Robittybob1

You could be right, for if we have to use a line of sight argument we would have to be sure the GW was coming from the object behind it or the space behind it and we can't, so we will fail unless we can determine the source of the GW. If it is effectively from a line between the binary masses, I think we still have a chance. If we took the LIGO right up to the binary the end of arm that pointed toward the barycenter would experience the greatest G force so the test particles would move apart particularly when they were in the eclipsed position. So eclipsing is not the answer.

You are privileged to be able to answer like that. If one could tell where the gravity waves originates maybe we could see shapiro delay but atm we don't know if eclipsing a BH will be enough to make a block for the effect to go around and hence take a longer path.

So is that covering this situation? "Then, if the infall could take forever to allow us time to take the LIGO further and further away from the BBH but staying on the angular momentum vector, this toing and froing should continue but the amplitude will diminish. The alignment will depend on the speed/directness of gravity (can we draw straight lines or are they curves or whatever). The speed of gravity seems to be the difficult question for if gravity had to take a spiral path would light have to do the same?" In reality they were orbiting for at least a billion years, so when they estimate the distance back to the BBH is it a straight line or a spiral? I'm wrong for all the spiraling has finished now, it was only spiralling prior to the merger and we couldn't estimate its distance till the merger. If you can take most of the aberration effects away the line becomes straighter but not dead straight.

That would depend on a lot of factors, angle of inclination, orbital radius, precession and such. With the peaks always being spaced closer together as they infall it is really difficult to pick up even a microsecond change. One day there will be a detection with a lower angle of inclination to the line of sight with more "linear polarization in its equatorial plane" and then we might see if there is any Shapiro time dilation.

As far as doing a model I was trying to understand what would happen if we could take LIGO right alongside/into the BBH. If it was at the barycenter between the two BHs the masses in each arm would get "pulled" apart (distance apart would increase) when the BH masses were aligned with the ends of the arms and closer together when the masses were at right angles. I'm sure that makes sense but tell me, would that be correct thinking? Then, if the infall could take forever to allow us time to take the LIGO further and further away from the BBH but staying on the angular momentum vector, this toing and froing should continue but the amplitude will diminish. The alignment will depend on the speed/directness of gravity (can we draw straight lines or are they curves or whatever). The speed of gravity seems to be the difficult question for if gravity had to take a spiral path would light have to do the same? [That becomes more than I can comprehend]

That was good but it didn't go far enough to explain the position of the bodies to the phase of the wave. But it got very close. That has really helped and that was how I had imagined it "circular polarization along the angular momentum axis linear polarization in its equatorial plane (orbital plane). . .The arrow of the polarization (maximum) is like orthogonal with the distance vector between the two masses (BBH). It is harder to relate to linear polarization. (Do you agree with that?)

If we had the situation as in your second paragraph Dan is enquiring what effect that would have on the signal received by the LIGO. By eclipse that refers to LIGO only. The BBH would still be producing GWs but would LIGO be able to detect a signal change that corresponds to the timing of the eclipse? Example is the Sun is still shining during a solar eclipse but the signal (light) on Earth is different. So the BBHs will during their binary phase be producing GWs regardless of whether LIGO sees an eclipse. - I hope Dan agrees with that. OK that was all correct and understandable, but taking your alternator example, they can relate the different positions of the armature to the waveform produced. Can the same thing be done for a quadrupole wave? What position (or arrangement) of the accelerating masses creates a maximum and a minimum? A maximum would be defined as maximum distance between the test particles in the x axis. What position (or arrangement) of the accelerating masses in relation to the x axis creates a maximum separation in the test particles along the x axis? Can anyone answer that question for that is where we will see the change in the chirp waveform if it is going to show a Shapiro time delay by delaying the onset or making the onset earlier of the maximum or the minimum part of the waveform. Or it may even show up as a widening of one part of the curve.

Which figure number did that quadrupole waveform have? I can't see any in paper that would be helpful, sorry. Are you saying as shown in Wikipedia on gravitational waves? https://en.wikipedia.org/wiki/Gravitational_wave#Effects_of_passing .What I was trying to do is establish what phase of the BBH orbit produces the minimum strain, say when the test particles (in one arm of the LIGO interferometer) are pulled together horizontally (on the x axis). Was that caused by the two masses being equidistant (parallel to the x axis) or inline with the detector arm (parallel to the y axis)? I realise now I was asking about the chirp waveform before. A minimum on the chirp waveform is "no strain" so it is slightly different than just thinking about one arm of the LIGO at once.

