Editing Action (physics) (section)

== History ==
{{Main | History of variational principles in physics}}
[[Pierre Louis Maupertuis]] and [[Leonhard Euler]] working in the 1740s developed early versions of the action principle. [[Joseph Louis Lagrange]] clarified the mathematics when he invented the [[calculus of variations]]. [[William Rowan Hamilton]] made the next big breakthrough, formulating Hamilton's principle in 1853.<ref name=Kline1972>{{cite book|last=Kline|first=Morris|title=Mathematical Thought from Ancient to Modern Times|url=https://archive.org/details/mathematicalthou0000unse|url-access=registration|publisher=Oxford University Press|location=New York|year=1972|pages= [https://archive.org/details/mathematicalthou0000unse/page/167 167]–168|isbn=0-19-501496-0}}</ref>{{rp|740}}  Hamilton's principle became the cornerstone for classical work with different forms of action until [[Richard Feynman]] and [[Julian Schwinger]] developed quantum action principles.<ref>{{Cite book |last1=Yourgrau |first1=Wolfgang |title=Variational principles in dynamics and quantum theory |last2=Mandelstam |first2=Stanley |date=1979 |publisher=Dover Publ |isbn=978-0-486-63773-0 |edition=Republ. of the 3rd ed., publ. in 1968 |series=Dover books on physics and chemistry |location=New York, NY}}</ref>{{rp|127}}