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SergUpstart

The speed of propagation of gravity

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Astronomers have recorded gravitational waves from the Betelgeuse star (ZN, ua)

If we see a flash after some time, it will mean that the speed of gravity propagation is higher than the speed of light. Recently, I proposed a system of equations on this forum, which implies that the speed of gravity is higher than the speed of light. Url deleted

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Maybe you should have waited till after the 'flash' was seen to post this.
Until then, it's just wishful thinking on your part.

ALL information is constrained to travel with an upper limit of c .

Edited by MigL

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34 minutes ago, SergUpstart said:

Astronomers have recorded gravitational waves from the Betelgeuse star (ZN, ua)

Can you provide a reference?

34 minutes ago, SergUpstart said:

If we see a flash after some time, it will mean that the speed of gravity propagation is higher than the speed of light. Recently, I proposed a system of equations on this forum, which implies that the speed of gravity is higher than the speed of light.

That seems to contradict observations at LIGO:

Quote

 

At the moment of collision, the bulk of the two neutron stars merged into one ultradense object, emitting a “fireball” of gamma rays. The initial gamma-ray measurements, combined with the gravitational-wave detection, also provide confirmation for Einstein’s general theory of relativity, which predicts that gravitational waves should travel at the speed of light.

https://www.ligo.caltech.edu/page/press-release-gw170817

Future observations will probably add more details. 

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1 hour ago, SergUpstart said:

Astronomers have recorded gravitational waves from the Betelgeuse star (ZN, ua)

If we see a flash after some time, it will mean that the speed of gravity propagation is higher than the speed of light. Recently, I proposed a system of equations on this forum, which implies that the speed of gravity is higher than the speed of light. Url deleted 

!

Moderator Note

Posting to link to your site is against the rules  

As is posting to advertise a pet theory in another thread

 

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1 hour ago, SergUpstart said:

Astronomers have recorded gravitational waves from the Betelgeuse star (ZN, ua)

I don't think so. 

1 hour ago, SergUpstart said:

If we see a flash after some time, it will mean that the speed of gravity propagation is higher than the speed of light.

Not necessarily. There are all sorts of reasons why the light might be seen after (or before) the gravitational waves. It depends on the cause of each event.

 

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 also provide confirmation for Einstein’s general theory of relativity, which predicts that gravitational waves should travel at the speed of light.

In my opinion, the speed of gravity and the speed of light coincide in the extreme case when there is no gravity. Gravity reduces the speed of light but does not reduce the speed of propagation of itself.

 

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On each continent, several LIGO observation sites are needed. Burst of heavy,  electrical neutral, particles or a "gravitational wave" would have come to Earth and would have been detected with a delay between observation sites. From the delays in the measurements, the propagation speed can be deduced.

Edited by Sensei

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31 minutes ago, SergUpstart said:

In my opinion, the speed of gravity and the speed of light coincide in the extreme case when there is no gravity. Gravity reduces the speed of light but does not reduce the speed of propagation of itself.

Your opinion is worthless unless supported by evidence. 

Especially when it is contradicted by both theory and evidence.

14 minutes ago, Sensei said:

Burst of heavy neutral electrical particles

What are "heavy neutral electrical particles"? How can they be both neutral and electrical? And what does this have to do with gravitational waves?

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On each continent, several LIGO observation sites are needed. Burst of heavy, electrical neutral, particles or a "gravitational wave" would have come to Earth and would have been detected with a delay between observation sites. From the delays in the measurements, the propagation speed can be deduced.

I guess that's not enough. At distances of the order of the earth's diameter in the conditions of earth and solar gravity, the measured phase difference between gravitational and electromagnetic waves will be within the statistical error.

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11 minutes ago, SergUpstart said:

At distances of the order of the earth's diameter in the conditions of earth and solar gravity, the measured phase difference between gravitational and electromagnetic waves will be within the statistical error.

Citation needed.

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42 minutes ago, Sensei said:

On each continent, several LIGO observation sites are needed. Burst of heavy,  electrical neutral, particles or a "gravitational wave" would have come to Earth and would have been detected with a delay between observation sites. From the delays in the measurements, the propagation speed can be deduced.

