User talk:R.e.b./2008

From Wikipedia, the free encyclopedia

This is an archive of past discussions. Do not edit the contents of this page. If you wish to start a new discussion or revive an old one, please do so on the current talk page.

Dickson polynomial and Cartan subalgebra questions

Howdy, I think you've already answered my question (Talk:Dickson polynomial#Schur conjecture reference) on Dickson polynomials, but I wanted to make sure. I am not terribly familiar with these sorts of objects, and so it was not entirely clear to me exactly when they were equivalent to Chebyshev polynomials. I think you explicitly say they are equivalent over the complexes, but I think some people might believe the article is implying they are equivalent over the rationals. I think they are not equivalent over the rationals, but the Schur conjecture part seems to suggest they are. Basically, I find the article confusing, but I cannot say whether it is the text of the article or my dim mind which is the cause.

I had another question (Talk:Cartan subalgebra#Maximal abelian subalgebras) about maximal abelian subalgebras that are not cartan subalgebras. Your recent sl(2n) example indirectly proves they exist, but I think it might be nice to give one explicitly. I tried to fill in a little of the detail of the argument, but I think all I showed was that an even larger abelian subalgebra existed. I think this is a standard remark explained perhaps in Jacobson's text, but I don't have it handy. Basically, I think the example can be improved with only a minor change, but I fear I don't know how to do it. JackSchmidt (talk) 18:34, 11 February 2008 (UTC)

Dickson polynomials are more or less the same as Chebyshev ones whenever the field has enough square roots (and contains 1/2), but as you say they are not equivalent over the rationals. I have no plans to add anything more to this (rather obscure) topic; feel free to make the article clearer.

The larger abelian algebra you found is in gl_2n (and is in fact maximal in gl_2n) but is not in sl_2n, at least not when the field has characteristic 0, as sl does not contain the identity matrix. R.e.b. (talk) 19:06, 11 February 2008 (UTC)

Thanks! Your correction to Cartan subalgebra is exactly what I was looking for. Sorry, I am used to working in (finite) Lie groups, and forgot I was looking for trace zero not determinant one. I don't know how to fix Dickson polynomial. I just marked the statement with {{fact}} and a comment. I suspect the explanation is simple, and there are lots of wikipedians who know more about polynomial families than I do. JackSchmidt (talk) 19:20, 11 February 2008 (UTC)

Thanks for Bad group fix

Merging the definition into the article where it is relevant whether they exist is a very clean solution. Thanks for taking care of it; all I know about Morely rank is it clutters my google searches for finite simple groups. I'll let the bad group author know the prod was changed to a redirect. JackSchmidt (talk) 05:29, 15 February 2008 (UTC)

Colleague request!

Dear colleague , please tell me how you got the formula

B n (x) = 2 x U n - 1 (x / 2) - 2 T n (x / 2)

(This is an emergent request )

please answer here!

Thank you. —Preceding unsigned comment added by 41.224.221.178 (talk) 20:18, 16 February 2008 (UTC)

I just happened to notice that the formula for B_n in the article was very similar to the usual explicit formula for Chebyshev polynomials. If you want to know how to prove it, it follows easily from the explicit formulas in Abramowitz and Stegun. R.e.b. (talk) 20:38, 16 February 2008 (UTC)

Colleague gratefulness!

Thank you R.e.b.

If only you can help us finding a 2-order differential equation for these polynomials as you did to the explicit expression above!! We can provide basical equations.. Thanks

P.S. Dear colleague can you help us writng this letter : B with the sign ~ on it?? (which is pronounced B-Tilda, in french?) Thank you for help and understanding.

You could find a 2nd order differential equation for B_n by expressing it as

B n (x) = 2 x T n'(x / 2) / n - 2 T n (x / 2)

Differentiating twice expresses B_n and its first two derivatives as linear combinations of derivatives of the Chebyshev polynomials. The differential equation of the Chebyshev polynomial gives two relations between Chebyshev polynomials and their first 3 derivatives. This gives 5 linear equations in B_n and its first two derivatives and T_n and its first 3 derivatives. Eliminating T_n and its first 3 derivatives from these equations should give a second order differential equation for B_n.

