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Author Topic: Do gravitational waves propagate faster than light waves?  (Read 21621 times)

Offline williampcochran

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« Last Edit: 11/01/2011 21:57:40 by Geezer »


 

Offline syhprum

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Re: Do gravitational waves propagate faster than light waves?
« Reply #1 on: 05/01/2011 22:53:02 »
My first inclination would have been to answer simply no but then I read this and now have my doubts.

http://metaresearch.org/cosmology/speed_of_gravity.asp

PS I now see the significance of the Little Greek squiggle (sigma ?)
« Last Edit: 05/01/2011 22:56:38 by syhprum »
 

Offline QuantumClue

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Re: Do gravitational waves propagate faster than light waves?
« Reply #2 on: 05/01/2011 23:59:20 »
The graviton, the mediator of the gravitational wave travels always at lightspeed. I have some math written down in some old jotters some where which I will seek out if I can :)
 

Offline QuantumClue

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Re: Do gravitational waves propagate faster than light waves?
« Reply #3 on: 06/01/2011 00:27:55 »
Right ok. The deAlembertian, a four dimensional wave equation will be represented as ▼. Not usual notation but box notation cannot be used here.

▼hμν=0

This is the same as saying

μμhμν=0

This means it will follow the speed of light since ▼∂t2 - c22x.

« Last Edit: 06/01/2011 00:29:38 by QuantumClue »
 

Offline yor_on

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Re: Do gravitational waves propagate faster than light waves?
« Reply #4 on: 06/01/2011 00:54:28 »
Here is a rebuttal to Van Flandern's beautiful arguments. Aberration and the Speed of Gravity
 

Offline QuantumClue

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Re: Do gravitational waves propagate faster than light waves?
« Reply #5 on: 06/01/2011 00:56:13 »
I'll look thanks. But if someone says its faster than light, there is no proof. If they say its slower, it would be a short range distance which does not work either.
 

Offline CliffordK

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Re: Do gravitational waves propagate faster than light waves?
« Reply #6 on: 06/01/2011 01:31:59 »
My first inclination would have been to answer simply no but then I read this and now have my doubts.
http://metaresearch.org/cosmology/speed_of_gravity.asp
Interesting article, I think it needs more study, along with some of the referenced articles:
http://xxx.lanl.gov/abs/gr-qc/9706082  (see full text PDF&PS Links)
http://metaresearch.org/cosmology/gravity/possiblenewpropertiesofgravity.asp  (another good summary article).

Light may be limited in speed by the particle nature of the photon which has the effect of a positive mass.
Gravity doesn't seem to have a corresponding particle (graviton), and thus wouldn't be limited by the same mass effect.

As far as gravity though, there seems to be two issues.

Static Field as in the planet orbiting around a central body which seems to be the easiest to measure with respect to the direction of the gravitational pull of the central body, however, it may only be measuring the interaction of bodies in a pre-existing field which may not adequately measure the speed of gravity (except with respect to the movement of our sun, which should then cause a measurable effect depending on the orbital position of the earth with respect to the center of the Milky Way and the direction of the sun's orbit if there was a delay).

Dynamic Field, as in two bodies progressing along a parallel path (or synchronously orbiting a third body as in the spiral arm model of many galaxies).  For the two parallel bodies, if there was a time delay with the gravity, then the gravity vector of the "partner" object would actually be behind each of the bodies, and there would be a significant gravitational drag component exerted on both bodies.

It would be hard to tease out this gravitational drag component if it existed, but it would be predicted to be greater on two parallel bodies (or 2 bodies such as planets passing each other in an orbit) than would be exhibited by a body traveling alone in its orbit.

 

Offline QuantumClue

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Re: Do gravitational waves propagate faster than light waves?
« Reply #7 on: 06/01/2011 01:46:52 »
I've been thinking a lot about gravity recently funnily enough, about how to approach a unified theory. Apparently according to a few sources the problem with doing this lyes in gravity being a gauge theory and how mass does not couple to the gravitational field. I think this can be approached by having a coupling term Ψ*ΦGMμΨ where it plays an alternative mass term in replacement of the Higgs field. In other words, the gravitational field provides a moving mass in a field with mass instead of a superfluous Higgs field.
 

