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Some conflicting information in the "difficulties of detection" section. Frequencies do not seem to be accurate, at least compared to Hawking's estimates cited earlier in the article (probably near the introduction)
This is a page about GRAVITATIONAL WAVES. And suddendly, this paragraph is obviously about GRAVITY. Confusion in some minds? see https://kn0l.wordpress.com/la-gravite-est-elle-instantanee/ (in french) — Preceding unsigned comment added by 163.47.106.116 ( talk) 01:12, 12 January 2017 (UTC)
In the Advanced Mathematics section, could someone kindly provide a reference to a proof of the claim that solutions of are waves traveling with velocity ?
Leonard Huang ( talk) 19:36, 25 February 2017 (UTC)
Dr Baker Jr's collaborator's work in HFGW finds a reference in the main article. His site GravWaves has a detailed account of the history and development of GW research. He is a pioneer in the HFGW field, however, this article is not restricted to LFGW; the article is called Gravitational waves. The US patents form an integral part of the technology researched to find applications for HFGW; therefore, they are very relevant for a general reader. The edits which added the links were started months back by another editor and there was no objection by the current editors who were very much observant even then. Now, why this war-like situation? In a Wikipedia article, a general account of the subject is given which includes technology and other educative pages from the internet. GW is a developing field, hence, all possibilities and potentials are to be respected and presented. Please, enlighten me, how taking away technology possibilities of HFGW would enrich the article? My request is to give what I discussed here a thought. Thanks User:Mandot —Preceding undated comment added 11:42, 13 September 2017 (UTC)
References
All editors watching this page please note that User:Deacon Vorbis is repeatedly indulging in abusive language usage on Edit summary. You may see the recent edits and reverts. The link of a US patent was added by me more than 2 months back. Nobody objected to it, there are more than 350 editors watching this page. Today, I noticed a group of editors led by User:Deacon Vorbis arbitrarily deciding that the link does not belong here. It is a US patent of a relevant technology also reported in national newspapers. It teaches a method to modulate the invariant mass of an object which creates gravitational waves. Why shouldn't it belong here? The man who holds a patent has a Wikipedia page on his works. The use of obscene and abusive words clearly show bias of this group of editors. They are behaving like dictators who suddenly decide to remove some relevant links in a motivated manner. The use of abusive language by Wikipedia editors has indeed lowered the dignity of Wikipedia Cottonmother —Preceding undated comment added 14:19, 13 September 2017 (UTC)
~~~~
.The current mathematics section is somewhat of a relic of an old version of this page from before any experimental confirmation of the topic. Since then this page has grown significantly, and has become of interest to a much wider audience. I think it might be better to relegate the rather technical (and textbooky) material of this section to other more relevant pages. What do others think? T R 15:08, 22 September 2017 (UTC)
It would be helpful if the article described the radiation pattern of the binary systems discussed. The purple diagram shows omnidirectional radiation in the orbital plane. From symmetry, I would guess this was +polarized. Can this radiate angular momentum? Is there also circular-polarized radiation in the polar directions? If so, is the power radiation pattern a sphere (isotropic)? Is the angular-momentum radiation pattern a doughnut, a sphere or a dumbbell? Thanks, -- catslash ( talk) 18:52, 25 September 2017 (UTC)
Many thanks for such a clear and comprehensive answer. -- catslash ( talk) 13:37, 26 September 2017 (UTC)
An anonymous comment under the Talk:Gravitational wave/Archive 5#Poincaré first predicted gravitational waves before Einstein section above says "Gravitational waves don't produce any gravity or gravitational effects." Is this true? Surely if gravitational waves carry energy they must create a gravitational effect of their own? Not detectable in front of the wave, any more than a sonic boom can be heard in front of the aircraft producing it, but detectable behind and to the sides. If this is not the case, the overall curvature of space-time would change every time black holes collide, which appears absurd. Do these secondary gravitational effects contribute materially to the question of dark matter, or is the cumulative effect of billions of years worth of waves still negligible?-- Keith Edkins ( Talk ) 17:25, 9 October 2017 (UTC)
Spope3 ( talk) 01:15, 11 November 2017 (UTC)
Graeme Bartlett - thanks. I agree on the definition of "hot". Thanks. I think the pulsar timing measurements are not indicative of the mass-energy of the gravitons that comprise the GWB; they instead measure the strain cause by such waves between the instrument and the pulsar. These will be very different when there are a large number of small sources contributing to the GWB. Sources that contribute to the strain may combine destructively, whereas the mass-energy of any one graviton is always positive and so these combine additively. Simplistically I would expect the mass-energy to scale with the number of sources, and the magnitude of the strain with the square root of this number. Spope3 ( talk) 21:57, 12 February 2018 (UTC)
Yes, there's no question that there are negative results from the pulsar timing study you referenced (Shannon) and also more extensive studies from the NanoGrav Collaboration (Mingarelli - here: https://arxiv.org/abs/1508.03024 ). The question is what is being ruled out. As I described above, at some point the central limit theorem figures into the negative outcome -- the GWB as measured by strain is combination of a large number of sources and so does not measure directly the mass-energy in the background. The link between these two is model-dependent. This is described in much more detail in Mingarelli - sections 1.2 and 1.3 of the introduction. But yes the results are so far negatvie. Spope3 ( talk) 19:00, 14 February 2018 (UTC)
