Am I the only one that is doubtful of LIGO’s detection of gravitational wave GW150914?

Dear Perer Hahn,

It seems a rather lucky coincidence. I have been doubtful about gravitational wave experiments that for almost a century gave nil. (In fact I skipped GW papers on arXiv just on their title.)

One of the authors said something like: 'This is almost too good to be true'.

But it seems pretty good.

Your question on why didn't we see it before could maybe be answered by two things. (i) Sheer luck. These cataclysmic events must be rare. (ii) The awfully strong effect through the old E=mc^2 where m here is 3 solar masses.

For myself, doubter that I was, the case seems rather strong.

Met hartelijke groeten,   Henk Smid 

Dear Dr. Perer Hahn,

It is interesting: "It’s like installing a microphone on the streets of a busy city and then detecting a horn beeping 1.3 billion miles away, but no sound detections from local traffic. (Our own milky-way galaxy is theorized to be full of gravitational wave sources).

My question is: before this waves arrives at the Earth, whether it is interacted with other fields, or it was absorbed by other fields?

Peter, happily you are not the only one! : 

But, of course, it is decided that gravitational waves were detected.. it will be so taught in universities, next generation will grow up sure that they have been detected  (as well as  Higgs boson) in the same way that present one is sure that the neutrino exists, that there is a global warming, that Earth rotation is slowing down, that space expands, that sunspots are due to a blocking of solar magnetic field, that the solar system formed from the condensation of a cloud of dust, that oceans are rising up, that dark matter and dark energy exist, and so on...

Very simple: the sensitivity of the detector before September 2015 was (ΔL/L) > 10^(-20), after the upgrade,  it improved by an order of magnitude to about 10^(-21), which rendered possible the detection of a signal at 70 Hz, of normalized amplitude 10^(-21), since

10^(-21) x 10 = 10^(-20).

 Background noise was taken into account and removed-that's why it's not displayed-and the signal that remained was consistent with the calculation of what a a merger would produce. While the general public, with some justification, isn't expected to know such technical details, people that wish to discuss technical issues ought to be expected to read the technical, not popular, literature, e.g. http://arxiv.org/abs/1602.03847 ,   http://arxiv.org/pdf/1602.03846v1.pdf , http://arxiv.org/abs/1602.03845 and references therein.

Stam,

Thanks for the reference links. The thing that concerns me is lack of confirmation by follow-up observation. To my knowledge, no other observatory has confirmed the GW150914 event by detecting any kind of alternate signals (optical, gamma rays, x-rays, radio, infrared, etc). This would have added a great deal of credibility to a claim of a GW detection.

Other systems have more than one method of cross validation. For instance, the detection of exoplanets are cross confirmed by detecting a brief dip in a star’s brightness during planetary transit, as well as measuring the star’s Doppler Shift. The Large Hadron Collider has two completely different detectors that are used to confirm the detection of a new particle (i.e. ATLAS and CMS).

Even calibration of the interferometer components of LIGO is no absolute validation that LIGO actually works. If I want to test a microphone, I generate sound waves and measure the microphone’s response. We don’t know how to generate gravitational waves in the lab, so we cannot do a thorough test. Wiggling the mirrors or modulating the laser is not an absolute way of mimicking gravitational waves.

I feel that GW150914 should have been written off as a “Guess I hit the ‘Inject Test Signal' button one more time than I thought”, and should not have gone public unless there was a number of alternate observational confirmations.

Dear Dr. Peter Hahn,

Do you think that there should be enough corroboration from other similar laboratories which is yet absent?  Do you think that the signal indicating arrival of gravitational waves is incredibly tiny and so beyond the detection capabilities of LIGO detector?

If everything is above board, as personally I believe it to be, all we need to do is wait: there should fairly soon be a reasonable number of events detected at relatively high significance level, in which case doubts ought to diminish considerably.

I guess one could try to ask what other signatures such an event should show, that would be visible on earth. It is pretty distant, though, so I am not sure one expects anything.

As for being in ``a busy street'', it seems as though the nearby Universe is rather quiet as far as gravity waves are concerned. What are these multiple theoretical gravity wave sources you talk about? I always heard that the people designing gravity wave experiments agreed that the theory did not predict that they were likely to detect anything, until recently. Also I had heard that this kind of event (collision of two black holes) was what they had considered to be one of the likely scenarios.

The LIGO team waited 4 months after detection to check the results from every possible technology, and only published 2 days after the detection was published from a leak to Scientific American magazine. This doesn't sound anything like a hoax. A group of 1000 insiders kept quiet about it for several months and did all sorts of evaluations that can be found in considerable detail on their LIGO web site.

It's OK to criticize original work, best received from people who have done original work of their own. LIGO has a lot of data that has not been analyzed or correlated. Also the several seconds before the published event are still in the data banks. An example of the microphone on the busy corner is not appropriate to the situation observed. The event was an exceedingly powerful one, and with a wave pattern that matched predictions of other research groups. The busy corner can be applied to noise and interference which makes the detection of a genuine event exceedingly difficult.

Detection during the calibration and check out phase is not too surprising. For those who read the source documents before giving an opinion, the calibration and checking continue routinely during all phases, and don't come to an end when a period of time is given a different name. Maybe I am biased just because the published results agree with my own published prediction of percent mass energy conversion to momentum energy at high speed. It open a new age for cosmology that will develop over a long time with many specialist working on it. The eventual result will be a practical technology for travel in deep space at high speed. 

LIGO has a public reading site with a large number of technical papers evaluating different aspects of the equipment and methods. It is very possible the group will eventually publish other detections of gravity waves in greater numbers closer to home.

With all due respect to all of my friends, colleagues, and followers, I take issue with the notion that what was detected was a gravity 'wave'. Please keep in mind that 'waves' transport energy. In gravitational terms, how can one possibly view transport phenomena in terms of a gravitational origin when by definition, what we're observing (if in fact the observations hold) is for lack of a better term a 'sink' effect? Gravitational energy is in no way being transported by a wave. If we are observing anything, we're observing a radially propagating 'well' of 4-space whose probable origin is so distant from us that it has no detectable radius of curvature. One could argue that if gravitational waves are propagating, then it's completely plausible for a bowling ball sitting atop Mt. Everest to radiate gravitational potential energy. Personally, I don't think that's happening. Are two binary black holes locked into orbits around each other causing 4-space to warp? Certainly, but one needs to accept the reality that black holes exist in the 1st place. There are several recently released peer reviewed technical journal publications throwing doubt onto the existence of black holes. If one looks at the origin of the Big Bang and a singularity event, how difficult is it to accept that the radially outward expansion of that infinite energy density isn't still propagating? I say it is. And I say that if gravity 'waves' (not really waves but measurable perturbations in 4-space) were observable, they'd be observable anywhere and everywhere as a result of their asymmetric arrival at any point in the physical universe except at the remnant focus of the singularity event. And this then begs the question as to why if gravity 'waves' aren't transporting energy, do they necessarily have to have a transport velocity limited to 'C'? I say if 4-space 'ripples' it does so instantly. There's no propagation to the ripple. If there was, the 'wall' or 'skin' of the Big Bang would have reacted to its own perturbations and collapsed in on itself within an instant of singularity. Thought/ comments?

