Editing Feynman diagram (section)

=== Alternate names ===
[[Murray Gell-Mann]] always referred to Feynman diagrams as '''Stueckelberg diagrams''', after Swiss physicist [[Ernst Stueckelberg]], who devised a similar notation many years earlier. Stueckelberg was motivated by the need for a manifestly covariant formalism for quantum field theory, but did not provide as automated a way to handle symmetry factors and loops, although he was first to find the correct physical interpretation in terms of forward and backward in time particle paths, all without the path-integral.<ref>{{cite news |author=George Johnson |title=The Jaguar and the Fox |url=https://www.theatlantic.com/issues/2000/07/johnson.htm |work=The Atlantic |date=July 2000 |access-date=February 26, 2013}}</ref>

Historically, as a book-keeping device of covariant perturbation theory, the graphs were called '''Feynman–Dyson diagrams''' or '''Dyson graphs''',<ref>{{cite book |last1=Gribbin |first1=John |last2=Gribbin |first2=Mary |title=Richard Feynman: A Life in Science |publisher=Penguin-Putnam |year=1997 |chapter=5}}</ref> because the path integral was unfamiliar when they were introduced, and [[Freeman Dyson]]'s derivation from old-fashioned perturbation theory borrowed from the perturbative expansions in statistical mechanics was easier to follow for physicists trained in earlier methods.<ref group=lower-alpha>"It was Dyson's contribution to indicate how Feynman's visual insights could be used [...] He realized that Feynman diagrams [...] can also be viewed as a representation of the logical content of field theories (as stated in their perturbative expansions)". Schweber, op.cit (1994)</ref> Feynman had to lobby hard for the diagrams, which confused physicists trained in equations and graphs.<ref>{{cite book |first=Leonard |last=Mlodinow |title=Feynman's Rainbow |publisher=Vintage |year=2011 |page=29}}</ref>