

text: Any moratorium on new images of sundials should only apply to images of northern-hemisphere sundials. The article has no image of a sundial from the southern hemisphere. This lack needs to be remedied so the article complies better with WP:NPOV. --<SPAN STYLE="font-family:monospace; color:#008800; background-color:#ffffcc; border:1px solid #ff4444;"> B.D.Mills </SPAN> (T, C) 11:45, 12 February 2010 (UTC)
replies: text: No. Two issues. The WP:NPOV is better handles by raising this in a new section- which I have done for you.--ClemRutter (talk) 13:33, 12 February 2010 (UTC)
replies: text: After reconsideration, I agree. I'll also add to your section below.--<SPAN STYLE="font-family:monospace; color:#008800; background-color:#ffffcc; border:1px solid #ff4444;"> B.D.Mills </SPAN> (T, C) 06:23, 23 February 2010 (UTC)
thread_title:  Moratorium on new upright images. 

message: The article has no image of a sundial from the southern hemisphere. This lack needs to be remedied so the article complies better with WP:NPOV. Could someone upload some images onto commons. --ClemRutter (talk) 13:33, 12 February 2010 (UTC)
replies: text: Also, we need a few pictures of sundials that are located between the tropics of Cancer and Capricorn. In this region the sun can pass to the north or the south depending on the time of the year, and this places different constraints on the design of sundials as opposed to sundials in more temperate latitudes. --<SPAN STYLE="font-family:monospace; color:#008800; background-color:#ffffcc; border:1px solid #ff4444;"> B.D.Mills </SPAN> (T, C) 06:27, 23 February 2010 (UTC)
replies: text: There are very few sundials in the Southern Hemisphere because the rapid variation of the Equation of Time ruins their accuracy during the southern summer. DOwenWilliams (talk) 05:30, 6 December 2011 (UTC)
thread_title:  Lack of meaningful sundial photographs from Southern Hemisphere 

message: BBC News article of 21 August 2009 discusses recent discovery of a Mass dial in Scotland - http://news.bbc.co.uk/2/hi/uk_news/scotland/edinburgh_and_east/8214948.stm .6,000+ Google hits for "mass dial" - http://www.google.com/search?q=%22mass+dial%22 . Apparently these are also called "Scratch dial".Our article apparently doesn't mention either of these terms. We should add a mention of these, and make Mass dial and Scratch dial redirect here. -- 201.37.230.43 (talk) 13:17, 22 August 2009 (UTC)
thread_title: [[Mass dial]] / [[Scratch dial]]

message: There is a coaching center established in 1985 in Rajshahi, Bangladesh, called Sun Dial. Which is the best coaching center for higher level education in the whole town.  —Preceding unsigned comment added by 180.234.30.194 (talk) 18:19, 1 September 2010 (UTC)
thread_title:  Sun dial coaching center 

message: There's a image (currently unlnked) of a pocket sundial at http://en.wikipedia.org/wiki/File:Sundial_pocket_watch.JPG
Might be worth adding to that section...
214.4.238.180 (talk) 21:14, 23 September 2010 (UTC)
thread_title:  Pocket sundials 

message: Shadow clock redirects here, but nowhere can an explanation of what they are (sp. as compared to a "regular" sundial) can be found... CielProfond (talk) 03:16, 2 November 2010 (UTC)
thread_title:  Shadow clock 

message: I question the statement that this style of sundial was popularized by Thomas Jefferson at Monticello.
It does not cite any sources to back the statement, and there's nothing about it either on 
Thomas Jefferson or Monticello.
I reckon this can be some sort of urban legend, but if so it should said so. Ebacci EN (talk) 11:19, 22 February 2011 (UTC)
replies: text: Agree.--ClemRutter (talk) 23:01, 22 February 2011 (UTC)
thread_title:  Questionable statement in "Globe Dial" under "Unusual Sundials" 

message: I see you have re-linked the reference to the book "The Story of Time", but I failed to find any source to reiterate that statement. I'll try to find the book but if you have a link, it would be much appreciated. It's not that I disagree with the "less common" statement, which I believe to be probably true. But on a quick search I could find evidence of pre-European sundials, and not just a few, in Ecuador, Mauritius and New Zealand - all oriented towards the South.
Also, the Thomas Jefferson reference remains without a source.
Acting as by your suggestions, I'm being bold and removing both controversial statements. I'll look for good sources in libraries that might corroborate or disprove such statements, but as it is now I believe some myths or misconceptions are being perpetuated (as I've seen many websites referencing this article, including the controversial statements).
I apologise if my actions were not taken in the correct manner. I'm more than willing to learn from my mistakes if you're kind enough to point them out for me. Ebacci EN (talk) 00:06, 28 August 2011 (UTC)
thread_title:  Being bold 

