Good question Gareth, since nobody could answer it until now!

Gravitational waves premise a space-time as a physical entity, such as Einstein postulated, to carry the waves. But if you analyze general theory of relativity in detail, this leads to a kind of modern ether, which is not a good model, we already know.

What is thus the nature of emitted energy from events with rapid moving masses?

The new Quantum Information Theory (QIT) provides an answer to this question: It is neutrinos!

As well as electrically charged particles radiate electromagnetic beams by sending out photons, massive particles beam neutrinos. Since we are yet not able to detect low energy neutrinos, the so called gravitational waves, which are in fact gravitational beams, are in disguise.

I have to mention, that in QIT neutrinos are particles without mass (not leptons) and belong to radiation such as photons. QIT provides a complete table of elementary particles, in analogy to the periodic table of elements.

Thus, in my opinion, all the efforts to detect gravitational waves with interferometers are useless, because they cannot interact with neutrinos!

Gravitational waves have been not yet directly detected.

However, there is a strong indirect evidence of gravitational waves from the pulsar PSR1913+16, discovered by Hulse and Taylor in 1974. They were awarded by Nobel prize.

The pulsar is acually a binary sysytem in which one star is a neutron star.

The pulsar slows down the rotation by emitting both elm radition and gravitational radiation (in a binary system).

The binary pulsar has been observed continuously since its discovery, and the orbiting period has in fact decreased. Agreement with the prediction of general relativity is better than 0.5%. This is considered to prove that gravitational radiation really exists. This in turn is currently one of our strongest supports for the validity of the General Theory of Relativity.

Thank you for your appropriate contribution, Emanuele. Yes, there are a few of such evidences for gravitational beams. General Theory of Relativity (GTR) is able to correctly calculate these effects, since it was made for calculations about gravity phenomena. My point was rather to explain the nature of the gravitational radiation as beams of neutrinos, and not waves in the space-time. Already in the mainstream theory there is the assumption that the energy of every wave through space-time, regardless electromagnetic (1) or gravitational (2), is borne away by photons (1) or the so called “gravitons” (2). This is the unsolved wave-particle duality (WPD) in the established theory.

QIT explains the WPD as an artificial relict of the conception of space-time as a continuous physical entity. Accordant to QIT space-time is quantized and only determined by matter and radiation. Therefore space-time is understood as the information between quantum states of every entity (elementary particle) in the universe. The sums of these quantum states are simply called the physical potential between particles and hence bodies in space. Space-time is not a physical entity and cannot be manipulated itself. Only the energies between the bodies in the universe form the current appearance of space and thus the metric of it. In this manner the distribution of matter in the universe built our space, according to QIT. By the way, this results to the same quantitative description as in GTR, to some extent, but can explain the unsolved cosmic mysteries such as the true nature of black holes or the phenomena which are explained by the inconvenient model of dark matter, since this couldn’t be detected either (http://www.sciencedaily.com/releases/2012/04/120418111923.htm).

This leads to the conclusion, that the long wanted “gravitons” are nothing else but low energy neutrinos. This situation is similar to the discovery of radio beams about 150 years ago which turned out to be composed of the same entities like visual light, just at lower energies. But electromagnetic interactions are much more likely than gravitational ones therefore we didn’t detect the gravitational radiation, until now.

http://www.sciencedaily.com/releases/2012/04/120418111923.htm

Interesting discussion, although I'm not conversant in GR and certainly not QIT. Actually, as a lay information systems analyst, I generally consider the concept of information as applied to physics to be invalid. That said, I don't intend to be argumentative. However, technically, IMO the requirement for galactic dark matter was and is merely a dark 'fudge factor' for those insisting (against their own evidence) that Kepler's empirical laws of planetary motion must apply to the highly distributed mass configuration of spiral galaxies. As two-body equations, they are actually quite specific to the peculiar mass distribution found within the Solar system, where system mass is highly localized.

Moving along, as I understand, the original concept of ether was intended to provide a material medium for the propagation of energy waves, but no evidence for the physical existence of any material ether has been found.

As I understand, GR very accurately describe the effects of gravitation as a transformational geometry represented by an abstract system of dimensional coordinates. There also seem to be no physicality of spacetime being described, except that its distorting effects (curvature) are equivalent to the acceleration of material objects.

As I understand, the gravitational waves predicted by GR would not be exhibited in any physical medium but rather in the dimensional coordinates of curved spacetime. The geometric effects of gravitation would wave, producing effective periodic acceleration/deceleration of matter.

