Do gravitational waves propagate faster than light waves?

  • 83 Replies
  • 21829 Views

0 Members and 1 Guest are viewing this topic.

*

Offline williampcochran

  • Jr. Member
  • **
  • 25
    • View Profile
« Last Edit: 11/01/2011 21:57:40 by Geezer »

*

Offline syhprum

  • Neilep Level Member
  • ******
  • 3890
    • View Profile
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 »
syhprum

*

Offline QuantumClue

  • Hero Member
  • *****
  • 613
    • View Profile
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

  • Hero Member
  • *****
  • 613
    • View Profile
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

  • Naked Science Forum GOD!
  • *******
  • 12188
  • (Ah, yes:) *a table is always good to hide under*
    • View Profile
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
"BOMB DISPOSAL EXPERT. If you see me running, try to keep up."

*

Offline QuantumClue

  • Hero Member
  • *****
  • 613
    • View Profile
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

  • Neilep Level Member
  • ******
  • 6321
  • Site Moderator
    • View Profile
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.

[attachment=13732]

*

Offline QuantumClue

  • Hero Member
  • *****
  • 613
    • View Profile
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

  • Naked Science Forum GOD!
  • *******
  • 12188
  • (Ah, yes:) *a table is always good to hide under*
    • View Profile
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 »
"BOMB DISPOSAL EXPERT. If you see me running, try to keep up."

*

Offline yor_on

  • Naked Science Forum GOD!
  • *******
  • 12188
  • (Ah, yes:) *a table is always good to hide under*
    • View Profile
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 »
"BOMB DISPOSAL EXPERT. If you see me running, try to keep up."

*

Offline QuantumClue

  • Hero Member
  • *****
  • 613
    • View Profile
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

  • Naked Science Forum GOD!
  • *******
  • 12188
  • (Ah, yes:) *a table is always good to hide under*
    • View Profile
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.
"BOMB DISPOSAL EXPERT. If you see me running, try to keep up."

*

Offline yor_on

  • Naked Science Forum GOD!
  • *******
  • 12188
  • (Ah, yes:) *a table is always good to hide under*
    • View Profile
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?
"BOMB DISPOSAL EXPERT. If you see me running, try to keep up."

*

Offline QuantumClue

  • Hero Member
  • *****
  • 613
    • View Profile
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

  • Naked Science Forum GOD!
  • *******
  • 12188
  • (Ah, yes:) *a table is always good to hide under*
    • View Profile
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 »
"BOMB DISPOSAL EXPERT. If you see me running, try to keep up."

*

Offline yor_on

  • Naked Science Forum GOD!
  • *******
  • 12188
  • (Ah, yes:) *a table is always good to hide under*
    • View Profile
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 »
"BOMB DISPOSAL EXPERT. If you see me running, try to keep up."

*

Offline yor_on

  • Naked Science Forum GOD!
  • *******
  • 12188
  • (Ah, yes:) *a table is always good to hide under*
    • View Profile
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 »
"BOMB DISPOSAL EXPERT. If you see me running, try to keep up."

*

Offline Foolosophy

  • Sr. Member
  • ****
  • 218
    • View Profile
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

  • Naked Science Forum GOD!
  • *******
  • 12188
  • (Ah, yes:) *a table is always good to hide under*
    • View Profile
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 »
"BOMB DISPOSAL EXPERT. If you see me running, try to keep up."

*

Offline QuantumClue

  • Hero Member
  • *****
  • 613
    • View Profile
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

  • Hero Member
  • *****
  • 613
    • View Profile
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

  • Naked Science Forum GOD!
  • *******
  • 12188
  • (Ah, yes:) *a table is always good to hide under*
    • View Profile
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 :)
"BOMB DISPOSAL EXPERT. If you see me running, try to keep up."

*

Offline QuantumClue

  • Hero Member
  • *****
  • 613
    • View Profile
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

  • Naked Science Forum GOD!
  • *******
  • 12188
  • (Ah, yes:) *a table is always good to hide under*
    • View Profile
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 »
"BOMB DISPOSAL EXPERT. If you see me running, try to keep up."

*

Offline Foolosophy

  • Sr. Member
  • ****
  • 218
    • View Profile
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?

