Wikipedia:Featured article review/Introduction to general relativity/archive1


 * The following is an archived discussion of a featured article review. Please do not modify it. Further comments should be made on the article's talk page or at Wikipedia talk:Featured article review). No further edits should be made to this page.

The article was kept by User:Marskell 10:42, 24 September 2008.

Introduction to general relativity

 * Markus Poessel, WP Relativity, WP Math, WP Physics notified.

Fails featured article criterion 1a because it's not well written. 66.68.23.41 (talk) 18:42, 6 September 2008 (UTC)


 * No examples have been provided. Without examples, this FAR will likely be removed.  Please provide examples, and complete the notifications per the instructions at the top of WP:FAR.  Sandy Georgia  (Talk) 18:53, 6 September 2008 (UTC)


 * You needn't look any further than the introduction. The fourth paragraph doesn't have a topic sentence, which makes it easy for the reader to confuse gravitational waves with lensing. More generally, the work does not flow throughout, including, for instance, too many (more than 50 by my count) parenthetical phrases. 66.68.23.41 (talk) 09:35, 7 September 2008 (UTC)
 * 66, please complete the notifications. Instructions are at the top of WP:FAR, and a sample is at Featured article review/Rudyard Kipling.  Sandy Georgia  (Talk) 17:55, 7 September 2008 (UTC)

While it's here, I corrected several issues that got by FAC: WP:ACCESSIBILITY, WP:MOS, WP:LAYOUT and mixed citation styles. Sandy Georgia (Talk) 03:21, 7 September 2008 (UTC)


 * Comment I'm wondering about the name. Is this even standard? Are these pages allowed? If so, I have some "intro" pages that I want to write. :) Ottava Rima (talk) 17:27, 7 September 2008 (UTC)
 * This has been debated many times at WT:FAC, and consensus has been to allow them. You'd have to check archives for the many discussions; I think they've occurred elsewhere as well.  Sandy Georgia  (Talk) 17:54, 7 September 2008 (UTC)
 * Some information about "Introduction to..." can be found at WP:Make technical articles accessible. Markus Poessel (talk) 00:16, 11 September 2008 (UTC)
 * There is an entire category of "introduction" pages. Awadewit (talk) 04:46, 15 September 2008 (UTC)


 * Comment. Some of the parenthetical statements in the article that the nominator is objecting to are useful in that they attempt to make the article even more WP:MTAA.  However, many of the parentheses in the article are gratuitous, and should be eliminated.  That said, WP:FAR seems to be a rather extreme measure.  Wouldn't it be easier simply to fix this one problem with the article?  siℓℓy rabbit  (  talk  ) 12:03, 8 September 2008 (UTC)
 * I've now gone through the article several times, eliminating parenthetical statements that might be unwarranted. At least for me, the text now flows nicely. Markus Poessel (talk) 01:45, 18 September 2008 (UTC)


 * Comment I have attempted to address some of the nominator's concerns by re-structuring the article's lead paragraphs - essentially the same information, but in a different order. Gandalf61 (talk) 12:49, 8 September 2008 (UTC)


 * Comment While there appears to have been some edit creep, I'm surprised that the anonymous nominator chose to start an FAR. Wouldn't it have been more appropriate to speak up on the talk page first?  That said, I'm perfectly willing to have another look at the article, and try to fix what needs fixing.  Markus Poessel (talk) 18:41, 10 September 2008 (UTC)


 * Image:Gravity Probe B.jpg should have a source. DrKiernan (talk) 09:12, 12 September 2008 (UTC)
 * Is this OK (I added one possible source - I didn't upload the image to the image's page)? Or did you mean a source in the caption (which, as far as I can see, would be rather unusual)? Markus Poessel (talk) 22:42, 12 September 2008 (UTC)
 * I couldn't find the image there, although I agree that it looks as though it is a likely source. I fear that the image may need to be replaced with one with a known provenance. No, there's no need for a source in the caption. Thanks, DrKiernan (talk) 07:22, 15 September 2008 (UTC)
 * I've now added the exact URL where it's at on that site, too. Markus Poessel (talk) 12:26, 15 September 2008 (UTC)


 * Comment I do not believe that this article fails the prose criterion. This is a good introduction to a very difficult topic. Can every article be improved? Yes. However, I do not believe that this one deserves to be de-featured. Furthermore, I'm not really seeing substantial lists of writing problems listed here. Awadewit (talk) 04:46, 15 September 2008 (UTC)


 * Comment: From what I can tell, there is absolutely no need to demote this article. In particular, the article does a good job telling hard things without pain. That said, I have two comments:
 * AFAIK the term geodesic means, in Riemannian geometry at least, not a ray, but a line. So, writing "A person sitting on a chair is trying to follow a geodesic" is a bit ambiguous (from my lay understanding of GRT, I guess you should somehow say that there is always a time aspect to any geodesic, i.e. they are no geodesics, whose time-part is constant?). The remark applies also to the Image:Earth geo.gif which makes also some choice of an orientation.
 * The second is more a question. I faintly remember that GRT has to be used to get correct coordinates for satellites etc. Is this right, or am I messing it up with SRT? If it is GRT, you might want to add something in this direction in the applications part. In general, as a lay reader looking at "Astrophysical apps" I wondered why you don't talk about other applications. Are there any? Jakob.scholbach (talk) 17:06, 19 September 2008 (UTC)
 * Still in the "apps" section, you write "Models based on general relativity play an important role in astrophysics, and the success of these models is further testament to the theory's validity." If this matches the section content, then the section should be merged with experimental verification. Jakob.scholbach (talk) 17:10, 19 September 2008 (UTC)
 * Thanks for your support – as for your specific questions:
 * As far as I can see, the usage of geodesic in this article is pretty common: geodesic is short for geodesic curve, and a curve is a map from an interval of R to a manifold.
 * Satellite coordinates: I'm not aware of practical applications beyond GPS. The real applications – in the sense of using general relativity as a tool to do something – are in astrophysics.
 * I think merging this section with the one on experimental tests would be putting the cart before the horse. The people doing relativistic astrophysics do so first and foremost to model astronomical phenomena, not to test general relativity. Again, this division – having experimental tests extra – is, as far as I can see, pretty common.
 * Markus Poessel (talk) 02:17, 21 September 2008 (UTC)
 * OK. A geodesic can be determined by giving a point on a manifold and a tangent vector. So, what is the tangent vector? "A person sitting on a chair is trying to follow a geodesic" doesn't answer this question, unless I'm completely blind. In particular, and that was why I stumbled over the point, it does not make explicit that the geodesic could not go back in time (which, I hope :), is practically impossible(?), but as far as general mathematics on a 4-dim manifold is concerned, is perfectly allowed). Jakob.scholbach (talk) 11:56, 21 September 2008 (UTC)
 * Unless I'm missing some subtlety in your question: The person sitting on the chair has a world line (approximately) which, at every point, has a tangent vector. Markus Poessel (talk) 20:08, 22 September 2008 (UTC)

I am going to shut this FAR down, which I probably should have done earlier. Any other prose concerns can be taken up on article talk. Marskell (talk) 10:38, 24 September 2008 (UTC)
 * The above discussion is preserved as an archive. Please do not modify it. No further edits should be made to this page.