Talk:Manifold/Archive 2

message: Please note that it looks as if manifold/rewrite has been merged into manifold by Deryck Chan (no, don't ask me why and what, I discovered this by accident). Oleg Alexandrov 03:22, 4 August 2005 (UTC)
thread_title:  rewrite moved to [[manifold]] 

message: I think that these two sections overlap in their content too much and are causing the article to look cluttered. Indeed, most of the examples deal directly with constructions. I prefer to look at them as examples of constructions rather than standalone examples. A new "construction" which just appeared due to Joshua deals with the double line (non-Hausdorff); I'm wondering how technically complicated this construction is to a newcomer? - Gauge 06:58, 5 August 2005 (UTC)
replies: text: Good points. My first thought is to move the "construction" section further down, under the definition of a topological manifold (which still needs to be written), and have the "construction" section refer to the examples. About Joshua's example: you indeed need to know quite some topology to understand it, but on the other hand I can see the use of including at least one pathological example. Perhaps we should just introduce the example better, saying that the details don't matter that much but that it's included to show that not manifolds are nice. -- Jitse Niesen (talk) 12:08, 5 August 2005 (UTC)
replies: text: I wrote the section on the double-dotted line primarily because it's listed in the comments right at the beginning of the More examples section as something one might want. I know that it's written at a fairly advanced, technical level. I'm trying to improve my mathematical exposition. After I wrote the example, my father (a computer programmer and amateur mathematician) read the entry and said, "Did you know what you were saying when you wrote that? I have no idea what you said!" Thus I know it's not written to help someone who's not actively studying mathematicians. It does comply with the "For the rest: graduates" target audience listed at the beginning of the article. I've been trying to think how to describe it, in a way that's more accessible but still correct, while making it clear that it's a pathology. JPB 19:06, 5 August 2005 (UTC)

text: I know. I intentionally used the allready present examples to illustrate the constructions. This article should be more than a list of manifolds. There are a lot of manifolds, but there should allways be a reason why a specific manifold is given as an example. I would prefer if this reason is explained and then illustrated by the example. So I would prefer a general section of Hausdorffness and the line with two origins as an example. Scientific method has an  example, which is separated into smaller pieces, each illustrating a single step of the method and linking to the other pieces. Maybe we could use a similar (improved) technique here. Markus Schmaus 20:48, 6 August 2005 (UTC)
replies: text: I like the idea of explaining a certain construction and then placing the example immediately afterwards, instead of a section for constructions and a separate section for examples. This would make the examples more immediately relevant to the discussion and avoid the "list of manifolds" trap . - Gauge 00:16, 7 August 2005 (UTC)
thread_title: "Construction" and "More Examples"

message: This section could be expanded to "Local topological criteria" or some similar title and refer not only to Hausdorff-ness, but also paracompactness (useful for partitions of unity), local metrizability, and so on. In other words, brief explanations of any local "niceness" conditions could go here. I'm not going to be around for the next week, so feel free to overwrite the old article while I am away. - Gauge 00:55, 13 August 2005 (UTC)
thread_title: "Hausdorff" section

message: I'm glad to see all the hard work that has gone into improving this article. Are we ready to replace the original yet? Either that or very close I think. Anything worthwhile that is not yet incorporated should be added to this version. But it probably already has a home here at or one of the other two articles. Talking about those, I see no activity there. How come? I also think the time has come to do a request for comments or whatever it's called.  --MarSch 15:41, 14 August 2005 (UTC)
replies: text: I've been delaying working on the other articles until the dust settles on this one. It will then be clearer to me what should be included and excluded from the other articles. - Gauge 21:40, 20 August 2005 (UTC)
thread_title:  hi guys 

message: Do we really need the second sphere example? the one with two charts. It's just stereographic projection, but somehow I find it much less enlightening than the first construction. If there is no strong reason to keep it here I propose to move it to circle.--MarSch 12:30, 23 August 2005 (UTC)
thread_title:  second sphere example 