*

Offline Foolosophy

  • Sr. Member
  • ****
  • 218
    • View Profile
Re: Do gravitational waves propagate faster than light waves?
« Reply #25 on: 06/01/2011 04:55:20 »
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 :)

This forum forbids speculation.

Only broing conservative scientific dogma is to be propagated in here.

Humour is banned





*

Offline QuantumClue

  • Hero Member
  • *****
  • 613
    • View Profile
Re: Do gravitational waves propagate faster than light waves?
« Reply #26 on: 06/01/2011 05:15:17 »
Humour is tolerated here, subjecting idea's to the wrong subforum however, is not.

*

Offline yor_on

  • Naked Science Forum GOD!
  • *******
  • 12188
  • (Ah, yes:) *a table is always good to hide under*
    • View Profile
Re: Do gravitational waves propagate faster than light waves?
« Reply #27 on: 06/01/2011 05:25:41 »
I also found Van Flandern interesting Foolosophy. but I found this pdf later, that I linked to above, and reading it I think he might be wrong. But I know what you mean, and yes, in some aspects I too see gravity as instantaneous. Inertia will be happening as fast here as in deep space not caring about where you are. And that's also why I think of it as a 'topology' that is circumstanced by lights speed in a vacuum. The weird thing is how this topology is able to 'remember' itself.

That one is instantaneous if so, and no, people smile when we joke :)
You've made me smile at least :)

We're not that serious. If we was I would be banned here.
==

Inertia= the reaction you feel to a change in direction or acceleration.
« Last Edit: 06/01/2011 05:28:13 by yor_on »
"BOMB DISPOSAL EXPERT. If you see me running, try to keep up."

*

Offline Foolosophy

  • Sr. Member
  • ****
  • 218
    • View Profile
Re: Do gravitational waves propagate faster than light waves?
« Reply #28 on: 06/01/2011 06:17:35 »
Humour is tolerated here, subjecting idea's to the wrong subforum however, is not.

And what is the punishment for this ULTIMATE moral crime?

*

Offline Foolosophy

  • Sr. Member
  • ****
  • 218
    • View Profile
Re: Do gravitational waves propagate faster than light waves?
« Reply #29 on: 06/01/2011 06:26:23 »
I also found Van Flandern interesting Foolosophy. but I found this pdf later, that I linked to above, and reading it I think he might be wrong. But I know what you mean, and yes, in some aspects I too see gravity as instantaneous. Inertia will be happening as fast here as in deep space not caring about where you are. And that's also why I think of it as a 'topology' that is circumstanced by lights speed in a vacuum. The weird thing is how this topology is able to 'remember' itself.

That one is instantaneous if so, and no, people smile when we joke :)
You've made me smile at least :)



It does look as though the Newtonian assumption of gravity acting instantaneously over any distance may indeed be the case.

I tend to think that the reason for this is that space is not perfectly FLAT everywhere in the universe. That is, even if there was only one speck of dust in existence in the entire universe, the distortion in the space-time continuum that it will create will head off to infinity. Even in this extreme case space will have some value of curvature at any distance away from this speck of dust - the delusional axioms of mathematics DEMAND this to be so.

The issue then becomes one of semantical mathematical lunacy

this is right up my alley
« Last Edit: 06/01/2011 06:28:52 by Foolosophy »

*

Offline QuantumClue

  • Hero Member
  • *****
  • 613
    • View Profile
Re: Do gravitational waves propagate faster than light waves?
« Reply #30 on: 06/01/2011 06:41:48 »
Humour is tolerated here, subjecting idea's to the wrong subforum however, is not.

And what is the punishment for this ULTIMATE moral crime?

That is not within my purview.

*

Offline Foolosophy

  • Sr. Member
  • ****
  • 218
    • View Profile
Re: Do gravitational waves propagate faster than light waves?
« Reply #31 on: 06/01/2011 06:46:00 »
Humour is tolerated here, subjecting idea's to the wrong subforum however, is not.

And what is the punishment for this ULTIMATE moral crime?

That is not within my purview.

...then are you able to direct me towards a Forum master or Tyrannical Thought lord so that I can obtain the details concerning this torturous punishment that is dished out for THE ULTIMATE MORAL CRIME?