The interferometer has two perpendicular arms, so when the wavefront of a passing gravitational wave is parallel to one arm and perpendicular to the other (as shown in the illustration), then the instrument is sensitive to the passing of the wave. Per the current text, this "is precisely the motion to which an interferometer is most sensitive". But what happens to the sensitivity if the wave happens to come from an equal (45 degree) angle to both arms? Would a wave from this direction be detectable at all? Is there some trigonometric relation between the sensitivity and angles between 0 and 45 degrees ? Similarly, what about a wave perpendicular to both arms, i.e. a wavefront parallel to the plane spanned by the two arms? Would a wave from this direction be detectable at all? I think the article could be expanded to cover such limitations. Further, I am guessing one reason interferometers suitable for detecting gravitational waves are being built on different parts of the Earth is exactly to try to avoid such blind (or deaf?) spots. Some information related to this would also be interesting. Lastly, I am thinking that the (millisecond scale) delay between the detections in different interferometers is what allows for the (coarse) localization of the source of the wave. This additional advantage of having multiple, well separated detectors would also be good to point out. Thanks! Lklundin ( talk) 20:05, 21 October 2017 (UTC)
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In this section: The sources of gravitational waves described above are in the low-frequency end of the gravitational-wave spectrum (10−7 to 105 Hz). An astrophysical source at the high-frequency end of the gravitational-wave spectrum (above 105 Hz and probably 1010 Hz) generates[clarification needed] relic gravitational waves that are theorized to be faint imprints of the Big Bang like the cosmic microwave background.[54]
It seems to me that high and low frequency ranges are mentioned incorrectly. The "waves described above" are in the high-frequency end; gravitational waves originating form the Big Bang have long wavelengths, low frequencies. Bookaneer ( talk) 12:22, 3 November 2017 (UTC)
In the Effects of Passing section of this page, there is a paraphrased reference to LIGO's sensitivity that compares it to measuring the distance between us and the nearest star to an accuracy of one human hair. That is the *limit* of LIGO's ability to sense the gravity waves, but it is not necessarily the actual size of the waves. Unless gravity waves AND the sensitivity of LIGO are exactly identical, this section needs corrected. — Preceding unsigned comment added by 40.0.40.10 ( talk) 08:13, 7 November 2017 (UTC)
Are the recent laser interferometer tests proof of a '"fabric" of reality," and is this simple three-word term, as are the two main ideas in it, aside from being a nice title for a book, rather or not quite eloquent and useful in the way of describing where gravitational waves live and their effects? Regards, Inowen (nlfte) 00:52, 18 January 2018 (UTC)
This part is junk. Either the writer means gravitational waves are a kind of radiation, which they arent; they are distortions in spacetime, or energy within gravitation waves is transformed in accord with a gravitational principle, which is technical and does not belong in the introduction. - Inowen ( nlfte) 02:39, 12 September 2018 (UTC)
The article leaves no doubt that gravitational waves as "disturbances of spacetime" are real, at least since they have been discovered experimentally (by measurement). I admit that the LIGO experiment has measured real effects; but did these effects say to the experimenter "Hello, here we are, and we are disturbances of spacetime"? I doubt this. Rather the identification of the measured effects as demonstrating the existence of "gravitational waves in the sense of Einstein's general relativity" evidently requires to presuppose Einstein's theory which predicts the existence of spacetime and of these waves as disturbances of it. Without the presupposed ART nobody would ever have understood some unidentified waves in this very sense. The suspicion then is well-founded that the identification results from a logical mistake, say of begging the question, and therefore is unjustified. Ed Dellian 2003:D2:9703:5941:A81D:7A1B:AD26:ABD0 ( talk) 11:39, 5 November 2018 (UTC)
Is this a real controversy that should be included in the article? Tom Ruen ( talk) 13:06, 4 December 2018 (UTC)
FWIW - Seems, more recently, in December 2018, a relevant report [1] was published in Quanta Magazine - in any case - Enjoy! :) Drbogdan ( talk) 14:09, 2 January 2019 (UTC)
References
There's a well known saying that starts off with, "If it quacks like a duck..." Cloudswrest ( talk) 15:01, 2 January 2019 (UTC)
This article should cover the expected effects on gravitational time dilation, not just space. 77.86.117.208 ( talk) 09:48, 13 November 2018 (UTC)
Hello everyone. As mentioned in the title, such operation would alter the meaning a bit and most importantly, suit the definition of the article nowadays such as: "In physics, gravitational radiation refers to the wave (or its quantum, gravitons) of the gravitational field, propagating (radiating) through space, carrying gravitational radiant energy." I would like to hear anyone's reply. Dominic3203 ( talk) 09:25, 30 January 2019 (UTC)
A Lagrangian point exists midway between two equal masses where their gravitational field cancel. I see no sign of cancellation between the black holes persisting in the simulation video. Is this correct? DroneB ( talk) 20:41, 7 May 2019 (UTC)
Apparently, recently added text/refs re a "Gravitational wave memory effect" (see copy of edit below) has been reverted as "not useful to include" - others may (or may not) agree - Comments Welcome from other editors - in any case - Enjoy! :) Drbogdan ( talk) 15:30, 8 May 2019 (UTC)
Copied, in part, from " Gravitational wave - diff - 05/08/2019"
---Gravitational wave memory effect--- Gravitational waves may interact with matter causing a gravitational wave memory effect, a permanent (and measurable) record of displacement, regarded byresearchers as persistent gravitational wave observables. One measurable example of such an effect is a geodesic deviation allowing for arbitrary acceleration; another, a holonomy observable; and finally, a particular procedure based on a spinning test particle. [1] [2] [3] [4] [5] [6] [7] [8] [9]
(Note: some references below may contain duplicated content)
References
- ^ Flanagan, Éanna É.; et al. (25 April 2019). "Persistent gravitational wave observables: General framework". Physical Review D. 99 (8). doi: 10.1103/PhysRevD.99.084044. Retrieved 8 May 2019.
