Editing Gyroscope (section)

==History==
[[File:Foucault's gyroscope.jpg|thumb|right|Gyroscope designed by [[Léon Foucault]] in 1852. Replica built by Dumoulin-Froment for the Exposition universelle in 1867. [[Conservatoire national des arts et métiers|National Conservatory of Arts and Crafts museum]], Paris.]]

===Early similar devices===
Essentially, a gyroscope is a [[Spinning top|top]] combined with a pair of [[gimbal]]s. Tops were invented in many different civilizations, including classical Greece, Rome, and China.<ref>{{cite web|url=http://solarsystem.nasa.gov/scitech/display.cfm?ST_ID=327 |title=Brief History of Gyroscopes |last1=Range|first1=Shannon K'doah |last2=Mullins|first2=Jennifer |url-status=dead |archive-url=https://web.archive.org/web/20150710113230/http://solarsystem.nasa.gov/scitech/display.cfm?ST_ID=327 |archive-date=10 July 2015}}</ref> Most of these were not utilized as instruments.

The first known apparatus similar to a gyroscope (the "Whirling Speculum" or "Serson's Speculum") was invented by [[John Serson]] in 1743. It was used as a level, to locate the horizon in foggy or misty conditions.

The first instrument used more like an actual gyroscope was made by [[Johann Bohnenberger]] of Germany, who first wrote about it in 1817. At first he called it the "Machine".<ref>Johann G. F. Bohnenberger (1817) "Beschreibung einer Maschine zur Erläuterung der Gesetze der Umdrehung der Erde um ihre Axe, und der Veränderung der Lage der letzteren" (Description of a machine for the explanation of the laws of rotation of the Earth around its axis, and of the change of the orientation of the latter), [http://www.ion.org/museum/files/File_1.pdf Tübinger Blätter für Naturwissenschaften und Arzneikunde] {{webarchive|url=https://web.archive.org/web/20110719070449/http://www.ion.org/museum/files/File_1.pdf |date=19 July 2011 }}, vol. 3, pages 72–83.</ref><ref>The French mathematician [[Siméon Denis Poisson|Poisson]] mentions Bohnenberger's machine as early as 1813: Simeon-Denis Poisson (1813) "Mémoire sur un cas particulier du mouvement de rotation des corps pesans" [Memoir on a special case of rotational movement of massive bodies], ''Journal de l'École Polytechnique'', vol. 9, pages 247–262. Available online at: [http://www.ion.org/museum/files/File_2.pdf Ion.org] {{webarchive|url=https://web.archive.org/web/20110719070631/http://www.ion.org/museum/files/File_2.pdf |date=19 July 2011 }}</ref><ref>{{Citation|last1=Wagner|first1=Jörg F.|title=The Machine of Bohnenberger|date=2014|url=https://doi.org/10.1007/978-3-642-39905-3_6|work=The History of Theoretical, Material and Computational Mechanics – Mathematics Meets Mechanics and Engineering|pages=81–100|editor-last=Stein|editor-first=Erwin|series=Lecture Notes in Applied Mathematics and Mechanics|place=Berlin, Heidelberg|publisher=Springer|language=en|doi=10.1007/978-3-642-39905-3_6|isbn=978-3-642-39905-3|access-date=20 February 2021|last2=Trierenberg|first2=Andor|url-access=subscription}}</ref> Bohnenberger's machine was based on a rotating massive sphere.<ref>A photograph of Bohnenberger's instrument is available on-line here: [http://www.ion.org/museum/item_view.cfm?cid=5&scid=12&iid=24 Ion.org] {{webarchive|url=https://web.archive.org/web/20070928044532/http://www.ion.org/museum/item_view.cfm?cid=5&scid=12&iid=24 |date=28 September 2007 }} ION Museum: The Machine of Bohnenberger.</ref> In 1832, American Walter R. Johnson developed a similar device that was based on a rotating disc.<ref>Walter R. Johnson (January 1832). [https://books.google.com/books?id=BjwPAAAAYAAJ&pg=PA266-IA2 "Description of an apparatus called the rotascope for exhibiting several phenomena and illustrating certain laws of rotary motion"] {{webarchive|url=https://web.archive.org/web/20160819023327/https://books.google.com/books?id=BjwPAAAAYAAJ&pg=PA266-IA2 |date=19 August 2016 }}, ''The American Journal of Science and Art'', 1st series, vol. 21, no. 2, pages 265–280.</ref><ref>Drawings of Walter R. Johnson's gyroscope ("rotascope") were used to illustrate phenomena in the following lecture: E.S. Snell (1856) [https://books.google.com/books?id=fEyT4sTd7ZkC&pg=PA175 "On planetary disturbances,"] {{webarchive|url=https://web.archive.org/web/20160819023557/https://books.google.com/books?id=fEyT4sTd7ZkC&pg=PA175 |date=19 August 2016 }} Board of Regents, ''Tenth Annual Report of the Board of Regents of the Smithsonian Institution....'' (Washington, D.C.: Cornelius Wendell, 1856), pages 175–190.</ref> The French mathematician [[Pierre-Simon Laplace]], working at the [[École Polytechnique]] in Paris, recommended the machine for use as a teaching aid, and thus it came to the attention of [[Léon Foucault]].<ref>{{cite web |url=http://www.ion.org/museum/item_view.cfm?cid=5&scid=12&iid=24 |title=ION Museum: The Machine of Bohnenberger |access-date=24 May 2007 |url-status=dead |archive-url=https://web.archive.org/web/20070928044532/http://www.ion.org/museum/item_view.cfm?cid=5&scid=12&iid=24 |archive-date=28 September 2007}}</ref>