The differential equation you get like this is probably rather complicated. You can instead write B_n as the sum 4U_n(x/2)−6T_n(x/2) for n>0, both of which satisfy well known differential equations.

<math>\tilde B_n</math> produces $\tilde B_n$ . R.e.b. (talk) 19:39, 17 February 2008 (UTC)

Colleague gratefulness and thanks!

This is great!

Thank you Sir! —Preceding unsigned comment added by 41.224.183.78 (talk) 22:47, 17 February 2008 (UTC)

Stability theory

Hello R.e.b., I see you have been active around stability theory. I haven't got the time to finish my draft article User:Hans_Adler/Stability_spectrum right now, but since you have just created a redlink for stability spectrum I thought I should mention its existence to avoid unnecessary duplication. You are very welcome to edit the draft, and to move it to article space whenever you feel it makes sense. --Hans Adler (talk) 18:20, 19 February 2008 (UTC)

OK; your draft looks fine apart from not yet having references, so I'll probably add these and move it into article space in a few days if you don't do so first. R.e.b. (talk) 18:52, 19 February 2008 (UTC)

Emergent Scientific request

Dear Colleague: you said : ...The differential equation of the Chebyshev polynomial gives two relations between Chebyshev polynomials and their first 3 derivatives..

We found only one differential equation (for each kind):

$(1-x^2)\,y'' - x\,y' + n^2\,y = 0 \,\!$

and

$(1-x^2)\,y'' - 3x\,y' + n(n+2)\,y = 0 \,\!$

Please can you write here the relations between Chebyshev polynomials and their first 3 derivatives ???

Thank you for patience !! —Preceding unsigned comment added by 41.224.191.69 (talk) 19:06, 19 February 2008 (UTC)

If you differentiate these differential equations you get extra linear relations between y', y'', and y''' R.e.b. (talk) 19:12, 19 February 2008 (UTC)

Emergent Scientific request, Thanks !!

Thank you for help! Can you provide links to these items?? —Preceding unsigned comment added by 196.203.50.144 (talk) 11:52, 20 February 2008 (UTC)

Links to which items?R.e.b. (talk) 15:21, 20 February 2008 (UTC)

Expressions of Chebychev Polynomials.... —Preceding unsigned comment added by 41.224.182.159 (talk) 15:40, 20 February 2008 (UTC)

This link and the following pages gives most of the properties of Chebyshev polynomials. There is also the article Chebyshev polynomials, which you probably know about. R.e.b. (talk) 15:49, 20 February 2008 (UTC)

Thanks !! we won't bother you more !!

Sir, we bothered you enough. We must not abuse .. Now, thanks to you we have a very intresting paper-project. We would add acknowledgment for you in this paper (or send it to you for eventual pre-revision and hints, and you will see the magnitude of your help!!), would you mind tell us if you agree?? We are waiting for a favorable answer.

No problem. There is no need to acknowledge me in your paper. R.e.b. (talk) 01:58, 22 February 2008 (UTC)

back-and-forth method

In this edit you said that in "more complicated situations" this can fail to be bijective. In the case actually considered, would it always be bijective? E.g. if the two sets are the rationals in their usual ordering and the real algebraic numbers in their usual order, would it always be bijective? I'd have thought not. In fact, I'd guess it would depend on which enumerations are chosen. I've never actually thought this through. Michael Hardy (talk) 03:39, 23 February 2008 (UTC)

I think it is indeed always bijective in the case you gave even if you only use step 1. This does not depend on the orders you choose, or whether one set is real algebraic numbers. (Though my edit was carefully phrased so it is still correct even if I made a mistake about this...) You need both directions in more complicated cases, such as showing two equivalent countable atomic models of a theory are isomorphic. If you want to modify your example so both directions are needed, then take a random element in the image satisfying the needed conditions instead of the first element. R.e.b. (talk) 04:22, 23 February 2008 (UTC)

You seem at least a little bit uncertain. Maybe the answers to these questions should eventually be made explicit in the article with any relevant proofs or counterexamples. After your edit linked to above, I changed it so that instead of saying in more complicated cases it might fail, it said in some more complicated cases it would fail. "Might" could be taken to imply uncertainty about whether there are any such cases. Michael Hardy (talk) 18:25, 23 February 2008 (UTC)

I changed your proof slightly so that "back and forth" is really needed, and added a note explaining this. R.e.b. (talk) 18:50, 23 February 2008 (UTC)

Boubaker polynomials?