- ^ Francis, Matthew r. (25 April 2019). "Synopsis: Persistence of Gravitational-Wave Memory - Researchers predict the existence of three new long-lived signatures of gravitational waves, as part of a unified mathematical framework for identifying such effects". APS Physics. Retrieved 8 May 2019.
- ^ Starr, Michelle (8 May 2019). "Gravitational Waves Could Be Leaving Some Weird Lasting Effects in Their Wake". ScienceAlert.com. Retrieved 8 May 2019.
- ^ Duffy, Alan (8 May 2019). "Wrinkles in the fabric of spacetime - New analysis suggests gravitational waves leave lasting marks on the particles they strike". Cosmos. Retrieved 13 May 2019.
- ^ Letzter, Rafi (9 May 2019). "The Universe Probably 'Remembers' Every Single Gravitational Wave". Live Science. Retrieved 9 May 2019.
- ^ Cornell University (9 May 2019). "Gravitational waves leave a detectable mark, physicists say". EurekAlert!. Retrieved 9 May 2019.
- ^ Glaser, Linda B. (9 May 2019). "Gravitational waves leave a detectable mark, physicists say". Phys.org. Retrieved 9 May 2019.
- ^ Glaser, Linda (12 May 2019). "Scientists Show Gravitational Waves Leave Detectable Mark". SciTechDaily.com. Retrieved 12 May 2019.
- ^ Letzler, Rafi (14 May 2019). "The Universe Probably 'Remembers' Every Single Gravitational Wave". Space.com. Retrieved 14 May 2019.
"1. Not rational; unfounded or nonsensical."You may not agree with me, but that doesn't justify your calling my revert "irrational", since I clearly spelled out my reasons above. Furthermore, there was no description in the edit history; it was merely a copy/paste of the text added to the article, which is rarely helpful. But even still, what's in the edit history is meaningless for what's in the article, so I don't know why you even brought that up. Finally, you haven't addressed the objections I raised initially, so I can't meaningfully respond. However, if you'd like to make any suggestions that begin to address the objections I had, then I'd be happy to listen. – Deacon Vorbis ( carbon • videos) 02:52, 14 May 2019 (UTC)
FWIW - worthy recent reference [1] (in some way?) for this (or related) article? - seems clear - and well written - Comments Welcome - in any case - Enjoy! :) Drbogdan ( talk) 14:59, 30 July 2019 (UTC)
Of course, all of this is just preliminary at this point. The LIGO collaboration has yet to announce a definitive detection of any type, and the IceCube event may turn out to be either a foreground, unrelated neutrino or a spurious event entirely. No electromagnetic signal has been announced, and there might not be one at all.
References
1. "Gravitational waves are disturbances in the curvature of spacetime, generated by accelerated masses" Because any movement in Kepler mechanics is result of gravity, it means that any mass movement generates gravitational waves. Isn't better to write that gravitational waves are result of mass M repeatable movement when dM≠0 or dR≠0 in any point of its trajectory, where R is a distance to foci?
2. According to /info/en/?search=Radiation and /info/en/?search=Conservation_of_energy any radiating system loses energy. It is good when we speak about merger of two black holes but certainly is not right in case of Earth that still orbits Sun. So we must choose one of two: gravitational waves aren't radiation or Earth orbiting Sun doesn't generate gravitational waves (that means that definition of gravitation waves is wrong).
