Editing Magnet (section)

== Discovery and development ==
{{Main|History of electromagnetic theory}}
{{See also|Magnetism#History|label 1=Magnetism history}}

Ancient people learned about magnetism from [[lodestone]]s (or [[magnetite]]) which are naturally magnetized pieces of iron ore. The word ''[[:wikt:magnet|magnet]]'' was adopted in [[Middle English]] from [[Latin]] ''magnetum'' "lodestone", ultimately from [[Ancient Greek|Greek]] {{lang|grc|μαγνῆτις [λίθος]}} (''magnētis [lithos]'')<ref>[https://archive.org/details/bub_gb_BkS2KW7u76MC ''Platonis Opera''] {{webarchive|url=https://web.archive.org/web/20180114235807/https://books.google.com/books?id=BkS2KW7u76MC&dq= |date=2018-01-14 }}, Meyer and Zeller, 1839, p. 989.</ref> meaning "[stone] from Magnesia",<ref>The location of Magnesia is debated; it could be [[Ancient Magnesia|the region in mainland Greece]] or [[Magnesia ad Sipylum]]. See, for example, {{cite web |url=http://www.languagehat.com/archives/001914.php |title=Magnet |work=Language Hat blog |date=28 May 2005 |access-date=22 March 2013 |url-status=live |archive-url=https://web.archive.org/web/20120519140810/http://www.languagehat.com/archives/001914.php |archive-date=19 May 2012 }}</ref> a place in [[Anatolia]] where lodestones were found (today [[Manisa]] in modern-day [[Turkey]]). Lodestones, suspended so they could turn, were the first [[magnetic compass]]es. The earliest known surviving descriptions of magnets and their properties are from Anatolia, India, and China around 2,500 years ago.<ref>{{cite web|url= http://galileoandeinstein.physics.virginia.edu/more_stuff/E&M_Hist.html|title= Historical Beginnings of Theories of Electricity and Magnetism|access-date= 2008-04-02|last= Fowler|first= Michael|year= 1997|url-status= dead|archive-url= https://web.archive.org/web/20080315042431/http://galileoandeinstein.physics.virginia.edu/more_stuff/E%26M_Hist.html|archive-date= 2008-03-15}}</ref><ref>{{Cite journal|title=Early Evolution of Power Engineering|first=Hugh P.|last=Vowles |journal=[[Isis (journal)|Isis]]|volume=17|issue=2|year=1932|pages=412–420 [419–20]|doi=10.1086/346662|s2cid=143949193}}</ref><ref>{{Cite journal|author=Li Shu-hua|title=Origine de la Boussole II. Aimant et Boussole|journal=Isis|volume=45|issue=2|pages=175–196|year=1954|jstor=227361|doi=10.1086/348315|s2cid=143585290}}</ref> The properties of lodestones and their affinity for iron were written of by [[Pliny the Elder]] in his encyclopedia ''[[Naturalis Historia]]'' in the 1st century AD.<ref>[https://www.perseus.tufts.edu/hopper/text?doc=Perseus:text:1999.02.0137:book=34:chapter=42&highlight=magnet Pliny the Elder, The Natural History, BOOK XXXIV. THE NATURAL HISTORY OF METALS., CHAP. 42.—THE METAL CALLED LIVE IRON] {{webarchive|url=https://web.archive.org/web/20110629131820/http://www.perseus.tufts.edu/hopper/text?doc=Perseus:text:1999.02.0137:book=34:chapter=42&highlight=magnet |date=2011-06-29 }}. Perseus.tufts.edu. Retrieved on 2011-05-17.</ref>

In 11th century China, it was discovered that quenching red hot iron in the Earth's magnetic field would leave the iron permanently magnetized. This led to the development of the navigational [[compass]], as described in [[Dream Pool Essays]] in 1088.<ref name=":1">{{Cite book |last=Coey |first=J. M. D. |url=https://www.worldcat.org/oclc/664016090 |title=Magnetism and magnetic materials |date=2009 |publisher=Cambridge University Press |isbn=978-0-511-68515-6 |location=Cambridge |pages=1–3 |oclc=664016090}}</ref><ref>{{Cite web |date=2004-12-13 |title=Four Great Inventions of Ancient China |url=http://za.china-embassy.gov.cn/eng/znjl/Culture/200412/t20041213_7631027.htm |access-date=January 8, 2023 |website=Embassy of the People's Republic of China in the Republic of South Africa}}</ref> By the 12th to 13th centuries AD, magnetic compasses were used in navigation in China, Europe, the Arabian Peninsula and elsewhere.<ref>{{Cite journal|title=Two Early Arabic Sources On The Magnetic Compass|first=Petra G.|last=Schmidl|journal=Journal of Arabic and Islamic Studies|year=1996–1997|volume=1|pages=81–132|url=http://www.lancs.ac.uk/jais/volume/docs/vol1/1_081-132schmidl2.pdf|url-status=live|archive-url=https://web.archive.org/web/20120524152412/http://www.lancs.ac.uk/jais/volume/docs/vol1/1_081-132schmidl2.pdf|archive-date=2012-05-24|doi=10.5617/jais.4547|doi-access=free}}</ref>

A straight iron magnet tends to demagnetize itself by its own magnetic field. To overcome this, the [[horseshoe magnet]] was invented by [[Daniel Bernoulli]] in 1743.<ref name=":1" /><ref>{{Cite web |title=The Seven Magnetic Moments - Modern Magnets |url=https://www.tcd.ie/physics/research/groups/magnetism/facts/the-seven-magnetic-moments/modern-magnets/ |access-date=January 8, 2023 |website=Trinity College Dublin}}</ref> A horseshoe magnet avoids demagnetization by returning the magnetic field lines to the opposite pole.<ref>{{Citation |last1=Müller |first1=Karl-Hartmut |title=Permanent Magnet Materials and Applications |date=2021 |url=https://doi.org/10.1007/978-3-030-63210-6_29 |work=Handbook of Magnetism and Magnetic Materials |page=1391 |editor-last=Coey |editor-first=J. M. D. |place=Cham |publisher=Springer International Publishing |language=en |doi=10.1007/978-3-030-63210-6_29 |isbn=978-3-030-63210-6 |access-date=2023-01-08 |last2=Sawatzki |first2=Simon |last3=Gauß |first3=Roland |last4=Gutfleisch |first4=Oliver |s2cid=244736617 |editor2-last=Parkin |editor2-first=Stuart S.P.}}</ref>

In 1820, [[Hans Christian Ørsted]] discovered that a compass needle is deflected by a nearby electric current. In the same year [[André-Marie Ampère]] showed that iron can be magnetized by inserting it in an electrically fed solenoid.<ref>{{cite book |last=Delaunay |first=Jean |title=Ampère, André-Marie |work=Complete Dictionary of Scientific Biography |volume=1 |pages=142–149 |publisher=Charles Scribner's Sons |year=2008}}</ref> This led [[William Sturgeon]] to develop an iron-cored electromagnet in 1824.<ref name=":1" /> [[Joseph Henry]] further developed the electromagnet into a commercial product in 1830–1831, giving people access to strong magnetic fields for the first time. In 1831 he built an ore separator with an electromagnet capable of lifting {{Convert|750|lb}}.<ref>{{Cite web |title=Joseph Henry – Engineering Hall of Fame |url=https://edisontechcenter.org/JosephHenry.html |access-date=January 8, 2023 |website=Edison Tech Center}}</ref>