Editing Physics (section)

== Other aspects ==

===Education===
{{excerpt|Physics education}}

===Careers===
{{excerpt|Physicist|paragraphs=1,2|files=no}}

===Philosophy===
{{Main|Philosophy of physics}}
Physics, as with the rest of science, relies on the [[philosophy of science]] and its "[[scientific method]]" to advance knowledge of the physical world.<ref name="rosenberg2006ch1">{{harvnb |Rosenberg|2006|loc=Chapter 1}}</ref> The scientific method employs ''[[a priori and a posteriori]]'' reasoning as well as the use of [[Bayesian inference]] to measure the validity of a given theory.<ref name="godfreysmith2003ch14">{{harvnb |Godfrey-Smith|2003|loc=Chapter 14: "Bayesianism and Modern Theories of Evidence"}}</ref>
Study of the philosophical issues surrounding physics, the [[philosophy of physics]], involves issues such as the nature of [[Spacetime|space and time]], [[determinism]], and [[Metaphysics|metaphysical]] outlooks such as [[empiricism]], [[naturalism (philosophy)|naturalism]], and [[Philosophical realism|realism]].<ref name="godfreysmith2003ch15">{{harvnb |Godfrey-Smith|2003|loc=Chapter 15: "Empiricism, Naturalism, and Scientific Realism?"}}</ref>

Many physicists have written about the philosophical implications of their work, for instance [[Pierre-Simon Laplace|Laplace]], who championed [[causal determinism]],<ref name="laplace1951">{{harvnb |Laplace|1951}}</ref> and [[Erwin Schrödinger]], who wrote on quantum mechanics.<ref name="schroedinger1983">{{harvnb |Schrödinger|1983}}</ref><ref name="schroedinger1995">{{harvnb |Schrödinger|1995}}</ref> The mathematical physicist [[Roger Penrose]] has been called a [[Platonism|Platonist]] by [[Stephen Hawking]],<ref name="hawkingpenrose1996p4">{{harvnb|Hawking|Penrose|1996|p=4}}. "I think that Roger is a Platonist at heart but he must answer for himself."</ref> a view Penrose discusses in his book, ''[[The Road to Reality]]''.<ref name="penrose2004">{{harvnb |Penrose|2004}}</ref> Hawking referred to himself as an "unashamed reductionist" and took issue with Penrose's views.<ref name="penroseshimonycartwrighthawking1997">{{harvnb |Penrose|Shimony|Cartwright|Hawking|1997}}</ref>

[[File:Pahoeoe fountain original.jpg|thumb|This [[parabola]]-shaped [[lava flow]] illustrates an application of mathematics in physics — in this case, Galileo's [[law of falling bodies]].]]
[[File:Physics and other sciences.png|thumb|upright=0.5|left|Mathematics and ontology are used in physics. Physics is used in chemistry and [[cosmology]].]]

Mathematics provides a compact and exact language used to describe the order in nature. This was noted and advocated by [[Pythagoras]],<ref name="dijksterhuis1986">{{harvnb|Dijksterhuis|1986}}</ref> [[Plato]],<ref name="mastin2010-plato">{{harvnb|Mastin|2010}} "Although usually remembered today as a philosopher, Plato was also one of ancient Greece's most important patrons of mathematics. Inspired by Pythagoras, he founded his Academy in Athens in 387 BC, where he stressed mathematics as a way of understanding more about reality. In particular, he was convinced that geometry was the key to unlocking the secrets of the universe. The sign above the Academy entrance read: 'Let no-one ignorant of geometry enter here.{{'"}}</ref> Galileo,<ref name="toraldodifrancia1976p10-galileo">{{harvnb|Toraldo Di Francia|1976|p=10}} 'Philosophy is written in that great book which ever lies before our eyes. I mean the universe, but we cannot understand it if we do not first learn the language and grasp the symbols in which it is written. This book is written in the mathematical language, and the symbols are triangles, circles, and other geometrical figures, without whose help it is humanly impossible to comprehend a single word of it, and without which one wanders in vain through a dark labyrinth.' – Galileo (1623), ''[[The Assayer]]''"</ref> and Newton. Some theorists, like [[Hilary Putnam]] and [[Penelope Maddy]], hold that logical truths, and therefore mathematical reasoning, depend on the [[empirical]] world. This is usually combined with the claim that the laws of logic express universal regularities found in the structural features of the world, which may explain the peculiar relation between these fields.

Physics uses mathematics<ref name="applicationsofmathematics">{{cite web |url=http://www.math.niu.edu/~rusin/known-math/index/tour_sci.html |title=Applications of Mathematics to the Sciences |date=25 January 2000 |access-date=30 January 2012 |archive-url=https://web.archive.org/web/20150510112012/http://www.math.niu.edu/~rusin/known-math/index/tour_sci.html |archive-date=10 May 2015 |url-status=dead}}</ref> to organise and formulate experimental results. From those results, [[analytic solution|precise]] or [[simulation#Computer simulation|estimated]] solutions are obtained, or quantitative results, from which new predictions can be made and experimentally confirmed or negated. The results from physics experiments are numerical data, with their [[units of measure]] and estimates of the errors in the measurements. Technologies based on mathematics, like [[scientific computing|computation]] have made [[computational physics]] an active area of research.