I noticed you comments at talk:Boubaker polynomials. Do you have any particular opinion that would be relevant at Wikipedia:Articles for deletion/Boubaker polynomials (2nd nomination)?

I don't (yet?) have an opinion on whether the article should be kept, but I find some of the arguments purporting to support deletion somewhat disturbing, and I've commented accordingly on the deletion page. Michael Hardy (talk) 22:32, 27 February 2008 (UTC)

It looks like a rather strange discussion. I dont have anything useful to say about these polynomials (beyond my comment on the talk page that they are a trivial variation of Chebyshev polynomials). I had some questions about them on my talk page (see above) from someone who seems to be working on them. R.e.b. (talk) 23:52, 27 February 2008 (UTC)

Commutative von Neumann regular rings

Howdy, I changed the "Commutative vN regular if and only if subring of fields" to "only if", but I think more is true. It is not completely iff, since an integral domain that is not a field is never vN regular (Frac(D)/D is not flat). However, the point really is that these rings are special subrings of infinite direct products of fields that act very much like direct products of fields. I couldn't find a reference, but I think it was something like "subrings such that the projection map for each factor is surjective". So "1 + Sum(K_i)" as a subring of "Prod(K_i)" should be vN regular, and should be something similar to the "ring of compact operators with 1 adjoined".

I tend to stick with finite or at least very special rings these days, so I could easily be wrong. I figured if you had the reference at hand, it would be easy to fix. Otherwise I'll check Goodearl's text sometime this week. JackSchmidt (talk) 18:09, 27 February 2008 (UTC)

I'm at least a little wrong. Every von Neumann regular ring is semiprimitive, and the commuative semiprimitive rings are the ones I described (subdirect products of fields). So there are some subdirect products of fields that are not von Neumann regular. Hopefully the "reduced and Krull dimension 0" characterisation is useful enough. Please let me know if you find a nice if and only if along the lines of subrings of fields. JackSchmidt (talk) 18:34, 27 February 2008 (UTC)

You are right; I was not paying attention when I wrote that, and meant to say "subring of a product of fields that is closed under taking quasi-inverses". R.e.b. (talk) 19:43, 27 February 2008 (UTC)

Thanks for fixing this, and for the steady stream of improvements to the math articles. I enjoy checking my watchlist, and reading your new additions every few days. It is like an eclectic course on all things interesting. You've even convinced me model theory is worth my time to learn, though it might be a few years before I need more than wikipedia already has on the subject. Thanks again, JackSchmidt (talk) 05:51, 3 March 2008 (UTC)

Model companion

A tag has been placed on Model companion, requesting that it be speedily deleted from Wikipedia. This has been done under the criteria for speedy deletion, because it is a redirect to a nonexistent page.

If you can fix this redirect to point to an existing Wikipedia page, please do so and remove the speedy deletion tag. However, please do not remove the speedy deletion tag unless you also fix the redirect. Feel free to leave a note on my talk page if you have any questions about this. -WarthogDemon 19:07, 29 February 2008 (UTC)

I was fulfilling an editprotected request, where the author had made a one-character error that nonetheless made a huge mess. I hope I've now fixed the problem - let me know if there are any outstanding errors and I'll revert and let them work out what's wrong. Happy‑melon 15:56, 3 March 2008 (UTC)

For the caching issue, see WP:BYC#Server cache: it's slightly quicker to purge than make a trivial edit. Geometry guy 17:10, 3 March 2008 (UTC)

Sync of the ordinal analysis and large countable ordinal articles

Hi! I agree with the move of creating the article on ordinal analysis, however I draw your attention to the existence of the article on large countable ordinals: it would be nice to keep them from overlapping too much, by moving material from one to the other, and by adding abundant links. I did a bit of that, I'll let you judge of what else needs to be done. (Unfortunately we have quite a mess of ordinal-related articles sharing much of the same content without clear relations between them.) --Gro-Tsen (talk) 19:06, 4 March 2008 (UTC)

Thanks. I already know about large countable ordinals (having written some of it in the days before it was split off). I was wondering whether to give Feferman-Schutte and Bachmann-Howard ordinals their own articles, but havn't yet decided whether this would make the ordinal mess better or worse. R.e.b. (talk) 19:35, 4 March 2008 (UTC)

Hoax?