When I heard LIGO answering a reporter's question, "the probability of an error in the experiment is zero," I dropped to 20%. from 80% on their credit rating.

I would also like to add that the very orientation of the detector array adds to the mystery of the observation. Doesn't anyone else feel that having an array oriented in the same direction as the ecliptic plane of the Galaxy add's suspicion to the measurement?  I would have more faith in the observation if the array detectors were oriented in a direction mutually orthogonal to the galactic ecliptic plane, or at least in direction that cover all 3 axes. 

Ales, I remind you that there is no 'gravitational push'. It's true that tidal forces allow for the conversion of potential energy into kinetic energy, but it's not happening because of 'inner viscous friction'. It's happening because the radius of 4-space curvature is incrememtally different along any tangential path through the 'geometrical' gradient. If there are gravitational waves, I'm skeptical that there are - not a disbeliever in them -  then this opens up an entirely new arena of discussion relating to gravitational precession, gravitational Doppler, gravitational interference nodes, to name a few. I haven't seen much in the literature about these topics but perhaps now we will. But personally, I don't think gravity waves propagate at C.  I don't think they propagate period. I think the 4-space effects are instantly observable. 

Peter we are 2. 

GW are pure theoretical failure. http://arxiv.org/ftp/astro-ph/papers/9906/9906058.pdf

see also my discussion on Higgs and GW. 

@ Mark: Maybe a comparison with electrodynamics is helpful: a charge repels other charges of the same sign via an electric field. That is static. Such a field does not carry its own energy, and does not move away from the charge.

Similarly for magnetostatics: stationary currents yield stationary magnetic fields, that do not carry energy away from their sources. In both cases, the fields---in other words the forces---decay as 1/r^2. The corresponding energy goes as 1/r^4.

If, however, you consider distinctly non-static situations, in which charges move and the current itself is not stationary, then you have radiation. When radiation is emitted, energy is actually lost to the system that emits it: thus an antenna experiences a ``radiation resistance'' additional to whatever, usually negligible, ohmic resistances might exist.

Where does this energy go? It goes to the EM field, and as such is capable of being picked up again at arbitrary distances. The amplitude of radiation decreases with distance as 1/r, and hence the energy, which is proportional to the square of the amplitude, goes as 1/r^2. Thus the energy flow through a sphere of radius R does not decrease with R. That is the essential characteristic of radiation, which distinguishes it from static fields.

Now to gravitation: it is all the same. Stationary gravitational fields around a mass at rest are quite familiar: earth gravity. Gravitmomagnetic phenomena have been detected around Earth as well, but they are quite small.

Now gravity waves: you may have read somewhere that there is no such thing as gravitational energy. Leaving that aside for the time being (it is a complex, technical subject, and my impression is that the statement is rather misleading), we see that a lot of energy was lost when the two black holes merged, and that some motion created by the wave was detected here. In any case, the effect of energy being lost to gravitationally radiating systems (the equivalent of ``radiation resistance'') has been well known for a while: binary pulsars have been shown to come ever closer to each other to an extent well described by the emission of gravitational radiation. Now we are actually seeing the waves themselves moving the mirrors of an interferometer.

F. Leyvraz, Jerry Decker,

Leyvraz, the other GW sources I am referring to are pulsars. Jerry, the street noise I am referring to in my microphone analogy is similar to the constant hum from pulsars, not unwanted background noise. There are over 2,000 known pulsars in our galaxy that are emitting radio waves, and some of them should be radiating gravitational waves as well. I’ve read that there could be as many as a billion pulsars in our galaxy that are not emitting radio waves, and some of them could also be radiating GWs.

The reason why GW physicists believe that the universe is quieter than theory predicts is because LIGO (and Virgo) have consistently failed to detect GWs from known pulsars in our own galaxy. Each failure produces an erroneous conclusion (I feel) that GW sources (such as pulsars) are weaker than theorized and results in an adjustment in the “upper limits on the emission amplitude” (i.e. http://arxiv.org/abs/1309.4027).

I guess the question I would really like to ask is… can anyone point me to a site or article that shows an actual follow-up confirmation of GW150914 that was performed by anybody other than LIGO? I have not found anything yet! Observatories such as VISTA, Swift and IceCube have come up empty handed.

The original question asked for independent confirmation. I just stumbled upon this, which is surely relevant:

The paper "GW150914: The Advanced LIGO Detectors in the Era of First Discoveries" answers to the questions "Why seen now and not by initial LIGO ?", "Would have Virgo (in 2011 status) helped to the detection ?". You can download the paper at

https://tds.ego-gw.it/itf/tds/index.php?callContent=2&callCode=12177.

In figure 1 left, you have the sentitivity of "Advanced LIGO". You see how the upgrade helped a lot to improve it: a factor of 3 the sensitivity, hence by a factor 30 the volume of universe. In figure 1 right you see that an event similar to the one seen on sept. 15th would not have been detected by LIGO, Virgo or GEO600 in 2011.

The event happened very early on a monday morning, the detectors were not "full of people".

The "observing run" is a defined status, its date is decided well in advance. It is not surprising that the detectors are ready to go before the official date.

Dear F. Leyvraz, I am completely comfortable with your answer relating to the particle charge issues of electrodynamics. I was schooled early on with H. J. Piddington's Cosmic Electrodynamics, and I very much appreciate your shared insights. I do not however subscribe to the 'particle solution' school of Gravity. I also politely take issue with your statement that 'it's all the same'.  Regarding Gravity, nothing could be further from the truth. Are you inferring that Gravitational fields 'radiate'?  If so why is there no Doppler equivalent to a decaying gravitational field as the field 'propagates'?  It's because the field itself is due to the collapse of 4-space as a function of energy density - not particle density. It's true that particles have an energy representation, but gravitational fields manifest only when the gravitational wavelength is >> than the quantum wavelength. 

`` Are you inferring that Gravitational fields 'radiate'?'' No, and neither do EM fields. Accelerated *charges* emit EM radiation. Accelerated masses emit gravity waves. The only difference, one entirely predicted by GR, is that it takes a powerful antenna to emit substantial power in gravity waves, and, consequently, a sensitive antenna to detect them.

