Editing Gyroscope (section)

{{Short description|Device for measuring or maintaining the orientation and angular velocity}}
{{About||other uses and non-rotary gyroscopes}}
{{Use dmy dates|date=July 2022}}
[[File:3D Gyroscope.png|thumb|250px|right|A gyroscope]]
[[File:Gyroscope operation.gif|thumb|right|A gyroscope in operation, showing the freedom of rotation in all three axes. The rotor will maintain its spin axis direction regardless of the orientation of the outer frame.]]

A '''gyroscope''' (from [[Ancient Greek]] γῦρος ''gŷros'', "round" and σκοπέω ''skopéō'', "to look") is a device used for measuring or maintaining [[Orientation (geometry)|orientation]] and [[angular velocity]].<ref>{{cite web|url=http://www.oxforddictionaries.com/definition/english/gyroscope|website=Oxford Dictionaries|title=Gyroscope|access-date=4 May 2015|url-status=dead|archive-url=https://web.archive.org/web/20150505003851/http://www.oxforddictionaries.com/definition/english/gyroscope|archive-date=5 May 2015}}</ref><ref>{{Cite web|last=Kabai|first=Sándor|title=Gyroscope|work=[[Wolfram Demonstrations Project]]|url-status=live|date=28 September 2007|archive-url=https://web.archive.org/web/20080430090205/http://demonstrations.wolfram.com/Gyroscope/|archive-date=30 April 2008|url=https://demonstrations.wolfram.com/Gyroscope/|access-date=|publisher=[[Wolfram Research|Wolfram]]}}</ref> It is a spinning wheel or disc in which the axis of rotation (spin axis) is free to assume any orientation by itself. When rotating, the orientation of this axis is unaffected by tilting or rotation of the mounting, due to the [[angular momentum#Conservation of angular momentum|conservation of angular momentum]].

Gyroscopes based on other operating principles also exist, such as the microchip-packaged [[Vibrating structure gyroscope#MEMS gyroscopes|MEMS gyroscopes]] found in electronic devices (sometimes called '''gyrometers'''), solid-state [[ring laser gyroscope|ring lasers]], [[fibre optic gyroscope]]s, and the extremely sensitive [[quantum gyroscope]].<ref>{{cite journal|last1=Tao|first1=W.|last2=Liu|first2=T.|last3=Zheng|first3=R.|last4=Feng|first4=H.|title=Gait Analysis Using Wearable Sensors|journal=[[Sensors (journal)|Sensors]]|location=Basel, Switzerland|date=2012|volume=12|issue=2|pages=2255–2283|doi=10.3390/s120202255|pmid=22438763 |pmc=3304165 |bibcode=2012Senso..12.2255T |doi-access=free }}.</ref>

Applications of gyroscopes include [[inertial navigation system]]s, such as in the [[Hubble Space Telescope]], or inside the steel hull of a submerged submarine. Due to their precision, gyroscopes are also used in [[gyrotheodolite]]s to maintain direction in tunnel mining.<ref>{{cite web |url=http://discovermagazine.com/2009/may/20-things-you-didnt-know-about-tunnels |title=20 things you didn't know about tunnels |work=[[Discover (magazine)|Discover]] |date=29 April 2009 |url-status=live |archive-url=https://web.archive.org/web/20090615212002/http://discovermagazine.com/2009/may/20-things-you-didnt-know-about-tunnels |archive-date=15 June 2009}}</ref> Gyroscopes can be used to construct [[gyrocompass]]es, which complement or replace [[Magnetic Compass|magnetic compasses]] (in ships, aircraft and spacecraft, vehicles in general), to assist in stability (bicycles, motorcycles, and ships) or be used as part of an [[inertial guidance system]].

[[MEMS gyroscope|MEMS (Micro-Electro-Mechanical System) gyroscopes]] are popular in some consumer electronics, such as smartphones.