Talk:Introduction to Dirac's constant

Merge this page to somewhere?
I know this text used to be part of the Introduction to quantum mechanics page, but rather than create a separate page for it, would it perhaps be better to say anything from it that needs to be said on that page, add anything important to the Planck constant page, and then delete this page? (Rather than add links to this page into various other QM-related pages!) In no particular order, some reasons are:
 * Dirac constant is just a redirect to Planck constant (which is as it should be - they're not separate concepts). It seems silly to have an "Introduction to X" when we don't want to have "X".
 * It's good to have an "Intro to QM" article, but this is far enough - having a whole load of "Intro to QM subtopics" articles seems to be giving up on the idea that WP articles should be accessible to non-specialists.
 * Most of the content is unnecessary in an intro article (and seems to be more of an intro to radians). In an "Intro to QM" article, all we need to say is that h often appeared in equations in the form (h/2pi), and the hbar notation was introduced for convenience.

Djr32 (talk) 20:31, 24 August 2009 (UTC)


 * As far as I am concerned it can be deleted. I never saw the need for it myself, but other people put it in and nobody else suggested deleting the material so I thought perhaps I held a minority position.P0M (talk) 21:07, 24 August 2009 (UTC)


 * I'm putting this up for deletion. It is not like Planck constant is such a complicated subject that the main article on it can be written in such a way that it is accessible to any body that is remotely likely to be interesseted in it in the first place. (TimothyRias (talk) 12:57, 26 August 2009 (UTC))

Un-indenting.

Djr32 said: "Having a whole load of "Intro to QM subtopics" articles seems to be giving up on the idea that WP articles should be accessible to non-specialists." I don't know the history of "the idea," but if anybody had thought about it in detail they would have seen that there are some "contradictions" implicit in it and some other restraints. Articles are limited, theoretically, to 32k. Sometimes with the best intentions people have been unable to do justice to an issue within that limit, and originally the size 32k was probably chosen because of the limitations of the computers and the browsers of the day. (I tried to edit one long article and had to switch from my old Mac to my new IBM because the Mac got all choked up.) The idea that an article should be compact, and that side issues be handled in linked articles is still valid.

The present Dirac equation article is 37k. It starts with a hairy equation and, if you click down electronic "page" by "page", you go to the last two out of three "pages" before you hit anything that could be called even readable by non-specialists. Whether non-specialists could read with comprehension is another issue.

I do not advocate rewriting the Dirac equation article so that people with no more than a high school math background could read it. If anybody were successful in becoming the arbiter of such issues and decreed that the article in its present form be scrapped and replaced with a dumbed-down version, then there would hardly be a (non-Intro) physics article that would escape the same fate.

If one were to try to add popularization buffers to the present version so that a reader with high school math could read the buffers and skip the heavy math, then the size of the article would probably double. The advanced readers would end up skipping the popularization stuff, and the not-advanced readers would have to skip the advanced stuff.

Dirac himself wrote a couple of books and what I have been able to see on Google books indicates to me that he was very well able to write about his take on quantum physics in plain English, give the truth, and not mislead readers. But he did not inject heavy math. At the same time when he is writing for the physics community, e.g., in articles reproduced as chapters 14 and 17 of B. L. van der Waerden's Sources of Quantum Mechanics, he does not both to explain the obvious or wade slowly into the heavy math.P0M (talk) 17:27, 29 August 2009 (UTC)


 * Patrick - I absolutely agree with you about the undesirability of re-writing the Dirac equation article! The first paragraph tries to give an overview for the general reader of what the Dirac equation is all about.  A skilled writer who really understands this stuff (= not me!) could expand this into an accessible introductory section to the article, followed by the current maths-heavy discussion.  If the article really got too long it might then be necessary to split out a separate intro article. (According to WP:SIZE the dividing line these days is 40-60 kB.  In reality, I can't see this ever happening for the Dirac equation - it's just too specialised!)


 * Perhaps a better way of putting my view is that I'm in favour of "Intro to X" being spun out of "X" once the "X" article gets too long, but I don't think that creating "Intro to X" to shorten "Intro to Y" is such a good idea. Djr32 (talk) 13:54, 31 August 2009 (UTC)

Performing the merge
The AfD discussion seems to be converging on either merge-and-redirect or merge-then-delete. I've added some more discussion of hbar to the Planck constant article. In my view, that's the merge done, and the article can now be redirected or deleted as soon as the AfD closes. If anyone thinks that anything more from this article should be rescued and put somewhere else, please go ahead and do so. Djr32 (talk) 13:32, 31 August 2009 (UTC)


 * Done. Djr32 (talk) 10:44, 5 September 2009 (UTC)