Of course, there are peculiarities about the gravitational ``field'' in GR, since it is involved in the geometry of space-time. But I believe one does not need to take this too much into consideration to obtain a correct qualitative picture of what is going on.

@ F. Leyvraz,

You rightly said "........and, consequently, a sensitive antenna to detect them."

I always felt that the extreme smallness of the signal to be detected to imply existence of gravitational waves is the only reason why it made almost impossible to detect this signal for so long time. The most sophisticated laboratory at LIGO could detect these waves only after it was changed into Advanced LIGO, a ten times more sensitive Lab! 

About the question "why a signal 1.3 billion light-years away, and not in our galaxy ?"

For two orbiting bodies, a useful formula is the "quadrupole formula" to give accurate orders of magnitudes (see for example in wikipedia). To give an order of magnitude, LIGO/Virgo detectors are sensitive to h=10^{-21} levels. The formula shows that the source should have a quadrupole moment : a perfect sphere with spin does not give any signal. A neutron star could emit gravitational waves if it has "mountains", and nobody knows if there are some. Because of the G/c^4 factor in the quadrupole formula, in order to emit waves to which LIGO/Virgo detectors are sensitive, the sources should be "compact" (i.e. have a large Mass/radius factor) and with speeds not negligible with respect to the speed of light. It happens that compact objects seems to be rare in our galaxy, and that a synchronous detection of known pulsars did not provide yet a detection. Binary systems (for example PSR1913+16) do not radiate waves large enough for a detection with terrestrial instruments, except of the last orbits before the merger. To increase the statistics, the instruments do need to increase the sensitivity and thus the volume of universe explored.

The "city" is indeed "busy", but does no perturb that much the fabric of space-time. There is no "sound from the local traffic": it is orders of magnitude lower the detectability levels.  "Our milky way is full of gravitational wave sources": this is true, any accelerated body radiates, even when you throw a piece of sugar.. but the level is totally negligible, by billions of orders of magnitude.

"Am I the only one that is doubtful of LIGO’s detection of gravitational wave GW150914?"

Me too: 

Extraordinary claims, extraordinary diligence.

Ales: The actual threshold for signal to noise was below 5. Nature was generous enough to give a "golden ratio" 5.1 sigma, but it could have been lower.

It would be in principle possible to lower the threshold, but it would degrade the false alarm probability, and the estimates of the parameters. Figure 4 of the PRL paper and associated discussion will give details.

Good morning Peter, my compliments on using the analogy of the 'Oil Sniffing Scandal'. Hopefully, this is not the case. Although I was young at the time bits and pieces of the story started circulating in major US news papers, I do remember it and I remember how it seemed to just drag on and on. 

Here are a couple of excerpts from phys.org with reports on follow-up observations: 

But they did seem to observe some kind of gamma ray burst, if I understand correctly.

I gave the ref on my post in p. 2

In heritage of physics (Newton and GR) gravity is immediate. How now is possible that gravity is transported with GW which needs duration? I cannot understand how LIGO is ignoring fact that gravity is immediate. Will LIGO now develop a new physics where gravity requires time, means gravity has duration ? We cannot build physics without respecting heritage of physics which also are Newton gravity and GR where gravity is immediate. What is going on here? Are we losing the compass in physics?

@ Thierry: Surely, iwhat you state is quite possible. To make it into actual physics, all you need is to make it quantitative: what masses would be needed to produce such a signal, how would they need to revolve around each other etc... Does GEM also predict black holes? If not, what happens when two large masses move around each other so close that their velocity is close to the speed of light. You will presumable need a covariant for of GEM. In any case, I do believe the supporters of GEM have a beautiful opportunity to show what they can do besides merely stating ``whatever GR does, I can do better.''

Amrit: The gravity is instantaneous because the field tells matter how to move. But the changes, when masses alter their postions in respect of each other, propagate at speed of light. So gravitational waves are ripples in spacetime and carry information for the gravity field how to curve.

Leyvraz,

Thanks for the link to the article “Fermi GBM Observations of LIGO Gravitational Wave event GW150914”

It is unfortunate, however, that the find wasn’t more conclusive. The article says “If the GBM transient is associated with GW150914, this electromagnetic signal from a stellar mass black hole binary merger is unexpected.” In other words, the GBM detected a gamma ray burst that was in the vicinity of GW150914, but not a signal that is expected of a binary black hole merger.

Also… to be fair… LIGO is working on another possible candidate signal in the article. “New insights emerge from LIGO’s gravitational-wave data”.

However, the signal is not yet verified “While LVT151012 is the next most interesting candidate event, the data for it are currently not statistically significant enough (about 2σ) for it to be declared a “detection” and the team will need to analyse it further to say if it is a true event or noise.”

Esa: The gravity is instantaneous because the field tells matter how to move.

Really matter and field are talking....they have mobile phones?

Curvature of space is generating gravity. Curvature has origin in variable energy density of quantum vacuum. 

GW are pure theoretical failure. 

Amrit,

Thanks for your comments. However, I do find it difficult to believe that “gravity is instantaneous” and that “GW are pure theoretical failure”. There is enough indirect evidence that GWs are real and that they travel at the speed of light. I think that in the future, the detection of GWs will become fairly routine (providing we have a detector that actually works). This will give us the ability to support or reject many gravitational theories (including yours and mine).

What I am doubting, in this feed, is the ability of ‘interferometers’ to directly detect GWs. During the development of FET, I came to the conclusion that the speed of light increases or decrease as space gets stretched or compressed while a GW passes by. This results in the two returning laser beams to always remain ‘in phase’ when they hit the photo detector. This renders an interferometer completely ineffective in detecting GWs, similar to how the Michelson-Morley experiment failed to detect the Earth’s motion through the aether.

Experimentation is a wonderful thing in that it puts our ideas to the test. Only time will tell whether GW150914 was an error or the beginning of new science; with the lack of solid follow-up observations, I’m still leaning towards the former.

@ Peter Hahn: I fully agree with your assessment. Still, I must say I am a lot more impressed by the agreement with the predictions of GR (the fact that numerical simulations of a black hole merger predicted a signal very similar to that actually observed) than you seem to be. The gamma ray burst may be unrelated, or it may not. I mentioned it because this was very much an integral part of your question. On the other hand, theory does not predict much of an EM signal, so even if the gamma ray signal is a coincidence, it does not mean that GW150914 has a major problem.

In any case, I am optimistic. But I think we can agree that time will tell. If no further detections are made in too long a time, this will be the end of that particular story. If, on the other hand, we obtain more signals, then there will be little room for doubt left.