Offline yor_on

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Re: Do gravitational waves propagate faster than light waves?
« Reply #8 on: 06/01/2011 01:50:10 »
Maybe you could see 'space' as an imprint of gravitation. That meaning that 'space's' topology 'remember' at the speed of light. Then you have a topology communicating itself at the speed of light at the same time that it will keep whatever topology it express until a new such communication comes.

So does that mean that there have to be 'something' communicating it?
We would like to think so :) as we work with particles and 'forces' but, maybe not?
If Lorentz contraction is 'real' as in 'really, you know, like real' :) then that same space can 'shrink, contract and decease' from the 'reality' we know normally, turning itself into some weird point possibly.

What do that do to our topology?
And why would the guys & gals in that spaceship be wrong saying that it have?
You would be dead I better remind you, so their answer would in fact be the final one :)
==

Ah this answer was to ye all.
Okay:)
« Last Edit: 06/01/2011 01:59:10 by yor_on »
 

Offline yor_on

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Re: Do gravitational waves propagate faster than light waves?
« Reply #9 on: 06/01/2011 01:57:39 »
And what would that 'alternative mass term in replacement of the Higgs field' do?
Are you thinking of it as a relation only QC, needing no 'virtual' existence?
==

Like waves on top of an ocean?
And those possibly 'waves' being 'everywhere' in that ocean?
But you still need a reason to why, don't you?

« Last Edit: 06/01/2011 02:13:32 by yor_on »
 

Offline QuantumClue

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Re: Do gravitational waves propagate faster than light waves?
« Reply #10 on: 06/01/2011 02:09:04 »
Well, I think that some kind of interaction between a particle which has an internal energy reduced to some kind of condensed existence as an inertial mass is a particle by definition a particle which internally interacts with a field. The spark inside a particle therefore when in contact with a local graviational potential field around it ΦG creates some kind of inertial matter.

Ok, enough of my words, i'll get banned this way! lol
« Last Edit: 06/01/2011 02:10:49 by QuantumClue »
 

Offline yor_on

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Re: Do gravitational waves propagate faster than light waves?
« Reply #11 on: 06/01/2011 02:18:21 »
Okay, a particle that communicates through 'fields' with itself. that makes a sort of sense, I've though about it similarly, especially when considering those examples and experiments where the electron seems to be superpositioned, in two places simultaneously.

Why not:)

like it all being 'densities' but in the form of fields.
 

Offline yor_on

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Re: Do gravitational waves propagate faster than light waves?
« Reply #12 on: 06/01/2011 02:30:50 »
That is, if we give those 'fields' a topology resembling what I gave space. But then the question becomes, why do they stay the same? What are the constants defining their existence if it is so?
 

Offline QuantumClue

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Re: Do gravitational waves propagate faster than light waves?
« Reply #13 on: 06/01/2011 02:47:20 »
Well, a particle under electromagnetism can interact with its field, so I don't see why we give such a superior credence with gravitons.
 

Offline yor_on

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Re: Do gravitational waves propagate faster than light waves?
« Reply #14 on: 06/01/2011 02:56:05 »
Yeah, I'm not particularly enthralled by gravitons myself :)
The Higgs field seems more 'understandable' to me. But they both involves some Sort of particles, don't they?

Let me ask you all a question. I have two exactly identical springs, one that I compress and leave compressed, the other I don't do a thing to. I now take my perfectly sensitive atomic scale and weight them.

Will they weight the same?

And if you say no.
What have changed?
==

And do you expect time to rectify it, if you said yes (to no) that is :)
« Last Edit: 06/01/2011 02:58:44 by yor_on »
 

Offline yor_on

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Re: Do gravitational waves propagate faster than light waves?
« Reply #15 on: 06/01/2011 03:18:52 »
To see it we first need to consider if something have 'changed' here.
Well the spring that's compressed isn't 'normal' any more, and that's because I compressed it.
And when I did, I expended 'energy', right?

