User talk:Linas/Archive9

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[edit] Linas, could you take a look at...

... what User:Enormousdude did to Vacuum energy and Zero-point energy? i think that this guy with an enormously high estimation of himself has only recently discovered WP and is crapping up a lot of pages with his own personal POV. he's getting into a lot of revert wars. Vacuum energy and Zero-point energy are two of the only articles he has modified substantively that has not been reverted. i am guessing that they have not been reverted for the same reason the John Seigenthaler Sr. article was not (no one knowledgeable has stumbled upon it to notice what is wrong). Rbj 01:15, 6 May 2006 (UTC)

[edit] Variational number theory

You took down the 'expert' tag from variational number theory, but I'm not able to verify any of it. The ISBN of the reference appears not to exist. There is no way to find the book of Harrison and Cheng at the Cambridge University Press site. 'Variational number theory' has no Google hits as exact phrase. I need to be convinced about this topic. Charles Matthews 21:03, 6 May 2006 (UTC)

Jitse asked me to take a look. I've never heard of "variational number theory", although I don't do any analysis so that doesn't mean much. I also couldn't find the ISBN, I used http://www.isbn-check.de/ which uses the ISBN checksum to give suggested mis-typings too. Couldn't find the book on harvard's library catalogue either. I get a single Google hit for "variational number theory" to the wikipedia article on analytic number theory, which includes a paragraph written about a week ago by the same editor. It's difficult to say exactly where User:Karl-H is coming from. I reverted one of his edits to Riemann hypothesis last week, because it was poorly worded and appeared to be trying to say something trivial. I've noticed other edits to things like prime counting function which again were poorly written (which is always forgivable), but I didn't have the energy or time to check the material itself; it looked at first glance like it could possibly be correct. I suggest asking him directly whether he can back up this "variational number theory" thing. Dmharvey 12:47, 7 May 2006 (UTC)
I added a question on User talk:Karl-H. Perhaps I should have done that first, but I had just come across John Maximum (the guy who invented the maximum principle, apparently) which made me rather predisposed to suspecting a hoax. -- Jitse Niesen (talk) 13:17, 7 May 2006 (UTC)
My mistake; I put the expert tag back in. I was in a hurry while cleaning the thing up; it looked plausible; and I vowed to study it later... I'm sure I've heard the term before, but not sure where. Perhaps in the context of physics, as some "low-brow" spin-off from string theory, but I am not at all sure. linas 01:17, 10 May 2006 (UTC)

[edit] Renormalization

Hi Linas, Along these same lines, Karl-H has been making some very questionable edits to renormalization, culminating in the addition of a link to this shoddy-looking paper. It all looks vaguely plausible, and Wiki-etiquette demands some open-mindedness, but I'm really suspicious of this stuff. Are we being duped? Do you have an opinion on it? -- Xerxes 15:52, 16 May 2006 (UTC)

Ewww. That preprint looks terrible. It presents a garbled review of textbook basics on the zeta function. Its then followed by the introduction of an ultraviolet cutoff, but it then tries to re-invent, badly, the idea of dimensional regularization. Sigh. Both of these are texbook topics, and have been, for decades, so this looks like a garbled mess to me. linas 22:43, 16 May 2006 (UTC)
OK, I now see the problem. I took Karl-H's edits as "plausible" only because I am not up on the latest and greatest in renormalization. I had assumed that his edits described some new whiz-bang technique that was "common knowledge" to physics grad students, i.e. was broadly accepted by thier professors and was being taught in seminars. However, this seems mistaken: the edit seems based on this shoddy preprint, and as such, is inappropriate for inclusion in this WP article. I'd recommend a whole-sale revert of of his edits (taking them to the talk page to be nice), and going from there. linas 22:59, 16 May 2006 (UTC)
Argh. Maybe I'm being too harsh. Upon second reading, I guess that section can stay. Here's why: (1) There are zeta function regularization techniques that can be applied to QFT integrals, and the article on zeta function regularization completely fails to describe these. I can only hope that someday, someone will come and add a description of these techniques to that article. (2) Although the section added by Karl-H looks a tad off-kilter, its not implausibly wrong. Thus, I am hoping that someday, someone who is immersed in this topic comes along, notices that the WP article is askew, and fixes it to bring it into line with more accepted norms. linas 23:10, 16 May 2006 (UTC)
I think the part that really trips my crazy-meter is "one may turn a non-renormalizable theory into a renormalizable one". Regularization schemes may differ, but none of them make nonrenormalizable theories renormalizable, right? -- Xerxes 03:32, 17 May 2006 (UTC)
ROTFL. OK, you got me. Of course. Since 99.9999% of all Lagrangians you can dream up are not renormalizable (e.g. any effective Lagrangian), that would not just be a feat to boast about, but would open a passage to a new world. linas 03:54, 17 May 2006 (UTC)
Oh, I suppose one shouldn't laugh. Sometimes real breakthroughs are made. I cut the whole section and moved it to the talk page, so as to be polite. linas 04:34, 17 May 2006 (UTC)

[edit] Esperanza Newsletter, Issue #3

The Administrator Coaching program is a program aimed at preparing Wikipedians for Adminship or helping them understand the intricacies of Wikipedia better. Recently, changes have been made to the requirements of coachees. Please review them before requesting this service.
This would be something like the Welcoming Committee, but for people who have figured out the basics of editing articles; they're not newcomers any more, but they might want some help in learning new roles. Some might like suggestions about how to learn vandal patrol, or mentoring on taking an article to featured status, or guidance with a proposal they plan to make at the Village Pump, for example. In this way, Esperanza would help keep hope alive for Wikipedia because we would always be grooming the next generation of admins.
Stressbusters
The Stressbusters are a subset of Esperanza aiming to investigate the causes of stress. New eyes on the situation are always welcome!
Note from the editor
As always, MiszaBot handled this delivery. Thank you! Also, congratulations go to Pschemp, Titoxd and Freakofnurture for being elected in the last elections! An Esperanzial May to all of the readership!
  1. Posting logs of the Esperanza IRC channel are explicitly banned anywhere. Violation of this rule results in deletion and a ban from the channel.
  2. A disclaimer is going to be added to the Esperanza main page. We are humans and, as such, are imperfect.
  3. Various revisions have been made to the Code of Conduct. Please see them, as the proposal is ready to be ratified by the community and enacted. All members will members to have to re-confirm their membership after accepting the Code of Conduct.
  4. Referendums are to be held on whether terms of AC members should be lengthened and whether we should abolish votes full stop.
  5. Admin Coaching reform is agreed upon.
Signed...
Celestianpower, JoanneB, Titoxd, Pschemp and Freakofnurture
20:29, 7 May 2006 (UTC)


[edit] User:Lakinekaki and Bios theory

Hi, Linas, I see you have fingered Lakinekaki as being Lazar Kovacevic (BSEE, University of Belgrade) in real life and that you have also criticized Bios theory.

This article has been created almost entirely by Lakinekaki and one ameritech.com anon in Chicago. I have presented some pretty startling evidence in Talk:Bios theory that Lakinekaki is also the ameritech.com anon and thus pretty much the sole author of this highly dubious article. Even worse, it appears that Kovacevic is employed at something called the Chicago Center for Creative Development, which is apparently run by one Linnea Carlson-Sabelli, who appears to be affiliated with Rush University Medical Center. Indeed, it seems that the CCCD is the organization which has been promoting bios theory!

This seems to be a clear violation of WP:VAIN, WP:RS, and more. What to do?

