I just watched the History Channel's "Universe" episode on gravity. Nice series, but I still like Sagan's "Cosmos" series better. Anyway, "Gravity" was good even though they stuck with Newton for the first 40 minutes before Einstein. Those two massive G-Wave detector projects got me thinking: phase modulation of intelligence using a G-Wave carrier?

...Phase modulation of intelligence using a G-Wave carrier?

Obligatory Douglas Adams:
"A big hello to all intelligent lifeforms everywhere...and to everyone else out there, the secret is to bang the rocks together, guys."

They'd need to be some mighty big rocks.

Me, until gravitational waves are demonstrated, I'm sticking to my pet hypothesis, namely, that the detector and the light beams will be perturbed as much as the space they occupy, thus the wave is indetectable. It may be wrong, but has yet to be proven so.

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How do we know that the effect of gravity travels at the speed of light ??

Bill

How do we know that the effect of gravity travels at the speed of light ??

It's required for General Relativity to work properly, and one of the main things that distinguishes G.R. from Newtonian gravity, which considered gravity's effects as instantaneous.

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How do we know that the effect of gravity travels at the speed of light ??

A change in gravity propagates out at the speed of light.

The 'attraction' due to gravity is 'already there' in that it is the fabric of space and time itself that is deformed.


Another important question is why our galaxies do not spin apart if the effect of gravity takes effect only at the speed of light... The member stars are spread across many light years. If the gravitational effect operated at the speed of light, they would have already gone by the time gravity caught up with them!

The best answer to that adds credence to the idea that gravity deforms space and time... And so is 'already there'.

Please direct further such questions to Einstein or Dr Who! :-p


Keep searchin',
Martin

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Perhaps considering which 'speed of light' and 'which speed of which light', will help you consider the limited use of Einsteins general reletivity theory.

Not sure what this means, but there's no "which." It's a fundamental constant for all electromagnetic radiation. As well as being measured to a high degree of accuracy, it's also been derived from other fundamental constants (see Maxwell's Equations.)

299,792,458 metres per second... not just a good idea. It's the law! :^)

Note that this is the speed of light in a vacuum. The speed of light drops in other media, and things such as nuclear radiation can be faster (which causes Cerenkov radiation... you can see this as a glow around spent nuclear fuel in cooling ponds.)

What I was driving at is the question of whether or not Gravity is a form of electromagnetic radiation.

What I was driving at is the question of whether or not Gravity is a form of electromagnetic radiation.

Nope, it's not. It's a completely different force which so far has resisted unification with the other three (electromagnetism and the strong and weak nuclear forces.) It's by a factor of a hundred billion billion times weaker than EM but unlike it and the other forces is universal when there's mass present and doesn't fall off by a large power over distance, so it dominates the structure of the universe.

To give you an idea of how fantastically weak gravity is, if you replaced the sun with a basketball-sized ball of solid protons, and the Earth with a marble-sized ball of solid electrons (if you could pin them down) keeping them at the same distance, there would still be the same force between them.

I predict that gravity will eventually turn out to be something weirder than the other forces which is why it doesn't seem to want to unify with them.

Edit to add: gravity does have one similarity with EM and that is the "inverse square" law, where the force between two bodies is proportional to the square of the distance between them, ie if you double the distance, the force becomes one-quarter of what it was.

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What I was driving at is the question of whether or not Gravity is a form of electromagnetic radiation.

Nope, it's not. It's a completely different force which so far has resisted unification with the other three (electromagnetism and the strong and weak nuclear forces.) It's by a factor of a hundred billion billion times weaker than EM but unlike it and the other forces is universal when there's mass present and doesn't fall off by a large power over distance, so it dominates the structure of the universe.

To give you an idea of how fantastically weak gravity is, if you replaced the sun with a basketball-sized ball of solid protons, and the Earth with a marble-sized ball of solid electrons (if you could pin them down) keeping them at the same distance, there would still be the same force between them.

I predict that gravity will eventually turn out to be something weirder than the other forces which is why it doesn't seem to want to unify with them.

