User talk:Sbyrnes321/Archives/2010

Thank you for the pseudovector diagram!

I wanted to thank you for this edit. I had complained on the discussion page for that article about how confusing the text was about pseudovectors, but that diagram makes it immediately clear. I already understood the right-hand rule, but for some reason it didn't click that a mirror image would flip the orientation like that until I saw your picture. Then it became obvious. I learned something new, and the article is much better now! CosineKitty (talk) 16:01, 8 January 2010 (UTC)

You're welcome! Thanks for the compliment, and happy to have helped! :-) --Steve (talk) 18:21, 8 January 2010 (UTC)

Hi, just to let you know: I fixed the problems in the File:BIsAPseudovector.svg. So, if you feel like it, you can nominate the PNG version for deletion. And while I'm here: thanks for this nice little diagram. :) —Quibik (talk) 00:00, 9 January 2010 (UTC)

Thanks! Would you mind telling me what I was doing wrong? I know about the cropping and the stretched letters, but how did you get the text to display? --Steve (talk) 00:09, 9 January 2010 (UTC)

For some reason, instead of using the <text> tags for the letters, <FlowRoot> and the like were used. I have no idea where these could come from – I saw them for the first time, especially in an Inkscape file. I cleaned up that mess by hand in the source code. Another noteworthy change: I merged the arrowheads with the "shafts". Otherwise my browser, Inkscape and Adobe Illustrator would all display the image a bit differently (flipped heads, etc.). Also, as a suggestion, I recommend using the most basic "sans-serif" and "serif" fonts, as others often have problems displaying properly on Wikipedia. —Quibik (talk) 00:47, 9 January 2010 (UTC)

the change relating the derivative of the momentum/position operator

$\langle p|{\hat {x}}|p'\rangle =i\hbar {d \over dp}\delta (p-p')$

$\langle x|{\hat {p}}|x'\rangle =-i\hbar {d \over dx}\delta (x-x')$

I dont agree with this. I just referred to the R. Shankar book on quantum mechanics. The basic postulates in Chapter 4 just has the dirac function but no the differntial of the dirac function. The momentum operator as a form in the position basis should just give the dirac function multiplied by the constant. —Preceding unsigned comment added by 65.209.127.195 (talk) 22:09, 14 January 2010 (UTC)

Start with the equation [1]

$\langle x|{\hat {p}}=-i\hbar {d \over dx}\langle x|$

OK, now take the inner product of both sides with $|x'\rangle$

$\langle x|{\hat {p}}|x'\rangle =-i\hbar {d \over dx}\langle x|x'\rangle$

Now the right-hand-side can be simplified by orthonormality of the position basis vectors:

$\langle x|{\hat {p}}|x'\rangle =-i\hbar {d \over dx}\delta (x-x')$

OK, that's my "positive argument" of why it is the expression I think it is. (It would be better to have a direct citation for the equation of course, I will look for one when I get a chance.) Next, I'll give a "negative argument" for why it isn't the expression that you believe, i.e.

$\langle x|{\hat {p}}|x'\rangle =-i\hbar \delta (x-x')$ (I claim this is false.)

Let's compare this equation to an equation related to the identity operator "${\hat {1}}$", defined by ${\hat {1}}|\psi \rangle =|\psi \rangle$ for all $\psi$:

$\langle x|{\hat {1}}|x'\rangle =\langle x|x'\rangle =\delta (x-x')$

If your equation were also true, it would follow mathematically that

${\hat {p}}=-i\hbar {\hat {1}}$

Therefore, if your equation is true, the momentum operator would be a trivial operator that just multiplies every wavefunction by $-i\hbar$...which we know is not the case.

One more thing, maybe a bit simpler. You can view the ket $|x\rangle$ as a wavefunction, in which case it is a delta-function wavefunction. See the article wavefunction for the relation between a wavefunction (complex-valued function of space) and its representation as a ket in a position basis. Anyway, then p is proportional to the derivative operator acting on the wavefunction, so you end up with the derivative of a delta function.

All this could and should be explained better in the article. I've started to write a more thorough explanation but haven't finished yet. :-)

Does this make sense? --Steve (talk) 22:30, 14 January 2010 (UTC)

Wiki punctutation style

> I just want to point out that it's not always correct to put punctuation inside quotation marks on wikipedia... See WP:TQ.

So Wikipedia doesn't follow standard (well, what was standard) English (American English?) punctuation rules that periods and comma go inside regardless (while semicolons, question marks, etc., do depend on whether they're from the quoted material vs. the quoting statement)?

(Also, do you know if common (American) English style guides still recommend the traditional form (or now recommend placing periods and commas the same way as other punctuation?)