Did I mention that if "bios theory" is being applied to make critical care decisions in the treatment of patients in neonatal ICUs, lives could literally be at risk?---CH 05:31, 12 May 2006 (UTC)

I'm note sure what to say. There are several points I'm resting on:
  • The Bios theory page is incoherent and smacks of pseudoscience.
  • The page author(s) seem remarkably ignorant of chaos theory, and of prior research, and seem to want to stay ignorant.
  • Particularly irritating is the ignorance of prior literature connecting the circle map and cardiac rhythms, a connection that Bios theory claims for itself.
This is counterbalanced by:
  • One of the coauthors seems to be a legit, above-board, respected knot theorist who has wandered out of his field of specialty...
  • The long list of various coauthors with respectable credentials seems to indicate that this is not the work of a lone crackpot, but seems to be the work of a small group. Curiously, this is not unusual outside of the hard sciences. There are any number of small groups of academics from anthropology to zoology who seem to have used non-scientific shifting sand as the foundation for their towering theoretical edifices to explain the universe. Such is human nature. linas 13:53, 12 May 2006 (UTC)

[edit] You for admin?

Hello, long time no see :) I am not sure it it was discussed somewhere before (too lazy to do digging around) but why aren't you an admin? With almost 12k edits you should be one... at least 6k edits ago :) Renata 06:09, 23 May 2006 (UTC)

I've been ambivalent about pursuing nomination. I sure would like to have one-click revert, but haven't otherwise wished I'd been an admin. linas 04:06, 26 May 2006 (UTC)
Would you like to become one? I could nominate (well, I have a horrible admin nomination record and some consider me to be a bad luck, but I could try at least). So what would you say? Renata 18:04, 28 May 2006 (UTC)
I've no particular desire to become one. Seems like an obligation; not being one has not prevented me from acomplishing anything I'd wanted. linas 15:21, 4 June 2006 (UTC)
Fair enough :) Good luck! Renata 15:24, 4 June 2006 (UTC)

[edit] Troubling patterns of edits and what to do about them

Hi, can you drop by my user talk page? User:ObsidianOrder and User:Omegatron are very upset over my recent activity in "outing" Haisch or whatever. Obsidian is threatening to ArbCom me. ---CH 21:59, 25 May 2006 (UTC)

OK. FYI, I've certainly argued with ObsidianOrder before, he's had a habit of pushing pseudoscience as if it were the real thing. Its a shame that he can't devote similar energies to actually trying to find out the truth, instead of swallowing hogwash as if it were chocolate ice cream. Oh well. linas 04:11, 26 May 2006 (UTC)


[edit] Thanks for the invite!

Hi, Linas, thanks for your nice invitation to join the math and physics WikiProjects! I had noticed them earlier, but I wasn't sure how WikiProjects work (still a little fuzzy) and the discussion seemed over my head (heterotic strings, branes, amd all that), so I just shut my eyes and plowed ahead with my own articles. Just FYI, the computer seemed to complain that the list of participants in the math WikiProject was too long (>47kb).

If you get a chance, could you please look over a few of my articles and let me know if I should do anything differently to conform with the WikiProjects? I'm still working on classical mechanics, most recently canonical transformation and Hamilton-Jacobi equations, which you might enjoy. WillowW 08:47, 4 June 2006 (UTC)

You are welcome! To answer your questions: -- the wikiprojects are there to coordinate efforts. Thus they set the style guidelines, as to what should and should not be included, how its formatted, etc. The Physics wikiproject mostly follows the style guidelines of the (much larger and more active) math project. Then there are discussions of disputes; these often involve agressive newcomers specializing in pseudoscience. The string/brane discussion was perhaps typical: an appeal for help, although admittedly on a topic few have abilities in. Why, you make the same appeal youself, just above; the right place to do this would be at the Physics project, where you'll have more eyes and more experts. linas 15:05, 4 June 2006 (UTC)
p.s. ignore the "article too long warning" when its applied to talk pages, non-article pages, etc.
I reviewed the article on HJE and canonical transformations. Looks good, although we have a systemic problem: everything you wrore is from the perspective of an undergrad physics/engineering major. However, the best way of understanding what is "really going on" is by means of geometry, in the language of manifolds. I'm not sure how to resolve this tension; both perspectives are needed. linas 17:14, 4 June 2006 (UTC)
Hi, Linas, thanks for the quick feedback! I agree that Wikipedia would benefit from having both perspectives on the HJE, but I'm concerned that they might not both fit well into one article. For example, some readers might not want the full geometrical description in terms of manifolds, since the concepts would be unfamiliar and understanding the article would likely require more effort than they could easily invest. I confess, I find concepts like cotangent bundle a little scary, although I'm sure they'd be clear if I spent more time trying to understand them. Perhaps we should have two articles, Hamilton-Jacobi equations (physics) and Hamilton-Jacobi equations (mathematics), and a disambiguation page that clarifies the differences between them? That might give enough room to have two cogent articles at different levels, without trying to do everything in one article. What do you think? I tried something simiar with canonical transformation vs. symplectomorphism. WillowW 17:54, 4 June 2006 (UTC)
Hmm, I disagree. First, re the titles: even physicists use the language of manifolds now; so the distinction math/physics is false. The folks writing the textbooks are employed by physics depts. I was tempted to say that only engineers stick to the rather dry Euclidean form, but even that's not true: I've seen books on robotics that launch into algebraic varieties on page one, and holonomy by page 20 or 30. Work on both satellite motion, and space-craft inter-planetary travel also uses the modern language; I am hard-pressed to think of an application in physics or engineering that doesn't use the modern language. No, it would be a dis-service to split in this way. A better split might be to devote a single article page to each separate example. linas 18:14, 4 June 2006 (UTC)
Hi, Linas, I can see why it's good to keep the article together. However, I feel that we have to keep the initial part of the article intelligible to people who have learned only multi-dimensional calculus. Otherwise, we're likely to lose >98% of our readers, since most scientists and even lay people have learned calculus but very few have studied Riemannian geometry or manifolds/cotangent bundles/algebraic varieties/etc. According to the Science Citation Index from 1980-2006, there were 2284 articles about the Hamilton-Jacobi equation; of these, only 1 (!) mentioned "tangent bundle", "symplectic form" or "holonomy" in their title, keywords or abstract; exact zero of the HJE articles mentioned "symplectomorphism" or "algebraic variety" in the same places. "Manifold" and "geodesic" fared a little better, with 54 (~2.4%) and 35 (1.5%) articles, respectively. These data suggest that >98% of scientists are using the HJE in its old-fashioned calculus-based form. So I suggest that we include the more sophisticated, modern topics at the end of the article -- do you agree? WillowW 23:51, 4 June 2006 (UTC)

I think you severly underestimate the intelligence of authors. I doubt anyone who publishes an article today on the HJE would not have had a good grounding in parital differential equations, and it is impossible to study PDE's without learning a good bit of geometry. Tangent bundles are not exactly complicated; this is part of the undergraduate math curiculum, with the bare basics coming at the sophomore level. All math majors and most physics majors will have at least the basic concepts down. What edits are you proposing? linas 00:10, 5 June 2006 (UTC)

I agree with Willow here. It never hurts to keep things accessble. Besides, we don't want to address it to people who publish on HJE, rather, to people who want to learn about it. See also Wikipedia:Make technical articles accessible. Oleg Alexandrov (talk) 01:28, 5 June 2006 (UTC)
Aww, com'on. You know me better than that. Anyway, perhaps we should move this to the talk page of that article. The only proposal that I'd have is to promote the various examples to thier own WP articles, and leave the main article to talk about generalities, instead of diving into specifics.

linas 02:56, 5 June 2006 (UTC)

Continued at Talk:Hamilton-Jacobi equations. Oleg Alexandrov (talk) 05:15, 5 June 2006 (UTC)