*

Offline QuantumClue

  • Hero Member
  • *****
  • 613
    • View Profile
Re: Do gravitational waves propagate faster than light waves?
« Reply #32 on: 06/01/2011 06:52:40 »
The mods, would be a thoughtful place to start.

*

Offline yor_on

  • Naked Science Forum GOD!
  • *******
  • 12188
  • (Ah, yes:) *a table is always good to hide under*
    • View Profile
Re: Do gravitational waves propagate faster than light waves?
« Reply #33 on: 06/01/2011 07:06:37 »
"I tend to think that the reason for this is that space is not perfectly FLAT everywhere in the universe. That is, even if there was only one speck of dust in existence in the entire universe, the distortion in the space-time continuum that it will create will head off to infinity. Even in this extreme case space will have some value of curvature at any distance away from this speck of dust "

Okay, I follow your idea abut how even a speck of dust will distort SpaceTime. I would expect that to be true too, to some infinitesimal degree. But from there to saying that it is the reason? For gravity being instantaneous? Do you mean that all objects of invariant mass carry its own 'distortions' with them and that inertia would act in those?

Or how do you see it, as if gravity would be a constant field created by invariant mass maybe, a spiders web? That's one analogy I like to use :)

There have been observations describing gravitational waves propagating when observing binary stars if I remember right so I think Einsteins idea of it taking 'time' to build is correct. the thing left is to explain why it creates a net, instantly reacting to inertia. That's what the Higg's particle (God particle:) try to do, but I I'm not sure if there is needed to be any particles?

And you seem to share that idea, even though I'm not sure how you see it?
"BOMB DISPOSAL EXPERT. If you see me running, try to keep up."

*

Offline syhprum

  • Neilep Level Member
  • ******
  • 3890
    • View Profile
Re: Do gravitational waves propagate faster than light waves?
« Reply #34 on: 06/01/2011 13:01:07 »
I begin to believe in instantaneous gravity, there are two other phenomena that are similar entanglement of particles and the reaction to rotation as postulated by Mach.
I cannot recall the source of the quote but I have heard that you have to believe in three impossible things before breakfast (was it Dodgson ?)
« Last Edit: 06/01/2011 17:47:32 by syhprum »
syhprum

*

Offline Foolosophy

  • Sr. Member
  • ****
  • 218
    • View Profile
Re: Do gravitational waves propagate faster than light waves?
« Reply #35 on: 06/01/2011 13:28:56 »
"I tend to think that the reason for this is that space is not perfectly FLAT everywhere in the universe. That is, even if there was only one speck of dust in existence in the entire universe, the distortion in the space-time continuum that it will create will head off to infinity. Even in this extreme case space will have some value of curvature at any distance away from this speck of dust "

Okay, I follow your idea abut how even a speck of dust will distort SpaceTime. I would expect that to be true too, to some infinitesimal degree. But from there to saying that it is the reason? For gravity being instantaneous? Do you mean that all objects of invariant mass carry its own 'distortions' with them and that inertia would act in those?

Or how do you see it, as if gravity would be a constant field created by invariant mass maybe, a spiders web? That's one analogy I like to use :)

There have been observations describing gravitational waves propagating when observing binary stars if I remember right so I think Einsteins idea of it taking 'time' to build is correct. the thing left is to explain why it creates a net, instantly reacting to inertia. That's what the Higg's particle (God particle:) try to do, but I I'm not sure if there is needed to be any particles?

And you seem to share that idea, even though I'm not sure how you see it?

I will elaborate further on the points I made in early September 2012

This gives you plenty of time to show how some Mathematical assumptions are referred to as axioms - the elite immutable constructs that may well trun out to be mere illusions

*

Offline Geezer

  • Neilep Level Member
  • ******
  • 8328
  • "Vive la résistance!"
    • View Profile
Re: Do gravitational waves propagate faster than light waves?
« Reply #36 on: 06/01/2011 18:02:12 »
Pardon me. I must have stepped into the wrong room. I didn't realize this was the carping and moaning thread.
There ain'ta no sanity clause, and there ain'ta no centrifugal force ćther.