Hello. Do you know anything about Troy Raeder? It has been suggested that the article is a hoax. Michael Hardy (talk) 15:59, 5 March 2008 (UTC)

Yes, its a hoax. R.e.b. (talk) 16:01, 5 March 2008 (UTC)

...and I now see that the person who created it has no other edits. Michael Hardy (talk) 16:14, 5 March 2008 (UTC)

Iwasawa decomposition and unipotent

Howdy, I wanted to salvage NBarth's edit, but I don't know enough math to handle part of it. I think it might be nice to phrase the example also in a "basis-free way", so that one could link to unipotent. Basically, the factorization is KAN, where K is a ???, A is a "maximal torus", and N is a "maximal unipotent subgroup" or "the unipotent radical of the normalizer of A" or something. K seems a little like a Weyl group, but I don't think it is (seems to contain it as a small subgroup). Is there something like this that is true? Maybe more specific questions are easier:

Is A a maximal torus?
Does A always normalize N?
Is N always the unipotent radical of the normalizer of A?
Is K a "Cartan subgroup"?

Thanks for any help, and no worries if they don't sound sane to answer. I'm still trying to learn this material, so there is no reason at all to think my questions are on target. JackSchmidt (talk) 00:54, 9 March 2008 (UTC)

A is not a maximal torus, but is a connected component of a maximal split torus (where "torus" is used in the algebraic group sense, not the Lie group sense).
Yes, A normalizes N
N is almost never the unipotent radical of the normalizer of A.
K is a maximal compact subgroup, and has little to do with Cartan subgroups.

These apply if G is well behaved (connected, semisimple, etc); I'd have to think more carefully about the general case. R.e.b. (talk) 01:10, 9 March 2008 (UTC)

Re Request for expert help

Request for expert help

The new article Landau-Lifshitz equation needs some expert help in expanding it; your comments suggest you might know about this topic.

As you have probably figured out by now, it is a complete waste of your time to argue with rude and ignorant editors about topics they do not understand. Wikipedia has an unlimited supply of such editors, and it is best just to ignore them. R.e.b. (talk) 19:28, 25 March 2008 (UTC)

Thanks for the offer, and the consoling remarks, but I am afraid I will not have the time to help on this. In fact - although it is obviously with good intentions, the equation that you have identified as the Landau-Lifschitz equation is not the right one. There are more than one equations going under this name. The ones being referred to in the discussion in hand are PDE's with one time and either one, or two space variables. This one is an ODE, with only time, an external magnetic field, and no space variables. (i.e. the PDE's represent a field theory of magnetism; these ODE's just represent the motion of a single spinning, charged object in an external magnetic field. A different problem.)

If you would like a good source for the correct L.L. equations, try looking up the book: L.D. Faddeev, L. A. Takhtajan (1987). Hamiltonian Methods in the Theory of Solitons. Addison-Wesley. ISBN 0387155791, ISBN 978-0387155791. R_Physicist (talk) 19:58, 25 March 2008 (UTC)

Thanks; I hadn't realized that there was more than 1 equation called this. R.e.b. (talk) 03:31, 26 March 2008 (UTC)

Thanks for creating the page for LLE. LLE or in other words LL model is a fundamental basic of the classical theory of magnetism. I added some information to your page. Ngn 89.218.69.143 (talk) 17:06, 26 March 2008 (UTC)

Thanks for your additions; it seems there are even more of these equations than I realized. Do you know any good references for the 1+2 dimensional case?