[edit] Iterated function

Hi Linas. I'm a bit worried about this edit. If x is a fixed point, then it does not iterate to something, so I think it is a bit misleading to say that "The set of points to which x iterates to is known as the unstable set". I'm not sure how unstable sets are defined when f is not a bijection, so I couldn't fix it myself. Hope all is well. Cheers, Jitse Niesen (talk) 02:10, 8 June 2006 (UTC)

Right; I got sloppy; sorry. I did a zillion edits today cross-linking related articles. I changed the wording, perhaps its better now? Also: in this context, f − 1(x) is not the inverse of f, but the preimage. Basically, the Julia set; I'll try to clarify that. (Actually, not the Julia set, but what it would iterate into, more or less.) (Maybe its time to knock off for the night....) linas 03:32, 8 June 2006 (UTC)


[edit] Questions about quantum chaos stuff

Hi, Linas, I posted a few newbie questions about the quantum chaos stuff on the Talk page at Constant of motion -- thanks! WillowW 10:45, 12 June 2006 (UTC)

I replied there. The point is not to get lost in quantum chaos, which is an interesting distraction, but not directly relevant. Its instead to make the clear statement that "integrable system == system with constants of motion == system with symmetries" and that "non-integrable==no constants of motion". linas 00:28, 13 June 2006 (UTC)

[edit] A hit-and-run thank you

I just recently revisited an old article I wrote, many a moons ago, Derivation of the cartesian formula for an ellipse (I had nothing to do, so I figured, what the hell, right?) To my complete and utter shock someone had actually visited it (!), and even more surprising tagged it with a nice little {{proof}}-template (!!). Thanks for that :P Oskar 22:23, 12 June 2006 (UTC)

You're welcome! linas 00:28, 13 June 2006 (UTC)


[edit] B. Roy Frieden's POV-pushing edits

I have some information about this.

Note that Frieden is Prof. Em. of Optical Sciences at the University of Arizona. The data.optics.arizona.edu anon has used the following IPs to make a number of questionable edits:

  1. 150.135.248.180 (talk • contribs)
    1. 20 May 2005 confesses to being Roy Frieden in real life
    2. 6 June 2006: adds cites of his papers to Extreme physical information
    3. 23 May 2006 adds uncritical description of his own work in Lagrangian and uncritically cites his own controversial book
    4. 22 October 2004 attributes uncertainty principle to Cramer-Rao inequality, which is potentially misleading
    5. 21 October 2004 adds uncritical mention of his controversial claim that Maxwell-Boltzmann distribution can be obtained via his "method"
    6. 21 October 2004 adds uncritical mention of his controversial claim that the Klein-Gordon equation can be "derived" via his "method"
  2. 150.135.248.126 (talk • contribs)
    1. 9 September 2004 adds uncritical description of his work to Fisher information
    2. 8 September 2004 adds uncritical description of his highly dubious claim that EPI is a general approach to physics to Physical information
    3. 16 August 2004 confesses IRL identity
    4. 13 August 2004 creates uncritical account of his work in new article, Extreme physical information

I posted fairly detailed criticisms of Frieden's "method" to sci.physics.research some years ago.---CH 21:54, 16 June 2006 (UTC)

Well, the edit that makes my brain pop is this one. linas 00:44, 17 June 2006 (UTC)

[edit] euler

I'm sorry, you posted a message on the main page of la:Painga prima about translating something of Euler into latin? Could you please link to exactly what you want translated, and not a discussion page? I'll be more than happy to help.--Josh Rocchio 03:01, 20 June 2006 (UTC) But better place to find me is: la:Usor:Ioshus_Rocchio

[edit] The certainty principle

Hi, Linas! You are one of a few people here, who does not look like a sockpuppet... ;-) Possibly, you noticed the strange things that happen here around the certainty principle? What do you think about them? You, usually so active and critical, are so silent in this case, that I am really puzzled. (Reply here.) Rcq 23:32, 20 June 2006 (UTC)