*

Offline Bill S

  • Neilep Level Member
  • ******
  • 1862
    • View Profile
Re: Do gravitational waves propagate faster than light waves?
« Reply #37 on: 07/01/2011 02:48:32 »
"As viewed from the Earth’s frame, light from the Sun has aberration. Light requires about 8.3 minutes to arrive from the Sun, during which time the Sun seems to move through an angle of 20 arc seconds. The arriving sunlight shows us where the Sun was 8.3 minutes ago. The true, instantaneous position of the Sun is about 20 arc seconds east of its visible position, and we will see the Sun in its true present position about 8.3 minutes into the future."

Surely this is evidence for gravity travelling faster than light only if gravity is regarded as a force, which GR says it is not.  If gravity is a distortion of spacetime, then the distortion which holds the Earth in orbit around the sun is already in place, and has been since the sun formed.  Any change, e.g. if the sun suddenly vanished, would, presumably, take 8.3 mins to reach Earth, but there is no comparison between light which is constantly travelling, and gravity which, according to GR, remains "in place".
OK, that's a non-scientist's interpretation, and could well be wrong, but it seem to me to make sense.  [:P]
   

*

Offline Supercryptid

  • Hero Member
  • *****
  • 606
    • View Profile
    • http://www.angelfire.com/sc2/Trunko
Re: Do gravitational waves propagate faster than light waves?
« Reply #38 on: 07/01/2011 03:05:25 »
If gravitational propagation were instantaneous, then it would allow you to send FTL signals by moving a large mass back and forth and measuring the change in apparent gravitational strength from some distant sensor...

Doesn't make sense to say it's instantaneous.
----
Jesus is coming soon. Be prepared for him.

*

Offline CliffordK

  • Neilep Level Member
  • ******
  • 6321
  • Site Moderator
    • View Profile
Re: Do gravitational waves propagate faster than light waves?
« Reply #39 on: 07/01/2011 03:55:23 »
If gravity is a distortion of spacetime, then the distortion which holds the Earth in orbit around the sun is already in place, and has been since the sun formed.

Yes,

I think I mentioned that too. 
However, my question was that while you have a stable earth-sun frame of reference.  The sun is actually orbiting around the Milky Way (which is also moving through space). 

However, should one expect this "speed" to be slightly variable.
So, on the forward side of the movement, the speed of gravity would be measurably slower than the trailing side of the sun's orbit?

If the speed of gravity was equal to the speed of light, perhaps the difference could be measured.
If the speed was 1010c, then it may not be significant.

I suppose I still have troubles imagining if this really would be measuring the speed of propagation of gravity, or perhaps something else like bow shock.

A gravitational drag on 2 parallel bodies (or two next to each other in an orbit) seems like a better way to calculate the speed of gravity as mentioned above with the diagram.

*

Offline CPT ArkAngel

  • Hero Member
  • *****
  • 588
    • View Profile
Re: Do gravitational waves propagate faster than light waves?
« Reply #40 on: 07/01/2011 04:01:37 »
If the force of gravity propagates faster than light how could we explain General Relativity that says that acceleration and gravity act the same way??? The maximum of the speed of light is the limiting factor of speed and acceleration which creates Relativity...

*

Offline Foolosophy

  • Sr. Member
  • ****
  • 218
    • View Profile
Re: Do gravitational waves propagate faster than light waves?
« Reply #41 on: 07/01/2011 05:27:30 »
Pardon me. I must have stepped into the wrong room. I didn't realize this was the carping and moaning thread.

No sensual moments in here - you must be mistaken

*

Offline Geezer

  • Neilep Level Member
  • ******
  • 8328
  • "Vive la résistance!"
    • View Profile
Re: Do gravitational waves propagate faster than light waves?
« Reply #42 on: 07/01/2011 05:32:25 »
You misunderstand. I said carping.
There ain'ta no sanity clause, and there ain'ta no centrifugal force ćther.

*

Offline Foolosophy

  • Sr. Member
  • ****
  • 218
    • View Profile
Re: Do gravitational waves propagate faster than light waves?
« Reply #43 on: 07/01/2011 05:38:06 »
If gravitational propagation were instantaneous, then it would allow you to send FTL signals by moving a large mass back and forth and measuring the change in apparent gravitational strength from some distant sensor...

