Editing Quantum electrodynamics (section)

{{Short description|Quantum field theory of electromagnetism}}
{{Quantum field theory}}
In [[particle physics]], '''quantum electrodynamics''' ('''QED''') is the [[Theory of relativity|relativistic]] [[quantum field theory]] of [[electrodynamics]].<ref name="feynman1" /><ref name="feynbook" /><ref name=":0" /> In essence, it describes how [[light]] and [[matter]] interact and is the first theory where full agreement between [[quantum mechanics]] and [[special relativity]] is achieved.<ref name="feynbook" /> QED mathematically describes all [[phenomenon|phenomena]] involving [[electric charge|electrically charged]] particles interacting by means of exchange of [[photon]]s and represents the [[quantum mechanics|quantum]] counterpart of [[classical electromagnetism]] giving a complete account of matter and light interaction.<ref name="feynbook" /><ref name=":0">{{Cite journal |last=Feynman |first=R. P. |date=1950 |title=Mathematical Formulation of the Quantum Theory of Electromagnetic Interaction |journal=Physical Review |volume=80 |issue=3 |pages=440–457 |doi=10.1103/PhysRev.80.440 |bibcode=1950PhRv...80..440F |url=https://authors.library.caltech.edu/3528/ |access-date=2019-09-23 |archive-date=2020-09-14 |archive-url=https://web.archive.org/web/20200914231627/https://authors.library.caltech.edu/3528/ |url-status=dead |url-access=subscription }}</ref>

In technical terms, QED can be described as a very accurate way to calculate the probability of the position and movement of particles, even those massless such as photons, and the quantity depending on position (field) of those particles, and described light and matter beyond the [[Wave–particle duality|wave-particle duality]] proposed by [[Albert Einstein]] in 1905. [[Richard Feynman]] called it "the jewel of physics" for its [[precision tests of QED|extremely accurate predictions]] of quantities like the [[anomalous magnetic moment]] of the electron and the [[Lamb shift]] of the [[energy level]]s of [[hydrogen]].<ref name=feynbook>{{cite book |last=Feynman |first=Richard |author-link=Richard Feynman |year=1985 |isbn=978-0-691-12575-6 |title=QED: The Strange Theory of Light and Matter |publisher=Princeton University Press}}</ref>{{rp|Ch1}} It is the most precise and stringently tested theory in physics.<ref>{{Cite book |last=Venkataraman |first=Ganeshan |title=Quantum Revolution II — QED: The Jewel of Physics |year=1994 |publisher=Universities Press |isbn=978-8173710032 |language=en |author-link=Ganeshan Venkataraman}}</ref><ref>{{Cite journal |date=2023-10-05 |title=Testing the limits of the standard model of particle physics with a heavy, highly charged ion |url=https://www.nature.com/articles/d41586-023-02620-7 |access-date=2023-10-23 |journal=Nature|doi=10.1038/d41586-023-02620-7 |pmid=37794145 |s2cid=263670732 |url-access=subscription }}</ref>