Talk:Physics/wip/leadproposal1

Lead Proposal 1
Physics is the science concerned with the discovery and characterization of the universal laws which govern matter, energy, space and time. Physicists formulate these laws as mathematical theories which attempt to model the behaviour of physical systems at some perceived fundamental level. The aim, however, is to go beyond describing physical phenomena, and to construct theories that can also predict how a physical system will behave. These predictions can then be tested experimentally to verify or falsify the theory.

Some theories are of such significance that they are referred to as the laws of physics. Typically, these are physical principles that are believed to be common to all physical systems, or at least are of very general applicability. Some principles, such as Newton's laws of motion, are still generally called "laws" even though they are now known not to be of such universal applicability as was once thought. The word 'law' is a misnomer since even a law of physics could, in principle, be disproved by experiment. Other theories are more limited: they describe the behaviour of specific physical systems only, or are applicable only under certain circumstances.

Since one of the major goals of physics is the formulation of theories of universal applicability, on a broad perspective physics can be viewed as the study of those univeral laws which define, at the most fundamental level possible, the behaviour of the physical universe.

Classical physics traditionally included the fields of mechanics, optics, electricity, magnetism, acoustics and heat. The more recent fields of general and special relativity have also usually been placed within this category. Modern physics is a term normally used to cover fields which rely on quantum theory, including quantum mechanics, atomic physics, nuclear physics, particle physics and condensed matter physics. Although this distinction can be commonly found in older writings, it is of limited current significance as quantum effects are now understood to be of importance even in fields previously considered purely classical.

Physics research is divided into two main branches: experimental physics and theoretical physics. Experimental physics focuses mainly on empirical research, and on the development and testing of theories against practical experiment. Theoretical physics is more closely related to mathematics, and involves generating and working through the mathematical implications of systems of physical theories, even where experimental evidence of their validity may not be immediately available.

=Discussion=

This is definitely my all-time favorite. The only suggestion I can make is to replace space and time with spacetime in the first sentence. Nick Mks 20:36, 30 November 2006 (UTC)

I like this too, although my previously voiced reservations about introducing a false separation between matter/energy and space/time still stand. Also, I'm not in favor of the statement that the distinction between classical/modern is of little importance. There is a big difference between classical and quantum(specifically how one uses the Hamiltonian/Lagrangian and what is observable) and I think that the distinction is pretty important. Joshua Davis 21:56, 30 November 2006 (UTC)

If mass were to replace matter then I would have no problems with the first sentence, although it could then segue right into general relativity, which is problematic. That is the reason I would not support referring to spacetime in the first paragraph. The classical/modern physics discussion of the 4th paragraph is not fundamental and merely reflects historical development of the last few centuries. It could be struck without harm to an introduction. The last paragraph uses the word empirical as almost a synonym for 'experimental', where experimental physics is really the use of technology to prove/disprove physics conjectures. In other words, experiment and theory go hand-in-hand and are not quite so disjoint as the word empirical implies. --Ancheta Wis 00:46, 1 December 2006 (UTC)

The major concern that I have with this proposal is that a lot of the material should really be placed in the Introduction section: the lead section should really just outline what physics is without going in to too much detail. By the way, I owe you an apology for the law/theory dichotomy - it seems that Young and Freedman discuss it too! Krea 02:25, 1 December 2006 (UTC)


 * On second thought, I think Krea has a point here that this proposal may be too long for the lead. For instance, the modern/classical discussion is probably more appropriate for the Introduction. Perhaps the same goes for the theory/experiment discussion. —Preceding unsigned comment added by Joshua Davis (talk • contribs)

I do not quite agree that there is a problem with length. If we ever want to get this article featured (which I hope is the eventual purpose of all this), we will need a four-paragraph introduction or lead or whatever you want to call it (the thing before the TOC). I think this is perfect for that. We should still work out the space/time (and indeed also matter/energy, even though this distinction is still quite natural if you look at the fermion/boson distinction: it's not because mass and energy can be converted into each other that they are the same) thing though. Nick Mks 08:24, 1 December 2006 (UTC)


 * OK, I'm on board for now. I might argue later that a sentence here or there should be removed/modified. But all told this is nice. Joshua Davis 18:58, 3 December 2006 (UTC)

Well, I don't want to make a big fuss about it - it's just that this is a criticism that I think people will make of it, which, thusly, may hinder the proposal when it comes to the vote. All of what is said probably needs to be said somewhere, and if you would like it before the TOC, that's fine too. My concern is just a matter of structure. We have a clear Definition/lead section, and a separate Introduction section, and the two should not step on each other's feet. Krea 13:19, 7 December 2006 (UTC)


 * I agree, but we are discussing the lead here (that's obviously the part before the TOC). In my view, the post TOC introduction should be edited to match the lead, not the other way around. Nick Mks 18:33, 7 December 2006 (UTC)

From the forest level
To me, this proposal looks pretty good. But I would hope that the authors keep in mind that they are not writing for physicists but for the average well-informed reader. Beginning with concepts that are part of the experience of general readers and that can be sharpened and clarified in the course of this and related articles is preferable, IMHO, to jumping immediately to concepts that would send the average reader immediately to other articles or a dictionary. In particular, discussion of the meaning of "law" seems out of place in a basic article. P0M 22:50, 24 December 2006 (UTC)