Dear Dr. Peter Hahn, 

You said  ".......I came to the conclusion that the speed of light increases or decrease as space gets stretched or compressed while a GW passes by. This results in the two returning laser beams to always remain ‘in phase’ when they hit the photo detector. This renders an interferometer completely ineffective in detecting GWs, similar to how the Michelson-Morley experiment failed to detect the Earth’s motion through the aether........."

I have developed a completely new method to detect gravitational waves which I think is free of any objections of yours for interferometric methods. Only full fledged design with provision which I call  INDIRECT AMPLIFICATION OF SIGNAL and certain technical details are yet to be added in this version of my paper.

Please go through the new proposal summarized sketchily in

  https://www.researchgate.net/publication/294580524_Detecting_Gravitational_Waves_by_video_shooting_the_Standing_Wave_Pattern_and_Diffraction_Pattern

Best Regards, DPM

``I also find it hard to believe that LIGO can detect a gravitational wave 1.3 billion light years away, but it has not, in four months of observational run (O1), detected anything in our own galaxy'': 

It is not strange at all, but quite natural. Events like the coalescence of massive black hole binary in the single galaxy take place only one time in million years.

“…t is not strange at all, but quite natural. Events like the coalescence of massive black hole binary in the single galaxy take place only one time in million years.”

- indeed, the probability of an event similar to claimed GW150914 in our Galaxy is roughly lesser in 5^.10^-13 times [(volume of Galaxy): (volume of 1.3 billions light years)]. But for events inside the Galaxy to make the same signal level in the LIGO is enough roughly to produce an energy that in 1.7^.10⁸ times lesser [(surface of volume of Galaxy): (surface of volume 1.3 billions light years)].

Such [very much lower energy] events evidently can be happen with much greater probability then the event with “a collapse of two black holes having masses tens of Sun’s mass”…

Cheers

The gravitational-wave signal lasted in both of LIGO's interferometers for 0.2 seconds and has been measured to a statistical certainty above 5.1σ. In fact, the signal from the event was so strong that it could be visually "seen" in the data by eye. It was measured in both of LIGO's interferometers, arriving within seven milliseconds of each other. The observation is also the first time a stellar-mass binary black-hole system has been detected. The data also showed that gravitational waves travel at light speed and that gravity has no mass, as predicted by general relativity.

Vyacheslav,

Thanks for your input. I am sure that most people are aware that binary black hole mergers are extremely rare. I should have used the phrase “other events” instead of using the word “anything”. For example:

Supernovae, x-rays and GRBs are powerful events, which are theorized to be excellent sources of gravitational waves. Having a supposed range of 80Mpc, I find it extremely odd (and a bit disappointing) that aLIGO could not produce any GW counterparts to these 91 events.

@Peter Thanks for your comments. However, I do find it difficult to believe that “gravity is instantaneous” and that “GW are pure theoretical failure”. 

Peter gravity cannot be other than immediate. That's why in Newton formalism there is no symbol t and in GR gravity is expressed by curvature of space. If you think gravity has speed than this means Newton and GR are wrong. I think not. 

@ Amrit: Study GR just a bit. You will find, for example, that gravitational fields in the low-speed approximation satisfy a wave equation, which, of course has finite propagation speed. So it is inded not GR, which is wrong, but someone else.

The gravity in GRT seem to be instantaneous in respect to the source body when there is no change. Always it is instantaneous in respect to the space because the real source of the gravity is the space, not bodies. With bodies the instantaneous effect is the inertia, which is the same whole concept with the space and the gravity.

The field changes between the inertia and the gravity propagates at the speed of light c.

Peter,

I wouldn't spend much time wondering whether they have seen or not these waves. This discovery is in truth not so revolutionary as they say.

Every rotating non spherical mass distribution (such the quadrupole => binary system of black holes) generates a gravitational attraction (or better a gravitational potential) which periodically varies over time with respect to a far point of detection (in our case LIGO's mirrors). Newton is enough to predict this. And what perdiodically varies is a wave.

If I shake your hand every second, once strong and the other weak, that's also mathematically a wave. This discovery is NOT quantum gravity. If true, it's more an astronomical discovery and will be mostly useful for astronomical observations.

In my paper "A superfluid theory of everything?"  (section 1.3) I illustrate with a clear image what gravitational waves are (also according to a fluid quantum space).

Thierry: I imagine every star will simply keep the rotational momentum it had before contraction and spins up just in order to conserve rotational momentum. Regarding our sun, the spin frequency should increase by (R₀/R_n)² ~ 5x10⁹ on contraction from present status with radius R₀ ~ 7x10⁵ km to a neutron star with radius R_n ~ 10 km, so the rotational period should shorten from present t₀ ~ 25 d to t_n ~ 0.44 ms.

@Esa   The gravity in GRT seem to be instantaneous in respect to the source body when there is no change. Always it is instantaneous in respect to the space because the real source of the gravity is the space, not bodies.

Energy, mass and gravity are inherent properties of every massive particle and they have origin in diminished eneegy density of quantum vacuum caused by the presence of a given particle. 

@ Sergey: it is not 10^{-8} but only 10^{-4}: LIGO is an amplitude measurement, so the signal measured only decays as 1/r, not as 1/r^2.

Dear Peter Hahn and other RG-ers,

Am I the only one that is doubtful of this discussion ?

The measurement is clear (almost too good to be true).

Best wishes,   Henk Smid

Henk Smid: No doubt, indeed, but the real meaning of the data may be worth being discussed. I've a strange feeling that apparently nobody doubts about the hypothetical source.

there is also a question:

“…The measurement is clear…”, “…No doubt, indeed…”

- seems as next rather bold statements for an unique experimental result that relates to some non-controlled and non-reproducible event.

A few years ago some experimentalists on some other also very complex installation, but, at that, in well controlled conditions, a couple of months were obtaining well reproducible experimental output that the neutrinos’ speed is more then the speed of light. And in these months rather big number of theorists published seems near hundred papers, including in rather respectable physical journals, where were proven that the neutrinos indeed can move with such speed…

Cheers

@F. Leyvraz : “it is not 10^{-8} but only 10^{-4}: LIGO is an amplitude measurement, so the signal measured only decays as 1/r, not as 1/r^2.”

- nobody knows now – what LIGO measures now; though indeed,  if we consider some waves, then indeed, the waves energy is proportional to the square of the amplitude.