I don't know what to say. I saw the controvresy, it didn't seem interesting. After a quick review of the arxiv article by Arbatsky, I lost interest. The derivation in the article appears to be correct, however, it doesn't say anything deep or interesting. To summarize what it says in very simple terms, it says this: "In order for a spinning disk to turn at least one radian, or more, the product of the angular velocity and the elapsed time must be greater than one. We call this the Certainty Principle". This is obvious to a 10 year old, or any one who has looked at a spinning object. That fact that its formulated in Hilbert space doesn't make it any less trivial. Clearly Arbatsky understands the basics of Hilbert spaces ... but this is expected of college students studying physics. The arxiv.org paper doesn't say anything interesting; it may be a good excercise for the author, and maybe enterataing to some young student learning Hilbert spaces, but its was a waste of my time to read it. linas 00:55, 21 June 2006 (UTC)
  • I like your popular, "obvious to a 10 year old" ;-), explanation. Unfortunately, it is incorrect. In the complex Hilbert space, even in 3-dimensional, situation is not so obvious at all. The "trivial" fact of existence of the Fubini-Study metric was discovered only in 1905 by Fubini and Study. Most physicists do not know about that thing at all.
  • The connection between quantum angular speed (in the complex Hilbert space) and standard deviation of generator is not obvious, and is almost unknown (at least among physicists).
  • The "trivial" Mandelshtam-Tamm inequality was discovered only in 1945. For 18(!) years the best minds of physics searched for that! (BTW, the article about the uncertainty principle contained BS about energy and time before the reference to Mandelshtam and Tamm appeared there.)
  • The idea to generalize the UP and Mandelshtam-Tamm relation, applying the theory of Fubini-Study metric to generators of the Poincare group, is new and original. Have you read the article about the CP, created by Hryun? Did you see the table there? (If not, see [1].) Do you agree with that table? Do you agree that the suggested inequalities are unknown in physics? Have you read the second paper about the CP? Do you agree that the CP allows to get new inequalities describing the UP?
  • Everything genial is simple. :-) Rcq 14:10, 21 June 2006 (UTC)
Perhaps I was too harsh. Let me rebut. I didn't say that complex Hilbert spaces are easy. And I don't think the Fubini-Sudy metric is easy. Furthermore, I know for a fact that most physicists don't know much about Hilbert spaces. Most don't need to. The people who do know a lot about Hilbert spaces are mathematicians who study topological vector spaces and C-star algebras and the like. The Arbatsky paper doesn't "open my eyes", it doesn't tell me anything I don't know, it doesn't make me think "wow that's interesting".
It also fails in rigor in several places: when talking about operators, it should state whether they are compact operators or trace-class, or not. It appears to assume that they are trace-class, without ever saying so. It also assumes that the derivative is well-defined; however, its known that for non-compact operators, such as the position or momentum, the derivitve is *not* well-defined. See, for example, Fréchet derivative and Weak convergence (Hilbert space). Finally, it assumes that the Riesz representation theorem, holds, without actually saying so. Its not clear that it necessarily does.
Finally, the Arbatsky paper is badly named. The paper, (and you), present this idea that the "certainty principle" is somehow "better" or "stronger" than the uncertainty principle. Even if it was (and I don't think it is), there is at least a dozen different ways of understanding the uncertainty principle. One of the textbook explanations is the Fourier transform. More generally, there's Pontryagin duality. It shows up, in a special way, in chaos theory, where you can work in a Hilbert space basis that gives you either detailed, filigreed fractals, or smooth decaying corellation functions, but not both at the same time. This is true both for classical chaos, and also for quantum chaos. I tried reading about schemes in algebraic geometry and noted it showed up there. I skimmed through a good intro to K-theory the other day, and it had a marvelous review of duality that feeds directly into the ideas underlying the uncertainty principle. The uncertainty principle is "old news"; and trying to claim that the "certainty principle" is some earth-shaking idea will not impress anyone. linas 01:29, 22 June 2006 (UTC)
OK, I really have been too mean. The Arbatsky paper does say something interesting; unfortunately, it does not say it in either the abstract nor in the introduction, The interesting thing is this: the angular velocity of a vector being acted on by a unitary transformation is equal to the RMS deviation of the generator of the unitary transform. I did not know that. That is interesting, and it merits further thought and exploration. Its not immediately intuitive, and understanding this makes me now want to go and double-check your calculations. To me, that is the principle result of the paper; the metaphysics of the uncertainty principle is less important. linas 03:18, 22 June 2006 (UTC)
Now that I understand this ... perhaps you can write a WP article about Mandelshtam-Tamm relation? But please try to do this without hyping Arbatsky's work ... linas 03:20, 22 June 2006 (UTC)
Yes, very interesting, now that I've thought about it some more. If you are in conact with Arbatsky, please tell him to state this relationship in the abstract, and also state it in the introduction, put it right out front. linas 04:11, 22 June 2006 (UTC)
  • Sounds funny. ;-) The papers were already published and read by very many people. One of them, S. Lorentz, an Austrian specialist in QM and molecular biology created the article about it. (He cannot be a sockpuppet of Arbatsky here: See what he wrote on his user page in 2004(!).) Then it was deleted. Hryun, whose origin is unknown, re-created the article under the proper name (without capitalization of "principle"). It was immediately deleted. What is more, Zarniwoot and SCZenz decided to delete all links to Arbatsky's site from all articles of WP. And they also desided to block all accounts and all IP-addresses of people, who put those links back (as they say, it must be made "on sight", because they all are "obvious" sockpuppets of Hryun). After all this you suggest me to write something about Mandelshtam-Tamm relation? No, thanks.
  • In fact, we already have some "real" (i. e. those, whose "reality" is obvious from the Internet) people, who approved the CP. For example, A. Kleyn, an American specialist in general relativity.
  • Arbatsky's work obviously supersedes Mandelshtam-Tamm relation. It is more general, more geometrical, easier to understand. Some people even think that it is "obvious to a 10 year old". ;-)
  • As regards your concern about the mathematical rigor. You are certainly right: when the generator is unbounded the derivative may be "infinite". But even in this situation it does not break the theorem: of course, "infinity" is "greater" than the Planck's constant. :-) Rcq 14:12, 22 June 2006 (UTC)
You misunderstood my enthusiasm. Its a fairly trivial manipulation that has none-the-less interesting result. However, it is not a "general principle", and it certainly does not supersede the uncertainty principle. It should not be added to WP articles. User:SCZenz did the right thing in deleting the links. Casually brushing off mathematical rigor as if its unimportant does not impress anyone except fools. And, for what its worth, the relation has nothing to do with quantum mechanics: exactly the same relations hold for the transport of a tangent vector on a (finite-dimensional) manifold: consider the motion of a tangent vector on a Lie group, generated by an element in the algebra; or consider more generally the "exp" map on a Riemannian manifold. No one would argue that coordinates on smooth manifolds are "uncertain" or obey an uncertainty principle, and yet Arbatsky's work generalizes in a simple and straightforward way to those situations. Its got nothing to do with quantum mechanics. linas 14:37, 22 June 2006 (UTC)
For the record, I've placed a non-quantum explanation at User:Linas/Arbatsky's principle unmaksed. linas 20:05, 22 June 2006 (UTC)
  • Smart boy. ;-) Attended a good kindergarten. ;-) You understand the theorem number 2 (Vepstas principle) already! ;-) Now you need to go to school and study the certainty principle. ;-) Then do not forget about the second paper. But do not over-exert your brain! ;-) That is only for those over 11! ;-)
  • I still would like to hear your answers to my questions from the second post. ;-) Rcq 14:32, 23 June 2006 (UTC)
I assume you mean these questions:
Have you read the article about the CP, created by Hryun? Did you see the table there?
No and No.
(If not, see [2].) Do you agree with that table?
I don't know how to answer. Certainly, physics students are told that the uncertainty principle holds for general conjugate operators, and its implied that it holds for the boosts and rotations that show up in special relativity (i.e. the last row in the table). The idea that the uncertainty principle holds in a covariant relativistic context is the underpinning of quantum field theory, so all physicists will beleive that its true. However, I do not know the status of any formal, mathematical proofs of this, or why such proofs might be viewed as inadequate by mathematicians. Physicists already beleive its true, and so don't need any additional proofs. On the other hand, all of the mathematical discussions I've seen were always based on pairs of non-commuting operators. The energy-time relationship is unusual, because (in non-relaivistic physics), time does not have an operator. Thus, derivations based on operator pairs fail for the time-energy relationship. The non-existance of a time operator follows from a theorem by von Neumann (I think the Stone–von Neumann theorem) However, I do not understand this fully; I am trying to understand it, its relevant to another problem I've been struggling with.
Do you agree that the suggested inequalities are unknown in physics?'
No. As indicated above, the last inequality is taken to be golden truth by physicists working in relativistic quantum field theory. I don't know what its status is among mathematicians. But maybe I misunderstand.
Have you read the second paper about the CP?
I'm looking at it now. It wuld be helpful if you modified the proof of the theorem so that it doesn't depend on choice of l and r. That is, I should be able to pick any l<r so that δX=l-r can be any value I wish. In particular, I expect that for a state with a very small l-r, the expecation value of Δ P would be very large for this state. This is not immediately clear from your proof.
Do you agree that the CP allows to get new inequalities describing the UP?
The introduction of the "spectral projector" is a major improvement over the first paper. It makes the connection between CP and UP much more clear. I really disliked the "changes substantially" part of the first paper. However, this leads to a different problem. Since there is no (self-adjoint) operator for time, (if I understand correctly), then your proof fails to hold for the time-energy relationship (it only holds for the position-momentum relationship). Its not immediately obvious how to fix this. A related problem is that, if your proof only holds for pairs of self-adjoint operators, then its not clear how your proof differs from traditional proofs of uncertainty for non-commuting operators. This seems like a serious problem to me.
Also, your second paper states that the first paper defines the "spectral projector", but it does not. My xpdf viewer cannot find the word "spectral" anywhere in the first paper. linas 23:13, 23 June 2006 (UTC)
By the way, I just found the following about the geometry of quantum mechanics including a discussion of the Fubini-Study metric, which looks intersting. linas 23:37, 23 June 2006 (UTC)
  • Do not pretend that I am Arbatsky.
  • The bullshit that you write without thinking starts to bother me. Look at the following phrases again: "physics students are told that the uncertainty principle holds for general conjugate operators", "its implied that it holds for the boosts and rotations that show up in special relativity", "Physicists already beleive its true, and so don't need any additional proofs", "The energy-time relationship is unusual, because (in non-relaivistic physics), time does not have an operator", "the last inequality is taken to be golden truth by physicists working in relativistic quantum field theory", "The introduction of the "spectral projector" is a major improvement over the first paper", "proof fails to hold for the time-energy relationship", "second paper states that the first paper defines the "spectral projector"". They all are just complete bullshit and do not deserve a comment.
  • The fact, that you are such an obscurantive snob, who "knows everything", is not a problem. But the problem is that you are a retard: You try to retard the progress of the humankind.
  • Your social behavior deserves deprecation. When I asked you, what you think about the situation, I have not asked you to read any papers (in contrast to the lie that you wrote on Zarniwoot's talk page). And you did not! When I asked you, I certainly implied that you, at least, will not hurt. But, instead, you started to distribute lie about me and about Arbatsky's papers. It must be a shame to you! Rcq 14:28, 24 June 2006 (UTC)
I don't know why you want to ruin a perfectly good conversation by writing what you wrote. You are Arbatsky, do not pretend you are not. I don't know why you single out those statements as "bullshit", they are all true. I'm sorry I sounded like a snob. I'm confused by your last statement. If you did not want me to read your papers, then what did you want? Finally, I am not "distributing lies" about you; I don't know why you wrote that. linas 14:50, 24 June 2006 (UTC)
Rcq, your statements above (both the one on 14:32, 23 June 2006 and the one on 14:28, 24 June 2006) are way beyond what is deemed acceptable here. You should always remain civil in discussions. Please keep that in mind, otherwise you will find very fast that editors are not interested in listening to what you have to say. Thanks. -- Jitse Niesen (talk) 15:41, 24 June 2006 (UTC)
  • Unfortunately, I do not see a "perfectly good conversation". I only see monologue of Linas with closed eyes and bunged up ears.
  • Have I ever said that I am not Arbatsky? I just said: "Do not pretend that I am Arbatsky". Nothing more. Your insinuations are obviously redundant in the context of scientific discussion.
  • About your "true" statements. Ok, let us discuss them a little. (1) "physics students are told that the uncertainty principle holds for general conjugate operators" Go to Talk:Uncertainty_principle and read "Introduction of the article" section. (2) "its implied that it holds for the boosts and rotations that show up in special relativity" Who implies that? Reference? (3) "Physicists already beleive its true, and so don't need any additional proofs" Do not pretend that physicists are idiots! (4) "The energy-time relationship is unusual, because (in non-relaivistic physics), time does not have an operator". It is the case of coordinate and momentum and the uncertainty principle are "unusual" and are connected with non-relativistic and semiclassical approximations. (5) "the last inequality is taken to be golden truth by physicists working in relativistic quantum field theory" Give me a reference to this "golden truth"! (6) "The introduction of the "spectral projector" is a major improvement over the first paper". The second paper, obviously, was written only for those, who cannot think about trivial things themselves. (7) "proof fails to hold for the time-energy relationship" The proof perfectly works in this case and gives relation almost equivalent to that of Mandelshtam and Tamm. (8) "second paper states that the first paper defines the "spectral projector"" Where have you seen such a bullshit there? Which page? Which line?
  • What did I want? Certainly, not distributing your incompetent opinion! If you do not want to think, nobody enforces you.
  • To Jitse Niesen. I am sorry, if I was too harsh. Unfortunately, the "best" members of the WP-comunity are not better than me. Rcq 17:17, 24 June 2006 (UTC)
You are picking a fight. I'll answer (8) only. The second paper has a footnote on the term "spectral projector". That footnote references the first paper. As to (5), see, Itzykson and Zuber, Quantum field theory, Glimm and Jaffe Quantum Physics, or Soviet Russia's very finest, Landau and Lifshitz, Relativistic quantum theory volume 4 of thier series on physics. linas 17:37, 24 June 2006 (UTC)
  • There is a footnote in the second paper that explains the term "spectral projector" for those physicists, who do not know it. It is just a remark. No reference to the first paper is given there.
  • Let us take the "very finest", Landau-Lifshits, for example. Which chapter, which paragraph presents the last relation from Arbatsky's paper? Rcq 21:12, 24 June 2006 (UTC)
  • Please, provide also the name of the paragraph. Rcq 21:22, 24 June 2006 (UTC)
It looks like you ignore me. Your personal ambition is, of course, more important than the progress of humankind and knowledge of the Golden Truth. O'kay. Possibly, I wanted too much from you, regular person. Sorry, if my harsh comments made you feel too uncomfortable. Bye. Rcq 20:24, 26 June 2006 (UTC)