Maybe not perfectly worded but worth a followup, delay of observation for gravitational waves are discussed in this paper:

Quote

We point out that the observed time delay between the detection of the signal at the Hanford and Livingston LIGO sites from the gravitational wave event GW150914 places an upper bound on the speed of propagation of gravitational waves, cgw1.7 in the units of speed of light. Combined with the lower bound from the absence of gravitational Cherenkov losses by cosmic rays that rules out most of subluminal velocities, this gives a model-independent double-sided constraint 1cgw1.7. We compare this result to model-specific constraints from pulsar timing and cosmology.

https://arxiv.org/abs/1602.04188

 

30 minutes ago, SergUpstart said:

I guess that's not enough. At distances of the order of the earth's diameter in the conditions of earth and solar gravity, the measured phase difference between gravitational and electromagnetic waves will be within the statistical error.

 Combining gravitational signal and electromagnetic signal gives higher precision, distance to original source can be taken into account:

image.thumb.png.df17805c06a6a1f4ebf7716e7368fe4b.png

https://books.google.se/books?id=du60DwAAQBAJ&pg=PA199 ...

1 in 10^15 is pretty good?

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20 minutes ago, SergUpstart said:

If c g w  1,7 then the Betelgeuse outbreak will be observed in 400 years

That was for gravitational waves alone, a comment added as a follow up to Sensei's note that delays, when registered, are useful.
Then please read the whole post, the second source have better precision. Here is one reference documenting the observation of gravitational waves and electromagnetic radiation within approx 1.74 s.

Quote

On 2017 August 17, the gravitational-wave event GW170817 was observed by the Advanced LIGO and Virgo detectors, and the gamma-ray burst (GRB) GRB 170817A was observed independently by the Fermi Gamma-ray Burst Monitor, and the Anticoincidence Shield for the Spectrometer for the International Gamma-Ray Astrophysics Laboratory. The probability of the near-simultaneous temporal and spatial observation of GRB 170817A and GW170817 occurring by chance is 5.0×108. We therefore confirm binary neutron star mergers as a progenitor of short GRBs. The association of GW170817 and GRB 170817A provides new insight into fundamental physics and the origin of short gamma-ray bursts. We use the observed time delay of (+1.74±0.05)s between GRB 170817A and GW170817 to: (i) constrain the difference between the speed of gravity and the speed of light to be between 3×1015 and +7×1016 times the speed of light, (ii) place new bounds on the violation of Lorentz invariance, (iii) present a new test of the equivalence principle by constraining the Shapiro delay between gravitational and electromagnetic radiation.

https://arxiv.org/abs/1710.05834
 

 

Edited by Ghideon
grammar

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15 hours ago, SergUpstart said:

If we see a flash after some time, it will mean that the speed of gravity propagation is higher than the speed of light.

No, it just means that they weren’t emitted simultaneously - which is what one would expect, since these two forms of radiation are the result of different physical processes.

15 hours ago, SergUpstart said:

the speed of gravity is higher than the speed of light.

This is inconsistent with the basic principles of GR, as well as with the specific mathematics of gravitational waves.
The opposite is in fact the case - since the dynamics of gravitational waves are non-linear (unlike e.g. EM waves), they interact both with other gravitational waves as well as with themselves. In this manner you get a number of effects that are exclusive to gravitational waves, and some of these actually propagate slower than the speed of light (specifically so-called “wave tails”). However, a free wave in otherwise empty space must propagate at exactly c.

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4 hours ago, Markus Hanke said:

No, it just means that they weren’t emitted simultaneously - which is what one would expect, since these two forms of radiation are the result of different physical processes.

This is inconsistent with the basic principles of GR, as well as with the specific mathematics of gravitational waves.
The opposite is in fact the case - since the dynamics of gravitational waves are non-linear (unlike e.g. EM waves), they interact both with other gravitational waves as well as with themselves. In this manner you get a number of effects that are exclusive to gravitational waves, and some of these actually propagate slower than the speed of light (specifically so-called “wave tails”). However, a free wave in otherwise empty space must propagate at exactly c.

If gravity slows down the speed of propagation of both electromagnetic and gravitational waves in the same way, then how does gravity go beyond the event horizon of black holes?

Even in the movie interstellar the hero transmits information from a black hole using gravitational waves ))))

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9 minutes ago, SergUpstart said:

If gravity slows down the speed of propagation of both electromagnetic and gravitational waves in the same way, then how does gravity go beyond the event horizon of black holes?

Gravitational waves cannot leave the event horizon. Gravity is a consequence of the curvature of spacetime caused by the presence of the black hole so doesn't need to get through the event horizon. (I thought an expert like you would know the difference.)

 

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5 hours ago, Markus Hanke said:

No, it just means that they weren’t emitted simultaneously - which is what one would expect, since these two forms of radiation are the result of different physical processes.