message: Please forgive this newbie (both to Wiki and the Sundial article) question. In section 7.2 the last sentence of the section states in part "... object's shadow to measure time, not only the hours, as in normal sundials, but also weeks and months." (emphasis added). How exactly does the shadow of the gnomon measure "weeks and months"? Jcflnj (talk) 13:01, 1 September 2011 (UTC)
replies: text: I presume it is because the length of the shadow reflects the height of the sun, and thereby the time of year. --Brian Josephson (talk) 09:08, 14 December 2017 (UTC)
thread_title:  Analemmatic sundials 

message: Tyger27 had said:
"Unlike horizontal dials, a vertical dial cannot ever receive more than twelve hours of sunlight a day, no matter how many hours of daylight there are."
Someone replied:
"Actually, that's not true. In the northern tropics, a north-facing vertical dial receives sunlight from sunrise to sunset.
Near the summer solstice, this can be substantially more than 12 hours per day."
Yes, at the summer solstice, just barely south of the Tropic of Cancer, a north wall can get almost 13.6 hours of sunlight.
(your text resumes)
The same is true for a south-facing dial in the southern tropics.
I have Waugh's book, which you cited frequently. I don't see anywhere where he says that a vertical dial cannot receive more than 12 hours of sunlight per day.
DOwenWilliams (talk) 20:34, 13 June 2013 (UTC)
thread_title:  Hours of sunlight 

message: Someone wrote:
"in the lede we learn that the "style" is the shadow creating edge of the gnomon and must be parallel to the Earth's axis.  In the Introduction ( in its 2nd paragraph as of 9/21/2013) we learn the the gnomon is "aligned with the Earth's axis, or oriented in an altogether different direction determined by mathematics."  This seems to be contradictory.  Please fix.173.189.74.6 (talk) 18:08, 21 September 2013 (UTC)
thread_title:  Edit request 

message: Awaiting input from ip-user.-- Clem Rutter (talk) 19:37, 29 November 2013 (UTC)
replies: text: Warning: a lot of good faith recent input is with out references - and reads like a undergrad maths essay and so is un-intellible to the general reader- this week end I will be culling unreferenced materials and standardising the symbols on those defined by the British Sundial Society Glossary also found in the North American Sundial Society repository. Unreferenced interesting maths will be trasfered here for discussion.-- Clem Rutter (talk) 10:23, 28 March 2014 (UTC)
thread_title:  Reclining-declining dials 

message: I just was looking at the Ambassador's article and its discussion of various timekeeping instruments, which brought me to this article. 
It says here that it was invented in 1600, however, according to the Ambassadors discussion it would have had to have been invented by 1533 for it to be included in that painting. 
I don't know how to resolve this kind of discrepancy according to wikipedian common practice, since both claims seem to be cited, but they definitely seem to be mutually incompatible.
Mdpacer (talk) 21:50, 7 July 2014 (UTC)
thread_title:  Universal equinoctial dial & Holbein's *The Ambassadors* 