 But in this case – the waves of what? That cannot be, of course, “waves of the Matter’s spacetime” – that is impossible, the [5]4D real Euclidian Matter’s spacetime is absolute and cannot be “transformed” by any material object/ material process. As, for example there is no “time dilation”, “space contraction”, etc. that are claimed as real in the SR – that are some changings of rates of internal processes in concrete material objects, including in clocks; and decreasing of  lengths’ projections  of non-point-like concrete material objects [as the result of rotation of the objects in the (X, ct) plain] comparing with the lengths , if the objects move in the absolute spacetime  with some speed, V.

At that both effects are proportional to the 1/gamma(V) – as that Pythagoras prescribed. The “spacetime curvature ("ropples", etc.) in the GRT” by any means doesn’t differ from the “relativistic effects” in the SRT in this sense; it doesn't exist in the realitry..

Though the estimation 10^-8 in the SS post above is, of course, some zero approximation. The level of a detection and errors of experimental estimates of some effects/ parameters depend not only on the energy with corresponding measured effect impacts on the detector, they depend also on the detector’s background, detector’s spectral sensitivity, etc., etc., etc.

But a comparison of possible values of energy that could be spent at interaction radiation: detector remains be a first rough, but often useful, reference point.  

In the event in question seems seriously (if that isn’t an artifact, of course) can be considered [relating to the gravity] only two main version: (1) – that was indeed some wave of the gravity field – an analogue of the EM waves, and (2) – that was some impact of gravitons that were radiated (again as some analogue of photons that are radiated at decays of excited atoms or by an accelerated charge) in some system of masses.

Now there is no satisfactorily developed theory of the quantum gravity that could suggest reasonable models of possible spectrums of gravitons/ waves provided some known initial conditions (the gravitomagnetism seems isn’t a quantum theory till now).

 One can hope that after theorists, which worked hardly enough solving practically non-testable GRT problems, as a number of “holes in the spacetime”, “tunnels in the spacetime”, “spacetime foams”, etc., will develop the adequate to the reality theory of the gravity, then one can hope that some recommendations  for experimentalists will be obtained, and so the lasts will develop experimental installations that will more selectively detect and measure  gravitational events and their parameters.

An example  - already  now it is possible to estimate in a first approximation the quantum properties of the gravity – when measuring rather probable stochastics of the gravity force at interactions of indeed small gravitational masses – photons – with Earth gravity field (see http://arxiv.org/abs/0706.3979  (https://www.researchgate.net/publication/215526868_The_informational_model_-_possible_tests),    at least the section 2.1.2. Monochromatic photon beam distortion.

When to make the suggested experiment is enough to make (e.g. a vertical hole in Earth) an interferometer having arms parallel and orthogonal to Earth surface having lengths 300-400 m. Including, for example, by making additional vertical arm in LIGO or in practically any of earlier interferometers that were built for the GW detection, what could be cost a no more 10-50$ millions…

Cheers

Dear doubtful RG-ers,

'The measurement is clear'. The LIGO group seems to have taken lots of time before publishing. They probably carefully looked at the length of all of their cables.

This signal was recorded in two places. Of course, three would have been better.

What is your worry ?

Groetjes,   Henk Smid

@ Sergey: Experiments are interpreted in the light of theories. GR, as a theory, predicts gravitational waves, and predicts that these waves will move the LIGO mirrors by an amount proportional to the wave amplitude. So within that theory, the LIGO measurements are not so unlikely, since the gain in visibility of  nearby events is not really very large.

Of course, any alternative theory should first suggest what was observed, both by describing an appropriate phenomenon as well as it actions on the interferometer.

Of course, no other theory, to m y knowledge, has made any such predictions.

The latest results are in from Fermi GBM: http://arxiv.org/abs/1602.07352

The final conclusion from the article is as follows “we conclude that the Fermi GBM signal contemporaneous with GW150914 is unrelated to the BH merger.”

This essentially means that ALL follow-up observations from various observatories have come up empty handed.

So here are my latest thoughts…

1.    Because the LIGO team reported it as a valid detection.

1.    The signal occurred during the Engineering Run, not the Observational Run.

2.    The signal was quoted as “too good to be true”, "unexpectedly loud" and "unexpectedly perfect".

3.    No confirmation from Virgo since it was not operational.

4.    No confirmation from GEO600 because the signal just happened to peak in a dead zone.

5.    No infrared signals from VISTA.

6.    No gamma rays from Swift, Integral or Fermi GBM.

7.    No neutrinos from IceCube and ANTARES.

8.    No visible light detected from the Dark Energy Camera (DECam).

9.    No visible light detected from the Pan-STARRS Telescope.

Looks like this was a one-time event that could very well be a lucky fluke or a fake. I guess the next step is to patiently wait for the LIGO team to search through the four months of O1 data to see if they can find other sources of gravitational wave signals such as the kind from rapidly rotating neutron stars!

A good theoretical question though, would be:

Given the assumed nature of the signal, how many neutrinos, how much infrared and optical photons,do we expect to detect, given the nature of the event as well as its distance? That is exactly the kind of considerations whereby the author you cite arrives to the conclusions that the Gamma event is unrelated to GW150914. If the amount is far too small to be detected,as might well be the case, the arguments would essentially go away.

But in any case, we should wait and see what other events will be detected, if any.

“…Experiments are interpreted in the light of theories. GR, as a theory, predicts gravitational waves…”, etc

- that doesn’t change anything in that an fitting of some sketchy and fragmentary experimental data basing on a theory, which claims that real Matter’s spacetime is a “pseudo Riemannian” 4D spacetime and that some gravitational interactions of some masses can result in some transformations, i.e. - “curvature”, “waves”, etc. of the spacetime doesn’t allow to obtain indeed adequate physical information;

 - since the real Matter’s spacetime is [5]4D Euclidian empty container; besides -  the spacetime is absolute  and so cannot be impacted/ transformed by any material object by definition. When just this definition is quite adequate to the reality.

But  true GR believers steadily continue the “solving” of physical problems by using this theory, when yet 100 years of this solving resulted in, in fact, in hundreds of tons of pages of mainstream journals that are mainly nothing more then some fairy tales about black,  white, worm  holes, tunnels between Universes, foams, etc. in/of the spacetime (!?).

When a good theoretical approach though, would be the development of an adequate theory of the gravity force.

Besides, what is worse, they block and marginalize any alternatives, first of all - rejecting even evidently publishable papers, but not only…

Cheers

You are not alone! Look at this discussion: https://www.researchgate.net/post/Does_a_Fraudulent_Joke_stand_behind_the_Discovery_of_Gravitational_Waves where you find this contribution of mine:

The alleged motion of a mirror by 1/1000 of a proton radius results in a phase shift between the two recombining interferometer beams of 2pi 10-18m/10-6m=2pi 10-12. As Ligo is working in destructive interference, the light amplitude in the dark field would be 2pi 10-12 of the light amplitude in the bright field where the interference is constructive. The intensity to be measured is then 36x10-24 times the circulating laser power of 100 kW. Expressing this light intensity as a photon flux one obtains about 20 photons/s, or 4 photons for the merging event. The signal presented to the public with a s/n ratio of 20 is certainly composed of many many more photons.