[[File:Mathematical Physics and other sciences.png|thumb|The distinction between mathematics and physics is clear-cut, but not always obvious, especially in mathematical physics.]]

[[Ontology]] is a prerequisite for physics, but not for mathematics. It means physics is ultimately concerned with descriptions of the real world, while mathematics is concerned with abstract patterns, even beyond the real world. Thus physics statements are synthetic, while mathematical statements are analytic. Mathematics contains hypotheses, while physics contains theories. Mathematics statements have to be only logically true, while predictions of physics statements must match observed and experimental data.

The distinction is clear-cut, but not always obvious. For example, [[mathematical physics]] is the application of mathematics in physics. Its methods are mathematical, but its subject is physical.<ref name="jmp-def">{{cite web | url=https://www.researchgate.net/journal/0022-2488_Journal_of_Mathematical_Physics | title=Journal of Mathematical Physics | access-date=31 March 2014 | quote=[Journal of Mathematical Physics] purpose is the publication of papers in mathematical physics—that is, the application of mathematics to problems in physics and the development of mathematical methods suitable for such applications and for the formulation of physical theories. | url-status=live | archive-url=https://web.archive.org/web/20140818231853/http://www.researchgate.net/journal/0022-2488_Journal_of_Mathematical_Physics | archive-date=18 August 2014 | df=dmy-all }}</ref> The problems in this field start with a "[[Boundary condition|mathematical model of a physical situation]]" (system) and a "mathematical description of a physical law" that will be applied to that system. Every mathematical statement used for solving has a hard-to-find physical meaning. The final mathematical solution has an easier-to-find meaning, because it is what the solver is looking for.{{clarify|date=August 2015}}

===Fundamental vs. applied physics===
{{Main|Applied physics}}

Physics is a branch of [[fundamental science]] (also called basic science). Physics is also called "''the'' fundamental science" because all branches of natural science including chemistry, astronomy, geology, and biology are constrained by laws of physics.<ref name="feynmanleightonsands1963v1ch3">[https://feynmanlectures.caltech.edu/I_03.html The Feynman Lectures on Physics Vol. I Ch. 3: The Relation of Physics to Other Sciences]; see also [[reductionism]] and [[special sciences]]</ref> Similarly, chemistry is often called [[the central science]] because of its role in linking the physical sciences. For example, chemistry studies properties, structures, and [[chemical reaction|reactions]] of matter (chemistry's focus on the molecular and atomic scale [[Difference between chemistry and physics|distinguishes it from physics]]). Structures are formed because particles exert electrical forces on each other, properties include physical characteristics of given substances, and reactions are bound by laws of physics, like [[conservation of energy]], [[Conservation of mass|mass]], and [[charge conservation|charge]]. Fundamental physics seeks to better explain and understand phenomena in all spheres, without a specific practical application as a goal, other than the deeper insight into the phenomema themselves.

[[File:Prediction of sound scattering from Schroeder Diffuser.jpg|thumb|upright|left|An [[acoustic engineering]] model of sound reflecting from an acoustic diffuser, implemented with classical physics]]
[[File:Archimedes-screw one-screw-threads with-ball 3D-view animated small.gif|thumb|[[Archimedes' screw]], a [[simple machine]] for lifting]]

Applied physics is a general term for physics research and development that is intended for a particular use. An applied physics curriculum usually contains a few classes in an applied discipline, like geology or electrical engineering. It usually differs from engineering in that an applied physicist may not be designing something in particular, but rather is using physics or conducting physics research with the aim of developing new technologies or solving a problem.

The approach is similar to that of [[applied mathematics]]. Applied physicists use physics in scientific research. For instance, people working on [[accelerator physics]] might seek to build better [[particle detector]]s for research in theoretical physics.

Physics is used heavily in engineering. For example, statics, a subfield of [[mechanics]], is used in the building of bridges and other static structures. The understanding and use of acoustics results in sound control and better concert halls; similarly, the use of optics creates better optical devices. An understanding of physics makes for more realistic [[flight simulator]]s, video games, and movies, and is often critical in [[forensic]] investigations.
[[File:Military laser experiment.jpg|thumb|Experiment using a [[laser]]]]

With the [[Uniformitarianism (science)|standard consensus]] that the [[Scientific law|laws]] of physics are universal and do not change with time, physics can be used to study things that would ordinarily be mired in [[uncertainty]]. For example, in the study of the origin of the Earth, a physicist can reasonably model Earth's mass, temperature, and rate of rotation, as a function of time allowing the extrapolation forward or backward in time and so predict future or prior events. It also allows for simulations in engineering that speed up the development of a new technology.

There is also considerable [[interdisciplinarity]], so many other important fields are influenced by physics (e.g., the fields of [[econophysics]] and [[sociophysics]]).