Talk:Classical central-force problem

equation of Binet and energy of Leibniz

--Guerinsylvie (talk) 18:33, 24 July 2010 (UTC) Good morning, it is the first time I come here, because I compare the item with the french Wikipedia item fr:mouvement à force centrale. Reading the article, I am surprised : in France, we consider that the équation of Binet "integrated" is the theorem of kinetic energy of Leibniz ( 1695) ! So, the two paragraphs are redundants ; they say the same thing (notations discarded )! In fact, the integral for polar angle \phi =f( u )are, of course, the same.

Therefore, I propose modification by simplification. With respects.

Potential energy is denoted by U, and the scalar potential is V (or phi), right?

Although the potential energy is usually denoted by U, many sources use V. The problem is, V is used to denote the potential. Many sources (wolfram.com) define U as potential energy, but then use V as the potential energy in the definition of the Lagrangian, and Hamiltonian, e.g. L=T-V, H=T+V. In fact, I've never seen the Lagrangian defined as L=T-U. It's possible that V is used to represent the potential energy more often than U. If so, the page on potential energy and hundreds of others need to be corrected.

Meanwhile the scalar potential article randomly uses p (the momentum) in it's equations while correctly noting that V and phi are the most common notation.

Currently, several Wikipedia articles use V as BOTH the potential energy and the potential. Something needs to be done. —Preceding unsigned comment added by NOrbeck (talk • contribs) 18:40, 21 August 2010 (UTC)

Needed: a Notational Conventions section

A persistent problem with physics articles on Wikipedia is that they use highly specific notations, but rarely bother to define their terms and meanings. These conventions are inconsistent across articles and are even frequently inconsistent within articles. Even where they are consistent, they are generally undefined within the article, seeming to assume that the reader has at least the pre-knowledge of a physics undergraduate (or more often, that we are already familiar with the conventions of whatever lecture or textbook the formulas have been copied from).

This is unfortunate because the audience for much of the material here is much larger than just Physicists and undergraduate physics students. I myself with degrees in Math/CS can only get through a few formula before I grind to a halt, completely stumped as to what some letter, diacritic or textual formatting is supposed to mean. And unlike textual terms, symbols are almost never cross-linked to an explanatory article.

While the notational footnotes are appreciated, they are not nearly enough. They are tiny superscript links that only appear on the first(?) use of a notation. This is a large article with many independently useful sections so someone jumping into a specific place has no idea that these footnotes exist, nor does going to the Table of Contents help. Finally, as noted in the preceding section here, there are symbols like "U" that are not explained anywhere (that I can find). And I have to confess, I have been to this article several times in the past few months, and I never realized that there were any symbol explanations in the footnotes.

What I think would help is to add a "Notational Conventions" section as the first sub-section under the "Basics" section, move all of the notation footnotes to there instead, and then fill it out with any missing symbols and terms.

RBarryYoung (talk) 13:41, 27 May 2021 (UTC)