If you get a wikipedia account it would be much easier for other editors to send you messages. R.e.b. (talk) 18:11, 26 March 2008 (UTC)

Now it is OK. Please see my page: Barstaw. Barstaw (talk) 18:48, 26 March 2008 (UTC)
Here time is 01:00 a.m. So may be tommorrow I return to you. Barstaw (talk) 19:01, 26 March 2008 (UTC)

Speedy deletion of EqWorld

A tag has been placed on EqWorld requesting that it be speedily deleted from Wikipedia. This has been done under section A7 of the criteria for speedy deletion, because the article appears to be about web content, but it does not indicate how or why the subject is notable: that is, why an article about that subject should be included in an encyclopedia. Under the criteria for speedy deletion, articles that do not indicate the subject's importance or significance may be deleted at any time. Please see the guidelines for what is generally accepted as notable, as well as our subject-specific notability guideline for web content.

If you think that this notice was placed here in error, you may contest the deletion by adding {{hangon}} to the top of the page (just below the existing speedy deletion or "db" tag), coupled with adding a note on the talk page explaining your position, but be aware that once tagged for speedy deletion, if the article meets the criterion it may be deleted without delay. Please do not remove the speedy deletion tag yourself, but don't hesitate to add information to the article that would would render it more in conformance with Wikipedia's policies and guidelines. Lastly, please note that if the article does get deleted, you can contact one of these admins to request that a copy be emailed to you. Wisdom89 _{(_T / ^C)} 01:25, 28 March 2008 (UTC)

Davey–Stewartson equation

The mention of "finite depth" in Davey–Stewartson equation makes me wonder if this article and shallow water equations should link to each other? (I've really only glanced at the former article for a few seconds, so maybe this doesn't make sense.) Michael Hardy (talk) 22:08, 31 March 2008 (UTC)

I dont know. They dont seem all that close mathematically, though they are both describing waves in fluids. Maybe just add them both to some category about waves in fluids (there seem to be loads of different differential equations related to this). R.e.b. (talk) 22:26, 31 March 2008 (UTC)

April Fool's Day DYK

On 1 April 2008, Did you know? was updated with a fact from the article Wiener sausage, which you created or substantially expanded. If you know of another interesting fact from a recently created article, then please suggest it on the Did you know? talk page.

Thank you for your part in the successful event! I really enjoyed seeing a math article on DYK, as math was my major at college! --Royalbroil 13:20, 1 April 2008 (UTC)

Conway groups

Is it settled that there are exactly 22 conjugacy classes of maximal subgroups of Co₁? Griess (1998) was not certain at the time. Scott Tillinghast, Houston TX (talk) 07:31, 2 April 2008 (UTC)

No, but it is settled that a reliable source (Robert Wilson) currently claims that there are exactly 22 conjugacy classes, which is good enough for wikipedia. R.e.b. (talk) 14:58, 2 April 2008 (UTC)

Is there a simple way to handle a reliable source being wrong? Image:Finitesubgroups.svg is a copy of the diagram on page 247 of Ronan's book on Symmetry and the Monster, ISBN 9780192807229. However, it has at least two errors. How should these be pointed out?

In case someone wants to check (my previous talk posts were blanked): The first error is clear: the diagram does not indicate that the Mathieu group on 11 points is a (maximal) subgroup of the O'Nan simple group (this is an error in the book). The second error is that either the line indicating M22 as a subquotient of HN is missing (this is an error in the book), or the line indicating M23 as a subquotient of Fi23 should be removed (this fixes an error in the caption on wikipedia, which claims all lines represent subgroup containment). JackSchmidt (talk) 15:16, 2 April 2008 (UTC)

You could try sending a note to whoever made the image, or put a warning where it is used, or if you are feeling really ambitious you could redraw it correctly. (Or you could adopt my solution of not worrying too much about minor errors on the grounds that wikipedia has so many major errors.) R.e.b. (talk) 16:07, 2 April 2008 (UTC)

I have used Robert Wilson's websites often and I find at times there is information that is incomplete. For example there are presentations of finite simple groups that alone would define infinite groups.

