Gravitational Wave ○꠹｜Definition｜1st｜20260912121615-00-⌔

Gravitational wave - Wikipedia

Gravitational wave

Gravitational waves are waves of spacetime curvature produced by the relative motion of gravitating masses and which propagate away at the speed of light. They were first predicted by Albert Einstein¹² as a consequence of his general theory of relativity, appearing as “ripples in spacetime curvature”.³⁴${}^{:326}$⁵${}^{:117}$ Hundreds of these gravitational waves have since then been observed, first indirectly using binary-pulsar observations⁶ and, since 2015,⁷ directly through dedicated observatories.

Gravitational waves transport energy as gravitational radiation, a form of radiant energy similar to electromagnetic radiation.⁸ Newton’s law of universal gravitation, part of classical mechanics, does not provide for their existence, instead asserting that gravity has instantaneous effect everywhere. Gravitational waves therefore stand as an important relativistic phenomenon that is absent from Newtonian physics.

Gravitational-wave astronomy has the advantage that, unlike electromagnetic radiation, gravitational waves are not affected by intervening matter. Sources that can be studied this way include binary star systems composed of white dwarfs, neutron stars,⁹¹⁰ and black holes; events such as supernovae; and the formation of the early universe shortly after the Big Bang.

The first indirect evidence for the existence of gravitational waves came in 1974 from the observed orbital decay of the Hulse–Taylor binary pulsar, which matched the decay predicted by general relativity for energy lost to gravitational radiation. In 1993, Russell Alan Hulse and Joseph Hooton Taylor Jr. received the Nobel Prize in Physics for this discovery.

The first direct observation of gravitational waves was made in September 2015, when a signal generated by the merger of two black holes was received by the LIGO gravitational wave detectors in Livingston, Louisiana, and in Hanford, Washington. The 2017 Nobel Prize in Physics was subsequently awarded to Rainer Weiss, Kip Thorne and Barry Barish for their role in the direct detection of gravitational waves.

Printed 2026-09-12.

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Footnotes

1. Einstein, Albert (June 1916). “Näherungsweise Integration der Feldgleichungen der Gravitation”. Sitzungsberichte der Königlich Preussischen Akademie der Wissenschaften Berlin. part 1: 688–96. Bibcode:1916SPAW…688E. Archived from the original on 2016-01-15. ↩

2. Einstein, Albert (1918). “Über Gravitationswellen”. Sitzungsberichte der Königlich Preussischen Akademie der Wissenschaften Berlin. part 1: 154–67. Bibcode:1918SPAW…154E. Archived from the original on 2016-01-15. ↩

3. Thorne, Kip S. (1994). Black holes and time warps: Einstein’s outrageous legacy. The Commonwealth Fund Book Program. New York: W.W. Norton. ISBN 978-0-393-03505-6. ↩

4. Susskind, Leonard (2008). The black hole war: my battle with Stephen Hawking to make the world safe for quantum mechanics (1st ed.). New York: Little, Brown. ISBN 978-0-316-01640-7. ↩

5. Hawking, Stephen W. (1996). The illustrated a brief history of time (Updated and expanded ed.). New York: Bantam Books. ISBN 978-0-553-10374-8. ↩

6. Damour, Thibault (2015-06-25). “1974: the discovery of the first binary pulsar”. Classical and Quantum Gravity. 32 (12) 124009. arXiv:1411.3930. Bibcode:2015CQGra..32l4009D. doi:10.1088/0264-9381/32/12/124009. ISSN 0264-9381. ↩

7. Abbott, B. P.; Abbott, R.; Abbott, T. D.; Abernathy, M. R.; Acernese, F.; Ackley, K.; Adams, C.; Adams, T.; Addesso, P.; Adhikari, R. X.; Adya, V. B.; Affeldt, C.; Agathos, M.; Agatsuma, K.; Aggarwal, N. (2016-02-11). “Observation of Gravitational Waves from a Binary Black Hole Merger”. Physical Review Letters. 116 (6) 061102. arXiv:1602.03837. Bibcode:2016PhRvL.116f1102A. doi:10.1103/PhysRevLett.116.061102. hdl:20.500.11820/76a6ee41-ae30-4d68-8e21-1f54fd97fb67. ISSN 0031-9007. PMID 26918975. ↩

8. Einstein, Albert; Rosen, Nathan (January 1937). “On gravitational waves”. Journal of the Franklin Institute. 223 (1): 43–54. Bibcode:1937FrInJ.223…43E. doi:10.1016/S0016-0032(37)90583-0. ↩

9. Chang, Kenneth (29 June 2021). “A Black Hole Feasted on a Neutron Star. 10 Days Later, It Happened Again – Astronomers had long suspected that collisions between black holes and dead stars occurred, but they had no evidence until a pair of recent detections”. The New York Times. Retrieved 29 June 2021. ↩

10. Abbott, R.; et al. (2021-07-01). “Observation of Gravitational Waves from Two Neutron Star–Black Hole Coalescences”. The Astrophysical Journal Letters. 915 (1): L5. arXiv:2106.15163. Bibcode:2021ApJ…915L…5A. doi:10.3847/2041-8213/ac082e. ISSN 2041-8205. S2CID 235670241. ↩