Editing Magnetic field (section)

===Modern developments===

In 1887, Tesla developed an [[induction motor]] that ran on [[alternating current]]. The motor used [[Polyphase system|polyphase]] current, which generated a [[rotating magnetic field]] to turn the motor (a principle that Tesla claimed to have conceived in 1882).<ref>{{cite book|title=Networks of Power: Electrification in Western Society, 1880–1930|publisher=JHU Press|page=117|url=https://books.google.com/books?id=g07Q9M4agp4C&pg=PA117|isbn=9780801846144|date=March 1993 }}</ref><ref>Thomas Parke Hughes, ''Networks of Power: Electrification in Western Society, 1880–1930'', pp. 115–118</ref><ref>{{cite book | url=https://books.google.com/books?id=1AsFdUxOwu8C&pg=PA204|title=Robert Bud, Instruments of Science: An Historical Encyclopedia | page=204|access-date=18 March 2013|isbn=9780815315612|last1=Ltd|first1=Nmsi Trading|author2 = Smithsonian Institution | year=1998 |publisher=Taylor & Francis }}</ref> Tesla received a patent for his electric motor in May 1888.<ref>{{US patent|381968}}</ref><ref>{{Cite journal | last1=Porter|first1=H. F. J.|last2=Prout|first2=Henry G.|date=January 1924|title=A Life of George Westinghouse| url=http://dx.doi.org/10.2307/1838546|journal=The American Historical Review| volume=29| issue=2|page=129|doi=10.2307/1838546| jstor=1838546|hdl=2027/coo1.ark:/13960/t15m6rz0r|issn=0002-8762|hdl-access=free}}</ref> In 1885, [[Galileo Ferraris]] independently researched rotating magnetic fields and subsequently published his research in a paper to the ''Royal Academy of Sciences'' in [[Turin]], just two months before Tesla was awarded his patent, in March 1888.<ref>{{Cite web |title=Galileo Ferraris (March 1888) ''Rotazioni elettrodinamiche prodotte per mezzo di correnti alternate'' (Electrodynamic rotations by means of alternating currents), memory read at Accademia delle Scienze, Torino, in ''Opere di Galileo Ferraris'', Hoepli, Milano, 1902 vol I pages 333 to 348 |url=http://ieeemilestones.ethw.org/images/a/a0/1-Galileo_Ferraris_Rotating-field--Rotazioni_Elettrodinamiche.pdf |url-status=dead |archive-url=https://web.archive.org/web/20210709182151/http://ieeemilestones.ethw.org/images/a/a0/1-Galileo_Ferraris_Rotating-field--Rotazioni_Elettrodinamiche.pdf |archive-date=9 July 2021 |access-date=2 July 2021}}</ref>

The twentieth century showed that classical electrodynamics is already consistent with special relativity, and extended classical electrodynamics to work with quantum mechanics. [[Albert Einstein]], in his paper of 1905 that established relativity, showed that both the electric and magnetic fields are part of the same phenomena viewed from different reference frames. Finally, the emergent field of [[quantum mechanics]] was merged with electrodynamics to form [[quantum electrodynamics]], which first formalized the notion that electromagnetic field energy is quantized in the form of photons.