Editing Electromagnetic induction (section)

===Faraday's law and relativity===
Faraday's law describes two different phenomena: the ''motional emf'' generated by a magnetic force on a moving wire (see [[Lorentz force#Force on a current-carrying wire|Lorentz force]]), and the ''transformer emf'' that is generated by an electric force due to a changing magnetic field (due to the differential form of the [[#Maxwell–Faraday equation|Maxwell–Faraday equation]]). [[James Clerk Maxwell]] drew attention to the separate physical phenomena in 1861.<ref>
{{cite journal
 |last=Maxwell |first=J. C.
 |year=1861
 |title=On physical lines of force
 |journal = [[Philosophical Magazine]]
 |volume=90 |issue=139
 |pages=11–23
 |doi=10.1080/14786446108643033
 |doi-access=free
 }}</ref><ref name=Griffiths1>
{{cite book
 |last=Griffiths
 |first=D. J.
 |year=1999
 |title=Introduction to Electrodynamics
 |url=https://archive.org/details/introductiontoel00grif_0/page/301
 |edition=3rd
 |pages=[https://archive.org/details/introductiontoel00grif_0/page/301 301–303]
 |publisher=[[Prentice Hall]]
 |isbn=0-13-805326-X
 }} Note that the law relating flux to EMF, which this article calls "Faraday's law", is referred to by Griffiths as the "universal flux rule". He uses the term "Faraday's law" to refer to what this article calls the "Maxwell–Faraday equation".</ref> This is believed to be a unique example in physics of where such a fundamental law is invoked to explain two such different phenomena.<ref name=Feynman2>"The flux rule" is the terminology that Feynman uses to refer to the law relating magnetic flux to EMF. {{cite book
 |last1=Feynman
 |first1=R. P.
 |last2=Leighton
 |first2=R. B.
 |last3=Sands
 |first3=M. L.
 |year=2006
 |title=The Feynman Lectures on Physics, Volume II
 |page=17{{hyphen}}2
 |publisher=[[Pearson Education|Pearson]]/[[Addison-Wesley]]
 |url=https://books.google.com/books?id=zUt7AAAACAAJ&q=intitle:Feynman+intitle:Lectures+intitle:on+intitle:Physics
 |isbn=0-8053-9049-9
 }}{{Dead link|date=October 2023 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>

[[Albert Einstein]] noticed that the two situations both corresponded to a relative movement between a conductor and a magnet, and the outcome was unaffected by which one was moving. This was one of the principal paths that led him to develop [[special relativity]].<ref>
{{cite journal
 |last=Einstein |first=A.
 |year=1905
 |title=Zur Elektrodynamik bewegter Körper
 |journal=[[Annalen der Physik]]
 |volume=17 |issue=10 |pages=891–921
 |bibcode=1905AnP...322..891E
 |doi=10.1002/andp.19053221004
 |url=http://sedici.unlp.edu.ar/bitstream/handle/10915/2786/Documento_completo__.pdf?sequence=1
 |doi-access=free
 }}<br />
:Translated in {{cite book
 |last=Einstein |first=A.
 |others=Jeffery, G.B.; Perret, W. (transl.)
 |year=1923
 |chapter=On the Electrodynamics of Moving Bodies
 |chapter-url=http://www.fourmilab.ch/etexts/einstein/specrel/specrel.pdf
 |title=The Principle of Relativity
 |publisher=[[Methuen and Company]]
 |location=London
}}</ref>