3. "Gravitational waves are disturbances in the curvature of spacetime" means that gravitational waves are changing of gravitational field, so it (mass and gravitational field) is similar to electric charge and electric field and means that according to /info/en/?search=Conservation_of_energy , movement of source of the field changes field at the same time that means that any changing of gravitational field aka "gravitational waves" occurs instantly and hasn't "speed" (this is difference between "field" and "radiation"). 178.140.161.126 ( talk) 15:35, 30 July 2019 (UTC)
There are two definitions of gravitational waves -
LeeMcLoughlinScientist ( talk) 18:44, 14 October 2022 (UTC)
A wave is a property of something, it can't be an entity in itself. Particles are just that, partlicles. And so a wave can be a property of particles. As I said before, photons must have a frequency/wavelength because that determines how fast the electric and magnetic forces peak in turn. Gravitons are not like photons. Photons carry two forces (E and M) but gravity is singular. It doesn't require a frequency. Gravitons can propagate flat with no frequency. If gravity had a frequency then there would be different energies of gravity for different frequency. This is not consistent with observations. LeeMcLoughlinScientist ( talk) 19:24, 16 October 2022 (UTC)
In the article's very first sentence today, it claims that gravity waves 'propagate as waves outward from their source at the speed of light.'
That's an important assertion, and much may hang on it. But I found no citations to support it (none immediately follow it). Also unclear: is this a purely theoretical assertion? else what empirical evidence is there to support it? Supporting evidence needs to be cited; a discussion in the article would be welcome. Thanks, and the *only* reply I seek is clarification of the article. Twang ( talk) 17:38, 7 January 2020 (UTC)
UPDATE: Seems a gravitational wave may arrive before a light wave in some related instances, according to a recent science report. [2] - Drbogdan ( talk) 13:01, 26 October 2023 (UTC)
References
The article should include an explanation of the difference between spacetime and gravity. In the rod&bead experiment it is unclear why the gravitational waves would affect just the beads along the rod and not the space housing the atoms of the rod itself (and therefore the rod) as well. Gravitational waves are disturbances in spacetime, why affect and move just the beads and not the space housing the atoms of the rod (and the space anywhere the rod may be attached for that matter)? 86.93.208.34 ( talk) 00:49, 12 May 2020 (UTC)
There is the phrase: polarizations of a gravitational wave are 45 degrees apart with a {{ cn}}. If you look at the polarization videos, you can see that, in the same way that dipole waves have polarizations 90 degrees apart, quadrupole waves polarizations are 45 degrees apart. Rotating 90 degrees, results in the same signal (though with a phase shift). I suppose it would be nice to have a reference, though, but it is pretty much obvious for a quadrupole field. Gah4 ( talk) 10:02, 1 July 2020 (UTC)
The article uses the non-SI square degree for how well the direction can be determined, instead of the SI steradian. Should we also give the SI unit? Gah4 ( talk) 13:35, 8 July 2020 (UTC)
{{
convert}}
doesn't handle solid angle (that I could find). It might be worth adding there rather than doing by hand. Even more useful to a casual reader, though, might be to note that this is about 0.15% of the total sky, or about 320 times the area covered by a full moon. –
Deacon Vorbis (
carbon •
videos)
13:53, 8 July 2020 (UTC)
{{convert}}
will tell you the apparent age of your dog that you got 42 fortnights (0.23 dog years) ago! –
Deacon Vorbis (
carbon •
videos)
13:59, 8 July 2020 (UTC)
The section on redshift has a few {{ citation needed}}, and I might see if I can find some. In the case of light, redshift is useful as we can compare spectral lines to known lines, and compute the redshift. In the case of GW, there are no spectral lines, so there is nothing to compare. Presumably the physics requires it, but it doesn't seem so useful. Gah4 ( talk) 01:53, 26 November 2020 (UTC)
Earth-sized interferometry isn't big enough for very long primordial gravitational wave detection (it has a cut-off [frequency limit]). Write more. Ask NASA and CNSA (physicists are friendly).
future missions
— Preceding
unsigned comment added by
2A02:587:411F:F7D5:D013:D83D:B586:E11E (
talk)
17:26, 30 April 2021 (UTC)Which is the scientific document that expressed first loud and clear that "Gravitational waves are (disturbances in the curvature of spacetime,) generated by accelerated masses (, that propagate as waves)"? Yoxxa ( talk) 12:03, 12 June 2021 (UTC)
Would a physicist like to confirm that this sentence from the article is true – or correct it? "The magnitude of this effect decreases in proportion to the inverse distance from the source." I think that sentence contains a subtle double-negative; literally, it means that a gravitational wave grows as it propagates. I would have expected something like, "The magnitude of this effect is inversely proportional to the distance from the source." Also, I want a gold star for noticing this. Wegesrand ( talk) 17:42, 7 April 2022 (UTC)
Recently the North American Nanohertz Observatory for Gravitational Waves announced the successful culmination of 50 years of development of the idea of detecting gravitational waves by pulsar observations. Someone removed the reference to the research consortium and replaced it with the non-specific passive tense "was claimed to be detected", despite the consortium being clearly identified in the reference. This is not good Wikipedia practice! Wikilinking the consortium would have been, so I have done so in a new edit. Elroch ( talk) 19:57, 1 July 2023 (UTC)
![]() | This ![]() It is of interest to the following WikiProjects: | ||||||||||||||||||||||||||
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Some conflicting information in the "difficulties of detection" section. Frequencies do not seem to be accurate, at least compared to Hawking's estimates cited earlier in the article (probably near the introduction)
This is a page about GRAVITATIONAL WAVES. And suddendly, this paragraph is obviously about GRAVITY. Confusion in some minds? see https://kn0l.wordpress.com/la-gravite-est-elle-instantanee/ (in french) — Preceding unsigned comment added by 163.47.106.116 ( talk) 01:12, 12 January 2017 (UTC)
In the Advanced Mathematics section, could someone kindly provide a reference to a proof of the claim that solutions of are waves traveling with velocity ?