Back to ethereal thoughts, while space does not contain any consistent material medium for the propagation of waves, as I understand a ubiquitous quantum fluctuation has been discovered, including the emission of energy resulting from very real annihilations of virtual particles and antiparticle manifestations. This physical evidence seems to require that otherwise completely empty space must contain some energy. This energy might also be necessary and responsible for the physical expansion of universal spacetime...

If this view is correct, might not gravitation be imparted to material objects not through the mediation of some quantum particle or some abstract system of dimensional coordinates but rather through a directional, physical flow of kinetic vacuum energy produced by its interaction with localized potential mass-energy?

In this case, no material medium of ether would be necessary - the curvature of spacetime would represent gradient densities of vacuum energy. In this case, it should be necessary that measured quantum fluctuations should vary as a function of local gravitational effects: a sufficiently sensitive detector should indicate quantum fluctuation variations at varying altitudes on Earth, and within Earth orbit, or on the surface of the moon, for example.

If gravitation was a kinetic effect of vacuum energy density imparted by localized potential mass-energy, there would be no quantum gravity since it would be as much a macro-scale effect of spacetime as it would be a property of matter. The mass-energy of particles would be the ultimate medium through which the effects of external gravity would be imparted.

As for gravitational waves, the energy lost by massive rotating binary objects might be absorbed into the locally very dense external vacuum energy...

If long duration GRBs are associated with collapsers and short duration GRBs with coalescing binary neutron stars, then indeed gamma ray burst sources are potentially powerful emitters of gravitational waves. However, most GRBs are at cosmological distances, and hence, their gravitational wave (GW) amplitudes are likely to be very weak. LIGOs are expected see GWs from GRBs going off nearby.

I concur that current gravitational-wave detectors should be able to detect merging neutron stars in the nearest galaxies, though at the limit of their sensitivity. So far there have been no positive results from GRB-triggered searches for gravitational waves. This paper is an analysis of a particular nearby short GRB (in Andromeda) that would have been expected to give a detectable gravitational wave signature if it had been due to a merging neutron-star source:

http://arxiv.org/abs/0711.1163

This page at the LIGO collaboration site is a starting point if you wish to investigate the question further:

http://www.ligo.org/science/Publication-S6GRB/

LIGO will continue to monitor every nearby GRB for concurrent GW signals. As you may be aware, LIGO sees "signals" all the time that cannot be assigned to known sources of noise, though so far they also cannot be assigned to a real source. The most likely source of any given signal is statistical fluctuation, so time correlation is important. All proposed astrophysical sources are expected to be near or below threshold in current detectors. The challenge is to identify as many sources of noise as possible (for example from seismic events), and to correlate what is left with astronomical observations.

I agree that one of the most promising sources of gravitational waves are from the compact binary mergers which may also produce short GRBs. When Advanced LIGO comes online, the distance detection limits will start to get very interesting for short GRB progenitor studies.

There is a second short GRB which occurred near M81 which was also analysed by the LIGO collaboration. This GRB would have also been detectable if it was a merging neutron star system in M81: http://arxiv.org/abs/1201.4413

However for both of these short GRBs, it is important to add the caveat that a merging neutron star progenitor is only ruled out for only these two galaxies. There is no conclusive proof that the GRBs actually originated from those galaxies, because the position uncertainty is very large and we do not have redshifts for the actual GRB emission. So it is also very possible that they were compact binary mergers in background galaxies (which are not ruled out by the LIGO results).

I agree with Patrick. Unfortunately, GRBs are far away. As I know for GW detection the GRB should be closer than z=0.01 or even closer. For the last 15 years there have been only two GRBs detected closer than z=0.01. Roughly we detect every second GRBs, therefore we have 1-2 GRBs in every decade closer than this limit.

My guess is in the next decade we'll not detect GWs from GRBs. If we are lucky we'll have one in the late 20s.

For readings there are many papers.

LIGO: http://adsabs.harvard.edu/abs/2013AAS...22115208S

http://adsabs.harvard.edu/abs/2013MNRAS.430.2121P wrote: "take place at the detection horizon of advanced GW detectors ..., for several years"

http://adsabs.harvard.edu/abs/2013APS..APRQ10009C suggested: "We predict the rate of events in future networks of gravitational-wave observatories, finding that the first detection of a NS--NS binary coalescence associated with the progenitors of short GRBs is likely to happen within the first 16 months of observation"

But I am not that optimistic.