216.1.16.126 (talk) 19:25, 15 January 2010 (UTC)

I don't know what the standard is, I only know about the wikipedia style. Sorry. --Steve (talk) 21:31, 15 January 2010 (UTC)

Magnetic Monopole

Hi Steve,

I've yesterday fixed a broken link which was removed quite a while back (Jan 15, 2007) by User:Yevgeny_Kats. I think the linked work is relevant, verifiable (the underlined work was published in scientific journals - see references 3,4,5 in the paper) and notable for its fresh view of the subject matter (which is probably the reason why it was included in the EL section in the first place). If you agree, then please re-instate the link.

Thanks, Mita. —Preceding unsigned comment added by Mitalapo (talk • contribs) 14:00, 20 January 2010 (UTC)

Hello. I guess my problem is that the paper is extremely controversial, even "fringe". Professional particle physicists agree almost unanimously that QCD is the correct theory of quark interactions, and that QCD should not be replaced by a theory based on magnetic monopoles. Do you agree with this? If we link to a paper like that, a reader will click the link and assume that it's a mainstream point-of-view, which would be deceptive!

If this theory is included in the article, it would need to be in the article itself, with discussion that makes it clear that it is a widely-dismissed fringe theory. I don't know whether it should be discussed in the article itself like that, or whether it should be ignored entirely. So far I've seen four papers all by the same person. For it to be in the article, it would have to satisfy WP:NOTE, for example it should be mentioned in mainstream textbooks or newspaper articles.

I'm not saying the theory is wrong, I haven't read it in detail. Many but not all fringe theories are wrong! Some things are true but should still not be included in wikipedia, see WP:V. --Steve (talk) 19:46, 20 January 2010 (UTC)

half-life graphic

Cool gif, but I have a suggestion: Following KISS, can you change the top four boxes (few atoms) to the left four boxes and leave some space between it and the right (many atoms)? A timer over each would also emphasize that both are undergoing decay, but with different starting conditions. Finally, a half-second or so long pause at 0.0 would allow viewers to quickly see the starting conditions, rather than watch it several times to figure it out. Good work, thanks!

Mnnlaxer (talk) 18:12, 3 February 2010 (UTC)

Those are all good suggestions, I hope to get to it this weekend. --Steve (talk) 19:13, 3 February 2010 (UTC)

Done. Definitely better now, but is there further room for improvement? Let me know your thoughts. Thanks again! :-) --Steve (talk) 06:54, 5 February 2010 (UTC)

Benford links

Hi there.

I saw you partially reverted my removal of the WP:LINKFARM at Benford's Law, and I wanted to make it clear why I pulled the links that you put back up. There's a note on the talk page. Let me know what you think.

Thanks. — Bdb484 (talk) 21:16, 4 February 2010 (UTC)

Thank you for letting me know! I haven't written anything on the talk page because other people have said it first. :-) --Steve (talk) 07:47, 5 February 2010 (UTC)

Software

Hi! Unsure how often you check this page. I never check mine! I was wondering what software you used to generate the image used in the article Euler's Identity. Zaglabarg (talk) 18:42, 25 February 2010 (UTC)

Mathematica. I'm happy to send you the source code if you're interested. :-) --Steve (talk) 16:56, 26 February 2010 (UTC)

I was just curious, and it would have been fun to run the code myself, but I don't have Mathematica, just Matlab, Maple and R. ;) I suppose it would be too time consuming to rewrite the code for one of them. Thanks for answering! Zaglabarg (talk) 00:51, 4 March 2010 (UTC)

OK. If you do ever feel inspired, there's plenty of room for improvement, as was pointed out in this comment: "I'm thinking the animation can be avoided by showing many iterations at once, and a still image could be an svg, which looks smoother. The axes could be less busy, the "N =" could be better incorporated spatially, and color could be exploited a little more. Melchoir (talk) 16:34, 6 May 2008 (UTC)" :-) --Steve (talk) 02:23, 4 March 2010 (UTC)

Picture Nomination

Hi, See Wikipedia:FPC#Magnetic_Field_is_a_Pseudovector. File:DiffusionMicroMacro.gif and File:ExpIPi.gif are probably worth nominating too. Noodle snacks (talk) 02:49, 7 March 2010 (UTC)

Well shucks, thanks, I'm flattered!!! :-)

I'm glad you like those animations too, although in my opinion the pedagogy for those is great and the aesthetics is not so great. (I'm happy for you to disagree!) In fact, coincidentally, if you look just at the previous conversation on this page, I pasted someone's quote with 5 ways to make ExpIPi.gif more aesthetic. :-P Again, you're more than welcome to disagree. --Steve (talk) 03:51, 7 March 2010 (UTC)