Leonard Huang ( talk) 19:36, 25 February 2017 (UTC)
Dr Baker Jr's collaborator's work in HFGW finds a reference in the main article. His site GravWaves has a detailed account of the history and development of GW research. He is a pioneer in the HFGW field, however, this article is not restricted to LFGW; the article is called Gravitational waves. The US patents form an integral part of the technology researched to find applications for HFGW; therefore, they are very relevant for a general reader. The edits which added the links were started months back by another editor and there was no objection by the current editors who were very much observant even then. Now, why this war-like situation? In a Wikipedia article, a general account of the subject is given which includes technology and other educative pages from the internet. GW is a developing field, hence, all possibilities and potentials are to be respected and presented. Please, enlighten me, how taking away technology possibilities of HFGW would enrich the article? My request is to give what I discussed here a thought. Thanks User:Mandot —Preceding undated comment added 11:42, 13 September 2017 (UTC)
References
All editors watching this page please note that User:Deacon Vorbis is repeatedly indulging in abusive language usage on Edit summary. You may see the recent edits and reverts. The link of a US patent was added by me more than 2 months back. Nobody objected to it, there are more than 350 editors watching this page. Today, I noticed a group of editors led by User:Deacon Vorbis arbitrarily deciding that the link does not belong here. It is a US patent of a relevant technology also reported in national newspapers. It teaches a method to modulate the invariant mass of an object which creates gravitational waves. Why shouldn't it belong here? The man who holds a patent has a Wikipedia page on his works. The use of obscene and abusive words clearly show bias of this group of editors. They are behaving like dictators who suddenly decide to remove some relevant links in a motivated manner. The use of abusive language by Wikipedia editors has indeed lowered the dignity of Wikipedia Cottonmother —Preceding undated comment added 14:19, 13 September 2017 (UTC)
~~~~
.The current mathematics section is somewhat of a relic of an old version of this page from before any experimental confirmation of the topic. Since then this page has grown significantly, and has become of interest to a much wider audience. I think it might be better to relegate the rather technical (and textbooky) material of this section to other more relevant pages. What do others think? T R 15:08, 22 September 2017 (UTC)
It would be helpful if the article described the radiation pattern of the binary systems discussed. The purple diagram shows omnidirectional radiation in the orbital plane. From symmetry, I would guess this was +polarized. Can this radiate angular momentum? Is there also circular-polarized radiation in the polar directions? If so, is the power radiation pattern a sphere (isotropic)? Is the angular-momentum radiation pattern a doughnut, a sphere or a dumbbell? Thanks, -- catslash ( talk) 18:52, 25 September 2017 (UTC)
Many thanks for such a clear and comprehensive answer. -- catslash ( talk) 13:37, 26 September 2017 (UTC)
An anonymous comment under the Talk:Gravitational wave/Archive 5#Poincaré first predicted gravitational waves before Einstein section above says "Gravitational waves don't produce any gravity or gravitational effects." Is this true? Surely if gravitational waves carry energy they must create a gravitational effect of their own? Not detectable in front of the wave, any more than a sonic boom can be heard in front of the aircraft producing it, but detectable behind and to the sides. If this is not the case, the overall curvature of space-time would change every time black holes collide, which appears absurd. Do these secondary gravitational effects contribute materially to the question of dark matter, or is the cumulative effect of billions of years worth of waves still negligible?-- Keith Edkins ( Talk ) 17:25, 9 October 2017 (UTC)
Spope3 ( talk) 01:15, 11 November 2017 (UTC)
Graeme Bartlett - thanks. I agree on the definition of "hot". Thanks. I think the pulsar timing measurements are not indicative of the mass-energy of the gravitons that comprise the GWB; they instead measure the strain cause by such waves between the instrument and the pulsar. These will be very different when there are a large number of small sources contributing to the GWB. Sources that contribute to the strain may combine destructively, whereas the mass-energy of any one graviton is always positive and so these combine additively. Simplistically I would expect the mass-energy to scale with the number of sources, and the magnitude of the strain with the square root of this number. Spope3 ( talk) 21:57, 12 February 2018 (UTC)
Yes, there's no question that there are negative results from the pulsar timing study you referenced (Shannon) and also more extensive studies from the NanoGrav Collaboration (Mingarelli - here: https://arxiv.org/abs/1508.03024 ). The question is what is being ruled out. As I described above, at some point the central limit theorem figures into the negative outcome -- the GWB as measured by strain is combination of a large number of sources and so does not measure directly the mass-energy in the background. The link between these two is model-dependent. This is described in much more detail in Mingarelli - sections 1.2 and 1.3 of the introduction. But yes the results are so far negatvie. Spope3 ( talk) 19:00, 14 February 2018 (UTC)
