Shapiro (or Shapiro-like) delay of GW signals (split)

[Strange]

I don't think DanMP is interested in proving (or even providing any support for) any of his ideas. He appears to be of the "I thought of it, so it makes sense and must therefore be right" school of thought.

[Robittybob1]

I don't think DanMP is interested in proving (or even providing any support for) any of his ideas. He appears to be of the "I thought of it, so it makes sense and must therefore be right" school of thought.

Howabout you starting it and prove the null hypothesis, that you advocate?

 

1. You have convincing evidence that it is Not relevant to this situation (i.e. that there is NO independent "signal" from each black hole); and

2. You know how to calculate the Shapiro delay in an extreme case like that of a spinning black hole.

 

It is not easy is it?

[imatfaal]

!

Moderator Note

 

Can we stop commenting about DanMP's motivation or characteristics please? No matter how outwardly unlikely a proposal is it deserves to be argued on its merits and not on perceptions about the poster. We attack ideas never the person.

 

Do not respond to this moderation within the thread.

 

[swansont]

I thought you had accepted that there were two waves coming from the quadrupole.

 

No idea how you came to that conclusion.

Howabout you starting it and prove the null hypothesis, that you advocate?

 

1. You have convincing evidence that it is Not relevant to this situation (i.e. that there is NO independent "signal" from each black hole); and

2. You know how to calculate the Shapiro delay in an extreme case like that of a spinning black hole.

 

It is not easy is it?

Wrong target for the burden of proof. The person making the claim owns that.

[Robittybob1]

No idea how you came to that conclusion.

 

....

http://www.scienceforums.net/topic/93472-gravitational-lens-and-gravitational-waves-question/page-3#entry909686

[swansont]

http://www.scienceforums.net/topic/93472-gravitational-lens-and-gravitational-waves-question/page-3#entry909686

That says absolutely nothing about two waves. It's one wave, at twice the frequency of the orbit.

[Robittybob1]

That says absolutely nothing about two waves. It's one wave, at twice the frequency of the orbit.

http://www.physics.usu.edu/Wheeler/GenRel2013/Notes/GravitationalWaves.pdf

Just look at that diagram do you think that is correct? I don't, for if the masses are moving the line representing gravity should be a spiral or a dotted line but not a continuous line. I know what you are saying and it has been playing on my mind, so I'm not saying you are wrong but I'm trying to understand what it means.

 

So from the diagram if the BBH was directly above the LIGO detectors and the two distances were equal the detectors would get a signal compressing one way and after the BBH rotated through another 90 degrees and compressing in the other arm, another 90 degrees compressing in the first arm and so on , 2 cycles per orbit. I can see that but the point of maximum gravity comes from each body and the effect of this is a spiral through space heading toward the LIGO detectors. So are you going to get places where the gravity lessens or superimposes in space with spirals or pulses where the distances to the LIGO detectors are not equal?

I have tried to work this out.

 

When the BBH are the same distance apart as the two LIGO detectors and there was an absolute side on view to the orbital plane with a line of sight to the Earth of zero degrees the gravity from both black holes at two points in their orbit could reach one of each of the two facilities at the same time so they would be basically measuring parts of different orbits.

 

If the LIGO facilities are 2000 km apart and the BBH binaries are 2000 km apart the gravity from the furthest BH will travel through space and hit the closest detector at the same time as the closer BH will send gravity to the furthest detector. Here they would be measuring parts of 2 different orbits.

 

This could be the worst case scenario.

 

Would the optimum case be a black hole binary, with the orbital plane parallel to the plane through the ligo facilities, directly overhead the mid point between the two facilities with a 4 km separation of the binary bodies?

 

At 2000 km the orbital velocity would depend on their masses but the solar mass BHs will not being orbiting very fast even at this distance but if the LIGO team start picking up the lower frequency waves at greater separation of the BBHs they could end up with more issues with interference.

 

Am I understanding this right?

Edited March 16, 2016 by Robittybob1

[swansont]

http://www.physics.usu.edu/Wheeler/GenRel2013/Notes/GravitationalWaves.pdf

Just look at that diagram do you think that is correct? I don't, for if the masses are moving the line representing gravity should be a spiral or a dotted line but not a continuous line. I know what you are saying and it has been playing on my mind, so I'm not saying you are wrong but I'm trying to understand what it means.

 

 

 

You are reading waaaay too much into this. "r" represents the position vectors, standard in physics drawings.

[Strange]

I have tried to work this out.

At the risk of being boring, I will just say again: thousands of hours of supercomputer time.

 

When the BBH are the same distance apart as the two LIGO detectors and there was an absolute side on view to the orbital plane with a line of sight to the Earth of zero degrees the gravity from both black holes at two points in their orbit could reach one of each of the two facilities at the same time so they would be basically measuring parts of different orbits.