So where did that 'energy' go?


Yep, straight into that spring. And the springs new energy have an equivalence to mass according to Einstein. So according to him this spring will weight more than when it was 'normal' and untouched.

But won't that 'energy' cling off as the spring cools? Nope, it's not kinetic energy only, it's 'energy' as I understands it. That as I would expect 'kinetic energy' to dissipate with time, but as long as we keep this spring compressed it will weight more.

All as I understands it?

Weird? Yeah..
==

So how about heat, will that add a weight too?
As long as it's hot, yep.
« Last Edit: 06/01/2011 03:24:58 by yor_on »
 

Offline yor_on

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Re: Do gravitational waves propagate faster than light waves?
« Reply #16 on: 06/01/2011 03:33:02 »
Anyone remember Einsteins cosmological constant?

That's how he defined it. If energy could make something weight more, then there had to be a effect that contradicted it. He came to it when noticing that the galaxies was expanding instead of coming together, he needed to find a reason why the invariant mass (gravity) didn't bring it all into one big clump. And if we instead of energy call it pressure then normal gravity is a positive 'pressure' whilst a repulsive gravity is a negative 'pressure'.
==

So, the cosmological constant exerted a negative pressure according to him. But why the he* would that make the galaxies expand? Shouldn't a negative pressure just 'close up' under the positive pressure surrounding it?
« Last Edit: 06/01/2011 04:00:55 by yor_on »
 

Offline Foolosophy

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Re: Do gravitational waves propagate faster than light waves?
« Reply #17 on: 06/01/2011 03:39:42 »
Interesting question - I wonder what the experimentalist have to say about it???

"Standard experimental techniques exist to determine the propagation speed of forces. When we apply these techniques to gravity, they all yield propagation speeds too great to measure, substantially faster than lightspeed. This is because gravity, in contrast to light, has no detectable aberration or propagation delay for its action, even for cases (such as binary pulsars) where sources of gravity accelerate significantly during the light time from source to target." (Tom Van Flandern)

Conclusion: The Speed of Gravity is > 20,000,000,000 times the speed of light (c)

But can it be infinite? (ie instananeous?)
« Last Edit: 06/01/2011 03:42:46 by Foolosophy »
 

Offline yor_on

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Re: Do gravitational waves propagate faster than light waves?
« Reply #18 on: 06/01/2011 03:47:32 »
Don't expect me to be able to explain this one, but according to Einstein the negative pressure in fact 'pushes' on 'space'. Graham gave me this explanation when discussing dark energy and I compared it to the concept of invisible boxes.

"There are two aspects to the properties of matter that contribute to the gravitational attraction; one is mass density and the other is "pressure". This results from Stress-Energy tensor component in Einstein's Field Equations. The concept, in this case, is that dark energy has a negative pressure so that as the universe expands the pressure gets greater (making it expand more)."

What you're saying here, if I get you right, is that you can imagine space as something in where we have a lot of invisible boxes containing a negative pressure, restricting and constraining those boxes in a inverse direction, and as space around them grows bigger due to the 'expansion' the inverse pressure automatically become larger? The problem here is that you will need a 'box' it seems to me, to explain how this can happen?

"Yor-on, I think you have it right. The negative pressure concept means that as the universe's volume (V) increases, the vacuum energy increases (dW = -PdV) because P is itself negative. So the vacuum energy density stays the same. However the Pressure term in Einstein's field equations will dominate, and being a negative term, results in a net increasing gravitational repulsion.

However, I don't think this explains anything but rather just says what the equations reveal. I can't think of any analogy with everyday familiar behaviour that can help. I have tried to find a clear explanation on the web but have failed to do so."