[edit] tiny question

Hello,

in a few days my exams will be over and I plan to write some stuff, but before that, a tiny question :


(if F(w)\neq 0) or L\subset Q (if F(w) = 0).

This a part of the article I started, and plan to improve : Quadric (projective geometry)

Why does the F(w)=0 look bad and the other one doesn't?

Thanks,

Evilbu 16:13, 21 June 2006 (UTC)

The correct place to ask is on the talk pages of WP:WPM. The short answer is to change the preferences on your WP preference settings, or to "force rendering to gif", which changes it for everybody: like so:
(if F(w)\neq 0\!) or L\subset Q (if F(w)=0\!).
linas 00:10, 22 June 2006 (UTC)


Thanks, I clicked Always render PNG, and now all of a sudden here on in the article itself it looks better. Is this what basically all mathematicians here prefer? Evilbu 12:49, 24 June 2006 (UTC)

No. It depends on your screen resolution. I have a high-res screen (1600x1200) and use a large font, and as a result, the png and text are the same size, and either looks quite good. The next step, however, is MathML. linas 14:17, 24 June 2006 (UTC)

[edit] A short Esperanzial update

As you may have gathered, discussions have been raging for about a week on the Esperanza talk page as to the future direction of Esperanza. Some of these are still ongoing and warrant more input (such as the idea to scrap the members list altogether). However, some decisions have been made and the charter has hence been amended. See what happened. Basically, the whole leadership has had a reshuffle, so please review the new, improved charter.

As a result, we are electing 4 people this month. They will replace JoanneB and Pschemp and form a new tranche A, serving until December. Elections will begin on 2006-07-02 and last until 2006-07-09. If you wish to run for a Council position, add your name to the list before 2006-07-02. For more details, see Wikipedia:Esperanza/June 2006 elections.

Thanks and kind, Esperanzial regards, —Celestianpower háblame 16:00, 23 June 2006 (UTC)

[edit] Hartree-Fock

Hi Linas. I am not an expert, but I think Hartree-Fock doesn't really belong in Category:Perturbation theory. There is some perturbation there, but it is remotely related to what the model is about. I would suggest one put a topic in a given category only when that category is crucial to the topic, and not otherwise. Wonder what you think. Thanks. Oleg Alexandrov (talk) 19:59, 24 June 2006 (UTC)

OK, yes. I removed over 80 articles from Category:quantum mechanics and had to find homes for them somewhere :) I think we really need a cat such as Category:Many body problem for placing all of the articles dealing with quantum chemistry many-body calculations, such as Hartree-Fock, that are right now littered across multiple cats. However, I have not the energy, or the expertise, to assemble (or even properly name) such a cat. linas 20:05, 24 June 2006 (UTC)
(simultaneous edit) Same about Variational method (quantum mechanics). That should have been rather in Category:Quantum mechanics or any subcategoy than in Category:perturbation theory.
And if you are not sure, better leave it the way it is I would think. Oleg Alexandrov (talk) 20:06, 24 June 2006 (UTC)
Huh? I wanted to put all of the articles dealing with variational theories in Category: perturbation theory. I debated creating a Category:Variational principles to contain these beasts. Don't know what you mean by "if I'm not sure" -- I'm sure, I really wanted to kick all the cruft out of Category:Quantum mechanics. I know all these topics pretty well, I've studied this crap in textbooks till I turned blue. linas 20:12, 24 June 2006 (UTC)
Yes, please, create a Category:Variational principles category then. It is not obvious at all what Variational method (quantum mechanics) has to do with Category:Perturbation theory, and such a categorization is confusing rather than helpful. Oleg Alexandrov (talk) 20:48, 24 June 2006 (UTC)
Hmm. Well, on further exploration, it seems we have an existing and well-populated Category:Calculus of variations, which seems to contain mostly math articles. Would it not make sense to reserve Category:Perturbation theory for the application of variational principles in physics? That could maintain a fairly clean split between the math and the physics side of the topic. linas 21:28, 24 June 2006 (UTC)