message: I don't know why this article is pointing on :fr:Cadran bifilaire instead of :fr:Cadran solaire. 
[endquote]
That Bifilar-Sundials section of the wikipedia Sundial article, if it links to something, should link to something that is specificlly about bifilar sundials.  "Cadran Solaire" just means "sundial". It makes sense for the Bifilar section to link to a reference about bifilar sundials--the Cadran Bifilair article.
The two bifilar references in the article were to an article in French, and an artice in German. You might want to consider, instead, for each article, linking to the url at which the articles are translated into English. How do you fnd it? Search google for "Cadran Bifilaire". The line for it in Google will have a click-place that says "Translate this to English". Click on that. Then copy the url from the address-window at the upper left of your screen. I'd do it, except that I'm not going to make a modification just so that it can be deleted.
For that reason, I won't make any more modifications to this article.
By the way, that automated translation of the French article is a lot more error-free than is the automated translation of the German article. Evidently the automated translation software does better at translating French into English, than it does at translaing German into English.
The wikipedia sundial's Bifilar Sundials section is seriously, preposterously, lacking. It doesn't explicitly say that one wire (or string) is higher than the other, or for what purpose. It doesn't say what the Bifilar sundial is supposed to accomplish. It doesn't say what is the purpose of the Bifliar sundial. I added that information: The intersection of the 2 wires' shadows moves around a certain point on the dial, at a uniform rate of 15 degrees per hour...as if it were an equatorial dial. In other words, it combines the unform rate, and consequent easy interpolation, of an equatorial dial, with the easy building and all-directions readability of a horizontal sundial.
I added all that information to the article. ...plus a few words about obvious disadvantage of the Bifilar dial. 
Everything that I added about the Bifilar was deleted. ...because there were no citations? Look, that information about the uniform rate is given in the French article. I so stated, in added explanation. If you don't believe that, then view the English translation of the French article (View it by the method that I described above). I merely added, to the article, some basic necessary information that is in the French reference. That information belongs in the article--Without it, the reader would have no idea of what the Bifilar's purpose is.
Such basic, relevant information belongs in the article, not just at a linked-to reference. Anyway, as the article is now, anyone who doesn't read French or German will have no way of finding out what the bifilar sundial is, and for what purpose it's made as it is.
If I'm writing additions to the article only to have them delted, than there's no reason why I should do so.
Michael Osspoff65.8.169.50 (talk) 01:49, 8 February 2015 (UTC)
replies: text: Didn't see your comment before I started todays odyssey- if you would like to go back to Bifilar sundial you will see I have taken across the fr:text and anglified it. French likes lots of maths- English gets twitchy. I have taken out some of your comments as they seem trivial now and they weren't backed by a reference. 
[/quote]
You took out my statement of the Bifilar's advantage. Most people are interested in relative advantages and disadvantages. That isn't trivial. Without the advantages and disadvantages being stated, we're offering an unexplained bare menu.
The Bifilar has the advantage of combining the Equatorial's uniform shadow-motion, and consequent ease of interpoltion, with the Horizontal Dial's ease of building, and all-directions readability.
[quote]
The German source is good fun to read- I would like to see his 1914 Leipzig work- it could be a useful article for referencing this page. I need you to check the Maths, and correct any silly mistakes- particularly I would like you to sort out the reference to the meridian-did they mean the meridian plane? Does the meridian article need changing too? 
.
[endquote]
.
Regarding the meridian, yes they must have meant the meridian-plane. They meant that string F1 lines on the meridian plane.
But it would be clearer just to say that string F1 lies north-south.
I looked at the meridian article, and it seemed ok.
[quote]
.
Is the point O the same as point I ( I think not)
.
[endquote]
I agree. Point "I" will be different from point "O".
[quote]
.
and is the point O (origin of the line segments) orthogonally below the crossing of the wires. 
.
[endquote]
.
Yes. The X,Y position of the crossing of the wires is the origin, "O", of the co-ordinate system.
But the point at which the hour lines intersect is point C, different from point O, the origin of the co-ordinate system, directly below the wires' intersection.
Point C is behind (north of) point O. Point C's y-coordinate is negative.
It is around point C, that the shadow-intesection moves at a uniform rate.
[quote]
.
I have the 2 illustration from his article to upload, I assume it is now PD. I would like to do a short example for a London dial(51deg 30) using a N-S wire at 10cm. Michael, why aren't you registered- then I can send you emails and wiki-ping?
.
[endquote]
.
I've just now registered. I don't yet know what wiki-ping is, and so, if a wiki-ping message is sent to me, would I know about it? Maybe, then, if you send one, you should notify me, so that I'll know to look for it.
By the way, I won't build a Bifilar dial, because I'd want the dial to be where it's visible to neighbors and passersby--But they wouldn't recognize the Bifilar as a sundial. Additionally, the Bifilar's disadvantage that I mentioned above argues against it, for a sundial displayed to neighbors and passersby. Besides, I prefer sundials whose construction is easily explained to people. 
I might make a Bifilar if it were only for me.
Yes I forgot to sign it! -- Clem Rutter (talk) 21:46, 8 February 2015 (UTC)
thread_title:  « Cadran bifilaire », Why ? 