The paper is called "Decoding mode-mixing in black-hole merger ringdown" It seems unlikely to answer my question for I was talking about the phase of the GW before the contact and ringdown.

Imagine being right next to it so we don't have to consider signal transmission times, what phase it it in then? Either two BHs equidistant to you and two BHs inline with you. Which arrangement gives the minimum?

Exactly, but there was a degree of mismatch. Was it in the order of 10%? The signal matches the model to what percentage? From memory if was 90% but this could be found and confirmed later. Dan used the term "smooth rate", and you say "continually increasing" but it is a continuously increasing rate. It definitely not a linear increase. Can we say it is an exponentially increasing rate?

Try and answer this question please? When the two masses are inline with our (LIGO) line of site (regardless of their inclination) what part of the GW chirp signal are we seeing? [minimum or a maximum on the chirp signal are possible answers, I'm picking minimum]

They would have to show that one part of that frequency change was more or less than expected. The frequency is changing because the orbit is decaying so the expected rate of orbit change maybe able to be calculated so we could see if the signal matched this.

Could the transmission of the "spacetime interactions" be affected by the arrangement of the two orbiting masses? When the two masses are inline with our (LIGO) line of site (regardless of their inclination) what part of the GW chirp signal are we seeing? Is it a minimum or a maximum on the chirp signal?

I can't immediately see the ringdown being affected by Shapiro time delay but there was a signal being produced so it is possible during the ringdown too.

The binary nature of the orbiting bodies was the similarity. The masses of the bodies involved are different. I read that paper looking to see if the methods they used could be useful to DanMP and I couldn't see how to use their methods. They had multiple recordings to compare timings of hundreds of signals compared to the BBH chirp which only gave approx 10 waves before the merger. Some of these waves could have shown Shapiro delay if there was precession occurring. In their case they had a system with the lowest recorded angle of inclination whereas GW150914 or GW 150914 was probably very inclined. OK they were measuring the pulsar signal and Dan would be trying to see the timing of the GW signal (but both signals travel at the speed of light).

Some of van's Flandern's ideas are a bit weird I agree.

That paper by S Carlip has a strange paragraph with an option in it. http://arxiv.org/pdf/gr-qc/9909087.pdf Has anyone tried to do that by treating "gravity and gravitational radiation as independent phenomena? So does that mean we could have gravity waves (a single wave) and gravitational radiation (coming from each member of the binary)? Gravity waves is what is being measured by LIGO but it is the loss of energy via the production of gravitational radiation that allows the BBH to experience relativistic orbital decay and final merger. Gravity waves travel at the speed of light but gravity ??.... I like the idea treating the two as independent phenomena. .

That second quote is worth investigating for it sounds very similar to a binary black holes. Footnote 7 http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.13.789 [You permission to view this one] Footnote 8 http://iopscience.iop.org/article/10.1086/449311/meta;jsessionid=1D8E4622AA6C3DDA76E9403E722853B2.c1.iopscience.cld.iop.org http://iopscience.iop.org/article/10.1086/449311/pdf

Did you link to the right aberration topic? There were 501 articles in Google Scholar mentioning "T van flandern" Carlip is not agreeing with van Flandern and I suppose you don't either, so that can't be a bad thing. What exactly were you implying about S Carlip?

This is the paragraphs that seems to highlight the issue So does that mean we expect aberration due to gravity propagating at light speed. But this expected aberration is cancelled by velocity dependent terms in the interaction. What does that actually mean?

Did you understand that letter from S Carlip? http://arxiv.org/pdf/gr-qc/9909087.pdf Your analysis "Newtonian would instantly shift the gravitational vector to the new position of the Sun (or force would disappear). GR would do the equivalent (approximately) but only after a lag...the effect would remain in the direction toward where the Sun was going to be until after the lag." would be different if I have any true understanding of what he says. No one has mentioned his work as yet. I think he is saying there is no or little lag in GR either but I'd like someone to confirm that.

I thought I see what some recent papers say about the Shapiro effect: http://arxiv.org/pdf/0711.3041.pdf and http://www.nature.com/nature/journal/v467/n7319/abs/nature09466.html .

I keep on hearing that GW will go through space, stars, planets etc nothing stops them, so why wouldn't it just go straight through a BH too then, and have no Shapiro delay? What makes a G-wave able to go through a star? It must be based on a theoretical basis only for we've only had one detect AFAIK.

No it is just like the example Mordred gave of the Sun disappearing. It is only a mental exercise to see what effects gravity at the SoL has. Yesterday when I was trying to figure it out my brain didn't feel like any sort of computer, it just froze.