As far as I am aware, Category:Perturbation theory should contain articles about perturbation theory, the epsilon kind of thing. Variational method (quantum mechanics) has something about approximation, but is not a true mathematical perturbation. I still think Category:Variational principles is the way to go. Oleg Alexandrov (talk) 21:32, 24 June 2006 (UTC)

I don't know what would distinguish Category:Variational principles from Category:Calculus of variations; they seem to be the same thing to me. The latter cat consists of mostly physics articles anyway. I have no clue of what you mean by a "true mathematical perturbation", the perturbation theory of quantum mechanics is "true", its the matrix mechanics analog of classical perturbations of differential equations. The formulas are mostly identical. Its a *lot* easier to understand than the differential eq version. See for example Fredholm theory which I think gives a decent idea of how the continuous and discrete cases match up.
Perhaps we should just merge Category: perturbation theory into that. Another possibility would be to create Category: perturbation theory (classical mechanics) and Category: perturbation theory (quantum mechanics) ... ?? However, maybe that is too fine grained. linas 21:42, 24 June 2006 (UTC)
It is fine with me if you put stuff in Category:Calculus of variations. What I am saying (for the n-th time now) is that Variational method (quantum mechanics) does not belong in Category:Perturbation theory, and any physics variational techniques do not belong in Category:Perturbation theory either. Oleg Alexandrov (talk) 21:46, 24 June 2006 (UTC)
Did you read the article perturbation theory? That's perturabation, as far as I know. Oleg Alexandrov (talk) 21:48, 24 June 2006 (UTC)

Hi Linas and Oleg, just to join in here. Part of the problem is that these methods are chemistry as well as physics. As a chemist I see no reason for these things to be categorised anywhere else than in Category:Quantum Chemistry and Category:Computational Chemistry, but no doubt you will disagree. Maybe we have both physics and chemistry categories as we do in effect already, but with some clarification and possible simplification. You could argue for HF to be perturbation theory on the grounds that it is the reference function for perturbation methods such as Moller-Plesset in Quantum Chemistry. --Bduke 23:19, 24 June 2006 (UTC)

Not sure how to respond. Bduke's comments are easier: not all of quantum chemistry is perturbation theory, and I see nothing wrong with having articles listed in 2-4 distinct categories, when appropriate. I suppose Bduke will say that 90% of quantum chemistry is perturbation theory. Similarly, 90% of quantum field theory is perturbation theory ... but I don't think those articles should be reclassed here; at most, only the small handful that directly present the perturbative expansions. Maybe.
To respond to Oleg... I just skimmed the article perturbation theory. It mentions Feymann diagrams as an example of perturbation in QFT, but misses entire swaths: The theory has its roots in 17th century celestial mechanics, in the theory of epicycles used to make small corrections in the Ptolemaic model. Poincare was doing perturbation theory of planetary orbits at the turn of the 20th century when he discovered the "problem of the small denominator" in perturbative expansions, where the n'th term can, due to its small denominator, can be bigger than the first order perturbative correction. A few decades later, famous applications of perturbation theory are the Zeeman effect and the Stark effect. Probably 90% of all ink spilled on perturbation theory is in undergrad quantum textbooks, where undergrads will see a footnote to the effect that "yes, there is also a concept called perturbation theory for differential equations, but it is vastly more complex than that presented here"... which is true. But its also true that the perturbative expansion for differential equations generally resembles that for the matrix mechanics of QM: both have the "same" denominators and the same small-denominator problem; the general resemblance of the first and second order terms is unmistakable ... the theory then shifts into third gear for general molecular theory and also Feynman's discovery that the perturbation series has a beautiful diagrammatic representation...
The "simple example" on the article perturbation theory sucks, and should be removed, and replaced by the text-book standard first order and second-order expansion to ε and ε2. Having a perturbative expansion that runs in fractional powers of ε is absurd; it smacks of failure ( However, even in this simple example it may be observed that for (arbitrarily) small ε > 0 there are four other solutions to the equation (with very large magnitude).). The "simple example" then explains its an example of singular perturbation theory, which is not simple at all, but is considered to be a more advanced topic. The non-singular, non-degenerate case should be developed first.. Sigh. I really don't want to start re-writing that article. linas 16:35, 25 June 2006 (UTC)
I added a section on history to perturbation theory. I'm contemplating adding a section on the actual math, but that is considerably harder, as its not clear how to talk about both the matrix mechanics and the diff eq at the same time with the same notation, and still make it clear. linas 17:58, 25 June 2006 (UTC)
I've mentally sketched out a nice, simple development for the technical side; I shall add it tonight. linas 19:08, 25 June 2006 (UTC)

You suppose wrong. I do not think that 90% of quantum chemistry is perturbation theory. The largest part perhaps remains Hartree-Fock molecular orbital theory, although density functional methods may have overtaken HF. It is true that configuration interactions methods, which are variational, are out of favour because they are not size consistent, and the most common correlation methods (excluding DFT here) are Moller-Plesset and Coupled Cluster. To return to Hartree-Fock, I suspect that by far the most references to the Hartree-Fock method occur in the chemical literature, not the physics literature, so my point about consulting the chemists is an important one. The article on perturbation theory has real issues here. There is essentially no mention od the methods chemists use except for an historical reference to LCAO-MO (I have fixed the redlink to go to the article on this). I'll try to have a look at it. --Bduke 23:08, 25 June 2006 (UTC)

Linas, thanks for the detailed comment and the work in that article. Oleg Alexandrov (talk) 02:05, 26 June 2006 (UTC)
Oleg, you are welcome. I usually like to stay away from topics like this, sticking to more obscure stuff (obscure to me, that is). Bduke, I know almost nothing about modern chemistry, other than what I've picked up by osmosis. To return to the original issue, I don't have any particularly strong feelings about categorization, my pollution of this category was the side-effect of a cleanup of other categories. linas 03:43, 26 June 2006 (UTC)
Oh, that, and the fact that Ugo Fano taught my quantum class. This was quite a mind-bender. He'd written a popular and eminently readable textbook on the topic in the 1950's, but by the time I got around, he was an old man, and appearently decided to go back to the very roots of QM, to make sure that something of importance hadn't been somehow over-looked. Thus, he taught a throughly arcane and confusing class, failing to visit any of the usual touchstones of QM, and instead concentrated heavily on the pre-wave-mechanics, pre-Schroedinger picture (although we did do the hydrogen atom in the standard way). It was all quite difficult and daunting. One day, one of the students discovered his earlier book in the library, and we marvelled at and were awed by its utter clarity. I cherish this memory, and am actually glad that I got the counter-cultural old-man's version; it nurtures my feelings that the mainstream is often wrong. linas 04:21, 26 June 2006 (UTC)

[edit] Gauge covariant derivative -- requests

Hi linas,

(Sorry. some of this duplicates from the talk page of gauge covariant derivative.)

I was wondering if you would be interested in writing up an article on gauge connection? Right now that page is just a redirect to gauge theory. A gauge connection (unless I'm mistaken) is like a connection form adapted to a particular gauge. It then behaves in a special way under gauge transformations. I know this can be viewed in the language of principal bundles to a certain extent. But I don't think that's the way physicists (or many mathematicians) view them.

Also, would it be possible to work the Vector Bundles section from connection form into gauge covariant derivative? These seem more "gaugey" than "formy" to me. If I'm wrong, just let me know -- I don't want to go around pigeonholing things.

