Talk:List of elementary physics formulae

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Articles for deletion This article was nominated for deletion on 25 January 2007. The result of the discussion was no consensus.

Contents

[edit] Needs context

This article needs lots of context (annotations of what the equations mean, or at least explanations of the symbols, etc.). More importantly, it needs an explanation of what this page itself is—hopefully something more than a fairly unfocused/indiscriminate list. I'll hold off pushing for deletion, but not for long. DMacks 03:11, 25 January 2007 (UTC)

Oops, looks like people aren't willing to wait. DMacks 03:23, 25 January 2007 (UTC)

[edit] improve?

I'm working on it. Please help! --N Shar 04:11, 25 January 2007 (UTC)

  • Gotta sign off for tonight soon. I'll be back, though. --N Shar 04:48, 25 January 2007 (UTC)

[edit] Thoughts

I'm not going to be much help on this page, but I do support keeping it. Do note that you have number of thigs to do here. One is to set a scope for it: This list should be for important equations. You should also be amenable to the concept of lists being created for the various subdisciplines to hold less signoficant equations.

You will also need to be open to the ideas of changing the name as well as determining which pages this should be referenced from (such as physics and classical mechanics). --EMS | Talk 19:28, 25 January 2007 (UTC)

Ok, let's start brainstorming then. Any ideas on what exactly is an "important" equation? enochlau (talk) 01:50, 26 January 2007 (UTC)
Here are some suggestions:
  • Formulae should be as general as possible. Example: "a = \frac{d^2x}{dt^2}", not "a = \frac{2x}{t^2} (constant acceleration)."
  • Formulae should not overlap with others on the page. Example: don't include both "v = \frac{dx}{dt}" and "x = \int_{t_i}^{t_f} v(t)\,dt."
  • Formulae should not be obvious from the definition of non-physical quantities. Example: don't include "v_{avg} = \frac{1}{t_f - t_i}{\int_{t_i}^{t_f}v(t)\,dt}", which follows directly from the definition of the average of a function.
  • As a "notability guideline" for formulas, let's say that multiple textbooks must list them in sections of "key formulas" or something like that. I'm a little concerned that this might be too expansive a definition of notability, but here's an example. A copy of Giancoli's Physics (5th ed), which is unfortunately algebra-only, lists the following formulae in the "Summary" of the rotational motion chapter:
  • (1) \omega = \frac{\Delta \theta}{\Delta t}
  • (2) \alpha = \frac{\Delta \omega}{\Delta t}
  • (3) v = r\omega\,
  • (4) a_{tan} = r\alpha\,
  • (5) a_{rad} = \omega^2r\,
  • (6) \omega = \omega_0 + \alpha t\, (constant acceleration)
  • (7) \theta = \omega_0 t + \frac{1}{2}\alpha t^2 constant acceleration)
  • (8) \omega^2 = \omega_0^2 + 2\alpha \theta (constant acceleration)
  • (9) \omega_{avg} = \frac{\omega + \omega_0}{2}\, (constant acceleration)
  • (10) \sum \tau = I\alpha
  • (11) KE = \frac{1}{2}Mv^2_{CM} + \frac{1}{2}I_{CM}\omega^2
  • (12) L = I\omega\,
  • (13) \sum \tau = {\Delta L \over \Delta t}
Fortunately, we can narrow this down a bit. Numbers (1), (2), and (13) should be calculified. Each of (3) and (4) can be deduced from the other, so one could be eliminated. Formulae (6) through (9) are not general, because they require constant acceleration. We should calculify and consolidate them. Number (11) conflicts with a formula from linear mechanics; since (11) is more general, the other formula should be removed or replaced with a link to (11). Finally, number (13) is just a restatement of (10) and (12).


Opinions? --N Shar 06:41, 26 January 2007 (UTC)
I would caution some care here, as you all treading on unstable ground. It seems that previous attempts to create a page like this have gotten deleted fairly quickly, but I will assume that they were nowhere near as organized and comprehensive as this article is. With the above list of formulae for rotational motion, you are threatening to make that section way to cumbersome. I would strongly advise restricting that section to the attributes of constant angular momentum. (The full sub-list could be a topic in its own right in theory.) Beyond that, I advise
  • Giving each section a short introduction (1 - 3 sentences) introduction.
  • Providing references to textbooks and handbooks that contain these formulae.
  • Adding material on electronics and possibly electromagnetism.
  • Only accept as sections subfields of physics which as considered to be important to theoretical physics.
  • Restrict the contents of each section to the most important equations for each acceptable subfield.
  • At some point either change the name to include "classical" or include equations from relativity and quantum mechanics.
I do wish you all well with this project. Please realize that you all are going to need keep this article "ahead of the curve" so to speak. If it stagnates in its current state, it will be deleted. In fact I can almost guarentee you all another deletion attempt within the next year, and I will not guarentee even my own support for this article at that time. Yet you all have done well so far, and I encourage you all to keep up the good work. --EMS | Talk 03:55, 28 January 2007 (UTC)

[edit] Why delete ?

I would like to understand why this article is to be deleted ? --npettiaux 20:42, 28 January 2007 (UTC)

[edit] Re: move

I support the move. It resolves some of the issues from the AfD. I imagine that some people will not support it, so I've started this thread for discussion just in case. --N Shar 07:29, 5 February 2007 (UTC)

  • Support - The new name is not my first choice, but it works nicely. --EMS | Talk 16:58, 7 February 2007 (UTC)