The inevitable conclusion is then: We were confronted with a theoretical simulation, not with a real measurement. Can we call this "fraud"? I think we can...

Does a “Fraudulent Joke” stand behind the Discovery of Gravitational Waves? - ResearchGate. Available from: https://www.researchgate.net/post/Does_a_Fraudulent_Joke_stand_behind_the_Discovery_of_Gravitational_Waves/8 [accessed Apr 20, 2016].

@ Engelhardt: I believe you are at the very least missing a factor of 300 in the final result, since that is the number of back and forth trips the light makes in the interferometer.

I am missing much more:

How do they manage to keep the amplitudes of the interfering beams exactly equal within a factor 10^-12?

How do they manage to reduce the stray light in the dark field by a factor of 10^-24 compared to the bright field?

How do they keep the circulating power constant within a factor 10^-12 in order to avoid motions of the mirrors induced by fluctuating radiation pressure?

Where is the calibration curve showing displacement of the mirrors as a function of the radiation pressure? (10^-18 m displacement are caused by 10^-7 W light power during .2 s)

How do they know that the velocity of light is unaffected when "spacetime" is "compressed"?

Looks like fraudulent science pays well!

Here is an excerpt from my local CBC news.

LIGO's three founders — Rainer Weiss, Kip Thorne and Ronald Drever, who dedicated much of their careers to gravitational wave detection — will share $1 million. More than 1,000 contributors to the project will also split $2 million equally.

Hot off the press! The prizes keep rolling in!

Drever, Thorne, and Weiss Receive $500,000 Gruber Cosmology Prize for Detection of Gravitational Waves.

Wow, another prize to the amazing trio:

“$1.2 Million Shaw Prize Awarded to LIGO Founders, One MIT and Two Caltech Professors”.

Joseph Weber would be envious. He was unable to convince the scientific community that he had detected gravitational waves because of lack of follow-up observations and lack of repeatability. Speaking of repeatability… I included a graph from a 2009 slide presentation (LIGO-G0900546 page 24). It shows the number of merger events that Advanced LIGO was expected to detect. The (pessimistic) numbers were:

40 binary neutron star mergers per year

10 neutron star/black hole mergers per year

20 binary black hole mergers per year.

That’s a total of 70 events per year, or over five per month. The four months of O1 should have revealed at least 20 events. Where are they? And (to be fair) shouldn’t the prizes wait until at least one more GW event is detected in O1?

And speaking of follow-ups… check out articles: arXiv:1602.08492 and 1604.07864. No electromagnetic counterparts found!

Peter, it alarms me that the interpretation drawn from the data is so biased. I don't dispute that two massive objects collided to generate the gravitational waves but Kip Thorne is a well known black hole proponent and we know that luminaries of the past, who can no longer express their views (including Einstein and Dirac), dismissed black holes as unphysical for good reason: they cannot form in a universe of finite age owing to infinite time dilation prohibiting ingestion of matter through an event horizon.

This was meant to be an experiment that set out to detect gravitational waves, not to "prove"/continue to fool us that black holes truly exist in nature. So why was the detection of GW150914 not promptly reported? Surely simulations would have been already performed prior to the long-awaited signal's detection - why the five month wait before further confirmation of Einstein's genius? From what I've read here, it might have been much longer than five months had it not been for a leak. This raises the obvious question of how many other detections there could have been which did not leak out?

As we know, there was a near-simultaneous detection from Fermi GBM. It is astonishing how this extremely interesting fact has since been downplayed. It's not at all easy to detect such events when they originate from over a billion light years away, especially if the detector not nicely pointing as the source.

So let me ask a couple of question. Firstly, why did none of the ~1000 authors (or the peer reviewers) express any curiosity concerning that great blob, present in both signals, emerging during the height of the coalescence? It strongly suggests that the "black holes" spewed forth matter from within their event horizons (officially impossible). Perhaps, due to the embarrassing 50 years in which BH fantasists have been indulged, nay adulated, the strategic decision was taken not to draw any attention to it, gambling that nobody would notice...

I strongly suspect there have been several/many unannounced detections of coalescing pseudo-BHs, so we also need to ask why that might be. As these latest posts confirm, millions of dollars of prize money were at stake. Of course, one cannot dismiss the pressure to report the detection of gravitational waves, especially when there might be Nobel gongs in the offing, but if nature wants to challenge the beliefs of the Hawkings/Thornes of this world then it can jolly well keep shtum as long as these "heroes of science" are still alive. I suspect this is the real reason why GW150914 exhibited such rare and "unexpected" characteristics, and why nothing else has been reported since (despite the high sensitivity of LIGO since the upgrade). This was no merger of supermassive black holes, a fairly common occurence in galaxy clusters following galaxy mergers. Nor was it a merger of ordinary sized stellar mass black holes/neutron stars in the Milky Way or its neighbouring galaxies. The implication appears to be that this was a very carefully selected example, chosen for its remoteness (greater immunity to electromagnetic scrutiny) which in turn guaranteed its intrinsic weakness (suppressing the more interesting signal artefacts).

Do we expect to detect electromagnetic radiation coming out from such event? Sorry if it is a dumb question. But I see it -- at the time of collision -- to be clean of ordinary matter structures, like accretion disk. I understand that some time before the collision, if there is/are collision disk(s), it will be perturbed and accretion would happen, but that would be cleaned out -- kicked off -- when the compact objects get closer to a merge. Again, in other words, I really don't understand expectations on detecting electromagnetic radiation among low-energy frequencies (I'm considering here "low-energy" anything below soft x-ray).

Also, if anybody has references about observational works on binary systems (galaxies or compact objects) where accretion (and possible evolution) is discussed I would like to read them.

Carlos,

See my paper ( 1996, PhRvD, 53, 2901 ) by Chakrabarti, Sandip K.  ON

Gravitational wave emission from a binary black hole system in the presence of an accretion disk  and references therein and the follow up papers of mine with students. It is not true that GW wave emission period disk need not be there. When a small black hole rotates around a big black hole (AGN) it would be accreting low angular momentum matter and GW emission profile would change.

