Talk:Sign convention

message: Perhaps some new theore which 'might' bring some order to different usant in discerning of one theory's correctness?.. --XJamRastafire 02:05, 26 Aug 2003 (UTC)
thread_title: Untitled

message: Don't even think about using +--- in a WP article! :-/  ---CH 02:09, 25 May 2006 (UTC)
thread_title:  Anecdote 

message: I'm not convinced that it's necessary to include the (fairly long) story about Einstein, Veblen and the sign convention. Surely the story could be summarised in a few sentences while giving a weblink or some other ref. to the actual story. MP   (talk) 06:52, 27 June 2007 (UTC)
replies: text: Agreed. I've deleted it.--Fashionslide (talk) 01:29, 10 November 2012 (UTC)

text: The anecdote could be summarized and supported with a reference citing the source. The source is the transcript of an extended interview with "James Wallace Givens, Abraham H. Taub, and Angus E. Taylor (also with Leon Henkin and Albert Tucker)" collected by the Princeton Oral History Project. --50.39.99.121 (talk) 20:59, 2 April 2022 (UTC)
thread_title: Story

message: The contraction of the Riemann Tensor is wrong for R_{ab} \, = R^c{}_{cab}, since this yields zero due to the anti-symmetry of the Riemann tensor.  I'm changing it to R_{ab} \, = R^c{}_{abc} to be correct.  Koroll (talk) 15:51, 10 June 2008 (UTC)
thread_title: Curvature

message: Does a defining of the "positive" directions of forces and moments, in a section of a beam (like the convention mentioned in the Shear and moment diagrams article), relates to this article? 21:01, 16 December 2008 (UTC)
replies: text: Yes, it does. Feel free to add this to the article. MP (talk•contribs) 21:11, 16 December 2008 (UTC)
thread_title:  s.c. in statics and mechanics of materials 

message: This edit seems to be wrong; at least it makes no sense to me. However, as a layman, I hesitate to undo it. --Florian Blaschke (talk) 23:52, 29 June 2011 (UTC)
replies: text: It is in fact accurate, allthough this is the same as -+++. Check Gravitation and cosmology, Weinberg 1972, p 26. It is also correct that it really doesn't make sense to put the 0th index after 1, 2, 3, but that is how he does it: "In our notation, \alpha, \beta, \gamma will always run over the four values 1, 2, 3, 0 [...]". 83.254.85.135 (talk) 16:23, 23 January 2012 (UTC)
thread_title:  Dubious edit 

message: As an amateur, I don't want to add this without getting some other opinions, but it seems to me that there is a straightforward link to classification of Clifford algebras: (-+++) corresponds to a 4x4 matrix of real numbers, while (+---) corresponds to a 2x2 matrix of quaternions, as can be seen by checking row 4, columns 2 and -2 of the table on that page. (Interestingly the direct product of two copies of either form results in an algebra corresponding to an 8x8 matrix of quaternions, rather than the other form of 8-D algebra which is a 16x16 matrix of reals. If one is going to end up working with quaternions anyway in multi-particle systems, then perhaps the (+---) form is preferable.)Enon (talk) 20:50, 1 July 2012 (UTC)
replies: text: There is some related discussion here although I would say that there is no consensus on which is better (or even if one is better, most treat as the same)Selfstudier (talk) 11:25, 12 July 2012 (UTC)
thread_title:  Classification of Clifford algebras / matrix forms 

message: Should something be said about active vs. passive rotations, in the context of Euler angles for instance?  —Quantling (talk | contribs) 00:07, 10 February 2023 (UTC)
replies: text: There is an article on Active and passive transformations, and it doesn't say anything about signs. --50.39.102.0 (talk) 16:04, 10 July 2023 (UTC)
thread_title:  Active vs. passive transformations (such as rotations) 

message: Astronomy uses a left-hand coordinate system in some cases whereas right-hand coordinate systems are normal most everywhere else.  Is this relevant to sign conventions? —Quantling (talk | contribs) 00:15, 26 June 2023 (UTC)
replies: text: The See also section has a link to Orientation (vector space), which describes the relevant terminology. --50.47.152.192 (talk) 04:12, 28 June 2023 (UTC)
thread_title:  Right-hand vs. Left-hand coordinates