Firstly, I suspect that when they were that far apart, the gravitational waves would have been undetectable.

 

Secondly, the line of sight was not "side on".

[Robittybob1]

 

 

You are reading waaaay too much into this. "r" represents the position vectors, standard in physics drawings.

I read them as distances:

 

 

• Imagine observing a distant binary star and trying to measure the gravitational field at

your location. It is the sum of the field from the two individual components of the binary,

located at distances r1 and r2 from you.

OK position vector:

 

 

In geometry, a position or position vector, also known as location vector or radius vector, is a Euclidean vector that represents the position of a point P in space in relation to an arbitrary reference origin O. Usually denoted x, r, or s, it corresponds to the straight-line distances along each axis from O to P:

Makes sense.

 

At the risk of being boring, I will just say again: thousands of hours of supercomputer time.

 

 

Firstly, I suspect that when they were that far apart, the gravitational waves would have been undetectable.

 

Secondly, the line of sight was not "side on".

I was not talking about that particular BBH but the possible limits of LIGO, seeing whether it was even possible to get the "Gravity" lines to overlap and superimpose as they did in that 3D animation. I came to the conclusion it is virtually impossible as gravity operates at the speed of light and if the orbit is large the orbital frequency is low so the G-waves are always really well separated.

[DanMP]

I don't think DanMP is interested in proving (or even providing any support for) any of his ideas. He appears to be of the "I thought of it, so it makes sense and must therefore be right" school of thought.

 

Here: http://arxiv.org/pdf/1511.01901.pdf

 

I found this:

For reasonable distances of closest approach (see, e.g, discussion in [4, 5, 10]), the amplitudes of these effects are of the order of 100 ms−10 s.

 

 

and the 2 BHs that merged were much closer ...

 

 

From here: https://en.wikipedia.org/wiki/First_observation_of_gravitational_waves

 

I found this:

The chirp signal lasted over 0.2 seconds

 

 

It's enough?

I can't imagine why. It is just another crackpot idea from another random crackpot.

 

Nice "gift" for my birthday. Thank you.

[Mordred]

No the Shapiro delay and the chirp are two different things. A Shapiro delay will affect all frequencies and polarizations of the chirp equally.

 

The paper you posted uses the quadrupole spin 2 statistics but doesn't state differences in each polarization (correctly so).

 

" The chirp indicates that as gravitational waves are emitted, they carry energy away from the binary. The gravitational binding energy decreases, and the orbital frequency increases." See below paper on the chirp calculations in the pocket handbook section

 

The Shapiro delay would have the same influence upon each emitted wave.

 

http://www.physics.usu.edu/Wheeler/GenRel2013/Notes/GravitationalWaves.pdf

Edited March 16, 2016 by Mordred

[DanMP]

Black holes (BHs) are surrounded by "gravity wells". If gravity "travels" with the speed of light, then close to a BH, we should have/see a delay, as in Shapiro time delay. If this delay is big enough (minutes, hours), in the final seconds before merging, the "gravity well" of the BH in the front appear to mask the gravity pull of the BH in the back. So we have/"see" M1+M2 when the BH's are side by side and M1 or M2 when they are one in front of the other. This alternance of apparent mass produces the waves, the signal we detected.

Edited March 16, 2016 by DanMP

[Mordred]

Yes but that's not the chirp or not the rate the chirp occurs.

 

See the equations page 10.

 

http://www.physics.usu.edu/Wheeler/GenRel2013/Notes/GravitationalWaves.pdf

 

The Shapiro delay will affect how long it takes us to see each signal equally.

Edited March 16, 2016 by Mordred

[DanMP]

... if the delay is bigger then the whole "chirp" (few seconds?), the information (gravity pull) from BH-1 when is behind BH-2 would arrive (long) after the chirp, giving the impression that BH-1 disappeared ... The same is valid with BH-2 pull when it gets behind BH-1. This is a good (extra) reason for a GW:

 

By the way, if this Shapiro delay idea is not good/important, then we should have big enough GWs from there long before the chirp/merger, because the BHs are moving fast enough long before the "crush". Did they record them? [No - see the "chirp"]

 

My Shapiro delay idea has (maximum) effect only when the BHs are very close to each other, right before they merge, as it happened ... The angle of observation was also just right for such an effect ... Do you think that it was a coincidence?

[Mordred]

No you obviously don't understand the Shapiro delay or the chirp.

 

The Shapiro delay is essentially the time dilation due to travelling through a gravity well.

 

Now in the Binary BH scenario NEITHER BH produces gravity waves. They are both symmetric rotating objects.

 

The gravity waves emitted is due to the changes of the assymmetric spacetime changes encompassing BOTH BHs.