===Foucault's gyroscope===
{{main|Foucault gyroscope}}

In 1852, Foucault used it in an experiment demonstrating the rotation of the Earth.<ref>L. Foucault (1852) "Sur les phénomènes d’orientation des corps tournants entraînés par un axe fixe à la surface de la terre – Nouveaux signes sensibles du mouvement diurne" (On the phenomena of the orientation of rotating bodies carried along by an axis fixed to the surface of the earth – New perceptible signs of the daily movement), ''Comptes rendus hebdomadaires des séances de l’Académie des Sciences (Paris)'', vol. 35, pages 424–427. Available on-line (in French): [http://gallica.bnf.fr/ark:/12148/bpt6k2992n/f428.image Gallica.bnf.fr] {{webarchive|url=https://web.archive.org/web/20120716224438/http://gallica.bnf.fr/ark:/12148/bpt6k2992n/f428.image |date=16 July 2012 }}</ref><ref>Circa 1852, Friedrich Fessel, a German mechanic and former secondary school teacher, independently developed a gyroscope. See: '''(1)''' Julius Plücker (September 1853) "Über die Fessel'sche rotationsmachine", ''Annalen der Physik'', vol. 166, no. 9, pages 174–177; '''(2)''' Julius Plücker (October 1853) "Noch ein wort über die Fessel'sche rotationsmachine", ''Annalen der Physik'', vol. 166, no. 10, pages 348–351; '''(3)''' Charles Wheatstone (1864) [https://books.google.com/books?id=CtGEAAAAIAAJ&pg=RA1-PA307 "On Fessel's gyroscope"] {{webarchive|url=https://web.archive.org/web/20160819020402/https://books.google.com/books?id=CtGEAAAAIAAJ&pg=RA1-PA307 |date=19 August 2016 }}, ''Proceedings of the Royal Society of London'', vol. 7, pages 43–48.</ref>

It was Foucault who gave the device its modern name, in an experiment to see (Greek ''skopeein'', to see) the Earth's rotation (Greek ''gyros'', circle or rotation),<ref name="OED">{{cite book|title=The Oxford English Dictionary|edition=2nd|year=1989|volume=VI|page=985|url=https://www.oed.com/view/Entry/82917|access-date=11 March 2023|archive-date=15 September 2024|archive-url=https://web.archive.org/web/20240915102809/https://www.oed.com/dictionary/gyroscope_n|url-status=live}}</ref><ref>{{cite journal | author-link= Léon Foucault |first=Léon |last=Foucault | journal=Comptes rendus hebdomadaires des séances de l'Académie des Sciences | publisher=Gauthier-Villars | title= Mécanique: Sur les phénomènes d'orientation des corps tournants entraînés par un axe fixe à la surface de la Terre. Nouveaux signes sensibles du mouvement diurne| issue=Week of Monday 27 September 1852|volume=35 | year=1852b | url=https://books.google.com/books?id=KHJFAAAAcAAJ&pg=PA421 | language=fr|page=427}}</ref> which was visible in the 8 to 10 minutes before friction slowed the spinning rotor.