message: Wikidata element is correct and the German Wikipedia gives the good element. Simon Villeneuve (talk) 13:31, 23 December 2014 (UTC)
thread_title:  Wikidata 

message: I've just now edited the Multi-Face Dial section. (and summarized the edits in the Edit-Summary field).
I clarified what the Polyhedral's advantage is, and also its disadvantage with respect to the Horizontal Dial.
The relative advantages and disadvantages of the various dials is something imporant to include.
The already-existing article-section had some discussion of sundial-orientation methods. That discussion needed to be filled-in more. It needed to be more complete.
But I fully realize that, especially in its current more complete form, that sundial-orientation (or alignment) discussion should be in a more general section of the article, rather than a section about one particular kind of sundial (the Polyhedral).   ...maybe merged with alignment-discussion already in that other more general section.
The Multi-Face Dial section has a paragraph about faceted dials whose facets are on the inside of a hollow concave space, like that of a Hemispherium or Hemicyclium--a hollow that is roughly cylindrical or spherically concave, except that it's faceted instead.
Such dials must be quite rare. And it's questionable whether they'd have any advantage over a genuinely cylindrical or spherical dial-face. Certainly they have a big disadvantage compared to the usual, convex, faceted dial, the Polyhedral: The Polyhedral can be read (during the right time of day) from any direction, even if the dial is above the person reading it. A concave-faceted dial would have no such advantage. It would merely complicate cylindrical or spherical dial-face sundials, for no purpose or gain.
Because of their rarity, and because they apparently have no advantage (can anyone name an advantage for them?), I suggest that that paragraph be deleted from the article.
--65.8.169.50 (talk) 02:17, 11 February 2015 (UTC)
thread_title:  The Multi-Face (Polyhedral) Dial section 

message: It would be alright for the article to be long, if it were more systematic and orderly.
1. Sundials in which the style (shadow-casting edge) consisting of the edge of a hole or slit positioned at the circumference of a cylinder (instead of being at the cylinder's axis) casts a shadow or light-spot on the inner surface of the cylinder:
...a) The article didn't clarify that the cylinder is positioned with its axis parallel to the Earth's axis. 
...b) The article should say something about the use and usefulness of such a sundial...the motivation, purpose, advantages ( & disadvantages) or value of the style being on the cylinder's circumference rather than at its axis.  In fact, the article's description of cylindrical or conical surface sundials mentions some handheld objects, without addressing the matter of the task of orienting them properly for sundial use.
I propose to make those additions to that section.
2. Analog calculating sundials:
The article doesn't state its principle or give a detailed description.
Internet-search finds no support for the cardioid analog calculating sundial. What is found on the Internet is a number of websites that all repeat the same comments about "analog calculating sundials", always with exactly the same wording.
There are, of course, sundials that automatically correct to give a direct reading of standard time. But there's no support anywhere for the cardioid "analog calculating sundials" described in that article-section and elsewhere on the Internet.
I've deleted the Analog Calculating Sundials section.
65.8.169.50 (talk) 21:29, 19 January 2015 (UTC)
replies: text: I like quite a few other editors are following your changes and developments, and if necessary will edit them again. Can I personally ask one favour could you please not edit the talk page yet as that enables me to follow your train of thought, ideas and proposals.  I know it may become bulky but one can either edit it at the end or archive it so that future editors can see how thet article arrived in the form it is in. Thanks Edmund Patrick –  confer 06:46, 12 February 2015 (UTC)
thread_title:  A few initial comments and suggestions. Suggesting additions for circumference-hole cylindrical dial. 

message: I've just done some clarifiation and completion of the Non-Planar Surfaces" section of the article.
Tomorrow I'll go over it to fix the few typing-errors.
Comments, criticisms, objections or proposed changes regarding that edit?
--65.8.169.50 (talk) 15:18, 12 February 2015 (UTC)
thread_title:  Polar-Axis-Aligned Cylinder Dials, and Other Non-Planar Surfaces 