 

So the Shapiro delay will be the same for all measurement points on the chirp signal.

 

 

Not all objects emit gravity waves. Any symmetric rotating object of constant velocity will not produce waves.

Edited March 16, 2016 by Mordred

[DanMP]

Now in the Binary BH scenario NEITHER BH produces gravity waves. They are both symmetric rotating objects.

 

Not all objects emit gravity waves. Any symmetric rotating object will not produce waves.

 

Not waves but gravitational pull. See here: http://www.physics.usu.edu/Wheeler/GenRel2013/Notes/GravitationalWaves.pdf

 

The idea that gravitational information can propagate is a consequence of special relativity: nothing can travel faster than the ultimate speed limit, c.

 

[Mordred]

[latex]M_c =\frac{(m_1m_2)^{3/5}}{(m_1 + m_2)^{1/5}}[/latex]

 

This is the formula for chirp mass. You can see both masses are included.

 

The gravitational force is in the next three equations on that link you posted page 10. It already accounts for changes in orbit via two maxima and minimal values.

 

"In practice what it means is

that for each cycle made by the binary motion, the gravitational wave signal goes through two

full cycles there are two maxima and two minima per orbit. For this reason, gravitational

waves are called quadrupolar waves."

 

See pages 6,7 and 8. Where you account for position of the two objects, they include the time components on page 8

 

The chirp formula relates to the number of waves which includes the polarization

Edited March 16, 2016 by Mordred

[Strange]

 

... if the delay is bigger then the whole "chirp" (few seconds?), the information (gravity pull) from BH-1 when is behind BH-2 would arrive (long) after the chirp, giving the impression that BH-1 disappeared ... The same is valid with BH-2 pull when it gets behind BH-1. This is a good (extra) reason for a GW:

 

By the way, if this Shapiro delay idea is not good/important, then we should have big enough GWs from there long before the chirp/merger, because the BHs are moving fast enough long before the "crush". Did they record them? [No - see the "chirp"]

 

My Shapiro delay idea has (maximum) effect only when the BHs are very close to each other, right before they merge, as it happened ... The angle of observation was also just right for such an effect ... Do you think that it was a coincidence?

 

 

The angle of observation was not what you claim. The references that you have previously provided show that we were looking "down" at the orbital plane, not sideways on.

 

The characteristics of the signal were exactly that predicted by GR - this would include any delays or distortions to the waveform caused by the self-interaction of the gravitational waves with the local curvature of space time - these non-linear effects are one reason why these things are to hard to model and require hours of supercomputer time.

[Robittybob1]

 

The angle of observation was not what you claim. The references that you have previously provided show that we were looking "down" at the orbital plane, not sideways on.

 

The characteristics of the signal were exactly that predicted by GR - this would include any delays or distortions to the waveform caused by the self-interaction of the gravitational waves with the local curvature of space time - these non-linear effects are one reason why these things are to hard to model and require hours of supercomputer time.

@Strange - when the two BBH were approaching the merger even at that probable 60 degrees inclination to the line of site the Shapiro Effect could have some effect. The size of the EHs at that stage are quite large in proportion to their separation.

Would the size of the photosphere have to be considered as well?

[Mordred]

The time delay effects are already included in the [latex]T^{ij}[/latex]

 

Formulas on page 8

 

That's the beauty of tensor usage in the Einstein field equations. You handle 4d coordinate change without specifically using a specific coordinate system

Edited March 16, 2016 by Mordred

[Strange]

@Strange - when the two BBH were approaching the merger even at that probable 60 degrees inclination to the line of site the Shapiro Effect could have some effect.

 

But the simulations that calculate the gravitational waves are complete solutions to the Einstein Field Equations. Any effects that could be attributed to time dilation, Shapiro delay, gravitational lensing, or anything else are already included. You can't pick one effect and ask for it to be included.

 

It is a bit like asking to special relativistic time dilation to be taken into account in GPS satellites "because you have only used general relativity".

[Robittybob1]

 

But the simulations that calculate the gravitational waves are complete solutions to the Einstein Field Equations. Any effects that could be attributed to time dilation, Shapiro delay, gravitational lensing, or anything else are already included. You can't pick one effect and ask for it to be included.

 

It is a bit like asking to special relativistic time dilation to be taken into account in GPS satellites "because you have only used general relativity".

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.

[Strange]

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.

 

They are affected very slightly by passing through matter. Just not much.

[swansont]

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.

 

 

The Shapiro delay is a time dilation effect (or length contraction effect, depending on how you look at it). IOW it is an effect on time and space. It's not an interaction as you would have for e.g. a photon passing through a material. Just like there is no interaction that causes time dilation in any other circumstance.