I made a few relatively minor changes to the image to satisfy a little nitpicking. In my opinion the educational value of an image is more important than aesthetics anyway (since the latter depends on the viewer). In the diffusion image I noticed "If you'd like the Mathematica source code, I'm happy to email it to you". It might be sensible to just include the source at the bottom of the image page. It is fairly commonplace with graphs already (eg File:Cauchy pdf.svg). Noodle snacks (talk) 04:37, 8 March 2010 (UTC)

Thanks! Mathematica code isn't inputted as plain text so I originally didn't think of directly posting it, but it turned out that translating to plain text wasn't too hard. I did a couple, I'll do my others when I get a chance, and do that routinely if I make other programmed images in the future. I'm very happy for that idea, thanks! :-) --Steve (talk) 20:33, 8 March 2010 (UTC)

merge

keep it separate, just link it as it different enough to warrant it —Preceding unsigned comment added by 70.70.159.247 (talk) 02:10, 30 March 2010 (UTC)

I'm sorry but I don't know what you're talking about. --Steve (talk) 06:07, 30 March 2010 (UTC)

You are now a Reviewer

Hello. Your account has been granted the "reviewer" userright, allowing you to review other users' edits on certain flagged pages. Pending changes, also known as flagged protection, is currently undergoing a two-month trial scheduled to end 15 August 2010.

Reviewers can review edits made by users who are not autoconfirmed to articles placed under pending changes. Pending changes is applied to only a small number of articles, similarly to how semi-protection is applied but in a more controlled way for the trial. The list of articles with pending changes awaiting review is located at Special:OldReviewedPages.

When reviewing, edits should be accepted if they are not obvious vandalism or BLP violations, and not clearly problematic in light of the reason given for protection (see Wikipedia:Reviewing process). More detailed documentation and guidelines can be found here.

If you do not want this userright, you may ask any administrator to remove it for you at any time. Courcelles (talk) 18:34, 19 June 2010 (UTC)

Activity coefficient

This is a very pretty animation, but I don't see how it relates to activity coefficients. What is the source of the idea?

You might like to look at SIT theory and Pitzer equation to see how things have moved on since Debye-Hueckel and extensions like Davies equation and Bromley equation. Im going to be away for a couple of weeks, but I'll return to the discassion when I get back. Petergans (talk) 22:22, 12 July 2010 (UTC)

Hello! Let me explain my idea, hopefully more clearly.

Start with water with very-dilute ions. Adding a lot of salt to the water decreases the chemical potential of other ion species in the water, even without changing the concentration of those other species. The reason is that the salt stabilizes the charges with a cloud of counter-ions. Because of this extra stabilizing effect of salt, the concentration of an ion alone is not enough information to say what its chemical potential is. This is an activity coefficient effect: The chemical potential of a species is not just proportional to log concentration, but also related to the ionic strength. This is described by Debye-Hueckel theory. Of course it's described more accurately by other theories. But I don't see how that matters. The qualitative idea of Debye-Hueckel theory is not wrong. The theory leaves out other things, but it still captures a correct and important qualitative idea, and that's the idea I'm trying to convey.

I agree, activity is a function of ionic strength

I can't convey a chemical potential on its own...only relative chemical potentials are physical. So I had to show some process that is affected by altering the activity coefficients by adding salt. One thing is, the higher the charge, the more important this stabilizing effect is. Therefore, in a reaction like A^- + A^- <--> A₂^2-, the right side will get stabilized more than the left side: Adding salt will shift the equilibrium to the right. The equilibrium constant doesn't change when you add the salt, but the activity coefficients do change. Therefore the shifting of the equilibrium is an activity coefficient effect. (Right?)

No. Strictly speaking an equilibrium constant is a quotient of (dimensionless) activities, so it does change when the activity coefficient quotient changes. Look at what I wrote in equilibrium chemistry for the thermodynamics.

But, I wasn't quite sure how to clearly depict equilibrium concentrations, although maybe it's possible. Instead I opted to show that the reaction enthalpy gets smaller, which to me makes it clear that the equilibrium will shift right. Maybe it's not clear to others.

Please let me know what you think. Maybe I'm really confused, and even if I'm not, I'm sure it's possible to make it clearer by changing the image and/or description.

Thanks! :-) --Steve (talk) 23:06, 12 July 2010 (UTC)

Three points: 1) the reaction you postulate is chemically unreasonable. I don't know of any such reaction in solution. 2) The point about looking at SIT theory and Pitzer parameters is that the effect of extraneous ions becomes specific for the ions concerned, while DH theory is non-specific. 3) The equilibrium constant is related to the standard free energy change, not just the enthalpy change. Changing the ionic medium has a non-zero effect on the standard entropy change.