This may be of interest

http://arxiv.org/abs/1302.4368

Louis Rancourt · Collège Boréal

It was possible to measure the force that 11 000 lumen lamp that blocked some of the gravitational force on a 100 g mass. The forced blocked is small, only 3,4 x10-8 Newton. The article was published in GRAVITYFORCES.COM.

Gravity control panel.

Since light does block part of gravitational force, it is possible to use light in a closed panel to block some of gravitational effect. An object placed under the panel looses some weight when the lights are activated.

The panel used in my experiment measures 4 feet by 4 feet. It uses 9 fluorescent lamps. Each lamp uses 105 watts and is suppose to give 7000 lumen according to manufacturer.

A series of aluminum mirrors reflect light in the enclose box.

The results for May 10 show that the 200 g mass + the small stick supporting the mass had a decrease of 0.04% reduction in weight in 32 minutes when placed under the panel.

Some modification could increase the efficiency of the panel by using ultraviolet fluorescent tube because the energy of that light is double the energy of green light.

The green part of white light is most responsible for the lumen value measured.

More mirrors could also increase the effect.

The effect was named Boreal effect in honour of College Boreal who helped in the discovery of that effect.

The experiment to find the value for the increase of weight when the object is over the panel gave good results. 63000 lumen increased the weight of the mass and support by 0.06 % in a 20 minutes period. The graph was posted on GRAVITYFORCES.COM.

Now, no one can say that we cannot change the effect of gravity. With more powerful lights, we could have the gravity experienced on Mars, for example.

The new approach to LIGO data analysis shows that GW associated with GRB were registered already 2005 Year (see links)

http://www.academia.edu/4810992/Indirect_Observing_of_the_Low-Frequency_Gravitational_Waves_Associated_with_the_Gamma-Ray_Burst_GRB_051103_by_Analysis_of_LIGO_Data

http://vixra.org/abs/1405.0019

Alexandr,

I have no expertise here, but as I understand, the frequency of gravitational waves produced by non-axially symmetrical rotating masses should directly correspond to their rate of rotation. I also understand that gravitational wave amplitudes should be determined by the variation between gravitational field amplitudes presented to an observer during each rotation.

Wouldn't the merger of more massive objects produce _higher_ frequency gravitational waves as a result of their increased rotational velocity? Have I misunderstood?

BTW, an overview of the LIGO findings regarding GRB 051103 can be found at http://www.ligo.org/science/Publication-GRB051103/.

Separately, in the case of merging binaries producing high energy polar radiation, it seems to me that any gravitational wave emissions should be strongest for observers aligned with the plane of rotating bodies, while the polar EMR emissions would be strongest for observers aligned with an axis of rotation (see the illustration in the ref. above) - as a result, there may be very difficult to correlate any detection of gravitational waves to high energy EMR events...

James,

I’m not astrophysicist too, but I’m mechanic. For me the test mass of LIGO is only pendulum with the string suspension. And I determined that mechanical properties of the pendulum (in particular quality-factor) have changed synchronous with GRB 051103. I was must to make the astrophysical interpretation of the event too, because all astrophysicists ignore my work (I think by reason of corporative solidarity). The registered gravitational waves are longitudinal shock waves therefore polarization effects haven’t influenced on the results.

Alexandr,

Pleaase see http://www.ligo.org/science/GW-IFO.php.

Although I am not an expert in LIGO observations, I have spent a number of years researching Short GRBs and have directly worked on GRB 051103 (http://adsabs.harvard.edu/abs/2010MNRAS.403..342H). If GRB 051103 had been a compact binary merger of a neutron star and a black hole (or the merger of two neutron stars) in M81, we would expect the electromagnetic afterglow to be very bright and no optical counterpart was observed to very constraining limits. Therefore, even before the LIGO paper, we did not believe that it was a compact binary merger in M81. This GRB was either a giant flare from a magnetar near M81 (an extragalactic version of the giant flare from SGR 1806-20) or a standard short GRB from a galaxy much further behind M81.

Regarding the gravitational wave emission, the signal is typically predicted in computer simulations using two point masses. These simulations show that, for binary neutron star mergers or neutron star - black hole mergers, the gravitational waves will be most luminous down the rotation axis of the binary merger. This is because you are able to see both polarisations of the gravitational wave emission, whereas looking along the plane of the merger means you can only see 1 polarisation.

When the LIGO team search for gravitational waves following a short GRB, they use 2 different strategies:

1. targeted search: where they input models developed by simulating a wide range of point masses merging.

2. blind search: they search for any signal that cannot be accounted for (i.e. terrestrial effects).

