Editing Fundamental interaction (section)

=== Classical theory ===
In his 1687 theory, [[Isaac Newton]] postulated space as an infinite and unalterable physical structure existing before, within, and around all objects while their states and relations unfold at a constant pace everywhere, thus [[absolute space and time]]. Inferring that all objects bearing mass approach at a constant rate, but collide by impact proportional to their masses, Newton inferred that matter exhibits an attractive force. His [[law of universal gravitation]] implied there to be instant interaction among all objects.<ref>{{cite web |title=Newton's Laws of Motion |url=https://www.grc.nasa.gov/www/k-12/airplane/newton.html |website=www.grc.nasa.gov |publisher=NASA}}</ref><ref>{{cite web |title=Newton's law of gravitation {{!}} Definition, Formula, & Facts |url=https://www.britannica.com/science/Newtons-law-of-gravitation |website=Encyclopedia Britannica |access-date=22 March 2021 |language=en}}</ref> As conventionally interpreted, Newton's theory of motion modelled a ''[[central force]]'' without a communicating medium.<ref>{{cite journal |last1=Nauenberg |first1=Michael |title=Newton's graphical method for central force orbits |journal=American Journal of Physics |date=October 2018 |volume=86 |issue=10 |pages=765–771 |doi=10.1119/1.5050620|bibcode=2018AmJPh..86..765N |s2cid=125197336 }}</ref><ref>Newton's absolute space was a medium, but not one transmitting gravitation.</ref> Thus Newton's theory violated the tradition, going back to [[Descartes]], that there should be no [[action at a distance]].<ref>{{cite journal |last1=Henry |first1=John |title=Gravity and De gravitatione: the development of Newton's ideas on action at a distance |journal=Studies in History and Philosophy of Science Part A |date=March 2011 |volume=42 |issue=1 |pages=11–27 |doi=10.1016/j.shpsa.2010.11.025|bibcode=2011SHPSA..42...11H |url=https://www.pure.ed.ac.uk/ws/files/9845098/HENRY_2011_Gravity_and_de_gravitatione.pdf |hdl=20.500.11820/b84d5f3c-47b3-453a-849f-eb9add123210 |hdl-access=free }}</ref> Conversely, during the 1820s, when explaining magnetism, [[Michael Faraday]] inferred a ''field'' filling space and transmitting that force. Faraday conjectured that ultimately, all forces unified into one.<ref>{{cite journal |last1=Faraday |first1=Michael |title=Experimental Researches in Electricity |date=2012 |doi=10.1017/cbo9781139383165.018}}</ref>

In 1873, [[James Clerk Maxwell]] unified electricity and magnetism as effects of an electromagnetic field whose third consequence was light, travelling at constant speed in vacuum. If his [[classical electrodynamics|electromagnetic field theory]] held true in all [[inertial frames of reference]], this would contradict Newton's theory of motion, which relied on [[Galilean relativity]].<ref>{{cite journal |last1=Goldin |first1=Gerald A. |last2=Shtelen |first2=Vladimir M. |title=On Galilean invariance and nonlinearity in electrodynamics and quantum mechanics |journal=Physics Letters A |date=February 2001 |volume=279 |issue=5–6 |pages=321–326 |doi=10.1016/S0375-9601(01)00017-2 |quote=no fully Galilean-covariant theory of a coupled Schrödinger-Maxwell system (where the density and current of the Schrödinger field act as source of the nonrelativistic Maxwell field) is possible|arxiv=quant-ph/0006067 |bibcode=2001PhLA..279..321G |s2cid=5398578 }}</ref> If, instead, his field theory only applied to reference frames at rest relative to a mechanical [[luminiferous aether]]—presumed to fill all space whether within matter or in vacuum and to manifest the electromagnetic field—then it could be reconciled with Galilean relativity and Newton's laws. (However, such a "Maxwell aether" was later disproven; Newton's laws did, in fact, have to be replaced.)<ref>{{cite journal |last1=Farhoudi |first1=Mehrdad |last2=Yousefian |first2=Maysam |title=Ether and Relativity |journal=International Journal of Theoretical Physics |date=May 2016 |volume=55 |issue=5 |pages=2436–2454 |doi=10.1007/s10773-015-2881-y|arxiv=1511.07795 |bibcode=2016IJTP...55.2436F |s2cid=119258859 }}</ref>