I was hoping that you could cite a publication from which you obtained this idea. Otherwise it is not verifiable, which is a primary requirement on Wikipedia.Petergans (talk) 17:56, 14 July 2010 (UTC)

Hello! Thanks again for helping me with this!

I was hoping that the animation would be simple textbook chemistry, so universally clear and accepted that I don't need a source that uses the exact same example. But I was wrong! I took the animations down for now. :-)

I opened a discussion at Wikipedia talk:WikiProject Chemistry asking for advice, please provide input! :-) --Steve (talk) 20:01, 14 July 2010 (UTC)

Unit Infobox

Hi Steve, why do you think the unit infobox in elementary charge is misplaced? Since the elementary charge is not only a fundamental constant but also a unit in some systems of units it certainly deserves this infobox. See here at NIST: [2] and at BIPM: [3]

Kehrli (talk) 07:10, 25 October 2010 (UTC)

Hello! Someone says "I want to talk to you about the elementary charge. Please tell me, what is its 'standard'?". I would say "what are you talking about?". They say "Please tell me, what is its 'quantity'?". I would say, "1.6E-19 coulombs". I would not say "electric charge". They say "Please tell me, what is its 'expressed in'?" I would again say "what are you talking about?". I would not say "1 e =". All these are thoughts that passed through my head when I first saw the box, and they will pass through other readers' heads too. What I'm saying is, this box is confusing if not incomprehensible in this article. People think of the elementary charge as first and foremost a physical constant, and only secondarily as a unit. Using a units infobox leads to confusion because the categories are named and chosen as if it were primarily a unit -- for example, "quantity". And who cares about statcoulombs anyway? Isn't it good enough to say the statcoulombs value in the fifth sentence of the article? It doesn't make sense to give such prominence to an obscure factoid like what is the value of the elementary charge in statcoulombs. This is a classic Disinfobox, adding much more confusion than clarity, emphasizing obscure trivia but skipping important information! I replaced it with one that was an easy-to-understand summary of the most important facts. Do you see what I mean? :-) --Steve (talk) 18:34, 25 October 2010 (UTC)

Also responded at Talk:Elementary charge/Archive 1#infobox. :-) --Steve (talk) 22:03, 25 October 2010 (UTC)

Also opened a discussion at Template talk:Infobox unit. :-) --Steve (talk) 02:32, 26 October 2010 (UTC)

Steve, I completely agree with you. It also took me some time to figure out what all the meanings are. You have my support with your improved version of a standard infobox. Kehrli (talk) 19:55, 26 October 2010 (UTC)

g factor

Hi, I created a disambig page for g factor. I have little idea what the physics term means, so could you take a look at it?--Victor Chmara (talk) 22:57, 28 October 2010 (UTC)

Thanks for letting me know!! :-) --Steve (talk) 03:01, 29 October 2010 (UTC)

I need your help

Steve, you seem like a reasonable and smart guy. This is why I ask for your help. I am stalked by two Chemists that unfortunately have no clue about metrology. As you know, I try to make sure that articles are written in correct metrological terminology. Now they are planing to ban me again (see here User_talk:Kkmurray/1). I hope you are one of those people that can see that his article Kendrick mass is full of incorrect language (even though it is all taken from reviewed papers) and that my article Kendrick (unit) is better.

Here you find the whole story of the current argument: Talk:Kendrick_mass.

We had an argument before on which he achieved to have me banned for one year. I still think this ban was incorrect. The argument was about a physical quantity in mass spectrometry, the mass-to-charge ratio. Some in the chemistry branch of mass spectrometry use a "dimensionless" m/z and my claim is that a mass-to-charge ratio by definition cannot be dimensionless and therefore needs a unit and that a symbol m/Q would be more appropriate. I partly won the argument because my article Thomson (unit) is still alive.