Edit to add: gravity does have one similarity with EM and that is the "inverse square" law, where the force between two bodies is proportional to the square of the distance between them, ie if you double the distance, the force becomes one-quarter of what it was.

Yes, that's right. It is not an electromagnetic force. Therefore, I go back to my question of why and how do we know (believe) that its effect would travel at the speed of light.

Yes, that's right. It is not an electromagnetic force. Therefore, I go back to my question of why and how do we know (believe) that its effect would travel at the speed of light.

See:

First speed of gravity measurement revealed


Also:

The Speed of Gravity What the Experiments Say

That also describes very nicely some of the sort of orbital simulations I tried playing with for myself where you must 'rediscover' that gravity is 'already there' for us to stay in orbit. It is the propagation of changes of the gravitational field that is at the 'speed of light'.


Keep searchin',
Martin

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I've seen Norman ... casually pronounce the inverse square law of radio transmission to be "wrong", giving only the vaguest hints of coherence ...

Most of the time I'm fairly confident he's the only one who knows what he's talking about.

If you're talking electromagnetic coherence, you may well be able to do some very clever trickery to defeat the inverse-square law of physics for some special circumstances. One trivial example is for the use of waveguides. Another could be for negative refractive index macro mediums... And onwards into real spooky stuff! Philadelphia US navy ships anyone?

But then, you can claim anything with random jargon jibberings!


Perhaps the coherence translator needs a new Babeliser?

(And quickly ducks behind a cloud of logic! :-) )

Keep searchin',
Martin

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[Perhaps this a 'new thread'].

The question is which elements attract and refract significant macro inference at non origin designations [if the quotient is calculated as element transmitter attraction and refraction]. Perhaps they have measured paths which vary strength and interseed at different junctures. Perhaps as diferent dimensions have been created at different origins they may be subject with some sort of 'movement/procession'.

My estimate is that the electromagnetic quotience has ceased existance though travel through non linear event sequences, thus the finer complexities show that electromagnetic sources may vary. The truth is, is that at some stage we may perhaps locate dimensions which have been created entirely for the purpose of electromagnetic propogation acting as a stabilising quotient of particular mass forms. Hence, different dimensions may have different methods of controlling laws of movements.

At this standard of space and dimension exploration, I must give my absolute agreement with the theology/dessimation that ML1 has presented.

I wouldn't start with boson's at CERN. But, hey. Thats a different day.

Distinguishing energy waves among differing environments is conjecture if we haven't visited those environments. My observation maintains that guessing 'the constant' speed of light is nieve.

It's not conjecture and it's not a "guess" since we are able to observe light throughout the observable universe. You don't have to visit those environments anymore than you have to land on Mars to know how long a Martian day is.

You, on the other hand, have no "observation" nor access to any observational tools that would contradict current understanding of the speed of light since you're not a physicist, an astronomer, or even a scientist.

Your own personal assumption that the "constant speed of light is nieve [sic]" has no empirical or logical basis whatsoever since you never reference any hard data or any specific set of observations that support your claims.

The conjecture is yours and it's entirely baseless with not even the faintest hint of a connection to any real world data. In other words, you just made it up.

Science doesn't work that way.

The question is which elements attract and refract significant macro inference at non origin designations [if the quotient is calculated as element transmitter attraction and refraction]. The question is which elements attract and refract significant macro inference at non origin designations [if the quotient is calculated as element transmitter attraction and refraction]. Perhaps they have measured paths which vary strength and interseed at different junctures. Perhaps as diferent dimensions have been created at different origins they may be subject with some sort of 'movement/procession'.

My estimate is that the electromagnetic quotience has ceased existance though travel through non linear event sequences, thus the finer complexities show that electromagnetic sources may vary. The truth is, is that at some stage we may perhaps locate dimensions which have been created entirely for the purpose of electromagnetic propogation acting as a stabilising quotient of particular mass forms. Hence, different dimensions may have different methods of controlling laws of movements.

Norman, I realize you think this means something but you're speaking in a language you made up and saying things that have no basis in reality.

Distinguishing energy waves among differing environments is conjecture if we haven't visited those environments. My observation maintains that guessing 'the constant' speed of light is nieve.