===Commercialization===
In the 1860s, the advent of electric motors made it possible for a gyroscope to spin indefinitely; this led to the first prototype [[heading indicator]]s, and a rather more complicated device, the [[gyrocompass]]. The first functional gyrocompass was patented in 1904 by German inventor [[Hermann Anschütz-Kaempfe]].<ref>Hermann Anschütz-Kaempfe and Friedrich von Schirach, [http://v3.espacenet.com/publicationDetails/originalDocument?CC=DE&NR=182855C&KC=C&FT=D&date=&DB=&locale= "Kreiselapparat"]{{Dead link|date=September 2024 |bot=InternetArchiveBot |fix-attempted=yes }} (Gyroscope) Deutsches Reichspatent no. 182855 (filed: 27 March 1904; issued: 2 April 1907).</ref> American [[Elmer Sperry]] followed with his own design later that year, and other nations soon realized the military importance of the invention—in an age in which naval prowess was the most significant measure of military power—and created their own gyroscope industries. The [[Sperry Gyroscope Company]] quickly expanded to provide aircraft and naval stabilizers as well, and other gyroscope developers followed suit.<ref>MacKenzie, Donald. ''Inventing Accuracy: A Historical Sociology of Nuclear Missile Guidance''. Cambridge: MIT Press, 1990. pp. 31–40. {{ISBN|0-262-13258-3}}</ref>{{full citation needed|date=July 2022}}

Circa 1911 the L. T. Hurst Mfg Co of Indianapolis started producing the "Hurst gyroscope" a toy gyroscope with a pull string and pedestal. Manufacture was at some point switched to Chandler Mfg Co (still branded Hurst). The product was later renamed to a "Chandler gyroscope", presumably because Chandler Mfg Co. took over rights to the gyroscope. Chandler continued to produce the toy until the company was purchased by TEDCO Inc. in 1982. The gyroscope is still produced by TEDCO today.<ref>{{cite web|url=http://blog.makezine.com/archive/2009/02/tedco_toys_cool_company_history_gre.html |title=TEDCO Toys – Cool company history, great science kits |last=Anon |work=TEDCO Toys company website |publisher=O'Reilly Media Inc |access-date=23 December 2010 |url-status=dead |archive-url=https://web.archive.org/web/20090309071225/https://blog.makezine.com/archive/2009/02/tedco_toys_cool_company_history_gre.html |archive-date=9 March 2009 }}</ref><ref>{{cite web|url=https://www.gyroscope.com/history-of-the-tedco-gyroscope.asp |title=History of the Tedco Gyroscope |publisher=Brightfusion Ltd |access-date=10 May 2024}}</ref>

In the first several decades of the 20th century, other inventors attempted (unsuccessfully) to use gyroscopes as the basis for early [[flight recorder|black box]] navigational systems by creating a stable platform from which accurate acceleration measurements could be performed (in order to bypass the need for star sightings to calculate position). Similar principles were later employed in the development of [[inertial navigation system]]s for [[ballistic missile]]s.<ref>MacKenzie, Donald. ''Inventing Accuracy: A Historical Sociology of Nuclear Missile Guidance''. Cambridge: MIT Press, 1990. pp. 40–42. {{ISBN|0-262-13258-3}}</ref>{{full citation needed|date=July 2022}}

During World War II, the gyroscope became the prime component for aircraft and anti-aircraft gun sights.<ref>[http://www.popsci.com/archive-viewer?id=PiEDAAAAMBAJ&pg=86&query=destroyer+escort The Little Top That Aims a Gun] {{webarchive|url=https://web.archive.org/web/20110710151152/http://www.popsci.com/archive-viewer?id=PiEDAAAAMBAJ&pg=86&query=destroyer+escort |date=10 July 2011 }} by Gold Sanders, ''[[Popular Science]]'', July 1945</ref> After the war, the race to miniaturize gyroscopes for guided missiles and weapons navigation systems resulted in the development and manufacturing of so-called '''midget gyroscopes''' that weighed less than {{convert|3|oz|g}} and had a diameter of approximately {{convert|1|in|cm}}. Some of these miniaturized gyroscopes could reach a speed of 24,000 revolutions per minute in less than 10 seconds.<ref>{{cite web|url=https://books.google.com/books?id=nNwDAAAAMBAJ&pg=PA148|title=Popular Mechanics|first=Hearst|last=Magazines|date=1 March 1954|publisher=Hearst Magazines|url-status=live|archive-url=https://web.archive.org/web/20170202032244/https://books.google.com/books?id=nNwDAAAAMBAJ&pg=PA148|archive-date=2 February 2017}}</ref>

