Gelombang gravitasi: Perbedaan antara revisi

Dalam [[fisika]], '''gelombang gravitasi''' adalah riak dalam [[lengkung]] [[ruang-waktu]] yang bergerak dalam bentuk [[gelombang]] menjauhi sumbernya. Keberadaan gelombang ini diprediksi pada tahun 1916<ref>{{cite journal |author=Einstein, A |title=Näherungsweise Integration der Feldgleichungen der Gravitation |date= June 1916 |url=http://einstein-annalen.mpiwg-berlin.mpg.de/related_texts/sitzungsberichte |journal=[[Prussian Academy of Sciences|Sitzungsberichte der Königlich Preussischen Akademie der Wissenschaften Berlin]] |volume=part 1 |pages=688–696 |access-date=2016-02-11 |archive-date=2016-01-15 |archive-url=https://web.archive.org/web/20160115224321/http://einstein-annalen.mpiwg-berlin.mpg.de/related_texts/sitzungsberichte |dead-url=no }}</ref><ref>{{cite journal |author=Einstein, A |title=Über Gravitationswellen |date=1918 |url=http://einstein-annalen.mpiwg-berlin.mpg.de/related_texts/sitzungsberichte |journal=Sitzungsberichte der Königlich Preussischen Akademie der Wissenschaften Berlin |volume=part 1 |pages=154–167 |access-date=2016-02-11 |archive-date=2016-01-15 |archive-url=https://web.archive.org/web/20160115224321/http://einstein-annalen.mpiwg-berlin.mpg.de/related_texts/sitzungsberichte |dead-url=no }}</ref> oleh [[Albert Einstein]] sebagai dasar teori [[relativitas umum]] yang dipaparkannya.<ref>{{cite web |last=Finley |first=Dave |title=Einstein's gravity theory passes toughest test yet: Bizarre binary star system pushes study of relativity to new limits. |url=http://phys.org/news/2013-04-einstein-gravity-theory-toughest-bizarre.html |publisher=Phys.Org |access-date=2016-02-11 |archive-date=2018-09-23 |archive-url=https://web.archive.org/web/20180923122924/https://phys.org/news/2013-04-einstein-gravity-theory-toughest-bizarre.html |dead-url=no }}</ref><ref>[{{Cite web |url=http://www.dpf99.library.ucla.edu/session14/barish1412.pdf |title=The Detection of Gravitational Waves using LIGO, B. Barish] |access-date=2016-02-11 |archive-date=2016-03-03 |archive-url=https://web.archive.org/web/20160303205650/http://www.dpf99.library.ucla.edu/session14/barish1412.pdf |dead-url=no }}</ref> Gelombang gravitasi mengangkut [[energi dalam]] bentuk '''radiasi gravitasi'''. Gelombang ini terbentuk akibat [[invariansi Lorentz]] dalam [[relativitas umum]] yang menjelaskan bahwa segala pergerakan interaksi fisik dibatasi oleh kecepatan cahaya. Sebaliknya, gelombang gravitasi tidak dapat terbentuk dalam [[hukum gravitasi universal Newton|teori gravitasi Newton]] yang menyatakan bahwa interaksi fisik bergerak dengan kecepatan tak hingga. Sebelum gelombang ini terdeteksi, sudah ada bukti-bukti tak langsung mengenai keberadaannya. Misalnya, pengukuran sistem [[biner Hulse–Taylor]] menunjukkan bahwa gelombang gravitasi bukan sekadar [[hipotesis]]. Gelombang gravitasi yang dapat terdeteksi diduga berasal dari sistem [[bintang biner]] yang terdiri atas [[katai putih]], [[bintang neutron]], dan [[lubang hitam]].

