This level-5 vital article is rated C-class on Wikipedia's content assessment scale. It is of interest to the following WikiProjects: | ||||||||||||||||||
|
This article is or was the subject of a Wiki Education Foundation-supported course assignment. Further details are available on the course page. Student editor(s): Lorchave.
Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT (talk) 03:55, 17 January 2022 (UTC)
Hello Everyone, I have made edits the meridian article. I have added references, and have also added sections such as "Pre-Greenwich" and "Measurement of Earth Rotation". I have also added parts to "Magnetic Meridian" and "Geographic". Please feel free to edit and ask questions. Lorchave (talk) 05:15, 26 July 2018 (UTC)
In this paragraph:
The position of the meridian has changed a few times throughout history, mainly due to the transit observatory being built next door to the previous one (to maintain the service to shipping). Such changes had no significant effect. Historically, the accuracy of the determination of longitude was much larger than the change in position. The adoption of WGS84 as the positioning system, has moved the meridian 102.5 metres east of its last position (measured at Greenwich). The position of the current meridian is not identified at all in Greenwich but is located using a GPS receiver.
He says
"the accuracy of the determination of longitude was much larger than the change in position."
Its apparent to me that the author intends to compare the endemic error in measurement with the size of the change in position in order to show that the changes in position had little significance.
However the sentence as found doesnt say this. I believe that he uses the word accuracy when he means to use the word error. If I were correct, it should read:
"the error in the determination of longitude was much larger than the change in position."
It may have been a translation issue. — Preceding unsigned comment added by 58.160.134.33 (talk) 04:17, 29 December 2014 (UTC)
Anyone ever think of including the term for a line of latitude here? —Preceding unsigned comment added by 69.159.219.48 (talk) 15:28, 20 September 2007 (UTC)
parallels, methink 64.56.229.144 (talk) 14:42, 23 March 2008 (UTC)
meridian circles. GrzegorzWu (talk) 09:50, 25 March 2008 (UTC)
Circles of latitude or, perhaps more commonly, parallels. Backspace (talk) 09:08, 4 February 2009 (UTC)
During my visit to Greenwich on the 3rd of May 2008 I took my GPS navigator (MIO 268, SW 3.2) and hoped to see the coordinate being exactly zero for longitude. I was surprised to see around 0.00147 degrees West, which I roughly calculated into approximately 150m (!) offset. The navigator had a good satellite reception and indicated a 1.6m accuracy. Also the altitude had quite an offset compared to the plaque on the observatory, but I did not make a note of that unfortunately.
How is it possible that the navigator has this enourmous offset and how is it possible that it works fine on the road, on which I believe it is closer to the 1.6m offset than the 150m offset. Does anyone have the same or other experiences? (Marc van Beek, The Netherlands) —Preceding unsigned comment added by 193.173.39.45 (talk) 09:42, 5 May 2008 (UTC)
what is true meridian —Preceding unsigned comment added by EverGreg (talk • contribs) 20:11, 12 January 2009 (UTC)
Several meridian articles have been renamed around 14/15 April.
HTML2011 (talk) 03:38, 17 April 2012 (UTC)
I did look, but this section is not relevant if one wants to know why the titles were changed to lower case. It says "unless the title is a proper noun". Salt Lake Meridian is a proper noun, so should be capitalized. This is analogous to Rocky Mountains which are not named Rocky mountains in Wikipedia. Also the articles are named South Pole, Southern Hemisphere, New York City, Liard River, Brooks Range and not South pole, Southern hemisphere, New York city, Liard river, Brooks range. The massive renaming by one user brought the meridians out of line with Wikipedia house style. HTML2011 (talk) 21:12, 18 April 2012 (UTC)
An editor has asked for a discussion to address the redirect Central meridian. Please participate in the redirect discussion if you have not already done so. -- 70.51.200.101 (talk) 05:43, 7 February 2015 (UTC)
"The magnetic meridian is an equivalent imaginary line connecting the magnetic south and north poles and can be taken as the horizontal component of magnetic force lines along the surface of the earth.[1][dubious – discuss] Therefore a compass needle will be parallel to the magnetic meridian."
If the magnetic meridian is a component of the magnetic force line (i.e.they are not prallel), and a compass needle alignes with the magnetic force line, then the needle will not be parallel to the magnetic meridian. The one exeption to this is where the magnetic force line is horizontal, which only happens at the equator.
So even if the first section is left unchanged the second section of the quote cannot be correct. I suggest removing the second sentence. — Preceding unsigned comment added by Kabivose (talk • contribs) 20:51, 14 February 2015 (UTC)
Hello fellow Wikipedians,
I have just modified one external link on Meridian (geography). Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.
This message was posted before February 2018. After February 2018, "External links modified" talk page sections are no longer generated or monitored by InternetArchiveBot. No special action is required regarding these talk page notices, other than regular verification using the archive tool instructions below. Editors have permission to delete these "External links modified" talk page sections if they want to de-clutter talk pages, but see the RfC before doing mass systematic removals. This message is updated dynamically through the template ((source check))
(last update: 5 June 2024).
Cheers.—InternetArchiveBot (Report bug) 07:38, 14 December 2017 (UTC)
Hello fellow Wikipedians,
I have just modified one external link on Meridian (geography). Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.
This message was posted before February 2018. After February 2018, "External links modified" talk page sections are no longer generated or monitored by InternetArchiveBot. No special action is required regarding these talk page notices, other than regular verification using the archive tool instructions below. Editors have permission to delete these "External links modified" talk page sections if they want to de-clutter talk pages, but see the RfC before doing mass systematic removals. This message is updated dynamically through the template ((source check))
(last update: 5 June 2024).
Cheers.—InternetArchiveBot (Report bug) 01:09, 23 January 2018 (UTC)
No. The meridians are not perpendiculars with the small circles, but with the great circles (only East-West). The meridians are of course perpendiculars to Equator (cosinus ray=1). Carlassimo (talk) 21:56, 9 April 2020 (UTC)
It's not obvious to me what cross and pass means here, and particularly whether the two verbs mean different things. —Tamfang (talk) 23:17, 17 July 2023 (UTC)