As to the question of whether GW emission was actually seen, Some are speculating that the timing of the announcement was synchronized to attract Prime Minister Modi who would be so elated to see so many Indian co authors that he would immediately dole out funds in the budget session to INDIGO which started in the same week. Modi would be happy to see that Gujrat would have a lab on GW. It is said that the whole thing is fine tuned to sale the spare detector of USA to India to get funds to improve existing LIGO performance even further. Modi did fall for the whole thing.

I have not made my mind yet.

See attached paper.

Reg C

FYI, Lawrence Krauss's view : 'Finding Beauty in the Darkness', New York Times, Feb 11, 2016 http://nyti.ms/1PQBA71

And let's not forget that Krauss showed mathematically that black holes cannot form:

In order to discover something more about black holes and gravitational waves problems I propose my new Relativistic Alpha Field Theory (RAFT). (See articles: ID - IJNTR01050015, IJNTR01050016, IJNTR01050017, IJNTR01070005, published in International Journal of New Technology and Research, ISSN:2454-4116). As it is well known, General Relativity Theory (GRT) cannot be applied to the extremely strong gravitational field at the Planck's scale, because of the related singularity. In the mentioned articles we show that Relativistic Alpha Field (RAF) theory extends the application of GRT to the extremely strong fields at the Planck's scale. This is the consequence of the following predictions of RAF theory: a) no a singularity at the Schwarzschild radius, b) there exists a minimal radius at r = r min = (GM/2c 2) that prevents singularity at r = 0, i.e. the nature protects itself, c) the gravitational force becomes positive (repulsive) if (GM/rc 2) > 1, that could be a source of a dark energy, and d) unification of electrical and gravitational forces can be done in the standard four dimensions (4D).If RAF theory is correct, then it could be applied to the both weak and strong fields at the Universe and Planck's scales giving the new light to the regions like black holes, gravitational waves, quantum theory, high energy physics, Big Bang theory and cosmology.

It is more than likely that there was no detection of gravitational waves and that, as you say, it was a fluke. That the "signal" was detected by two observatory only provides evidence that the source of the so-called signal may be the same, local and located between the observatory.

@Spivey: "And let's not forget that Krauss showed mathematically that black holes cannot form"

That is exaggerated. He used a bad time coordinate that diverges at the horizon and got the expected result in this time coordinate. But you simply cannot describe, with this time coordinate, the part of spacetime up to and beyond the horizon that has been shown -- equally mathematically -- to exist and not to be singular.

Using appropriate time coordinates, one can demonstrate the collapse of a star into a black hole in finite time and one can calculate the merger of black holes numerically, which also takes finite time. The detected signal shows details expected from such a merger, in particular the signature of the ring-down, after two horizons have become one. This happens in less than a second. That is not much compared with infinity.

What is the influence of GW151226 on all your claims?

Leyvraz,

GW151226 does not change my mind in the slightest. The timing of it is suspicious in that it happened in the middle of the night, on a holiday, when staffing of the facilities are at a bare minimum and most people are fast asleep or partying (I know, it sounds like conspiracy theory).

I’ll believe LIGO’s detections when other observatories like Swift and INTEGRAL detect gamma rays, IceCube and ANTARES detect nutrinos, or Virgo detects the same GW when its up and running. Forty two GRBs occurred during LIGO’s O1 run according to the site: http://www.mpe.mpg.de/~jcg/grbgen.html. So where are the corresponding GWs?

It’s just not good science to make a claim without some kind of third party confirmation!

To add to my last comment, here is a link to the latest followup results:

"Searching the Gamma-ray Sky for Counterparts to Gravitational Wave Sources: Fermi GBM and LAT Observations of LVT151012 and GW151226."

"No candidate electromagnetic counterparts were detected by either the GBM or LAT."

The question, of course, is: do we expect a measurable gamma ray or neutrino signal from the event? The paper you link to explicitly states:

``Prior to the watershed discovery of GWs from the binary black hole (BBH) merger

GW150914…there was little theoretical expectation for EM counterparts to BBH mergers.''

So if no theoretical grounds exist to think a detectable amount of gamma rays will be emitted, there is no reason to be surprised at their absence.

As to the ``corresponding'' GW to the GRB's you quote: we do not really know well what causes GRB's, so why should we think they should be associated with (noticeable) GW? Of course, the fact that we now have to rely on one single instrument is problematic, and even when Virgo starts operating, things will not change much, since the principle of these detectors are all the same.

I should finally remark that, whereas I find it unexceptionable to ask whether these detections could be an artifact---something which the second detection makes far less likely---I find the suggestion that fraud could be involved absolutely outlandish: for starters, with thousands of people involved, it would be essentially impossible to maintain. On the other hand, there is no motive whatever, particularly considering the fact that it would be bound to come out sooner or later.

From the data, Figure 1 in the PRL paper, it seems nearly impossible to imagine that GW150914 was not an observation of a gravitational wave event.  There does seem to be an open question, however, whether the event represented the merger of black holes or of some objects that do not possess event horizons.  A paper was published in PRL shortly after the GW150914 paper that raised that possibility.  The distinction is important because while GW150914 clearly seems to be the first "direct" observation of gravitational waves, it may not be the first "direct" confirmation of the existence of black holes or of the possibility that black holes, if they do exist, can merge.

@Francis: 'But the paper usually cited as having shown that, Oppenheimer and Snyder, actually only shows that it is possible in proper time for an infalling observer, and says that, from our perspective, “it is impossible for a singularity to form in a finite time”.'

No. All that the paper shows is that it is impossible for that particular kind of "singularity" (only a coordinate singularity!) to form in finite Schwarzschild time, i.e., using a particular time coordinate. But there are an infinity of other time coordinates that an external observer can use and which remain finite during crossing of the horizon by the surface of the star. A paper calculating the collapse without any infinities arising is given below [1].

[1] Kanai, Yuki, Masaru Siino, and Akio Hosoya. "Gravitational collapse in Painlevé-Gullstrand coordinates." Progress of theoretical physics 125.5 (2011): 1053-1065. arXiv:1008.0470v1

``The timing of it is suspicious in that it happened in the middle of the night, on a holiday, when staffing of the facilities are at a bare minimum and most people are fast asleep or partying''

Just checking: ``it'' happened at 03:38:53 UTC 26/12/2015. Now UTC is GMT, so it happened at 3:38:53 am at Greenwich, which corresponds to 7:38:53 pm of 25/12/2015 in Washington state, where LIGO is. So yes, it is still a bit of a holiday, but hardly the dead of night. I would not assume staffing to be at a minimum.

“Am I the only one that is doubtful of LIGO’s detection of gravitational wave GW150914?”