Pada tahun 2016, beberapa [[pendeteksi gelombang gravitasi]] sedang dibangun atau sudah beroperasi. Salah satu di antaranya adalah [[LIGO|Advanced LIGO]] yang beroperasi pada bulan September 2015.<ref>{{cite web|title=The Newest Search for Gravitational Waves has Begun|url=https://ligo.caltech.edu/news/ligo20150918|website=LIGO Caltech|publisher=[[LIGO]]|accessdate=29 November 2015|date=18 September 2015|archive-date=2022-01-22|archive-url=https://web.archive.org/web/20220122044448/https://www.ligo.caltech.edu/news/ligo20150918|dead-url=no}}</ref> Bulan Februari 2016, tim Advanced LIGO mengumumkan bahwa mereka telah [[deteksi gelombang gravitasi|mendeteksi gelombang gravitasi]] dari proses menyatunya [[lubang hitam]].<ref name="Discovery 2016">{{cite journal |title=Einstein's gravitational waves found at last |journal=Nature News| |url=http://www.nature.com/news/einstein-s-gravitational-waves-found-at-last-1.19361 |date=February 11, 2016 |last=Castelvecchi |first=Davide |last2=Witze |first2=Witze |doi=10.1038/nature.2016.19361 |accessdate=2016-02-11 |archive-date=2016-02-12 |archive-url=https://web.archive.org/web/20160212082216/http://www.nature.com/news/einstein-s-gravitational-waves-found-at-last-1.19361 |dead-url=no }}</ref><ref name='Abbot'>{{cite journal | title=Observation of Gravitational Waves from a Binary Black Hole Merger| authors=B. P. Abbott et al. (LIGO Scientific Collaboration and Virgo Collaboration)| journal=Physical Review Letters| year=2016| volume=116| issue=6| url=https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.116.061102 | doi=10.1103/PhysRevLett.116.061102| access-date=2016-02-11| archive-date=2019-10-25| archive-url=https://web.archive.org/web/20191025233058/https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.116.061102| dead-url=no}}</ref><ref name='NSF'>{{cite web|title = Gravitational waves detected 100 years after Einstein's prediction {{!}} NSF - National Science Foundation|url = http://www.nsf.gov/news/news_summ.jsp?cntn_id=137628|website = www.nsf.gov|access-date = 2016-02-11|archive-date = 2018-07-27|archive-url = https://web.archive.org/web/20180727172452/https://www.nsf.gov/news/news_summ.jsp?cntn_id=137628|dead-url = no}}</ref><ref name="NYT-20160211">{{cite news|last=Overbye|first=Dennis|authorlink=Dennis Overbye|title=Physicists Detect Gravitational Waves, Proving Einstein Right|url=http://www.nytimes.com/2016/02/11/science/ligo-gravitational-waves-black-holes-einstein.html?_r=0|date=11 February 2016|work=[[New York Times]]|accessdate=11 February 2016 }}</ref>

* [[Radiasi Hawking]], [[radiasi elektromagnetik]] yang tercipta lewat gravitasi dari lubang hitam

* Chakrabarty, Indrajit, "[http://arxiv.org/pdf/physics/9908041 Gravitational Waves: An Introduction] {{Webarchive|url=https://web.archive.org/web/20220127072846/https://arxiv.org/pdf/physics/9908041.pdf |date=2022-01-27 }}". arXiv:physics/9908041 v1, Aug 21, 1999.

* Will, Clifford M., ''[http://www.livingreviews.org/lrr-2006-3/ The Confrontation between General Relativity and Experiment] {{Webarchive|url=https://web.archive.org/web/20220127072900/https://www.springer.com/journal/41114 |date=2022-01-27 }}''. ''Living Reviews'' Relativity 9 (2006) 3.

* [http://www.ligo.caltech.edu/ Laser Interferometer Gravitational Wave Observatory] {{Webarchive|url=https://web.archive.org/web/20180126035147/https://www.ligo.caltech.edu/ |date=2018-01-26 }}. LIGO Laboratory, operated by the [[California Institute of Technology]] and the [[Massachusetts Institute of Technology]]