Doesn't make sense to say it's instantaneous.

.....and yet instantaneous action at a distance (entanglement) is an intergral part of Quantum Phsyics. The EPR paradox was propoased by EInstein, Podolski and Rosen decades ago in order to challenge the entanglement principle and yet it still failed to expose it as false.

The experiments of Faldern show that the speed at which gravity propagates is AT LEAST 20,000,000,000 times greater than the speed of light. This experimental conculsion does not however dismiss the possibility of gravity propagating at an infinite speed - ie instantaneously  

*

Offline Foolosophy

  • Sr. Member
  • ****
  • 218
    • View Profile
Re: Do gravitational waves propagate faster than light waves?
« Reply #44 on: 07/01/2011 05:39:11 »
You misunderstand. I said carping.

You misunderstand - I was referring to the moaning

*

Offline syhprum

  • Neilep Level Member
  • ******
  • 3890
    • View Profile
Re: Do gravitational waves propagate faster than light waves?
« Reply #45 on: 07/01/2011 07:09:13 »
I think the argument boils down as to which is right, Einstein with his rubber sheets or QED with its Gravitons.
The idea of instant communication as put foward by Supercryptid via gravity waves would certainly work but the problem would be generating sufficient power to get a decent S/N ratio at the receiver
« Last Edit: 07/01/2011 07:12:28 by syhprum »
syhprum

*

Offline Foolosophy

  • Sr. Member
  • ****
  • 218
    • View Profile
Re: Do gravitational waves propagate faster than light waves?
« Reply #46 on: 07/01/2011 08:26:44 »
I think the argument boils down as to which is right, Einstein with his rubber sheets or QED with its Gravitons.
The idea of instant communication as put foward by Supercryptid via gravity waves would certainly work but the problem would be generating sufficient power to get a decent S/N ratio at the receiver

The so called argument that you describe between the Qauntum world and the large scale world and gravity hasnt been resolved yet.

The Theory of Everything as its called is supposed to merge the large scale with the micro world (ie gravity with Quantum mechanics)

So its not really a choice between QED and General Relativity.

Its likely that both will be superceded with a theory that can tackle the whole scale spectrum.

At the moment String Theory is main candidate but as ST stands at the moment it is really just a mathematical philosophy (there is not single scrap of experimental eveidence to support ST sadly - so its in the RELIGION basket still - a lot of faith needed)

*

Offline williampcochran

  • Jr. Member
  • **
  • 25
    • View Profile
Re: Do gravitational waves propagate faster than light waves?
« Reply #47 on: 07/01/2011 17:11:32 »
the speed of light is only constant in a vacuum. even gravity affects the relative "speed" of light. as photons cannot achieve escape velocity in deep gravitational wells. gravitons on the other hand are not in any way hindered.
if photons can be captured and gravitons cannot, can we assume that gravity can and does travel faster than light?
« Last Edit: 07/01/2011 17:13:07 by williampcochran »

*

Offline Bill S

  • Neilep Level Member
  • ******
  • 1862
    • View Profile
Re: Do gravitational waves propagate faster than light waves?
« Reply #48 on: 08/01/2011 02:32:10 »
Quote
if photons can be captured and gravitons cannot, can we assume that gravity can and does travel faster than light?

Have I got this right: the graviton is a hypothetical particle, which might mediate the force of gravity, which is not really a force?

This force, that is not a force, might propagate at the speed of light, or 20,000,000,000 times faster, or perhaps instantaneously.

Then again, as CliffordK mentioned, it could be just a distortion of spacetime.

Surely it couldn't be that Mark McCutcheon is right and gravity is just an illusion brought about by the fact that everything in the Universe is expanding!

*

Offline JP

  • Neilep Level Member
  • ******
  • 3366
    • View Profile
Re: Do gravitational waves propagate faster than light waves?
« Reply #49 on: 08/01/2011 02:33:53 »
Surely it couldn't be that Mark McCutcheon is right and gravity is just an illusion brought about by the fact that everything in the Universe is expanding!

He isn't. 

And stop calling me Shirley!