message: Michael can you please log in- before making a post- it is so much simpler for the rest of use your personal talk page to pass messages and advice- in the same way you use mine.
Brilliant new text- but Wikipedia principles demand it is supported by a reference. For convenience I have added: 
*The text is littered with  tags. Certainly any new text must be covered with a citation. The easiest way is to use the  format- this requires a full citation in the Bibliography, we have Waugh, Rohr and Mayall& Mayall already there. 
*We refer to them by     . This is now of the highest urgency. 
*Other references can be written  As much detail as you can give- and someone will work up the format later!
Text must be written in an encyclopedic way not as a construction manual. 
Notation used should be in line with the conventions used by the British Sundial Society Glossary. (adopted by the American Society). Is it?
I am feeling this page is getting too long- and the technical detail in each section could be moved to separate articles. Thoughts?
I am feeling that more formatting care must be taken with out  sections- as they need to be read on phones, tablet and grown-ups computers- as well as from paper printouts. -- Clem Rutter (talk) 17:26, 12 February 2015 (UTC)
thread_title:  Back to basics 

message: Clem:
I’ll use [quote]…[endquote] to mark your text.
[quote]
Michael can you please log in- before making a post- it is so much simpler for the rest of use your personal talk page to pass messages and advice- in the same way you use mine.
[endquote]
I’ve nothing against logging-in. I’ve meant to do so. In fact, I meant to do so this time--but forgot to. 
But, even when I sign a post without being logged-in, the “talk” link is at the end of the post. What do you think it links to?
[quote]
Wikipedia principles demand it is supported by a reference.
[endquote]
See below.
[quote]
 For The text is littered with  tags. 
[endquote]
That’s funny; I didn’t find them. Are they something that’s visible only to you?
I did find _one_ such tag: It was where I said that there was a Universal Capuchin Dial. So I immediately added a line explaining that the Universal Capuchin Dial is described in the sundial book by Mayall & Mayall.
[quote]
Certainly any new text must be covered with a citation. 
[endquote]
Incorrect. Here is what Wikipedia says about that:
"Wikipedia's Verifiability policy requires inline citations for any material challenged or likely to be challenged, and for all quotations, anywhere in article space.
"Readers must be able to check that Wikipedia articles are not just made up. This means that all quotations and any material challenged or likely to be challenged must be attributed to a reliable, published source using an inline citation."
So, Clem, are you challenging one or more of my statements, or are you likely to?  Then do so.
If so, then you need to be _specific_.
If you think that I’ve said something incorrect, or if you think that something that I said requires verification to determine whether it’s correct, then say so. Share it with us. Don’t be shy.
[quote]
Text must be written in an encyclopedic way not as a construction manual.
[/quote]
My edits weren’t written as a construction manual. To what, in particular, are you referring?
As I’ve already said, in an article on sundials, the advantages and disadvantages of the various sundials is a necessary topic. Some of the advantages and disadvantages involve ease or difficulty of construction. When that’s the case, I’ve stated those advantages too.
[quote]
Notation used should be in line with the conventions used by the British Sundial Society Glossary. 
[endquote]
“Notation:  A system of characters, symbols, or abbreviated expressions used in an art or science or in mathematics or logic to express technical facts or quantities.”
Did you mean “terminology”? The glossary defines words.
This is the first I’ve heard about a mandatory sundial glossary for Wikipedia. 
I don’t know if there exists a self-consistent and complete sundial terminology. 
For example, a Polar Dial’s dial-face is parallel to the Earth’s polar axis. A (disk) Equatorial Sundial’s dial-face is parallel to the plane of the equator. But the word “Equatorial” is often used to refer to a sundial whose dial-face surface is a cylinder whose axis is parallel to the Earth’s axis. 
That dial’s dial-face is _not_ parallel to the equator. 
So, forgive me, but I didn’t know that there existed a self-consistent and complete sundial terminology. But, when I noticed that others were using the word “Equatorial” to refer to cylinder dials with the cylinder’s axis parallel to the Earth’s axis, I began using that usage too, taking it as a convention.
[quote]
Is it?
[endquote]
The fact that you need to ask that tells us that you don’t know of an instance otherwise.
How have I run afoul of the BSS glossary. Be specific.
If you think that I’ve run afoul of proper sundial terminology, then be bold and change the terminology that you think is incorrect in my text. Wikipedia guidelines tell us to not hesitate to immediately correct errors in spelling, grammar, or correct usage.
I looked at the BSS glossary, and of course it’s quite long. Therefore, if you think that I’ve violated it, then you need to specify which part of it you think I’ve violated.
A question: Isn’t it true that Wikipedia stores the text that my edits have replaced, and can easily restore the original text, as it was before my edits?
--65.8.169.50 (talk) 14:57, 13 February 2015 (UTC)
replies: text: I have continued this discussion ( which has become a conversation) on User talk:MichaelOssipoff. Please follow us there. -- Clem Rutter (talk) 19:35, 13 February 2015 (UTC)
thread_title:  Reply to Clem, regarding citations, glossary violations, construction-manual, etc. 

