Talk:Active and passive transformation

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Introduction[edit]

This article should be change, because the introductory sentence: "In the physical sciences, an active transformation is one which actually changes the physical state of a system and makes sense even in the absence of a coordinate system... ." is not clear. If author means "transformation" of coordinate system in physica (which seems likely from his text below)it's not correct. The change of coordinate systems never change the "physical state". If he means "change" of physical system, it should be expain in details (thermodynamics? mechanics?), otherwise it looks completely unclear. There is no any physical example.

Covariance and contravariance[edit]

Is this an accurate statement?: "Under active transformation, the components of vectors transform covariantly when the same basis is used. Under passive transformation, the basis transforms covariantly and so the components of vectors transform contravariantly so the vectors remain unchanged." —Ben FrantzDale 13:55, 11 May 2007 (UTC)

It seems that a mention (if not a brief discussion) of covariance and contravariance would fit in very well in this article. I don't understand them well enough to do so.All Clues Key (talk) 05:39, 3 September 2012 (UTC)

Alias and alibi transformations[edit]

Mathworld's article on Transformation uses "alias" for passive and "alibi" for active. Our own article on Rotation matrix also uses those same terms. Which terminology should Wikipedia standardise on? -- Cheers, Steelpillow (Talk) 15:44, 21 March 2010 (UTC)

I believe that active and passive transformation is much easier to interpret and remember. Alias and alibi are uncommon words, that I cannot easily remember. The origin of this weird terminology (that was apparently used in Berkley in the 50's) is in my opinion difficult to grasp, which makes its meaning difficult to remember. See AliasAlibi on MathPhys. Paolo.dL (talk) 08:57, 5 May 2013 (UTC)

Robotics[edit]

The current boom in robotics recalls many of the developments in algebraic kinematics in the 19th and 20th centuries. Many terms were developed and concepts of motion described. Active transformations were called alibi transformations, connoting a change of place. Passive transformations were called alias transformations, connoting a change of name. But in robotics one must remember that there are frames of reference for laboratory as well as the robot, and the use of referential terms like active and passive soon lose clarity. In geometry, the notion of an abstract motion that generates congruence became useful. Are there contributors to the project here that can build this article into an enduring reference? It looks like a job for an army.Rgdboer (talk) 19:37, 15 October 2010 (UTC)

Reqdiagram tag removed[edit]

Reqdiagram tag added in 2007, lead diagram in article added in 2009; Reqdiagram appears satisfied. Egmason (talk) 07:58, 25 January 2011 (UTC)

Notation??[edit]

Meaning of the 'a','b' and 'c' sub- and super-scripts in the Passive Transformation section are unclear, at least to me. Do they refer to different bases? Do they refer to dimensions (as in the Example section)? How does a superscript differ from a subscript? In general, notations in various Wikipedia articles are often inconsistent (unsurprisingly), so it would be kind of the author to explain conventions beyond the most basic and universal ones learned in High School or early College. Gkoulomz (talk) 16:53, 18 January 2013 (UTC)