The interferometer has two perpendicular arms, so when the wavefront of a passing gravitational wave is parallel to one arm and perpendicular to the other (as shown in the illustration), then the instrument is sensitive to the passing of the wave. Per the current text, this "is precisely the motion to which an interferometer is most sensitive". But what happens to the sensitivity if the wave happens to come from an equal (45 degree) angle to both arms? Would a wave from this direction be detectable at all? Is there some trigonometric relation between the sensitivity and angles between 0 and 45 degrees ? Similarly, what about a wave perpendicular to both arms, i.e. a wavefront parallel to the plane spanned by the two arms? Would a wave from this direction be detectable at all? I think the article could be expanded to cover such limitations. Further, I am guessing one reason interferometers suitable for detecting gravitational waves are being built on different parts of the Earth is exactly to try to avoid such blind (or deaf?) spots. Some information related to this would also be interesting. Lastly, I am thinking that the (millisecond scale) delay between the detections in different interferometers is what allows for the (coarse) localization of the source of the wave. This additional advantage of having multiple, well separated detectors would also be good to point out. Thanks! Lklundin ( talk) 20:05, 21 October 2017 (UTC)
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In this section: The sources of gravitational waves described above are in the low-frequency end of the gravitational-wave spectrum (10−7 to 105 Hz). An astrophysical source at the high-frequency end of the gravitational-wave spectrum (above 105 Hz and probably 1010 Hz) generates[clarification needed] relic gravitational waves that are theorized to be faint imprints of the Big Bang like the cosmic microwave background.[54]
It seems to me that high and low frequency ranges are mentioned incorrectly. The "waves described above" are in the high-frequency end; gravitational waves originating form the Big Bang have long wavelengths, low frequencies. Bookaneer ( talk) 12:22, 3 November 2017 (UTC)
In the Effects of Passing section of this page, there is a paraphrased reference to LIGO's sensitivity that compares it to measuring the distance between us and the nearest star to an accuracy of one human hair. That is the *limit* of LIGO's ability to sense the gravity waves, but it is not necessarily the actual size of the waves. Unless gravity waves AND the sensitivity of LIGO are exactly identical, this section needs corrected. — Preceding unsigned comment added by 40.0.40.10 ( talk) 08:13, 7 November 2017 (UTC)
Are the recent laser interferometer tests proof of a '"fabric" of reality," and is this simple three-word term, as are the two main ideas in it, aside from being a nice title for a book, rather or not quite eloquent and useful in the way of describing where gravitational waves live and their effects? Regards, Inowen (nlfte) 00:52, 18 January 2018 (UTC)
This part is junk. Either the writer means gravitational waves are a kind of radiation, which they arent; they are distortions in spacetime, or energy within gravitation waves is transformed in accord with a gravitational principle, which is technical and does not belong in the introduction. - Inowen ( nlfte) 02:39, 12 September 2018 (UTC)
The article leaves no doubt that gravitational waves as "disturbances of spacetime" are real, at least since they have been discovered experimentally (by measurement). I admit that the LIGO experiment has measured real effects; but did these effects say to the experimenter "Hello, here we are, and we are disturbances of spacetime"? I doubt this. Rather the identification of the measured effects as demonstrating the existence of "gravitational waves in the sense of Einstein's general relativity" evidently requires to presuppose Einstein's theory which predicts the existence of spacetime and of these waves as disturbances of it. Without the presupposed ART nobody would ever have understood some unidentified waves in this very sense. The suspicion then is well-founded that the identification results from a logical mistake, say of begging the question, and therefore is unjustified. Ed Dellian 2003:D2:9703:5941:A81D:7A1B:AD26:ABD0 ( talk) 11:39, 5 November 2018 (UTC)
Is this a real controversy that should be included in the article? Tom Ruen ( talk) 13:06, 4 December 2018 (UTC)
FWIW - Seems, more recently, in December 2018, a relevant report [1] was published in Quanta Magazine - in any case - Enjoy! :) Drbogdan ( talk) 14:09, 2 January 2019 (UTC)
References
There's a well known saying that starts off with, "If it quacks like a duck..." Cloudswrest ( talk) 15:01, 2 January 2019 (UTC)
This article should cover the expected effects on gravitational time dilation, not just space. 77.86.117.208 ( talk) 09:48, 13 November 2018 (UTC)
Hello everyone. As mentioned in the title, such operation would alter the meaning a bit and most importantly, suit the definition of the article nowadays such as: "In physics, gravitational radiation refers to the wave (or its quantum, gravitons) of the gravitational field, propagating (radiating) through space, carrying gravitational radiant energy." I would like to hear anyone's reply. Dominic3203 ( talk) 09:25, 30 January 2019 (UTC)
A Lagrangian point exists midway between two equal masses where their gravitational field cancel. I see no sign of cancellation between the black holes persisting in the simulation video. Is this correct? DroneB ( talk) 20:41, 7 May 2019 (UTC)
Apparently, recently added text/refs re a "Gravitational wave memory effect" (see copy of edit below) has been reverted as "not useful to include" - others may (or may not) agree - Comments Welcome from other editors - in any case - Enjoy! :) Drbogdan ( talk) 15:30, 8 May 2019 (UTC)
Copied, in part, from " Gravitational wave - diff - 05/08/2019"
---Gravitational wave memory effect--- Gravitational waves may interact with matter causing a gravitational wave memory effect, a permanent (and measurable) record of displacement, regarded byresearchers as persistent gravitational wave observables. One measurable example of such an effect is a geodesic deviation allowing for arbitrary acceleration; another, a holonomy observable; and finally, a particular procedure based on a spinning test particle. [1] [2] [3] [4] [5] [6] [7] [8] [9]
(Note: some references below may contain duplicated content)
References
- ^ Flanagan, Éanna É.; et al. (25 April 2019). "Persistent gravitational wave observables: General framework". Physical Review D. 99 (8). doi: 10.1103/PhysRevD.99.084044. Retrieved 8 May 2019.