- it seems that this question is little uncertain by a couple of reasons. First of all – seems as there is no much reason to discuss an unique event, where something possibly could be detected – some reasons can appear only if at least a few detections and in different experiments were obtained. Besides – even if indeed some gravitational waves were detected in this case, that doesn’t allow to obtain some concrete inference – the gravity force is rather similar to the EM force and some existence of some gravitational waves indeed seems as rather possible, besides some GR’s “ripples of the spacetime”, of course.

Though yeah, rather large money were spent in this case, when it could be more useful to spend the money on some more informative experiments with the gravity; for example:

-          the experiment where the quantum nature of the gravity force rather possibly can be observed

at least the section 2.1.2. “Monochromatic photon beam distortion”,

for this experiment any, including any “old” installation that was built for the gravitational wave detection can be directly used with a rather simple and cheap upgrade – it is necessary only to add the 3-th vertical arm   (for example – in a borehole) having length [depth] 300- 400 m; and

-  the experiment, where the net changes of atomic tick rate values dependently on Earth gravity potential https://www.researchgate.net/publication/277710038_The_informational_model_-_gravity_a_next_experiment are measured,

at that instead of the scheme that is suggested in the link above (with using some air balloon) it is possible to make corresponding measurements in some “skyscraper”, here is enough to expose a pair pf clocks at different  [~ 500 m]  heights in a few hours. The experiment’s outcomes will answer on at least two rather imprtant questions (i) – so what is the real change of   the tick rate? – the result will be used as the direct [and indeed] test of the GR ; and (ii) – if the result  will be lesser then the GR predicts, that will connote that the photons change their energy at motion in gravity field, what is again direct [and indeed] test of the GR;

 and the results outside the GR’s predictions would be rather useful at development of a physical theory of the gravity that could be adequate to the reality.

Both experiments would have cost no more then a few tens of $millions…

Cheers

Dear  Peter Hahn and other RG-ers,

It seems they have found another signal of bl;ack holes bumping into each other. 

Best regards,   Henk Smid

Watching LHC to getso  much publicity on their Higgs marketing campaign LSC could not stay in the dark any longer. 

The story was something different, I guess:

On December 26th they found a very weak signal, called it GW151226.

"Like LIGO's first detection, this event was identified within minutes."

The christmas signal was too weak to make some headline. Therefore they decided to give the more significant GW150914 to the public which was nothing but the result of a blind injection test. Having found GW151226 within minutes they felt confident about their power and marketed their test signals as of the 14th Sept 2015 having 5.1 sigma instead of the real and quite doubtful christmas findings. 

Good advice from jwd:

Don't forget your grandparents to meet or to give hugs. If you forget them you may probably join the Hug-Einstein-Club for reasons you cannot explain for yourself: "Spoiler: the signal agrees, again, perfectly with Einstein’s theory."

Henk,

When you say “another”, are you talking about a third detection or are you referring to GW151226? A reference to the news article would be nice.

Putting that aside, the number of detections that LIGO makes claim to is irrelevant. Unless the detections are confirmed by third party observatories (using gamma rays, x-rays, neutrinos, etc.), we can only assume that “they” have a bug in their test signal injection software or the test signal injection process.

It just isn’t good science to take the word of ONE observatory that has never been proven to actually work. (And I consider LIGO to be one observatory with two detectors because “they” share the same software, processes and people).

But, Peter, if there is no reason to expect a neutrino signal, or a gamma ray signal, or any other kind of signal, what then?

Consider, for example, the first neutrino detections. They were emitted in reactors and detected in a large detector. The discovery was made in one laboratory. Of course, it was later confirmed, but there were never any real doubts about authenticity. Why should there be here?

The events described by LIGO are distant and purportedly caused by events thta do not leave a strong signature in other domains. Further, LIGO is sensitive to amplitude, so that the signal decays only as 1/r, whereas for the other signals, onemeasures intensity, which decays as 1/r^2.

There would only be a problem if theory, which is well confirmed in the nature of the observed signal, also predicted a gamma ray, or a neutrino signal. To the best of my knowledge it does not. It is then altogether untenable to say: ``as long as there are no other detections, it can *only* be a bug in their apparatus''. Admittedly, it might be such a bug, but both the coincidences and the agreement with theory speak against it. I do agree that it would be good to have another laboratory, based on a slightly different principle, to confirm these detections. But in the mean time, I see no reason to disrust these particular findings, just as no one distrusted the first neutrino detections, which also only happened in one lab, and which were also for a long time only repeated in setups based on the same principle.

Just to add, there are other observatories being built and while there is some sharing of technology, they are not all the same. They should be on line in a few years.

Black hole mergers should not produce any other form of signal but neutron star mergers should. However, their masses will be less than 2 M_Sun so we just have to wait for one that is close enough. The nice part of that scenario is that only a few prompt neutrinos might get here as fast as the GW so there's a good chace LIGO would be able to identify the event more quickly than optical detections.

Leyvraz,

The major reason for doubt is that interferometers have not been proven to be an effective device for detecting gravitational waves. Wiggling the mirror at the end of one arm or modulating the laser beam is not a valid technique for testing an interferometer’s ability to measure distortions of space-time. (It’s a Newtonian measurement, not a GR measurement).

There are numerous articles describing how a laser’s wavelength increases and decreases as space stretches and compresses as a GW passes through an interferometer, so the number of light waves in each arm remains the same. The speed of light also increases and decreases as the arms stretch and compress so the photons will always remain in phase when reaching the photo detector. Alexander Unzicker describes it well in his book “Einstein’s Lost Key” where Einstein himself was seriously working on a variable speed of light theory.

We can test a microphone by generating sound waves or test a radio by generating radio waves or telescope by generating infra-red, optical, x-ray or gamma rays, and we can create neutrinos in accelerators, but we don’t know how to generate gravitational waves. We need a proper quantum theory of gravity before we can do that, and we are not even close. (And BTW, GR and QM are still incomplete and incompatible theories so they can’t be trusted when treading new territory).

So the sad reality is that (unlike EM wave devices) we have no way of truly proving that an interferometer is a valid device for detecting distortions in space-time because we don’t know how to generate GWs! Simply trusting the integrity and honesty of LIGO is not enough (sorry!). That’s why I’m sticking to my conclusion that GW150914 and GW151226 are artificial injections and we cannot and (ethically) should not consider them valid until we have third party confirmation. It’s the way good science should be done.

Agreed. But that is what we have theory for! GRT tells us that interferometers do detect gravitational waves: that is an exercise, about the result of which no doubts exist.

Dear Peter,

You are not the only one.

A discussion of this event goes on for months now in:

May be then they detected classical gravitational waves described by Maxwell equations as shown by Heaviside in 1893 or more recently those proposed by Jefimenko. What if there is no spacetime?