message: I just made some edits to the page, including changing the extra constructions into short examples and leaving out the technical details, which were already present on the respective article pages (torus, real projective space, cylinder, Klein bottle), with the exception of the latter two (I will fill these in as I find time; they are on my talk page if you'd like to do it yourself). Besides those things, the only other things that I see lacking with the article currently are:
# There should be mention of Riemannian manifolds in the other types and generalizations section, and more importantly...
# There needs to be a good description of what a "boundary" of a manifold is, since these are necessary to understand some of the methods of construction.
Happy editing, Gauge 05:27, 24 August 2005 (UTC)
thread_title:  Extra construction sections reduced to examples 

message: It's time to move Manifold/rewrite to Manifold. Markus Schmaus 19:55, 7 September 2005 (UTC)
thread_title:  Merge! 

message: It's time to move Manifold/rewrite to Manifold. Markus Schmaus 19:56, 7 September 2005 (UTC)
thread_title:  Merge! 

message: It's time to move Manifold/rewrite to Manifold. Oleg Alexandrov 21:38, 7 September 2005 (UTC)
thread_title:  Merge! 

message: I extend my thanks to everyone who has contributed to make this article what it is today. Merge! - Gauge 03:41, 8 September 2005 (UTC)
thread_title:  Merge! 

message: I concur. We can do two things to preserve history of the old page. Move it to manifold/old, or merge histories from the moment of the split (we loose history on old version after split). move --MarSch 15:13, 8 September 2005 (UTC)
replies: text: Also could someone move top. and diff. manifold. I can't get it to work --MarSch 15:24, 8 September 2005 (UTC)
replies: text:  Hey people, are we merging this or not? By the way, it is possible to merge the articles while merging the edit histories, see Wikipedia:How to fix cut and paste moves. In this case, merging manifold and manifold/rewrite would produce a bit of a mess since in the last two months both artilcles were edited, but the mess would not be really huge since manifold was not edited a whole lot. So, which way to go, and most importantly, when? Oleg Alexandrov 02:41, 26 September 2005 (UTC)
replies: text:  Actually, I am not sure any longer. I asked at Wikipedia talk:WikiProject Mathematics, and requested people to opine in here. Oleg Alexandrov 04:33, 26 September 2005 (UTC)
replies: text: I'm not sure the merged edit histories will be harder to follow than an edit war; but then I'm not an admin, and don't have to do it. Another possibility would be to userify the old article [or move it to Mannigfaltig and make it a redirect], move this one, merge in the old one, and leave a note on this talk page. Septentrionalis 14:54, 26 September 2005 (UTC)
replies: text:  OK, if I don't here other opinions anytime soon, I will merge the page histories. I also think that it is the best thing to do. Oleg Alexandrov 23:22, 27 September 2005 (UTC)

text: I prefer the "merge histories" approach, but it really doesn't matter to me since I'm not the one doing it. I think the recent edits to the rewrite were pretty good, btw, in terms of clarifying what we were trying to say :-)  - Gauge 04:21, 28 September 2005 (UTC)
replies: text: I never tried to merge the histories, but I think it would give a bit of a mess for the last two months. It seems better to me to move manifold to manifold/old and manifold/rewrite to manifold, adding a note at talk:manifold about what happened? Of course, somebody needs to check that everything from the current article has in fact found a place in the new articles. -- Jitse Niesen (talk) 23:29, 28 September 2005 (UTC)
replies: text: Sounds like a good plan to me. - Gauge 23:17, 2 October 2005 (UTC)
thread_title:  Merge! 

message: I implemented Jitse's suggestion. The old article is manifold/old, and its talk is talk:manifold/old. Also see talk:manifold/rewrite/freezer. If people feel like merging the histories later, it can still be done. Oleg Alexandrov (talk) 13:14, 18 October 2005 (UTC)
thread_title: Move of [[manifold/rewrite]] to [[manifold]] is complete