Wikipedia:Scientific peer review/Physics

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I would like to request input from other physicists about the definition and introduction to the subject. I have formulated my own personal definition and intro in the discussion page because I don't believe the current one is adequate (see Talk:physics), and would like professional input to highlight any mistakes I have made or objectionable entries I have included. For convenience, I have copied them here. Krea 12:00, 2 June 2006 (UTC)

Please note that the general issues raised in this page, but not necessarily these ones specifically, are being discussed in the physics improvement page and that is where any comments should be directed. Krea 11:26, 17 October 2006 (UTC)


Definition[edit]

In everyday terms, physics is the science of the world around us that attempts to describe how objects behave under different situations. As a simple example, physics tells us that objects at rest like to remain at rest (Newton's First Law of Motion), or that all known processes increase the total entropy of the system and its surroundings (the Second Law of Thermodynamics).

However, a more formal definition would be that physics is merely the description of, or the desire to acquire knowledge of, how physical objects interact, if indeed, they do so. The word "interaction" is understood to mean the influence of one "physical object" on another such "physical object"; and "physical objects" are objects that have been observed to have "interacted" in some way with other such "physical objects".

Note that there appears to be a circular definition between the terms "interaction" and "physical objects". This leads to a very important point about physics: that physical knowledge is otained only by observation. Physical inquiry can make astute predictions about nature; but, it is currently believed, there does not exist and there has never existed any theorem that knowingly describes the true nature of the physical world. That is, there exists no theorem that says "this is how nature really behaves": all that can be said is that "this is how we believe nature behaves from what has currently been observed". Therefore, it is not currently possible to give any intrinsic meaning to the words "interaction" or "physical objects" that is independent of the other. The definition can also be seen to have made no predictions about nature: it does not say what form the "interactions" take, or what the "physical objects" are.

It should be noted, that there does exist one subtle non-trivial axiom that is implied by physics: that entities that physically argue are assumed not to have knowledge of how natue actually behaves for what is being considered. This can be seen to truly be an axiom as it is required in order for physical enquiry to be conducted, and there is no reason to assume that such knowledge should not be available to the entities in question.

Introduction[edit]

Physics, as an ideal, has probably existed since man first questioned the nature of the world around him. However, although many great thinkers in antiquity questioned the world they lived in, it is generally regarded among physical historians that the birth of physics in a guise that resembles what we currently recognise as physics probably began with Aristotle. Over the two millenia since then, through defining periods such as the Renaissance and the Scientific Enlightenment, physics has evolved into the vast subject that has proved to be extraordinarily successful in understanding, and predicting how nature behaves.

As it currently stands, physics has formulated theories on the behaviour of nature over both small and large scales, involving most objects that exist, or have been created, which physicists can directly observe. More specifically, physics has created two influential theories that broadly explain the observations seen in the micro- and macroscopic worlds: the Standard Model, and General Relativity respectively.

The Standard model is a general framework that describes the micro, or "quantum" world. It is from this framework that physicists can define "particles" (either fermionic, or bosonic), that posses properties (such as energy, momentum, spin etc.) that interact with each other (through the electroweak, and strong interactions). However, the Standard model does not currently incorporate another fundamental interaction that is observed to exist: Gravity. The most complete description that physicists have of Gravity is called General Relativity, which is generally accepted to break down at quantum scales, and is thus called a description of the "macroscopic" world.

Such a classification, however, is too naive: neither the Standard Model nor General Relativity are poweful enough to describe all of the phenomena seen far from the domain of the quantum world. Therefore, there still exist many topics within physics that still exist outside these two descriptions. As such, it can still be possible to, and indeed useful to, break physics into several broad topics: Quantum Mechanics, Electromagnetism, Classical Mechanics, Thermodynamics and Statistical Mechanics, Relativity, and Particle Physics. Note that this is just one way to partition physics and there exists much overlap between these broad topics. Imdeed, physics can also be, and often is, split into two broad disciplines: Theoretical, and Experimental Physics. This distinction is more defined nowadays than it previously was since physics has now generally become too large a subject for most physicists too be able to be proficient in both. In practise, however, some subjects still require good grounding in both. Additionally, mathematical physics is sometimes regarded as separate from theoretical physics; however, the distiction is not always too clear when differentiating between theorists, and is more pronounced when applied to the output of a particular theorist.

With respect to science in general, physics is usually partnered with Chemistry and Biology to form the "hard sciences", as opposed to the "soft sciences", such as Sociology, Anthroplogy, and Economics, among others. Even this distinction within the "hard" sciences is not always clear-cut though, and the disciplines have together engendered relatively new topics that straddle the progenitor subjects, such as physical chemistry, biochemistry, and biophysics. It is also instructive to note that physics was known as natural philosophy until the modern era, and physics can still be regarded as the philosophy of nature: but, it is now more stringently controlled through the scientific method than it probably was pre-Renaissance.

Concerning the description of physics, it is almost entirely descibed through mathematics. That is, there appears to exist some relationship between physics and the objects of arithmetic and their operations. It is not currently known how deep this connection is and many professional physicists have their own views on the matter.

"How can it be that mathematics, being after all product of human thought which is independent of experience , is so admirably appropriate to the objects of reality?" -Albert Einstein.

Although physics has been very successful, there still exist numerous problems that have evaded our understanding. Whilst this includes new observations that defy our old understanding of nature, such as the implications of neutrino oscillations in the Standard Model; or the acceleration of the Universe requiring modifications, or even a completely new description, of Gravitation, there exist fundamental problems to theories that have been known for some time, or revealed because of newer theories, such as the energy density of the electric field of a point charge, or the apparent violation of locality due to Quantum Mechanics respectively. Therefore, physics is still a very dynamical subject that requires much more work to be done in order to accomplish the feat that most theoretical physicists believe is possible: the unification of all physical phenomena into one all-encompasing description.

comments[edit]

Seems like a very contentious introduction that forges its own philosophy of science -- have never heard of, for example, the distinction between "entities" and "interactions" although something more sophisticated may be appropriate for, e.g., the article on Lagrangian. In any case, serious WP:NOR problems. Sdedeo (tips) 20:23, 1 October 2006 (UTC)

This page is a bit outdated and useless now: I will propose it be deleted soon. Krea 22:09, 15 October 2006 (UTC)
I second that--Glas(talk) Try my User skin 14:39, 22 May 2009 (UTC)