message: I obtained the Compendium article referred to in Ref #42. It doesn't mention anything about Mayall & Mayall's formulas, or Rohr's formulas, being incorrect. Nor does it have the formulas that Clem re-posted.
The material that I deleted was entirely un-sourced, not supported by any citations, not supported in any manner.
I found the Compendium article Sundial Design Using Matrices, and that, too didn't mention the alleged incorrect formulas of Mayall & Mayall or Rohr, or the formulas that Clem re-posted.
The material deleted was entirely un-sourced, not supported by any valid citation. Surprising or implausible claims espectially neec citation.
Wikipedia has a policy against construction-instructions in an encylopedia. That's what formulas without derivation are. A cookbook impersonating a technical textbook--except that textbooks have some derivation of their formulas.
--MichaelOssipoff (talk) 21:31, 12 April 2015 (UTC)
thread_title:  I've just deleted un-sourced, completely unsupported text in Reclining-Declining. Ref #42 doesn't support any of that text. No valid citation is given. 

message: The subject line says it all.
Indeed, Clem's Ref 43 has Reclining-Declining formulas. The problem, for Clem, is that the article's formula for an hour-line is quite different from the one in the article-version that Clem keeps re-posting. 
Clem, you can't use a formula as a supporting citation, when it doesn't resemble the formula that you're trying to support.
The cited article also doesn't have Clem's formulas for the dial-orientation of the style.
And the cited article also doesn't contain the statement that Mayall & Mayall's Reclining-Declining formulas are wrong, or that it's only in the last decade that there's been agreement regarding the marking of Reclining-Declining dials. (I'll refer to those statements as Clem's "controversial statements").
In summary, the cited article, Ref 43, doesn't support Clem's formulas or his controversial statements.
It doesn't lend any support to Clem's article-version.
I'm deleting Clem's article version again.
--MichaelOssipoff (talk) 12:18, 13 April 2015 (UTC)
thread_title:  Ref #43, in Clem's latest version isn't a source for the implausible contested statements, or for Clem's formulas. Deleted. No valid citations.. 

message: Clem:
You have made a vague reference to an article in which Snyder summarizes Brandmaier, (available from NASS for $6.50).
I ask you three questions about that:
1. Is that, your latest vaguely-implied reference, something other than Compendium 22:1, March 2015, "Sundial Design Considerations", by Snyder?
2. Does it contain or support your implausible controversial statements? (By which I refer to your statement that the Reclining-Declining formulas of Mayall & Mayall are incorrect, and your statement that only in the last decade has there been agreement on how to mark a Reclining-Declining dial)
2. Does it contain the Reclining-Declining formulas that you keep re-posting to the Sundial article? (...in the literal same form, not some other formulas to which you claim that yours are equivalent)
-------------------------------------------
To justify your latest reversion, your re-posting of your deleted text, you need to start by answering the above 3 questions affirmatively (if such an answer would be truthful).
If you answer affirmatively, then I'll check to find out if that answer is truthful.
If you answer negatively, then you're admitting that you still haven't justified the deleted text that you've re-posted, and that you are continuing to re-post un-sourced material, without any valid citation.
If you don't answer, then it must be assumed that your reference to Snyder is Compendium 22:1, March 2015, "Sundial Design Considerations", which I've already checked,and which does not contain the formulas that you re-posted.   ...or that, whatever else you're referring to, it doesn't support your re-posting of your questionable deleted text, and that your latest reference is just as phoney as your references #42 and #43.
-------------------------------------------------
Given the falsity of your vague implication that your Ref #42 and Ref #43 supported your deleted text, surely you must understand that it's not unfair to ask you these simple Yes/No questions regarding what you're explicitly claiming about Snyder's alleged support for your questionable text.
--------------------------------------------------
--MichaelOssipoff (talk) 12:38, 14 April 2015 (UTC)
thread_title:  Clem has re-posted his text, reverting my deletion, without even a pretense of giving a new citation or reference. 

