Editing Physics (section)

===Classical theory===
{{Main|Classical physics}}

Classical physics includes the traditional branches and topics that were recognized and well-developed before the beginning of the 20th century—classical mechanics, thermodynamics, and electromagnetism.<ref name=Krane-2019/>{{rp|2|q=These three successful theories-mechanics, electromagnetism, and thermodynamics-form the basis for what we call "classical physics."}} Classical mechanics is concerned with bodies acted on by [[force]]s and bodies in [[motion (physics)|motion]] and may be divided into [[statics]] (study of the forces on a body or bodies not subject to an acceleration), [[kinematics]] (study of motion without regard to its causes), and [[Analytical dynamics|dynamics]] (study of motion and the forces that affect it); mechanics may also be divided into [[solid mechanics]] and [[fluid mechanics]] (known together as [[continuum mechanics]]), the latter include such branches as [[hydrostatics]], [[Fluid dynamics|hydrodynamics]] and [[pneumatics]]. Acoustics is the study of how sound is produced, controlled, transmitted and received.<ref name="britannica-acoustics">{{cite encyclopedia |title=acoustics |url=http://www.britannica.com/EBchecked/topic/4044/acoustics |encyclopedia=[[Encyclopædia Britannica]] |access-date=14 June 2013 |url-status=live |archive-url=https://web.archive.org/web/20130618235952/http://www.britannica.com/EBchecked/topic/4044/acoustics |archive-date=18 June 2013 }}</ref> Important modern branches of acoustics include [[ultrasonics]], the study of sound waves of very high frequency beyond the range of human hearing; [[bioacoustics]], the physics of animal calls and hearing,<ref>{{cite web |url=http://www.bioacoustics.info/ |title=Bioacoustics – the International Journal of Animal Sound and its Recording |publisher=Taylor & Francis |access-date=31 July 2012 |url-status=live |archive-url=https://web.archive.org/web/20120905120546/http://www.bioacoustics.info/ |archive-date=5 September 2012 }}</ref> and [[electroacoustics]], the manipulation of audible sound waves using electronics.<ref>{{cite web |publisher=[[Acoustical Society of America]] |title=Acoustics and You (A Career in Acoustics?) |url=http://asaweb.devcloud.acquia-sites.com/education_outreach/careers_in_acoustics |archive-url=https://web.archive.org/web/20150904010934/http://asaweb.devcloud.acquia-sites.com/education_outreach/careers_in_acoustics |url-status=dead |archive-date=4 September 2015 |access-date=21 May 2013 }}</ref>

Optics, the study of light, is concerned not only with [[visible light]] but also with [[infrared]] and [[ultraviolet radiation]], which exhibit all of the phenomena of visible light except visibility, e.g., reflection, refraction, interference, diffraction, dispersion, and polarization of light. Heat is a form of energy, the internal energy possessed by the particles of which a substance is composed; thermodynamics deals with the relationships between heat and other forms of energy. Electricity and [[magnetism]] have been studied as a single branch of physics since the intimate connection between them was discovered in the early 19th century; an [[electric current]] gives rise to a [[magnetic field]], and a changing magnetic field induces an electric current. [[Electrostatics]] deals with [[electric charge]]s at rest, [[Classical electromagnetism|electrodynamics]] with moving charges, and [[magnetostatics]] with magnetic poles at rest.