The only way that you can really show that the detection is not terrestrial in origin is by having multiple detections in different interferometers - i.e. in at least two of the interferometers built by LIGO and VIRGO.

However, you do not get a GRB from the merger of two black holes. You need normal mass to accrete onto the central engine (e.g. a black hole) to get observable electromagnetic emission. Therefore, the system proposed (1e4 M_solar and 5e4 M_solar black holes) would not produce GRB 051103.

Dear Antonia,

Very thank you for your arguments. I’m agreeing with you. Really ideal BH have not mass to accretion. But really BH can to have some mass as satellite outside horizon of event. My results correspond to coalescence of BH with strong magnetic fields (by NASA modeling). The bipartition of main wave top near GRB (after GRB) confirms collapse some mass onto the central engine, therefore the GRB 051103 is short-time GRB.

Alexandr,

The inset chart included above labelled "GW for magnetic BH mergers by NASA modelling" illustrates gravitational waves propagating laterally, perpendicular to a polar observer. This is consistent with the view that there are no significant GWs propagating in the direction of a polar observer...

James,

The picture is ecliptic plane section of 3D image (see animation on NASA site).

Alexandr,

Does the video illustrate gravitational waves propagating in the direction of a polar observer? Can you please provide a link? Thanks...

James,

http://www.nasa.gov/topics/universe/features/black-hole-secrets.html

Alexandr,

Thanks for the link. I can't see that the video clearly depicts gravitational waves at all - it certainly does not depict any polar emissions other than the magnetic fields...

James,

Simulation without magnetic fields

http://svs.gsfc.nasa.gov/vis/a010000/a011000/a011086/viz_shiftingall_21-H264_800x800_30.mov

I agree that the black holes are likely to have some mass orbiting them that could get accreted as part of the merger process. However, to achieve sufficiently rapid accretion (required for a GRB) onto the mass black hole proposed, a tidal disruption like event would most likely be needed (where a stellar object is rapidly accreted) such as suggested for GRB 060614 by Gao, Lu & Zhang (2010, http://adsabs.harvard.edu/abs/2010ApJ...717..268G). For a 1e5 M_solar black hole (i.e. comparable to the merged mass proposed), from equation 3 in this paper, the typical duration of the GRB would be 50 seconds - i.e. a long GRB and much longer than the observed duration of 0.17 s for GRB 051103. It seems unlikely that a compact stellar object, sufficiently close to be accreted within seconds of the merger, would survive the inspiral stages - I think that it would be tidally distorted into an accretion disk, accreted onto one of the black holes prior to merger or slingshotted out of the system. I believe other material would more likely form an accretion disk giving AGN-like behaviour with a fast outflow but not sufficiently fast for a GRB (see this model proposed for supermassive black hole mergers: Armitage & Natarajan 2002, http://adsabs.harvard.edu/abs/2002ApJ...567L...9A).

Assuming a stellar object was sufficiently close to the final black hole at the end stages and it was able to accrete sufficiently rapidly, I think that a bright afterglow would be expected at the distance of M81. For instance, Swift J1644+57 is an example of a tidal disruption event onto a supermassive black hole, with a GRB duration of >1000 seconds at a redshift of 0.3534, and it had a very bright multi-wavelength afterglow for months after the event (Levan et al. 2011, http://adsabs.harvard.edu/abs/2011Sci...333..199L). This is very different to the properties of GRB 051103, which was very short and had no optical or radio counterpart to deep limits (Ofek et al. 2006 http://adsabs.harvard.edu/abs/2006ApJ...652..507O, Hurley et al. 2010 http://adsabs.harvard.edu/abs/2010MNRAS.403..342H).

Alexandr,

Thanks - I also found the page describing the black hole merger simulation videos - http://svs.gsfc.nasa.gov/vis/a010000/a011000/a011086/. For the gravitational wave animation, the description states:

"Simulation of the merger of two black holes and the resulting emission of gravitational radiation. The colored fields represent a component of the curvature of space-time. The outer red sheets correspond directly to the outgoing gravitational radiation that one day may be detected by gravitational-wave observatories. The brighter yellow areas near the black holes do not correspond to physical structures but generally indicate where the strong non-linear gravitational-field interactions are in play."

Considering the red propagating gravitational waves only, It does seem that - at the moment of merger - there may be some that might be directed towards a distant observer with a polar viewing angle (which would provide the strongest GRB signal reception), but that conclusion is based on a loose interpretation of the imagery.