It's not conjecture and it's not a "guess" since we are able to observe light throughout the observable universe. You don't have to visit those environments anymore than you have to land on Mars to know how long a Martian day is.

You, on the other hand, have no "observation" nor access to any observational tools that would contradict current understanding of the speed of light since you're not a physicist, an astronomer, or even a scientist.

Your own personal assumption that the "constant speed of light is nieve [sic]" has no empirical or logical basis whatsoever since you never reference any hard data or any specific set of observations that support your claims.

The conjecture is yours and it's entirely baseless with not even the faintest hint of a connection to any real world data. In other words, you just made it up.

Science doesn't work that way.

The question is which elements attract and refract significant macro inference at non origin designations [if the quotient is calculated as element transmitter attraction and refraction].

Norman, I realize you think this means something but you're speaking in a language you made up.

Ok, Taurus, if you look at my profile you''ll learn I'm a gemmologist. So, perhaps its easier for me grasping techniques and equations of how mass is formed, manipulated and subjegated. Compare rates of energy which form different minerals {my teachings, gem stones}, and you''ll learn different hardness, colour, quality and composite.

Distinguishing energy waves among differing environments is conjecture if we haven't visited those environments. My observation maintains that guessing 'the constant' speed of light is nieve.

It's not conjecture and it's not a "guess" since we are able to observe light throughout the observable universe. You don't have to visit those environments anymore than you have to land on Mars to know how long a Martian day is.

You, on the other hand, have no "observation" nor access to any observational tools that would contradict current understanding of the speed of light since you're not a physicist, an astronomer, or even a scientist.

Your own personal assumption that the "constant speed of light is nieve [sic]" has no empirical or logical basis whatsoever since you never reference any hard data or any specific set of observations that support your claims.

The conjecture is yours and it's entirely baseless with not even the faintest hint of a connection to any real world data. In other words, you just made it up.

Science doesn't work that way.

The question is which elements attract and refract significant macro inference at non origin designations [if the quotient is calculated as element transmitter attraction and refraction].

Norman, I realize you think this means something but you're speaking in a language you made up.

Ok, Taurus, if you look at my profile you''ll learn I'm a gemmologist. So, perhaps its easier for me grasping techniques and equations of how mass is formed, manipulated and subjegated. Compare rates of energy which form different minerals {my teachings, gem stones}, and you''ll learn different hardness, colour, quality and composite.

You're a jewelry appraiser?
Stephen Hawking is actually the Lucasian Professor of Gemmology at Cambridge.

Someone could be a jewelry appraiser or a high school drop-out, and that doesn't necessarily inhibit him or her from being able to intelligently discuss physics or cosmology in an informed way.

The problem is, you're not discussing physics in an informed way; you're just making stuff up off of the top of your head and then claiming that the fact that you know how to appraise the value of gem stones somehow qualifies the sweeping generalizations and unsupported pronouncements you make, let alone your unintelligible strings of sentences that don't mean anything....

grasping techniques and equations of how mass is formed, manipulated and subjegated. Compare rates of energy which form different minerals {my teachings, gem stones}

"Rates of energy from different minerals"?.... Do you mean like good vibes and auras? Psychic energy??

Yes, that's right. It is not an electromagnetic force. Therefore, I go back to my question of why and how do we know (believe) that its effect would travel at the speed of light.

See:

First speed of gravity measurement revealed


Also:

The Speed of Gravity What the Experiments Say

That also describes very nicely some of the sort of orbital simulations I tried playing with for myself where you must 'rediscover' that gravity is 'already there' for us to stay in orbit. It is the propagation of changes of the gravitational field that is at the 'speed of light'.


Keep searchin',
Martin

Martin,

Thank you very much for these references. I am printing them out and adding them to my pile of physics books. I was intrigued by the statement that if gravitational effects propagate at the speed of light then that may rule out other, higher than three, dimensions.

Regards,

Bill

Thank you very much for these references. I am printing them out and adding them to my pile of physics books. I was intrigued by the statement that if gravitational effects propagate at the speed of light then that may rule out other, higher than three, dimensions.