Best regards, Silly rabbit 18:34, 27 June 2006 (UTC)

I answered perhaps too pompously or glibly, on Talk:gauge covariant derivative, I guess I was thrilled to be mistaken for an expert. The short answer that I think you are looking for is "section". The physicist's "gauge field" is the value of the geometer's connection on some indefinite section of the fiber bundle. The physicists "local gauge transformation" is a description of how this value transforms as one moves from one section to another. There's nothing "special" about it that I know of, other than that each section has to be continuous, smooth, single-valued. As far as I know, "this can be viewed in the language of principal bundles" completely, and not just "to a certain extent". I'll try to clean up gauge covariant derivative, but I have other obligations I've been guiltily ignoring that I really have to deal with first. linas 20:30, 27 June 2006 (UTC)
Well, I guess not "completely"; physicists almost always work in a presentation, usually the the fundamental rep (or its "complex conjugate") for spinors, and the adjoint rep (considered as the product of a fundamental rep and its conjugate) for the gauge fields. That's the only deviation from a "pure principal bundle" that I can think of at the moment; I guess you can call these "associated bundles"; this fine a distinction is rarely made. linas 03:17, 30 June 2006 (UTC)
On second thought... I think it's probably better to keep the Vector Bundles section in connection form where it is, despite my earlier protest. Silly rabbit 20:23, 27 June 2006 (UTC)
Vector bundles are a special case, and are best left as a special case, as they offer both a convenient spring-board to principle fiber bundles, if that's where the reader wans to go, but also have common applications in, for example, symplectic geoemtry ad/or differential equations, where the general gauge-field language would be inappropriate and confusing. linas 20:30, 27 June 2006 (UTC)
I notice you placed a fairly long writeup in Category:Connection (mathematics). For whatever reason, we tend to keep category writeups short. You probably want ot move most of that text to a new article Connection (mathematics) tht can act as the overview to all the other articles.linas 21:19, 27 June 2006 (UTC)
Yes, I was going to try to find a home for that material once the shocks of trying to reorganize everything have worn off. Silly rabbit 00:32, 30 June 2006 (UTC)

[edit] Transitional kinetic energy

You are right about that article. I found it on dead end pages and by that stage of wading through crap I could'nt be bothered to do anything with it. prod seems the correct action. Thanks, mate. --Bduke 05:05, 28 June 2006 (UTC)

[edit] Doublet

Hi Linas. It is me again with the same issue. I think putting doublet (physics) in Category:Rotational symmetry was a strech. It is not clear at all what that article has to do in that category, at most the rotational symmetry is a small part of what a doublet is about. I believe rotational symmetry has to contain articles like annulus (mathematics) etc, rather than far-fetched concepts like doublet. Wonder what you think. Oleg Alexandrov (talk) 20:01, 30 June 2006 (UTC)

And doublet is in Category:Quantum mechanics anyway, which has Category:Rotational symmetry as a subcat. Oleg Alexandrov (talk) 20:03, 30 June 2006 (UTC)
The article had been uncategorized previously. You are welcome to recategorize as you wish. I'm not sure what you mean by "far-fetched concepts like doublet"; its standard fare not only in undergrad introductory quantum, but also chemistry, geology, astrophysics. Every occurance of a doublet in physics that I can think of is associated with SU(2) symmetry, as the manifestation of spin (physics) in spectral lines, so I'm hard-pressed to imagine how its not associated with rotational symmetry. The reason that annulus (mathematics) isn't in there is because the annulus doesn't have an SO(3) symmetry. linas 21:34, 30 June 2006 (UTC)
More generally, I do make mistakes. Sometimes I notice them, and I fix them, and sometimes I don't. linas 21:44, 30 June 2006 (UTC)
I added a short history section to doublet (physics) to place it into context. linas 22:01, 30 June 2006 (UTC)
If your intent is to annoy me in sch a way as to get me to expand an article ... well, it worked; that article is now a bit bigger. linas 22:39, 30 June 2006 (UTC)
Thanks for expanding that. :)
I am just annoyed that you create mathematically-sounding categories but then fill them up with physics articles, and my bot then adds them to the list of mathematics articles. Admittedly the line between math and physics is blurry, but doublet (physics) does not belong there.
So I what I will do is banish Category:Rotational symmetry from the mathematics section of the list of mathematics categories and will always check categories you create for nonmath.
The ultimate irony is that doublet (physics) is in the List of mathematics articles, but it is not in the list of physics articles. Oleg Alexandrov (talk) 02:05, 1 July 2006 (UTC)
I'm sorry, I do appreciate your work. I actually have been wondering for quite a long time whether or how your bots made distinctions between math and physics. I really do wish someone would step up and emulate some of the mathbot infrastructure, but for physics. Ah well. Maybe someone will come along.
As to categories: virtually all the category work I do is not in math; I really don't know enough math, either the scope of the subject matter, or the history, to be competent in categorizing math articles. I may feel more confident someday, but only if I get to do a lot more reading ... linas 03:08, 1 July 2006 (UTC)

Come on, I think you know perl. If you really feel like making order in the physics articles I can give you my scripts. But they need some human supervision though. Oleg Alexandrov (talk) 03:35, 1 July 2006 (UTC)

I just want to say that I agree with the solution of considering category:rotational symmetry non-maths. There are many articles that can go in that category but are not mathematical. I thought of Taylor-Couette flow, but we don't have an article about it …. Linas, is a doublet a particular (namely, the simplest nontrivial) case of a spinor? Very confusing how physicists use all these different terms. -- Jitse Niesen (talk) 03:50, 1 July 2006 (UTC)
Oleg, I know perl, but the administration of the scripts is best left to someone else. I've dropped a hint once at WP:Phys, but no one picked up on it. WP:phys is not as lively as WP:Math; it needs some new blood and some enthusiastic new members; its devolved into pseudoscience patrol.
Jitse, yes, in a certain sense, the doublet can be said to be the simplest example of a spinor. As to the confusion, its certainly not intentional: someone (Raoul Bott?) said that the geometry of physics was arrived at after "a long series of subtle confusions". At every step of the way, it could have come out differently (but didn't). Each confusion thus carries along the historical baggage and naming conventions of what it might have been.
As to category:rotational symmetry, I was really hoping to keep it limited to articles dealing directly with SO(3) symmetry. Things like vortecies are more about SO(2) symmetry, and properly belong in Category:vorticies, along with tornadoes, hurricanes and Type-II superconductivity. linas 04:22, 1 July 2006 (UTC)

[edit] ProbDistributions

I see you removed this: [3] What's wrong with the template? Btyner 01:39, 2 July 2006 (UTC)

It appeared to be an improper use of a template, which is more appropriately fixed by placing the article in the correct category. linas 02:46, 2 July 2006 (UTC)
So, would you also consider Template:English dialects to be improper? Is there a page listing the proper and improper use of templates, and if so, would you please point it out so I may educate myself? Thanks, Btyner 16:19, 2 July 2006 (UTC)
I don't edit articles having to do with dialects, and its possible that the dialect wikiproject looks askance at markup like that. But, off-hand, yes, that template looks nasty. Templates like that are a recurring discussion theme, and they tend to get AfD'ed quickly. Certainly, I strongly discourage their use. The only page I can refer you to for these discussions is Wikipedia:WikiProject Mathematics, Wikipedia:Manual of Style (mathematics), and the discussions in the archives of Wikipedia talk:WikiProject Mathematics. The latter will be the easiest to find, as they tend to have giant templates splattered in the page during discussion. linas 16:51, 2 July 2006 (UTC)

[edit] References

While I completely agree, it might be better if you toned down the request slightly :) As you can see from previous posts on the page, there is no consensus to force the usage of Cite.php style references. Indeed in articles I work heavily on, I avoid them and leave a note at the top of the page requesting people not convert the references. See for example here. Anyway, good to know that I'm not the only one whos pissed off with the new reference system! :) - FrancisTyers · 15:33, 2 July 2006 (UTC)

