Talk:Jacobus Kapteyn

Wiki Education Foundation-supported course assignment
This article was the subject of a Wiki Education Foundation-supported course assignment, between 23 January 2019 and 10 May 2019. Further details are available on the course page. Student editor(s): Clandis0217, Igct27. Peer reviewers: Jcr9r2.

Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT (talk) 01:00, 17 January 2022 (UTC)

Untitled
I don't know if anyone thinks this worth mentioning, but Kapteyn starts a series of 4 academic generations of astronomers who have asteroids named for them: Kapteynia; his students: Willem de Sitter (1686 de Sitter}, Jan Schilt 2308 Schilt; Schilt's student:  4897 Tomhamilton; Hamilton's students: Fred Espenak 14120 Espenak and Sheldon Schafer (17601 sheldonschafer).  Probably very few other such cases.  Tom4897 (talk) 14:56, 30 December 2009 (UTC) It is also interesting that his daughter married Ejnar Hertzsprung one of the two astronomers responsible for the HR Diagram24.168.74.11 (talk) 19:15, 14 January 2013 (UTC) I might add that the Jan Oort mentioned was one of Kapteyn's former students  — Preceding unsigned comment added by 2604:2000:1600:4F49:4030:4F7E:2518:7BC0 (talk) 00:46, 16 December 2019 (UTC)

External links modified
Hello fellow Wikipedians,

I have just modified one external link on Jacobus Kapteyn. 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:
 * Added archive https://web.archive.org/web/20080202023546/http://www.rug.nl/sterrenkunde/onderzoek/geschiedenis?lang=en to http://www.rug.nl/sterrenkunde/onderzoek/geschiedenis?lang=en

When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.

Cheers.— InternetArchiveBot  (Report bug) 19:06, 28 November 2017 (UTC)

Hello, I added some information on the young age of Kapteyn and how he did while he was there and added a new citation. if you have questions feel free to talk to me here or on my talk page Clandis0217 (talk) 04:47, 9 March 2019 (UTC)

New "Kapteyn Universe" section
I will be adding a new section that focuses solely on the Kapteyn Universe. Short of rearranging the entire article, which at the moment I do not believe I have the information nor capability to do, this section should supplement the short bit of it mentioned in the "Biography" section. Feel free to arrange the article accordingly. Igct27 (talk) 21:19, 12 April 2019 (UTC)

I've decided to remove the portion mentioning the Kapteyn Universe from the section formerly known as "Biography", now known as "Career", and implement that into the section titled "The Kapteyn Universe" Igct27 (talk) 16:43, 9 May 2019 (UTC)

New Family section
I will be adding a new part about Kapteyn's family including his children and some of their accomplishments. Clandis0217 (talk) 04:18, 19 April 2019 (UTC)

Young Life
I added more information about Kapteyn's young life and schooling. Clandis0217 (talk) 02:14, 20 April 2019 (UTC)

Obeservations of Nebulae
I added information on some of Kapteyn's later observations of nebulae. Clandis0217 (talk) 17:09, 7 May 2019 (UTC)

Light absorption theory addition
I will be adding information on His Theory of light absorption. Clandis0217 (talk) 17:21, 7 May 2019 (UTC)

End of Kapteyn's Life
I will be adding information on the end of Kapteyn's life including his moving of jobs his final works and his death. Clandis0217 (talk) 17:21, 7 May 2019 (UTC)

family and career section
I made the family section named family and earyly life and mived nessasary information to that section and named the biography section career because all that remained in the old biography section was the aspects of his career Clandis0217 (talk) 16:41, 9 May 2019 (UTC)

"Light absorption would also cause the galaxy to disperse more quickly than it actually does."
Please speak clearly. This sentence on its face is impossible. Nothing can 'disperse' faster than it actually does. Nothing can do anything faster than it actually does. To escape this logical contradiction the reader's brain has to work harder to find a meaningful interpretation of this sentence. But you (whoever you are) have placed other impediments in the way of finding a reasonable interpretation. For one thing you've used 'more quickly' rather than the more typical 'faster', indicating that this might have some technical meaning - but I can't figure out what that technical meaning is, and in particular when you've used the term 'disperse', another term with a presumably technical meaning, and no obvious way to figure out what that means. And to top it all off the whole sentence gist about light absorption by space somehow affecting galactic dispersion is a non-trivial claim, and yet there's no explanation or citation for it. Please fix this. Comiscuous (talk) 20:25, 19 April 2021 (UTC)

Dark matter
In the previous edit, the introduction stated "Kapteyn was also among the first to suggest the existence of dark matter using stellar velocities as early as 1922". This highly suggestive statement, however, is easy to misinterpret. The "dark matter" to which Kapteyn refers is dust and gas between the stars. He was certainly not the first to suggest that such dark matter existed as it had been suggested by Edward Barnard and Max Wolf by the early twentieth century and was accepted knowledge by the 1920s. — Preceding unsigned comment added by ChaokangTai (talk • contribs) 12:44, 20 March 2024 (UTC)