It could also mean the photons had to pass through a region of space where n > 1, but IIRC the previously mention LIGO event where the signals were basically coincident, there was also confirmation that no significant gas/dust clouds were in the path.

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19 hours ago, SergUpstart said:

If gravity slows down the speed of propagation of both electromagnetic and gravitational waves in the same way

It doesn’t. Electromagnetic waves propagate exactly at c everywhere locally, they are never slowed down. The dynamics of gravitational waves are non-linear, and hence different from EM radiation.

19 hours ago, SergUpstart said:

how does gravity go beyond the event horizon of black holes?

Static gravity does not propagate at all, it is a geometric property of the entire spacetime, so nothing needs to “leave” the event horizon. It is only changes in the gravitational field that propagate as waves - and even then, these changes need to be of a specific nature (they need to have a quadrupole or higher multipole moment) to be the source of gravitational radiation. For the hypothetical case of there being a source of gravitational radiation below the event horizon of a black hole, this radiation would not cross the horizon, same as any other test particle.

18 hours ago, swansont said:

It could also mean the photons had to pass through a region of space where n >1

Good point!

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5 hours ago, Markus Hanke said:

Electromagnetic waves propagate exactly at c everywhere locally, they are never slowed down. The dynamics of gravitational waves are non-linear, and hence different from EM radiation.

 

The speed of propagation of electromagnetic waves is slowed down in the material environment. There is no absolute emptiness Natura abhorret vacuum. 

I consider the gravitational field as a material medium in which the velocity of electromagnetic propagation varies depending on the strength of the gravitational field.

 

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5 minutes ago, SergUpstart said:

The speed of propagation of electromagnetic waves is slowed down in the material environment. There is no absolute emptiness Natura abhorret vacuum. 

I consider the gravitational field as a material medium in which the velocity of electromagnetic propagation varies depending on the strength of the gravitational field.

 

Right but several physicists seem to disagree with you, what is the point of saying: "I consider the gravitational field as x " when they are TELLING you that that is not the right way of looking at it. You don't discuss or give counterarguments to their whole posts, and instead you tell us what you consider, but why?
Are you here to learn or to discuss or postulate, if its one of the first 2, it may be a good idea to: if you believe something different from what physicists are saying, to provide A LOT of evidence. One thing they have over a lot of laymen like me, is that they actually look at and understand the math. So why not post math to prove your point?

You are currently saying that basically the whole of special (? that is the one that sets the upper limit as c and also that anything mass-less can only travel at c, right?) relativity is wrong.
So for that you have to provide a lot of evidence.

As far as I understand the general consensus among physicists, GR and special relativity hold up particularly well, so if what you say is refuting GR/SR, you will need extraordinary evidence.  (I of course could be wrongly interpreting what you say as refuting GR, so I hope someone who actually knows physics can correct my mistake if SergUpstart's comment falls well within SR/GR).

-Dagl

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18 minutes ago, SergUpstart said:

The speed of propagation of electromagnetic waves is slowed down in the material environment. There is no absolute emptiness Natura abhorret vacuum. 

So it is epsilon larger than 1. You can estimate the effect this will have.

The index of air at STP is 1.0003.  n-1 is (3 x 10^-4) So now we have a vacuum, where the pressure is 10 to 20 orders of magnitude less. 

A year is 3.15 x 10^7 seconds, so a vacuum of order 10^-3 of atmosphere is an extra second for a light year. A vacuum of 10^-12 is an extra second for a billion LY

If it's much better than that, it would be hard to discern any difference between the gravitational ringdown and the light arrival.

 

Quote

I consider the gravitational field as a material medium in which the velocity of electromagnetic propagation varies depending on the strength of the gravitational field.

Then you need to provide evidence that this is true, or a way to test it. How big is the alleged effect?

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17 minutes ago, SergUpstart said:

I consider the gravitational field as a material medium in which the velocity of electromagnetic propagation varies depending on the strength of the gravitational field.

And do you have evidence of this? No, of course not. Because it is not true. It is something you made up for no reason at all.

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On 1/21/2020 at 5:52 AM, Markus Hanke said:

The opposite is in fact the case - since the dynamics of gravitational waves are non-linear (unlike e.g. EM waves), they interact both with other gravitational waves as well as with themselves. In this manner you get a number of effects that are exclusive to gravitational waves, and some of these actually propagate slower than the speed of light (specifically so-called “wave tails”). However, a free wave in otherwise empty space must propagate at exactly c.

That's interesting thanks. +1

I know almost nothing about the any theories of gravity waves.

Edited by studiot

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