- ^ Francis, Matthew r. (25 April 2019). "Synopsis: Persistence of Gravitational-Wave Memory - Researchers predict the existence of three new long-lived signatures of gravitational waves, as part of a unified mathematical framework for identifying such effects". APS Physics. Retrieved 8 May 2019.
- ^ Starr, Michelle (8 May 2019). "Gravitational Waves Could Be Leaving Some Weird Lasting Effects in Their Wake". ScienceAlert.com. Retrieved 8 May 2019.
- ^ Duffy, Alan (8 May 2019). "Wrinkles in the fabric of spacetime - New analysis suggests gravitational waves leave lasting marks on the particles they strike". Cosmos. Retrieved 13 May 2019.
- ^ Letzter, Rafi (9 May 2019). "The Universe Probably 'Remembers' Every Single Gravitational Wave". Live Science. Retrieved 9 May 2019.
- ^ Cornell University (9 May 2019). "Gravitational waves leave a detectable mark, physicists say". EurekAlert!. Retrieved 9 May 2019.
- ^ Glaser, Linda B. (9 May 2019). "Gravitational waves leave a detectable mark, physicists say". Phys.org. Retrieved 9 May 2019.
- ^ Glaser, Linda (12 May 2019). "Scientists Show Gravitational Waves Leave Detectable Mark". SciTechDaily.com. Retrieved 12 May 2019.
- ^ Letzler, Rafi (14 May 2019). "The Universe Probably 'Remembers' Every Single Gravitational Wave". Space.com. Retrieved 14 May 2019.
"1. Not rational; unfounded or nonsensical."You may not agree with me, but that doesn't justify your calling my revert "irrational", since I clearly spelled out my reasons above. Furthermore, there was no description in the edit history; it was merely a copy/paste of the text added to the article, which is rarely helpful. But even still, what's in the edit history is meaningless for what's in the article, so I don't know why you even brought that up. Finally, you haven't addressed the objections I raised initially, so I can't meaningfully respond. However, if you'd like to make any suggestions that begin to address the objections I had, then I'd be happy to listen. – Deacon Vorbis ( carbon • videos) 02:52, 14 May 2019 (UTC)
FWIW - worthy recent reference [1] (in some way?) for this (or related) article? - seems clear - and well written - Comments Welcome - in any case - Enjoy! :) Drbogdan ( talk) 14:59, 30 July 2019 (UTC)
Of course, all of this is just preliminary at this point. The LIGO collaboration has yet to announce a definitive detection of any type, and the IceCube event may turn out to be either a foreground, unrelated neutrino or a spurious event entirely. No electromagnetic signal has been announced, and there might not be one at all.
References
1. "Gravitational waves are disturbances in the curvature of spacetime, generated by accelerated masses" Because any movement in Kepler mechanics is result of gravity, it means that any mass movement generates gravitational waves. Isn't better to write that gravitational waves are result of mass M repeatable movement when dM≠0 or dR≠0 in any point of its trajectory, where R is a distance to foci?
2. According to /info/en/?search=Radiation and /info/en/?search=Conservation_of_energy any radiating system loses energy. It is good when we speak about merger of two black holes but certainly is not right in case of Earth that still orbits Sun. So we must choose one of two: gravitational waves aren't radiation or Earth orbiting Sun doesn't generate gravitational waves (that means that definition of gravitation waves is wrong).
