Wikipedia talk:Articles for deletion/Universality and quantum systems

From Talk:Universality and quantum systems:

Review comments
I had left the following comments at Wikipedia talk:Articles for creation/Universality and Quantum Systems; they were ignored. In short: this article should never have gone into mainspace. See below...
 * I'm not thrilled. As currently written, I'd strongly recommand against putting this into article space. The general concept of universaility already has an article here: Universality (dynamical systems) -- the whole field of physics was pioneered by Phil Anderson and Leo Kadenoff and really became hot stuff in the 1980's.  This article has nothing to say about this. Next, the entire middle section about the 'potential hill' is misguided -- first of all, this is a generic homework problem that pretty much every student of quantum is going to have to solve; its not suitable for a WP article. Second of all, its not normallly called 'potential hills' in english; its usually called a square barrier or a square trap, and is studied not just in quantum, but also optics, and is a prototype for tunneling, wave guides, lots of other common apps in scinece and engineering.  This is the wrong place to for this topic to be reviewed. Third of all, it seems to be confusing the concept of scale invariance with universaility: these are related, but not the same: lots of things scale. Scaling does not imply universality, though ... and then there's the mention of  renormalization group, which is related ... but ... is a different thing, again. This article fails to treat the topic correctly. User:Linas (talk) 22:27, 30 November 2013 (UTC)

Basically, its a bunch of confused OR. So I proded the thing. User:Linas (talk) 18:25, 2 December 2013 (UTC)

I agree, for the reasons you give. It should be deleted.  Waleswatcher  ( talk ) 16:05, 4 December 2013 (UTC)


 * The general concept of universality as developed by Kadanoff, Domb, Patashinski, Fisher et al has been discussed in detail on the wiki page for Universality in dynamical systems and does not require a superfluous discussion here. Moreover, on that particular WP, there is only a minor mention of the notion of universality with respect to quantum systems and a fully dedicated page on universality in QM is long overdue. I understand the merit of your observations and have edited to include now that the essential notion of universality is the closely related to the concept of universality studied in detail by Kadanoff and his contemporaries. This particular page discusses the notion of universality as applied to quantum systems specifically and for that reason it would probably do well to rename this page to Universality (Quantum Mechanics). The section on potential hills (or wells/barriers) picks up an extremely familiar problem and applies the notion of universality to it for better understanding. It lays emphasis on the important notion of how all the math behind ideal (perfect Heaviside potentials) potential barriers can actually be intuitively understood as being applicable to physical problems with finite transient distortions at boundaries instead of perfect Dirac-delta discontinuities. I had used the term “potential hill” to contrast it from the overpoweringly familiar idea of a Heaviside function for a potential well or barrier. This has been changed to potential barrier to avoid confusion. It is well known that the potential barrier is studied widely in various domains in physics but by illustrating the notion of universality in quantum mechanics using a problem as familiar as the potential well, I have tried to make it more accessible. I had mentioned that the concept of universality only LINKS to that of renormalization and scaling. Nowhere in the article were these three concepts treated as being one and the same, but I acknowledge the merit of your argument and have made a few changes making it clear that while the notion of universality is indeed closely linked to the concepts of scaling and renormalization, they are NOT one and the same. I have also added a very nice reference that talks extensively on “Scaling, Universality and Renormalization” by Dr. Eugene Stanley. Prashant K (talk) 05:36, 10 December 2013 (UTC)