Editing Time dilation (section)

==History==
{{Main|History of special relativity}}

Time dilation by the [[Lorentz factor]] was predicted by several authors at the turn of the 20th century.<ref>{{Cite book |last=Miller |first=Arthur I. |url=https://archive.org/details/alberteinsteinss0000mill |title=Albert Einstein's Special Theory of Relativity: Emergence (1905) and Early Interpretation (1905–1911) |publisher=Addison–Wesley |year=1981 |isbn=978-0-201-04679-3 |location=Reading, Massachusetts |url-access=registration}}.</ref><ref>{{Cite book |last=Darrigol |first=Olivier |url=http://www.bourbaphy.fr/darrigol2.pdf |title=Einstein, 1905–2005 |work=Séminaire Poincaré |year=2005 |isbn=978-3-7643-7435-8 |volume=1 |pages=1–22 |chapter=The Genesis of the Theory of Relativity |doi=10.1007/3-7643-7436-5_1}}</ref> [[Joseph Larmor]] (1897) wrote that, at least for those orbiting a nucleus, individual electrons describe corresponding parts of their orbits in times shorter for the [rest] system in the ratio: <math display="inline"> \sqrt{1 - \frac{v^2}{c^2}}</math>.<ref>{{Cite journal |last=Larmor |first=Joseph |year=1897 |title=On a Dynamical Theory of the Electric and Luminiferous Medium, Part 3, Relations with Material Media |journal=Philosophical Transactions of the Royal Society |volume=190 |pages=205–300 |bibcode=1897RSPTA.190..205L |doi=10.1098/rsta.1897.0020 |doi-access=free |title-link=s:Dynamical Theory of the Electric and Luminiferous Medium III}}</ref> [[Emil Cohn]] (1904) specifically related this formula to the rate of clocks.<ref name="cohn">{{Citation |last=Cohn |first=Emil |title=[[s:de:Zur Elektrodynamik bewegter Systeme II|Zur Elektrodynamik bewegter Systeme II]] |work=Sitzungsberichte der Königlich Preussischen Akademie der Wissenschaften |volume=1904/2 |issue=43 |pages=1404–1416 |year=1904 |trans-title=[[s:Translation:On the Electrodynamics of Moving Systems II|On the Electrodynamics of Moving Systems II]] |language=de,en}}</ref> In the context of [[special relativity]] it was shown by [[Albert Einstein]] (1905) that this effect concerns the nature of time itself, and he was also the first to point out its reciprocity or symmetry.<ref>{{Cite journal |last=Einstein |first=Albert |year=1905 |title=Zur Elektrodynamik bewegter Körper |url=http://sedici.unlp.edu.ar/handle/10915/2786 |journal=Annalen der Physik |volume=322 |issue=10 |pages=891–921 |bibcode=1905AnP...322..891E |doi=10.1002/andp.19053221004 |doi-access=free |language=de}}. See also: [http://www.fourmilab.ch/etexts/einstein/specrel/ English translation].</ref> Subsequently, [[Hermann Minkowski]] (1907) introduced the concept of [[proper time]] which further clarified the meaning of time dilation.<ref name="mink2">{{Citation |last=Minkowski |first=Hermann |title=Die Grundgleichungen für die elektromagnetischen Vorgänge in bewegten Körpern |work=Nachrichten von der Gesellschaft der Wissenschaften zu Göttingen, Mathematisch-Physikalische Klasse |pages=53–111 |year=1908 |orig-year=1907 |trans-title=[[s:Translation:The Fundamental Equations for Electromagnetic Processes in Moving Bodies|The Fundamental Equations for Electromagnetic Processes in Moving Bodies]] |title-link=s:de:Die Grundgleichungen für die elektromagnetischen Vorgänge in bewegten Körpern |language=de,en}}</ref>
{{Anchor|Velocity time dilation|Relation to velocity}}