I want to find out more about the history of research on the structure of the Conway groups. Scott Tillinghast, Houston TX (talk) 16:41, 2 April 2008 (UTC)

For the history, try the book Thompson, Thomas M. "From error-correcting codes through sphere packings to simple groups." Carus Mathematical Monographs, 21. Mathematical Association of America, Washington, DC, 1983. xiv+228 pp. ISBN 0-88385-023-0 R.e.b. (talk) 16:52, 2 April 2008 (UTC)

Thank you. I have a copy of Thompson's Carus Monograph.

Now, about Ronan's diagram. A complete diagram could be pretty cluttered. For example, the Monster is shown as directly containing 3 sporadic groups: Fischer 24, the Baby Monster, Conway 1. I just looked at the list of maximal subgroups on Robert A. Wilson's website, and I count 7 more. Of the 3, only Conway 1 is actually a subgroup and the other 2 are subquotients.

I have checked the lines between the 3 Fischer groups and 3 Mathieu groups against version 2 of Robert A. Wilson's website and they are correct at least as subquotients. For some reason version 3 does not list maximal subgroups of Fischer 24'.

The distinction between subgroups and subquotients is essential to serious study of simple groups, but I doubt it can be clearly incorporated into the diagram. For example, Hall-Janko is a subgroup both of Suzuki and Conway 1, but Suzuki is just a subquotient in Conway 1.

So I would not try to perfect the diagram, but make a cautionary note about its limitations. Scott Tillinghast, Houston TX (talk) 19:43, 2 April 2008 (UTC)

List of non-linear partial differential equations

(The comments below are replies to a comment here that was later removed by its writer)

Laws and wikipedia articles are like sausages. It's better not to see them being made. Bismarck (talk) 15:49, 2 April 2008 (UTC)

Wikipedia:Lists defines three purposes (Information, Navigation, Development) for lists. A list of nonlinear PDES could therefore be criticised if it failed all of these. But this is not so likely. In particular the Navigation purpose is fundamental, for people with a general interest in a topic. Charles Matthews (talk) 19:46, 2 April 2008 (UTC)

"First of all, the title is such a catch-all expression" That does not seem like a valid objection. List of Germans could be criticized in the same way. But of course it is not intended to list all Germans, but only those considered notable enough to be the topic of a Wikipedia article. The same thing applies here. Michael Hardy (talk) 21:11, 2 April 2008 (UTC)

Above, the anonymous comentator wrote:

"Integrability" has a very specific meaning. (Please look up the article on Integrable systems for a discussion of what this is. That article remains, for the moment, one of the more reliable ones in Wilkipedia

I just looked at that article. It never attempts to explain what that precise meaning is. Michael Hardy (talk) 21:18, 2 April 2008 (UTC) ....OK, I see that at one point it gives a terse definition of one of the kinds of integrability. Not really the more leisurely explanation such as one might hope to see. Michael Hardy (talk) 21:27, 2 April 2008 (UTC)

In response to Michael Hardy: Please have a more careful look at it (some improvements have since been made). It gives a precise definition of each of the notions of "integrability" listed: 1) Frobenius integrability (differential systems) 2) Liouville integrability (Hamiltonian systems) 3) Superintegrability and partial integrability (Hamiltonian systems). It furthermore discusses how this expression is used in more general dynamical systems, as well as in "quantum integrable systems" where, as is known, no good definition really exists. It also explains how the notion of "canonical transformation to linearizing variables" extends to the case of PDE's, through inverse spectral methods. The details are referred to the pages in which these various concepts are individually treated, with links. 24.202.238.172 (talk) 12:40, 4 April 2008 (UTC)(alias "R Physicist")

To R.e.b.: I see that you took my comments to heart, though not quite in the way I had suggested. Fair enough; there is also room for "formularies" - this is the way that Ramanujan learned mathematics, after all. I wish you good luck in keeping it "on track" through the sausage factory. 24.202.238.172 (talk) 00:14, 3 April 2008 (UTC) (alias "R Physicist")

R.e.b., the article Clairaut equation says that it is an ordinary differential equation. Looks like we need to disambiguate. Giftlite (talk) 22:12, 8 April 2008 (UTC)

No need to disambig: the ODE in the article is the 1-dim case of the PDE. R.e.b. (talk) 01:31, 9 April 2008 (UTC)