3. "Gravitational waves are disturbances in the curvature of spacetime" means that gravitational waves are changing of gravitational field, so it (mass and gravitational field) is similar to electric charge and electric field and means that according to /info/en/?search=Conservation_of_energy , movement of source of the field changes field at the same time that means that any changing of gravitational field aka "gravitational waves" occurs instantly and hasn't "speed" (this is difference between "field" and "radiation"). 178.140.161.126 ( talk) 15:35, 30 July 2019 (UTC)
There are two definitions of gravitational waves -
LeeMcLoughlinScientist ( talk) 18:44, 14 October 2022 (UTC)
A wave is a property of something, it can't be an entity in itself. Particles are just that, partlicles. And so a wave can be a property of particles. As I said before, photons must have a frequency/wavelength because that determines how fast the electric and magnetic forces peak in turn. Gravitons are not like photons. Photons carry two forces (E and M) but gravity is singular. It doesn't require a frequency. Gravitons can propagate flat with no frequency. If gravity had a frequency then there would be different energies of gravity for different frequency. This is not consistent with observations. LeeMcLoughlinScientist ( talk) 19:24, 16 October 2022 (UTC)
In the article's very first sentence today, it claims that gravity waves 'propagate as waves outward from their source at the speed of light.'
That's an important assertion, and much may hang on it. But I found no citations to support it (none immediately follow it). Also unclear: is this a purely theoretical assertion? else what empirical evidence is there to support it? Supporting evidence needs to be cited; a discussion in the article would be welcome. Thanks, and the *only* reply I seek is clarification of the article. Twang ( talk) 17:38, 7 January 2020 (UTC)
UPDATE: Seems a gravitational wave may arrive before a light wave in some related instances, according to a recent science report. [2] - Drbogdan ( talk) 13:01, 26 October 2023 (UTC)
References
The article should include an explanation of the difference between spacetime and gravity. In the rod&bead experiment it is unclear why the gravitational waves would affect just the beads along the rod and not the space housing the atoms of the rod itself (and therefore the rod) as well. Gravitational waves are disturbances in spacetime, why affect and move just the beads and not the space housing the atoms of the rod (and the space anywhere the rod may be attached for that matter)? 86.93.208.34 ( talk) 00:49, 12 May 2020 (UTC)
There is the phrase: polarizations of a gravitational wave are 45 degrees apart with a {{ cn}}. If you look at the polarization videos, you can see that, in the same way that dipole waves have polarizations 90 degrees apart, quadrupole waves polarizations are 45 degrees apart. Rotating 90 degrees, results in the same signal (though with a phase shift). I suppose it would be nice to have a reference, though, but it is pretty much obvious for a quadrupole field. Gah4 ( talk) 10:02, 1 July 2020 (UTC)
The article uses the non-SI square degree for how well the direction can be determined, instead of the SI steradian. Should we also give the SI unit? Gah4 ( talk) 13:35, 8 July 2020 (UTC)
{{
convert}}
doesn't handle solid angle (that I could find). It might be worth adding there rather than doing by hand. Even more useful to a casual reader, though, might be to note that this is about 0.15% of the total sky, or about 320 times the area covered by a full moon. –
Deacon Vorbis (
carbon •
videos)
13:53, 8 July 2020 (UTC)
{{convert}}
will tell you the apparent age of your dog that you got 42 fortnights (0.23 dog years) ago! –
Deacon Vorbis (
carbon •
videos)
13:59, 8 July 2020 (UTC)
The section on redshift has a few {{ citation needed}}, and I might see if I can find some. In the case of light, redshift is useful as we can compare spectral lines to known lines, and compute the redshift. In the case of GW, there are no spectral lines, so there is nothing to compare. Presumably the physics requires it, but it doesn't seem so useful. Gah4 ( talk) 01:53, 26 November 2020 (UTC)
Earth-sized interferometry isn't big enough for very long primordial gravitational wave detection (it has a cut-off [frequency limit]). Write more. Ask NASA and CNSA (physicists are friendly).
future missions
— Preceding
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2A02:587:411F:F7D5:D013:D83D:B586:E11E (
talk)
17:26, 30 April 2021 (UTC)Which is the scientific document that expressed first loud and clear that "Gravitational waves are (disturbances in the curvature of spacetime,) generated by accelerated masses (, that propagate as waves)"? Yoxxa ( talk) 12:03, 12 June 2021 (UTC)
Would a physicist like to confirm that this sentence from the article is true – or correct it? "The magnitude of this effect decreases in proportion to the inverse distance from the source." I think that sentence contains a subtle double-negative; literally, it means that a gravitational wave grows as it propagates. I would have expected something like, "The magnitude of this effect is inversely proportional to the distance from the source." Also, I want a gold star for noticing this. Wegesrand ( talk) 17:42, 7 April 2022 (UTC)
Recently the North American Nanohertz Observatory for Gravitational Waves announced the successful culmination of 50 years of development of the idea of detecting gravitational waves by pulsar observations. Someone removed the reference to the research consortium and replaced it with the non-specific passive tense "was claimed to be detected", despite the consortium being clearly identified in the reference. This is not good Wikipedia practice! Wikilinking the consortium would have been, so I have done so in a new edit. Elroch ( talk) 19:57, 1 July 2023 (UTC)