The deeper issue on this new argument is that chemists seem not able to make the difference between a quantity Q = n * unit, and the numerical factor n of a quantity. Please check yourself and I would really appreciate your support. --Kehrli (talk) 31 October 2010

Hi Kehrli, It looks like it would take a long time for me to read through all this debate and I am too busy right now. I suggest that you stop editing z/m-related articles that have caused you so much trouble. Instead, look around wikipedia and you will find many other articles that are every bit as important and every bit as flawed as the ones you're spending so much time on, but if you spent time on those other articles they would improve much more quickly and you'll experience much less frustration. You could start here: [4]. I hope you don't take that advice the wrong way. I feel it's good advice even if the current articles are horribly flawed and you already know exactly how to fix them. It's advice I wish someone had given me earlier in my own numerous time-consuming struggles against stupid people. Sorry I can't help more! :-) --Steve (talk) 22:16, 31 October 2010 (UTC)

Hi Steve, my time is also very limited, therefore I try to only edit articles on mass spectrometry where I am an expert. Anyway, I understand your point, too. I might still ask you for your opinion in the arbitration process. Have fun. --Kehrli (talk) 31 October 2010

Style changes on Magnetic Vector Potential

I'm new to this. It appears that you (and if not you I apologize) made some style changes to the math markup on 02 November. The effect was to leave some of the symbols rendered differently in different statements. The stylistic difference in some of the symbols, particularly \phi is so great that I think they could be taken for different symbols. I'm happy to learn a better way of doing things. What do you suggest?Constant314 (talk) 01:49, 7 November 2010 (UTC)

Very nice! I agree, $\phi$ and $\phi \,$ are very very different. A and $\mathbf {A}$ are kind of similar but not great. Good job!

FYI the official policies for this are here but they're not consistently followed, and you should use your best judgment. Let me know if you have any other questions. --Steve (talk) 02:03, 7 November 2010 (UTC)

That was a lot to absorb. I understand that it is desired to "avoid in-line PNG images" and I will try to hold closer to the manual. It is subjective whether a HTLM symbol is too diffent from the Tex symbol, but I'll try to use more of the former and less of the latter. Are you the person who made the changes? I just want to be sure that I contact the person who cared enough to make the changes before I format them again.Constant314 (talk) 14:00, 7 November 2010 (UTC)

Sorry, I didn't expect you to read that whole thing! I haven't.... This "official policy" page is usually used only to settle a dispute where one editor thinks it should be one way, another thinks it should be a different way.

If you think there's a way to improve an article, in big ways or small, you should do it! You don't need to ask permission of the last person. If they think your changes are bad, they might undo your edit (or part of your edit) and discuss it with you on the article talk page. But most of the time if you think an edit is an improvement, then other people will think so too. :-) --Steve (talk) 16:39, 7 November 2010 (UTC)

OK, I think I understand. Thanks. Constant314 (talk) 00:47, 8 November 2010 (UTC)

Animation

Your animation is intriguing. Can you tell me what sw you use and/or point me to a how-to site. Thanks Constant314 (talk) 03:52, 24 November 2010 (UTC)

Made in MS Powerpoint, save the presentation as a GIF (it makes one GIF image for each slide), then animate with Photobie following tutorial. Very fast and easy! --Steve (talk) 08:01, 24 November 2010 (UTC)

ThanksConstant314 (talk) 20:15, 24 November 2010 (UTC)

Do you have an opinion of edits from User:Just granpa to Natural units?

Just curious, I would like to see other editors get involved. 71.169.180.100 (talk) 15:48, 24 November 2010 (UTC)

Magnetic monopoles

you undid my revision concerning magnetic monopoles. Perhaps I put it in the wrong section?

because I did not see any article discussing 'actual' monopoles, and the article explicitly states that only emergent monopoles have been observed.

According to my article, a 'real' monopole was observed. Thea article *DID NOT* address said monopoles.

So, I ask you, why did you remove it? The reason you gave was simply inaccurate. — Preceding unsigned comment added by Zoooooooooaa (talk • contribs) 02:05, 15 December 2010 (UTC)

The article you're talking about is Direct observation of magnetic monopole defects in an artificial spin-ice system. You put it in the correct section, this is an article about magnetic monopole quasiparticles not magnetic monopole elementary particles. You can read the article abstract: "mobile excitations, termed ‘monopole defects’, emerge...". Then in the article they refer to the monopoles as "emergent excitations of the magnetic structure" and "quasi-particles". These are certainly not the elementary particle predicted in particle physics, they are emergent excitations, also called quasiparticles. Moreover, this is the exact same system, spin ice, as discussed in the rest of the section, and the wikipedia article does in fact have a source stating explicitly that the monopoles in spin ice have nothing to do with the elementary particle monopole.

Anyway, the first sentence of the section says "A magnetic monopole particle has never been conclusively observed" (note "particle" here means "elementary particle", the usual sense of the word and the sense used throughout the rest of the article). That sentence is still true today, it is not refuted by your article, and I undid your edit because you changed that sentence to say the opposite. Of course it is a fine article and it could certainly be put back into the section. Do you agree? Does that help? :-) --Steve (talk) 19:11, 15 December 2010 (UTC)