At the moment "Cauchy momentum" and "Navier-Stokes" are essentially the same. It appears to me that in Navier-Stokes equation the equations are interpreted too general as compared to the common notion, i.e. that Navier-Stokes is most often considered to be confined to a Newtonian viscous model for the shear stress tensor. Crowsnest (talk) 02:10, 9 April 2008 (UTC)

You are right; I was just feeling too lazy to write out the usual NS equations and just cut and pasted these

as a stopgap. Feel free to tidy them up. R.e.b. (talk) 03:33, 9 April 2008 (UTC)

Dispersive partial differential equation

Thanks for removing my silly remark about different wavelengths having different frequencies on dispersive partial differential equation. Crowsnest (talk) 19:21, 5 April 2008 (UTC)

No problem. I assumed it was a Thinko. R.e.b. (talk) 01:14, 6 April 2008 (UTC)

P.S. about LNLPDE

Someone (actually, the above user) wrote to say he (or she) thought it was a bad idea to remove the comments I had made at the discussion page, even after they had been attended to. I recalled your Bismarck sausages remark, and replied that I prefer to wash the utensils while cooking the meal, rather than later. If you find my suggestions at all helpful, I will perhaps continue (if there seems anything worthwhile saying) but, if you don't mind, I'll do it henceforth in this location, rather than at the article's "talk" page. (I prefer, as you probably understand, having 1 on 1 exchanges rather than "public ones" on matters like this, but I see from some of the above that anyone viewing such individual exchanges feels entitled to enter their 2c worth in any case.) I hope that you do not object to my deleting my own remarks though, once they seem to have become outdated? 24.202.238.172 (talk) —Preceding comment was added at 19:12, 6 April 2008 (UTC)

I found your comments and suggestions helpful and used most of them (as you presumably noticed). I don't mind whether you leave them here or on the article page. There is no such thing as 1-on-1 privacy on wikipedia: anyone can (and does) read and join in conversations on editor talk pages. (If you ever need to send a private message, you can use the "E-mail this user" link on the left.) For non-controversial subjects I don't see that it matters all that much whether or not old comments are deleted; the main disadvantages of deleting comments are that it can confuse other users, and may trigger wikipedia's anti-vandal defenses. The custom on wikipedia is that talk page comments are not usually deleted except for serious reasons (such as comments that reveal private personal information); instead out-of-date comments are sometimes struck through ~~like this~~, which makes it easier to follow old conversations. R.e.b. (talk) 21:06, 6 April 2008 (UTC)

The thing in question was whether one may delete one's own outdated comments. I feel there is very little in such intermediate exchanges, on things that have already been dealt with satisfactorily, that is worth preserving for future reference, so I prefer to just delete anything that I have written that has already been dealt with adequately. The user who suggested switching such comments then to your "talk" page thought that, as long as it is limited to deleting one's own old remarks, it is reasonable, but less so on the article's "talk" page. I have no strong thoughts on this, and had placed the remarks on the articles "talk" page because they were just suggestions or comments about the article. I prefer to delete old comments that are no longer an issue in order not to clutter current things with old things that have already been resolved. 24.202.238.172 (talk) 22:17, 6 April 2008 (UTC)

Another option is to use a bot to archive old comments automatically. To see how to do this, look at the top of the source of my talk page, or see User:MiszaBot/Archive_HowTo. R.e.b. (talk) 23:03, 6 April 2008 (UTC)

Emmy Noether

Everything in the mainspace article exists on my drawing board as well. I just want to get the basics of the math part done, then move it over to the mainspace to hammer out the details. I just need 3 paragraphs or so. – Scartol • Tok 11:09, 15 April 2008 (UTC)

Okay, I made the tweaks necessary for now and moved it into the mainspace. Sorry for the confusion! – Scartol • Tok 15:44, 15 April 2008 (UTC)

		The E=mc² Barnstar
		For inserting oodles of relevant and (I assume) insightful mathematical information into Emmy Noether, I award you this science-dealie barnstar. This numerical illiterate greatly appreciates your generous assistance. – Scartol • Tok 01:47, 17 April 2008 (UTC)

Categories: User talk archives