I'm usually polite, but this one seemed to need a slap across the face. It's ... words escape me .. mindboggling... jaw-dropping ... ? linas 15:46, 2 July 2006 (UTC)

[edit] Chebyshev function

Thanks for helping out on Chebyshev function. But I have to ask about your statement that the explicit formula for ψ(x) is conditional on the Riemann hypothesis. This just isn't the case... see Davenport p. 104 for a complete proof. Also, how did you generate the data for your two plots? Was it your own code or something else? I couldn't find this function in Mathematica... --Dantheox 20:14, 3 July 2006 (UTC)

Ah, maybe I misunderstood. I got that impression in something I'm reading, which I will double check. This impression was reinforced by what you'd written in the article. The graphs were from hand-written code; the mangoldt function is fairly easy to implement, if one doesn't need large values, by a rather trivial prime number sieve. Being a Linux user I have no mathematica. linas 20:28, 3 July 2006 (UTC)
After re-reading what I wrote, I can totally see how that happened.. "conjecture of Riemann's" is generally synonymous with Riemann hypothesis, but that wasn't how I had intended it. Would you be willing to send me your code? I'd love to toy around with it. --Dantheox 21:09, 3 July 2006 (UTC)
I posted the code at User:Linas/Mangoldt I have stopped using email due to the overwhelming flood of spam. linas 03:41, 4 July 2006 (UTC)

[edit] Pseudoscalar

Sorry about that. The page was tagged with {{disambig-cleanup}} for over two weeks before I touched it. --Usgnus

I think the person who put that tag there didn't understand the topic. :-/ linas 03:48, 6 July 2006 (UTC)

[edit] Super Kamiokande

I have started a new page for Kamioka Observatory, it's in development so right now you can find it here. I'd like to finish it as quickly as possible and see if we can get it into the "Did you know..." section of the main page, so any help would be appreciated! Flying fish 05:13, 12 July 2006 (UTC)

I strongly suggest that you edit the article in-place, rather than in a sandbox, especially when making large changes. It makes it somwhat easier to understand the changes. If you are worried about conflicts iwth other editros, you can place an {{inuse}} tag in the article while you are working on it (however, you don't want to leave that tag in there for more tha a day). linas 00:19, 13 July 2006 (UTC)
Hi Linas. The reason for doing it outside of the real article was that I knew a bunch of it was going to be left in a rough state even after the time I put into it the other night, and I also don't have appropriate references with me right now. The thing is that it's not an incremental update at all, it's a totally different page on technically a different topic. I'm not sure if I agree with you that it should be a "history of neutrino physics" entry, as that would take A LOT of work that I can't put in right now (maybe I'll be able to in the fall). In any case I think it makes sense to have a page dedicated to the Kamioka experiments, as they are all related and most of them use the same technology. I understand your point that much of what I wrote fits into a generic article, but I think that it wouldn't be right to just list the physical characteristics of the experiments without explaining the reason they were built and what the scientific motivation for each one was (leaving that to another article, or more likely with no consistant logical explanation at all). Does this make sense? Alternatively, I think the section on Kamiokande-II could be spun off and the page I wrote greatly reduced, but I don't really like that idea.Flying fish 04:20, 13 July 2006 (UTC)

[edit] Edits by --Michael C. Price on Afshar experiment page

Dear Linas, --As you weel know, Michael C. Price insists on using unsubstantiated claims without proper references on the article page. Regardless of the nature of his claims, I have requested that he does so, but instead he has produced at best irrelevant quotes from non-peer-reviewed sources. His edit follows:

Though Afshar's work is still the subject of ongoing interpretation and discussion, a significant portion of the scientific community is of the opinion that Afshar's experiment does not refute complementarity.
Some general criticisms are:
Bohr's philosophical views on the Complementarity Principle are generally seen in accordance with the Schrodinger wave equation. Since the latter is obeyed in Afshar's experiment it is not obvious how complementarity can be violated.[1][2]
The modern understanding of quantum decoherence and its destruction of quantum interference provides a mechanism for understanding the appearance of wavefunction collapse and the transition from quantum to classical. As such there is no need, in the decoherence view, for an a priori introduction of a classical-quantum divide as enshrined by complementarity. Any experiment that claims to violate complementarity needs to address this issue.

As Michael claims, those statments are supposedly "popular views" that preexisted my experiment, and as such must be present in peer-reviewed publication predating my work. All I have asked him to do is to provide such valid ref.s but he has persistently avoided doing so and instead engaged in personal attacks. He seems to have a lot of time on his hands to be on Wikipeida constatntly, but I don't. This is turning to oneupmanship, and I don't have time for such antcis. Maybe he would heed your request. Thanks!-- Prof. Afshar 13:51, 12 July 2006 (UTC)

P.S. I will be discussing this issue with Michael Price on the article talk page, and would highly appreciate if you could monitor our discussion and interject when you deem fit. I'm afraid it might get a little testy, as Michael has been persistent on personal attacks. Thanks very much for your help. Best regards.-- Prof. Afshar 17:02, 12 July 2006 (UTC)
As you will see on the talk page, as well as at Wikipedia talk:WikiProject Physics, I had already challanged that addition several times, and reverted twice before nearly violating 3RR. His additions are not exactly false (and, in a certain sense I beleive they are quite true, and would reflect the general gut impression of most physicists stumbling over this topic for the first time). However, they do obscure and demean the issue; they're amateur hand-waving, and, in my opinion, this topic is touchy enough that its time to move beyond hand-waving, and into something deeper and more concrete. However, I don't know how to further arbitrate the matter, or to disuade Micheal from his edits. I suggest putting your energies not into fighting Micheal, but into getting a more detailed theoretical structure in place for your experiment, and getting it published. This will enable an easier defense of your position. linas 17:33, 12 July 2006 (UTC)
Dear Linas, Thank you for your efforts. A peer-reviewed paper is due sometime in Sept. or Oct. Michael's edits do not reflect the definition of Complementarity used in the physics literature and I will chalenge him to produce a reference that does. It is not acceptable to misinform readers to think that PC as used by experts is a vague and unclear statement. It has a very definite formaulation, and predictions concerning welcher weg experiments that has manifestly been ruled out by the experiment. Half baked handwaving as you put itjust won't do for an encyclopedia article. Best regards.-- Prof. Afshar 20:18, 12 July 2006 (UTC)

[edit] Divisor function

Hi Linas. I am impressed with the graphs you have added to the divisor summatory function page. Can I ask how they were produced? One thing, though: my calculations (only done for powers of 10 up to 10^13, admittedly) show that D(x) − xlogx − x(2γ − 1) seems always to be greater than zero!? (I will try to do a more detailed set of calcs). Madmath789 17:46, 13 July 2006 (UTC)

I have a low-brow, brute force divisor function. Works great up to about 10^8 and then takes overwhelming cpu time. By contrast -- how are you computing D(x) for x=10^13? are you actually computing the integral? linas 18:57, 13 July 2006 (UTC)
I used a simple program in 'pari' which essentially counts the number of lattice points below the hyperbola xy=n, and does a bit of 'cleverness' by counting the points in the area bounded by 1<=x<=sqrt(n) and the hyperbola, then doubling it, and then subtracting the points counted twice [they are the points in the square 1<=x<=sqrt(n), 1<=y<=sqrt(n)]. It takes a few seconds to calculate D(10^13) :-) I could explain much more easily with a quick sketch! Madmath789 22:30, 13 July 2006 (UTC)
Dohh. Of course. Yes, that's a fast way of getting a single value. To make the graphs, I'm actually testing *all* the values, and at the moment, brute-force seems to be the fastest because its incremental. Im trying to put together a graph going up to 10^10, which will run overnight. linas 00:22, 14 July 2006 (UTC)
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