What is Gravitational waves: Definition and 330 Discussions

Gravitational waves are disturbances in the curvature of spacetime, generated by accelerated masses, that propagate as waves outward from their source at the speed of light. They were proposed by Henri Poincaré in 1905 and subsequently predicted in 1916 by Albert Einstein on the basis of his general theory of relativity. Gravitational waves transport energy as gravitational radiation, a form of radiant energy similar to electromagnetic radiation. Newton's law of universal gravitation, part of classical mechanics, does not provide for their existence, since that law is predicated on the assumption that physical interactions propagate instantaneously (at infinite speed) – showing one of the ways the methods of classical physics are unable to explain phenomena associated with relativity.
The first indirect evidence for the existence of gravitational waves came from the observed orbital decay of the Hulse–Taylor binary pulsar, which matched the decay predicted by general relativity as energy is lost to gravitational radiation. In 1993, Russell A. Hulse and Joseph Hooton Taylor Jr. received the Nobel Prize in Physics for this discovery. The first direct observation of gravitational waves was not made until 2015, when a signal generated by the merger of two black holes was received by the LIGO gravitational wave detectors in Livingston and in Hanford. 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.
In gravitational-wave astronomy, observations of gravitational waves are used to infer data about the sources of gravitational waves. Sources that can be studied this way include binary star systems composed of white dwarfs, neutron stars, and black holes; and events such as supernovae, and the formation of the early universe shortly after the Big Bang.

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  1. I

    B Could you use LIGO-technology to measure gravitational redshift?

    Don't know if this is the right forum, but I'll give it a try: If you build a bridge over a gorge that's a couple km deep the middle of the bridge would be as far away from the mountains on both sides as possible (and therefore as far away from the mountains' gravitational field as possible)...
  2. zinn

    I Separation angle between pulsars detecting Gravitational Waves

    I’m trying to understand the Hellings and Downs curve that is being used to argue for the existence of a gravitational wave background ([NANOGrav article][1]). How can it be that the angle between two pulsars is the only variable that determines if the gravitational waves will interfere...
  3. jedishrfu

    B Quanta Magazine Video on Biggest Breakthroughs in Physics in 2023

    Covers: - Low-frequency gravitational waves - Quantum energy teleportation - JWST Discoveries
  4. Precious Adegbite

    I Can gravitational lensing detect Very small deviations in light propagation?

    So normally with gravitational lensing Technique We get to see how spacetime curvature and gravitational waves affect propagation of light. So I got a questions: (1) I know gravitational waves are caused by supernovas, collisions and other related actions, but would a quantum fluctuations that...
  5. S

    I Would there be any way to avoid gravitational wave emissions?

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  6. S

    A Help with IPTA Gravitational Waveforms Detected

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  7. mfb

    I NANOGrav results on Thursday (June 29)

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  8. phinds

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  9. MrFlanders

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  10. M

    I Is there any way in the future to determine the Universe's size?

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  11. S

    I Can gravitational waves gain energy in an expanding FRW spacetime?

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  12. Z

    I Gravitational Waves from Vanishing Sun: What Happens?

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  13. SH2372 General Relativity - Lecture 11

    SH2372 General Relativity - Lecture 11

    0:00 Perihelion precession of Mercury 17:15 Bending of light 24:48 Shapiro delay 33:32 Pound-Rebka experiment 41:40 Spectral lines of stars 44:58 Gravitational waves 49:22 Other important effects
    • Orodruin
    • Media item
    • Gravitational redshift Gravitational waves
    • Comments: 0
    • Category: Relativity
  14. SH2372 General Relativity - Lecture 8

    SH2372 General Relativity - Lecture 8

    0:00 The weak field limit 27:15 The Newtonian limit 44:00 Gravitational waves 59:27 Geodesic deviation 1:22:15 Measuring gravitational waves
    • Orodruin
    • Media item
    • Gravitational waves
    • Comments: 0
    • Category: Relativity
  15. wcivch

    B Ride Gravitational Waves to Increase Speed?

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  16. A

    I Gravitational vs. Electromagnetic Waves: What's the Difference?

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  17. Oldman too

    I Exploring Gravitational Waves with Earth-Lunar Orbital Perturbations

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  18. N

    I Curved space and gravitational waves

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  19. Dinarchik

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  20. G

    I Information content in electromagnetic or gravitational waves

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  21. U

    Help with a calculation about gravitational waves

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  22. brucegoth123

    I Exploring the Speed of Light: Gravitational Waves

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  23. B

    I Why aren't Gravitational waves factored in to inflation formulas?

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  24. A

    I How do gravitational waves differ from the expansion of the Universe?

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  25. cianfa72

    I Detecting Gravitational Waves w/ Interferometers: Explained

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  26. A

    I Merging black holes: gravitational waves and information

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  27. thegroundhog

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  28. E

    A Cosmological gravitational waves

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  29. D

    B Gravitational Waves: Comparing Effects on Earth

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  30. G

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  31. veraamorim

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  32. lomidrevo

    I Gravitational Waves Emitted by a Binary System

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  33. ComradeConrad

    I Gravitational waves as not "proximal"?

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  34. K

    I Gravitational Waves: Hardest GR Topic?

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  35. L

    I Quantum Measurements with Gravitational Waves

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  36. R

    B Gravitational Waves: Impact & Effects on Gravity

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  37. R

    B Measuring Gravitational Waves w/ Elevator Accelerometer

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  38. R

    B Gravitational Waves: A Question on Earth's Magnitude & Frequency

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  39. T

    B Gravitational Waves in Positively Curved Universe?

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  40. R

    B Detecting Gravitational Waves: Earth-Like Planet Possibility

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  41. pelinkovac

    I Gravitational Wave Creation: Is a Stationary Wave Possible?

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  42. P

    B Consequences of the Existence of Gravitational Waves?

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  43. sbrothy

    B Lensing Gravitational Waves Like Light?

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  44. Prof Mark R Smith

    Insights Gaia and the Race to Detect More Gravitational Waves

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  45. X

    I Playing music with Gravitational waves

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  46. .Scott

    A Black Hole Eating Gravitational Waves - A Look at Physics

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  47. SamRoss

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  48. Raffaele

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  49. JD_PM

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  50. C

    A Do Moving Masses Slow Down Due to Gravitational Waves?

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