So the reasoning we have when it comes to dark energy seems directly traceable to Einsteins Cosmological constant.
==

And reading I realize why it would expand more between galaxies than inside. It's not true that we don't expand inside the galaxies. We do expand inside them too. But the more Space we have the more 'pressure'. So the intergalactic wastes, as Buck Roger would have expressed it, will have a greater pressure than space inside the galaxies. And also, if there is no measurable expansion inside a galaxy it might be that the 'positive' pressure of gravitation is able to take out the 'negative pressure' repulsing 'space'

I don't think he made a 'blunder'.
==

But it sure gives me a headache :)

We now have negative and positive pressure classically, as well as a positive and negative 'energy' non-classically, aka the Casimir effect (QM)

« Last Edit: 06/01/2011 04:10:34 by yor_on »
 

Offline QuantumClue

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Re: Do gravitational waves propagate faster than light waves?
« Reply #19 on: 06/01/2011 03:49:26 »
Interesting question - I wonder what the experimentalist have to say about it???

"Standard experimental techniques exist to determine the propagation speed of forces. When we apply these techniques to gravity, they all yield propagation speeds too great to measure, substantially faster than lightspeed. This is because gravity, in contrast to light, has no detectable aberration or propagation delay for its action, even for cases (such as binary pulsars) where sources of gravity accelerate significantly during the light time from source to target." (Tom Van Flandern)

Conclusion: The Speed of Gravity is > 20,000,000,000 times the speed of light (c)

But can it be infinite? (ie instananeous?)


Probably tunnels to reduce such an inconceivable idea in relativity.
 

Offline QuantumClue

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Re: Do gravitational waves propagate faster than light waves?
« Reply #20 on: 06/01/2011 04:09:19 »
Anyway, yoron, to reduce the probability I will end up banned for posting rogue theories - I am now terminating this lol :)
 

Offline yor_on

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Re: Do gravitational waves propagate faster than light waves?
« Reply #21 on: 06/01/2011 04:14:18 »
It's cool, post it in new theories if you like. Then we can be at like wolfs :)
Not really, but it would be interesting to see how you think :)
 

Offline QuantumClue

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Re: Do gravitational waves propagate faster than light waves?
« Reply #22 on: 06/01/2011 04:15:37 »
Oh I don't know... I could end up regretting it :)
 

Offline yor_on

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Re: Do gravitational waves propagate faster than light waves?
« Reply #23 on: 06/01/2011 04:22:34 »
It depends, to me it doesn't matter if your idea is perfect or not. It seems that we learn anyway :) And its the learning that's the ultimate kick for me :)

It's not the richest dying wins, it's the most knowledgeable :)

Maybe you're thinking of publishing it though.
Then it's another matter.
==

And QC, why I asked about the springs :)

Because you were thinking of a 'relational influences' instead of 'particles'
If we look at the compressed spring, how the he* does it keeps weighting more the whole time?
How could something I didn't 'send' get stored as mass?
What I sent was what I think of as 'kinetic energy' like kicking a ball.

That energy dissipates, doesn't it?
« Last Edit: 06/01/2011 04:28:24 by yor_on »
 

Offline Foolosophy

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Re: Do gravitational waves propagate faster than light waves?
« Reply #24 on: 06/01/2011 04:53:39 »
Interesting question - I wonder what the experimentalist have to say about it???

"Standard experimental techniques exist to determine the propagation speed of forces. When we apply these techniques to gravity, they all yield propagation speeds too great to measure, substantially faster than lightspeed. This is because gravity, in contrast to light, has no detectable aberration or propagation delay for its action, even for cases (such as binary pulsars) where sources of gravity accelerate significantly during the light time from source to target." (Tom Van Flandern)

Conclusion: The Speed of Gravity is > 20,000,000,000 times the speed of light (c)

But can it be infinite? (ie instananeous?)


Probably tunnels to reduce such an inconceivable idea in relativity.

Meaning?

Experimental evidence shows that the propagation of gravity is at least 20,000,000,000 times the speed of light (Tom Van Fandern)

The question is can this value be infinite?
 

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Re: Do gravitational waves propagate faster than light waves?
« Reply #24 on: 06/01/2011 04:53:39 »

 

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