Gyroscopes continue to be an engineering challenge. For example, the axle bearings have to be extremely accurate. A small amount of friction is deliberately introduced to the bearings, since otherwise an accuracy of better than <math>10^{-7}</math> of an inch (2.5&nbsp;nm) would be required.{{sfn|Feynman|Gottlieb|Leighton|2013|pp=148–149}}

Three-axis MEMS-based gyroscopes are also used in portable electronic devices such as [[tablet (computer)|tablet]]s,<ref>{{cite web|url=https://www.apple.com/ipad/compare/|title=iPad – Compare Models|website=Apple|url-status=live|archive-url=https://web.archive.org/web/20121024015359/http://www.apple.com/ipad/compare/|archive-date=24 October 2012}}</ref> [[smartphone]]s,<ref>{{cite web|url=http://www.ifixit.com/Teardown/iPhone-4-Gyroscope-Teardown/3156/1|title=iPhone 4 Gyroscope Teardown|date=24 June 2010|url-status=dead|archive-url=https://web.archive.org/web/20111124144402/http://www.ifixit.com/Teardown/iPhone-4-Gyroscope-Teardown/3156/1|archive-date=24 November 2011|access-date=11 November 2011}}</ref> and [[smartwatch]]es.<ref>{{cite news|url=https://www.bbc.com/news/technology-29107354|title=Smartwatches: Specs and reviews for the leading models|date=9 September 2014|last=Kelon|first=Leo|newspaper=[[BBC News]]|department=Technology|url-status=live|archive-url=https://web.archive.org/web/20150828140736/http://www.bbc.com/news/technology-29107354|archive-date=28 August 2015}}</ref> This adds to the 3-axis acceleration sensing ability available on previous generations of devices. Together these sensors provide 6 component motion sensing; accelerometers for X, Y, and Z movement, and gyroscopes for measuring the extent and rate of rotation in space (roll, pitch and yaw). Some devices<ref>{{Cite web|date=24 June 2018|title=Best Android phones with Gyroscope and Accelerator|url=https://aptgadget.com/android-phones-gyroscope-accelerator/|access-date=9 December 2020|website=AptGadget.com|language=en-US|archive-date=26 November 2020|archive-url=https://web.archive.org/web/20201126172745/https://aptgadget.com/android-phones-gyroscope-accelerator/|url-status=live}}</ref><ref>{{cite web|url=https://www.safaribooksonline.com/library/view/basic-sensors-in/9781449309480/ch05.html|title=Basic Sensors in iOS|url-status=dead|archive-url=https://web.archive.org/web/20150723214608/https://www.safaribooksonline.com/library/view/basic-sensors-in/9781449309480/ch05.html|archive-date=23 July 2015|access-date=23 July 2015}}</ref> additionally incorporate a [[magnetometer]] to provide absolute angular measurements relative to the Earth's magnetic field. Newer [[Vibrating structure gyroscope#MEMS gyroscopes|MEMS-based inertial measurement units]] incorporate up to all nine axes of sensing in a single integrated circuit package, providing inexpensive and widely available motion sensing.<ref>{{cite web |url=http://www.st.com/web/en/catalog/sense_power/FM89/SC1448/PF258556 |title=LSM9DS0 iNEMO inertial module:3D accelerometer, 3D gyroscope, 3D magnetometer - STMicroelectronics |access-date=23 July 2015 |url-status=dead |archive-url=https://web.archive.org/web/20150723233203/http://www.st.com/web/en/catalog/sense_power/FM89/SC1448/PF258556 |archive-date=23 July 2015}}</ref>