A search of the NASA SVS database for the term 'gravitational waves' returned several additional, seemingly simpler animations - http://svs.gsfc.nasa.gov/search/Keyword/GravitationalWaves.html. They all clearly illustrate only laterally propagating gravitational waves...

Thanks again for your help!

Regarding gravitational wave emission and the viewing angle, this paper is of interest: Foucart et al. 2011 http://adsabs.harvard.edu/abs/2011PhRvD..83b4005F

Using full general relativity, they simulate the merger of a neutron star and a black hole with a wide range of initial conditions. They specifically focus on the alignment of the black hole spin and the inclination of the orbit. However, they also extract the gravitational wave emission at three viewing angles to the event: 0, 30 and 60 degrees, where 0 degrees is looking down the binary rotation axis. Looking at figure 10 and the explanation in the final paragraph of section B, you can see that you obtain the maximal signal at 0-30 degrees and it reduces for 60 degree observing angles.

Antonia,

Thanks. As I understand, the results of this study represent the very specific late-merger conditions (about ~15 ms. - beginning at a separation distance of ~60 km, for example) thought likely to occur only for spinning black holes accreting a neutron star 1/3 its mass. The conclusion states that It's expected that in such mergers, the black hole spin will often be misaligned with the accretion disk produced - it is these conditions that produce the very specific viewing angle effects reported.

If I understand correctly, in these specific cases the GRB emissions will be aligned with the spin axis of the black hole, while the gravitational wave propagation will be aligned with the accretion disk. This angular mismatch produces greater overlap between the optimal viewing angles of the GRB and the gravitational waves than would be expected for neutron-star - neutron-star mergers, for example.

The report concludes:

"The late-time behavior of the black hole-accretion disk system is critical if we want to understand the potential of BHNS mergers as progenitors for short gamma-ray bursts. Currently, the measurement of the properties of the disk and their evolution in time suffers from the limitations of our simulations. The general characteristics of the disk can be obtained, but a more detailed evolution would certainly require the inclusion of magnetic fields and neutrino radiation. These effects will be added to our evolutions in the near future."

A video of Fig. 7 - the accretion disk precession ('wobble') is available at http://www.black-holes.org/explore2.html under the heading "Precessing Black Hole-Neutron Star Merger" near the bottom of the page.

It seems that many simulation studies of a wide range of interesting hypothetical compact mass merger conditions have been performed - their applicability to observations would have to be determined by statistical survey or individual analyses...

BTW - If I understand correctly regarding the simulation above, that the initial angular momentum of the approaching neutron star was specified at a separation distance of only ~60 km from the spinning black hole, I'd expect that if the simulation was allowed to run longer - starting at a much greater initial separation distance - that the neutron star's orbit would have more likely stabilized in perpendicular alignment with the black hole's spin axis. The effective mass distribution of a spinning black hole should be more elliptical than spherical - providing for increased gravitation along its equatorial plane...

I fully agree that this paper is dealing with a very specific circumstance, which is why it is always best to look at the original paper to fully understand the context of the results. But this was the only paper I could easily find that shows the gravitational waves peak down the rotation axis - I am sure there are more papers, but I am not familiar with the literature regarding the gravitational wave emission in simulations of binary mergers.

However, from directly asking this very question to members of the gravitational wave community over the years (including to the authors of the LIGO paper on 051103), I have been told that the gravitational wave emission peaks down the rotation axis of the binary system (and hence down the GRB jet) because you can detect both polarisations. This result is stated as fact in the 051103 LIGO paper (http://adsabs.harvard.edu/abs/2012ApJ...755....2A).

Antonia,

As I mentioned before, I did find several papers that stated in very general terms that GW emissions should be strongest from a polar viewing angle (I didn't note them), but this seems to contradict the findings of more detailed analyses in http://arxiv.org/abs/gr-qc/0101117 http://arxiv.org/abs/gr-qc/0405067 and http://arxiv.org/abs/astro-ph/0509787.

Personally, I think there's a great deal of uncertainty about what actual conditions affecting GW propagation are most prevalent. I can imagine that there might be a short burst of strong polar GWs at the moment of a massive merger. However, I'm afraid I can't follow the reasoning that "gravitational wave emission peaks down the rotation axis of the binary system (and hence down the GRB jet) because you can detect both polarisations" - the detectability of GW signals seems to more a product of propagation direction and amplitude. Most visualizations, and the analyses referenced above, indicate that most strong GWs do not propagate along the poles. At any rate I very much appreciate your informed discussion and helpful references!

Antonia,

Thanks for your additional information about GRB 051103. It was very interesting for me.

Regards