message: 1. The statement that the Reclining-Declining formulas of Mayall & Mayall, and Rohr are not correct lacks a citation. In the case of Mayall & Mayall, the statement is incorrect. Mayall & Mayall's formulas give the right answer for an example with arbitrarily chosen latitude, recline, decline-direction, and time-of-day. Additionally, Mayall & Mayall's formulas are correct when applied to a horizontal dial. 
Admittedly, whoever copied Mayall & Mayall's formulas into note (b) made a number of copying-errors that would result in wrong answers, if not fixed. But that's the fault of the person who copied them into note (b), not of Mayall & Mayall.
As for Rohr, I have no idea whether or not his formulas are correct. But, in any case, a citation is needed for such a claim--when contradicting a long-established classic authoritative source. Clem said or implied that there's a book that supports the statement that (at least one edition of) Rohr's book gives incorrect Reclining-Declining formulas. But Clem's citations have a really poor accuracy-record.
2. The statement that only in the last decade has there been agreement on how to mark a Reclining-Declining dial is likewise without any valid citation.  ...is completely un-sourced.
3. It's necessary for the reader to be warned that the formulas currently in the Reclining-Declining section are of unknown origin. It's bizarre that Clem thinks that that the reader doesn't have a right to that information.
Clem deleted the warning when I added it before, and I've restored it to the article.
Clem says that someone deleted the references, and then complained that the text was un-referenced. No, the statements that I deleted again today were unreferenced. And the formulas are, and always were, without any valid citation.
Wikipedia policy requires that if your text is deleted because it lacks citation (especially if it's controversial), then you must not re-post it to the article. Clem violated that rule when he re-posted his un-sourced statements, today, and on all the previous occasions when he did so. Likewise when he re-posted his un-sourced formulas.
The purpose of this message is to explain the justification for the edits that I did today.  ...the ones specified above in this messaage.
Wikipedia requires an explanation of reverts. That's another wikipedia requirement that Clem doesn't bother abiding by.
If Clem has a book that says that Rohr's formulas were wrong, then he should cite Rohr when he makes that claim. 
Was there a reference, regarding the Rohr-incorrect claim, that I didn't notice? If so, then my apologies. If there already is/was such a citation, then of course put the claim about Rohr back in the article.
But don't put the one about Mayall & Mayall back in, unless you have a citation for that. ...or an example in which Mayall & Mayall's formulas give a wrong answer.
Clem has been blatantly and knowingly violating wikipedia policy, giving readers at least one un-sourced false statement regarding a classic authoritative source, and a set of formulas of unknown origin.
--MichaelOssipoff (talk) 22:36, 26 April 2015 (UTC)
replies: text: Please do not add commentary - use tags as I have just done. I'm not seeing a lot of proper sources for equations. --NeilN talk to me 22:56, 26 April 2015 (UTC)
thread_title:  Have just now added (to Reclining-Declining) a readers-warning that the formulas are of unknown origin.  ...and deleted un-sourced false statements. 

message: ...and I've just restored the fixed version that the administrator had put up.
The version that has a template announcing the Reclining-Declining section's un-sourced material, and the tag identifying the formulas as possible original research.
That administrator advised me that warnings such as the one that I'd added (about the formulas of unknown origin) should be given in the form of a template instead of by adding text as I did. 
Then Clem reverted that administrator's fix.
As I said, I've just now restored it.
That restoration removes the un-sourced and demonstrably false statement regarding Mayall & Mayall, as well
--MichaelOssipoff (talk) 23:48, 26 April 2015 (UTC)
replies: text: If you're talking about me, I'm not an admin (though I am an experienced, uninvolved editor). , the fastest way to end this dispute is to provide proper sources. --NeilN talk to me 00:00, 27 April 2015 (UTC)

text: Thanks, Neil. If the page was ever stable enough long enough that could happen. We need to go back to Davids version before we have any hope of adding. vI have given him a lot of help on his talk page- which was subsequently deleted- and given him the primary source that supports the statement. I now have received the disk from the NASS with 21 years of primary sources. I am restoring the page that had evolved User talk:ClemRutter#Reclining-Declining Sundials in April 2014 but copying the page (that I basically commenced in 2008 ish) that  is so keen on into a sandbox so he cam demonstrate his ideas. See User talk:MichaelOssipoff for dialogue. I hope that lasts long enough so we can actually introduce some better references. Please feel free to contribute- or not.-- Clem Rutter (talk) 15:14, 27 April 2015 (UTC)
thread_title:  The version that Clem reverted this time had been put up by an administrator 

