User talk:Kiwiderpia

Edits to Wigner D-matrix
You reverted my original reversion in the connection of D-rotation matrices and spherical harmonics. Had you first brought it up in the talk page of the article, you could have been reminded that since the spherical harmonic does not depend on γ, its value is superfluous and can be set equal to 0, or anything else. All you needed see was the original exp(-imγ) further up the article. Citing chapter and verse on the correctness of keeping a variable and only then multiply it by zero is evidently not a service to the reader. Still, if you are trapped in the "I'm right" mode, I'm not sure the issue is worth discussing. As a concession, I am including the note here and not on the article's talk page that you ought to have addressed first. Cuzkatzimhut (talk) 22:25, 14 February 2018 (UTC)

Well all that was obvious, even though maybe not to you at first? Setting an irrelevant parameter to zero completely misses the point of this equation, and will mislead the future readers. So I just want to make sure that this is correct, and somehow hurt your feeling? Remember you're the first who revert before going to the talk page? kiwi (talk) 23:08, 14 February 2018 (UTC)


 * Trading specious charges does not reassure me you understand the system. Reversion to the status quo ante needs no discussion. Proposing a change does. Any literate reader can see the point above. That is the very reason I invited you to appreciate the triviality. It is customary to supplant the simplest value of the variable to be multiplied by 0, in this case, 0. Reflecting chastisements in "not me, you!"-style is not conducive to salutary cooperative interactions. Cuzkatzimhut (talk) 23:19, 14 February 2018 (UTC)

I doesn't understand the system indeed. To me it's just a typo to correct. But also your statement reassures me that you do not understand symmetry, in particular rotation invariance behind the said equation. kiwi (talk) 23:26, 14 February 2018 (UTC)


 * $$ D^{\ell}_{m 0}(\alpha,\beta,\gamma) =D^{\ell}_{m 0}(\alpha,\beta,0) $$. Facts are facts. You are not making any reader a favor by complicating them. For vanishing trailing m, γ has no meaning. Think about it. Cuzkatzimhut (talk) 13:24, 15 February 2018 (UTC)


 * Your equation is not wrong, but worse. By doing so, you are at best narrowing the applicability of the identity, and at worst mislead the reader to think that it's only true when $$ \gamma = 0 $$. Any other uncommon value would be more informative to this equation than zero, and make a reader realize that in this case the Wigner D is symmetric about the third Euler angle. All of this can be simply captured by a symbolic gamma. Now I am concerned that behavior like yours will prevent many technical wiki articles to be improved by experts who can contribute but lacks time for pointless argument like this. Anyway, hope life will treat you better.

kiwi (talk) 17:46, 15 February 2018 (UTC)