Editing Classical physics (section)

{{short description|Category of theories}}
{{merge|Modern physics|target=Classical and modern physics|discuss=Wikipedia_talk:WikiProject_Physics#Classical_and_modern_physics|date=February 2025}}
[[File:Modernphysicsfields 2.svg|thumb|upright=1.75|Impact of relativity and quantum mechanics on classical mechanics]]

'''Classical physics''' refers to [[physics]] theories that are non-quantum or both non-quantum and non-relativistic, depending on the context. In historical discussions, ''classical physics'' refers to pre-1900 physics, while ''[[modern physics]]'' refers to post-1900 physics, which incorporates elements of [[quantum mechanics]] and [[theory of relativity|relativity]].<ref>{{cite book|first1=Richard T. |last1=Weidner|first2=Robert L. |last2=Sells|title=Elementary Modern Physics|chapter=Preface|page=iii|year=1968}}</ref> However, relativity is based on [[classical field theory]] rather than [[quantum field theory]] and is often categorized with "classical physics."{{cn|reason=ref needed for relativity based on classical field theory|date=February 2025}}