View source for LIGO

[[File:LIGO simplified.svg|thumb|{{center|A simplified schematic of the LIGO detector}}]]
The '''Laser Interferometer Gravitational-Wave Observatory''' ('''LIGO''') is a large-scale [[physics]] [[observatory]] which [[wikt:detect|detect]]s [[Cosmos|cosmic]] [[gravitational wave]]s co-founded by Scottish physicist [[Ronald Drever]].<ref name="Physics_Today_Oct_1999">{{cite journal|last1=Barish|first1=Barry C.|last2=Weiss|first2=Rainer|title=LIGO and the Detection of Gravitational Waves|journal=Physics Today|date=October 1999|volume=52|issue=10|page=44|doi=10.1063/1.882861|url=http://scitation.aip.org/content/aip/magazine/physicstoday/article/52/10/10.1063/1.882861|bibcode = 1999PhT....52j..44B }}</ref> They were first [[wikt:fund|fund]]ed by the [[National Science Foundation]] (NSF) and were [[Concept|conceived]], [[wikt:built|built]] and are [[wikt:operate|operate]]d by [[Caltech]] and [[MIT]].<ref>{{cite web|title=LIGO Lab Caltech MIT|url=https://www.ligo.caltech.edu|access-date=24 June 2016}}</ref><ref>{{cite web|title=LIGO MIT|url=http://space.mit.edu/LIGO|access-date=24 June 2016}}</ref> 
The NSF has funded [[wikt:improvement|improvement]]s for LIGO to increase [[sensitivity (electronics)|sensitivity]], which allowed them to make the first detection of gravitational waves.<ref>{{cite web|title=Revolutionary Grassroots Astrophysics Project "Einstein@Home" Goes Live|url=http://www.aps.org/newsroom/pressreleases/athome1.cfm|access-date=3 March 2016|archive-date=9 April 2023|archive-url=https://web.archive.org/web/20230409133728/https://www.aps.org/newsroom/pressreleases/athome1.cfm|url-status=dead}}</ref><ref name="Census">{{cite web|title=LSC/Virgo Census|url=https://my.ligo.org/census.php|work=myLIGO|access-date=28 November 2015}}</ref> LIGO is the largest and most [[wikt:ambitious|ambitious]] project ever funded by the NSF.<ref> Larger physics projects in the [[United States]], such as [[Fermilab]], have traditionally been funded by the [[United States Department of Energy|Department of Energy]].</ref><ref>{{Cite web |title=LIGO Fact Sheet at NSF |url=http://www.nsf.gov/news/news_summ.jsp?cntn_id=103042 |access-date=2016-10-07 |archive-date=2011-10-31 |archive-url=https://web.archive.org/web/20111031004458/http://nsf.gov/news/news_summ.jsp?cntn_id=103042 |url-status=dead }}</ref>

LIGO is an [[interferometer]]. It fires a [[Laser|laser beam]] and splits it into two laser beams. Mirrors bounce them back towards a light detector and merge them. Normally, the two laser beams should cancel each other, so the light does not reach the detector, but any changes in [[space-time]] caused by [[Gravitational wave|gravity wave]]<nowiki/>s can change the laser beams, so that they don't cancel out fully. When this happens, the light detector will see some of the laser light, which it can then use to work out the size of the space-time distortion.<ref>{{Cite news|url=https://www.theregister.co.uk/2017/10/03/gravitational_wave_detection_wins_nobel_prize_for_physics/|title=Physicists win Nobel Prize for spotting ripples in fabric of space-time|access-date=2018-09-06|language=en}}</ref>

== References ==
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== Other websites ==
* [https://www.youtube.com/watch?v=vd1Pak5f6GQ Physicists Announce the Detection of Gravitational Waves; YouTube]
* [https://www.youtube.com/watch?v=RzZgFKoIfQI LIGO Gravitational Wave Observatory;] [[YouTube]]
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[[Category:Physics]]