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thread_title:  External links modified 

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thread_title:  External links modified 

message: According to the article & citation the ring dial "was likely invented by William Oughtred around 1600" (currently reference #60, Tuner p.25 ), however the painting The Ambassadors from year 1533 shows what scholar John North (amongst others, cited in the painting article) identifies as a disassembled ring dial as one of the scientific instruments in the painting.
I don't have a specific source that purports an earlier invention of the ring dial, but I think the conflicting analysis (not to mention potential visual evidence) makes it a bit difficult to say Turner's claim is "likely."  If it is a ring dial in the picture (I'm unaware that this is in dispute) from seventy-ish years before it was "likely invented", we should probably be less assertive with Turner's analysis.  //Blaxthos ( t / c ) 05:10, 1 March 2016 (UTC)
replies: text: A very valid point worth more investigations. In the wiki page for the painting it is listed as such alongside the polyhedral example, amongst others. Interesting??? Edmund Patrick –  confer 10:09, 1 March 2016 (UTC)
replies: text: but see this, others have headed down this road before. Edmund Patrick –  confer 10:16, 1 March 2016 (UTC)

text: Thanks to the Wellcome donation we have many clear illustrations of these portable dials. Compare the unnamed instrument in the Ambassadors with this one. I would love to know exactly what Holbein had found?  ClemRutter (talk) 14:44, 18 January 2018 (UTC)
thread_title:  Universal equinoctial ring dial inconsistency 

message: I deleted this section, which read as follows:
"This portable folding German sundial has a string gnomon (pointer), adjustable for accuracy at any latitude. As shadows fall across the sundial, the smaller dials show Italian and Babylonian hours. The dial also indicates the length of the day and the position of the sun in the zodiac."
My reasons:
* The text is clearly describing a specific object, rather than pocket sundials in general, and without an accompanying picture it really doesn't convey much useful information.
* When the text was orignally inserted, the words "Dorling Kindersley" appeared at the end. Could be a copyvio?
* I don't think it's appropriate to place a subsection on portable dials in a section which is basically about how the geometry (mainly the alignment) of dials affects their design, and in fact there's alreasy some relevant information about (presumably) this type of dial elsewhere in the article. 79.73.148.253 (talk) 02:24, 6 August 2016 (UTC)
thread_title:  Pocket sundials 

message: Some s challenged by an IP. Awaiting explanation.--ClemRutter (talk) 10:35, 14 December 2017 (UTC)
replies: text: I think the calls for citations in the Apparent Motion section are a little bit overblown.  For example, the linked article on the ecliptic refers to the connections between the ecliptic and the zodiac, and the linked conic section article starts " a conic section (or simply conic) is a curve obtained as the intersection of the surface of a cone with a plane. The three types of conic section are the hyperbola, the parabola, and the ellipse."  I suppose though clarifying notes would add some clarity. --Brian Josephson (talk) 11:01, 14 December 2017 (UTC)
replies: text: Thanks- I agree, if I thought a citation was necessary I would have added it when I wrote the text (I believe I wrote it). In a good faith attempt to improve the article- maybe for a GA, someone added those tags- so we have to address the issue not try and fight the system, and document our reasoning.--ClemRutter (talk) 12:38, 14 December 2017 (UTC)
thread_title:  More citations needed. 

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thread_title:  External links modified (January 2018) 

message: I know that there are already enough pictures so I won't add this one, but in case anyone wanted a picture of the Greenwich (England) sundial, it is here:  Gah4 (talk) 22:44, 16 April 2021 (UTC)
thread_title:  Greenwich 

message: Boy 103.15.63.94 (talk) 14:13, 20 August 2022 (UTC)
thread_title:  Science 

message: Is a horological divise that tells the time of day when the direct position of the sun in the sky  — Preceding unsigned comment added by 196.188.243.152 (talk) 16:37, 29 September 2022 (UTC)
thread_title:  Sundial  

message: main uses of sundial. 2409:4061:8EB3:5AC6:1125:639:9D54:D009 (talk) 02:59, 30 May 2024 (UTC)
thread_title:  Geography .