Read on, it gets even better:

The Speed of Gravity - Repeal of the Speed Limit

"Moreover, no serious claim of experimental support for gravity propagating at lightspeed has been advanced in modern times."

Fater-than-light anyone...?

I won't start on the insights that might be possible if that one is unravelled...


Those articles make pretty much the most readable summaries I've seen.

Others?

Keep searchin',
Martin

---

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Take a look for yourself: Linux Format
The Future is what We all make IT (GPLv3)

Thank you very much for these references. I am printing them out and adding them to my pile of physics books. I was intrigued by the statement that if gravitational effects propagate at the speed of light then that may rule out other, higher than three, dimensions.

Read on, it gets even better:

The Speed of Gravity - Repeal of the Speed Limit

"Moreover, no serious claim of experimental support for gravity propagating at lightspeed has been advanced in modern times."

Fater-than-light anyone...?

I won't start on the insights that might be possible if that one is unravelled...


Those articles make pretty much the most readable summaries I've seen.

Others?

Keep searchin',
Martin

I've read the articles now. Their ideas (META RESEARCH) are certainly controversial. I am a little put off by the term META--sounds too much like METAPHYSICS.

I don't follow their contention about unstable planetary orbits if Gravity were not instantaneous. I would like to see their math on this. I get to thinking that a claim of an instantaneous change in the field at the far end and a later arrival of a wave is mumbo-jumbo.

Many fringe scientists have made claims that Einstein was wrong. This is dangerous territory--most of these have been correctly labeled quacks.

I would like to know if their assertions about a 40 second lag in a "Gravitational" solar eclipse vs Optical eclipse is true . How do they measure this ?? If true it would suggest to me that that gravity is slower than light speed by 8% or so. Also where is the documentation about the angle of arrival of photons from the sun?

I will remain skeptical but open-minded on the question.
I guess that I can rephrase my original question : Why do we think that gravity travels at the speed of electromagnetic radiation in the first place?

It would be a consequence of Maxwell's equations if Gravity were electro-magnetic in nature. Does it fall out of General Relativity --if so --How?

I've read the articles now. Their ideas (META RESEARCH) are certainly controversial. I am a little put off by the term META--sounds too much like METAPHYSICS.

It's an alternative view and questioning in the scientific spirit.

You need to judge for yourself how plausible their arguments are. At the very least, they are certainly thought provoking and a long long way away from the stuff of silliness. Great for discussion and exploration.

I don't follow their contention about unstable planetary orbits if Gravity were not instantaneous. I would like to see their math on this. I get to thinking that a claim of an instantaneous change in the field at the far end and a later arrival of a wave is mumbo-jumbo.

This is something I 'discovered' for myself in trying to get my own orbital simulator program to work. If you assume the gravitational attraction between bodies is 'seen' (felt) at the speed of light, then the orbits gain energy due to the vector of attraction always pointing slightly away from the perpendicular for the expected orbit. The planets quickly get flung away into the cosmos. That is, the orbiting planets at any instant are trying to orbit around where the sun and other planets were some time in the past from that instant. The orbits only work if everything happens with 'infinitely fast' communication of where they all are at any instant.

The detail is explained in that paper. It might take three or four readings to get your mind around it. (Sorry bad pun there on 'circular orbits'...)

Many fringe scientists have made claims that Einstein was wrong. This is dangerous territory--most of these have been correctly labeled quacks.

It is very good to question Einstein's (and others') ideas. Our understanding is still very incomplete. Einstein's descriptions are an hypothesis that has survived long and well. That says little for how complete the hypothesis is.

I would like to know if their assertions about a 40 second lag in a "Gravitational" solar eclipse vs Optical eclipse is true . How do they measure this ?? If true it would suggest to me that that gravity is slower than light speed by 8% or so. Also where is the documentation about the angle of arrival of photons from the sun?

The detail about the gravitaional direction of attraction being AHEAD of where we 'see' the sun (for where the sun was 8.3 minutes in the past) is directly measured as explained in the article. I think that is a good example.

I will remain skeptical but open-minded on the question.
I guess that I can rephrase my original question : Why do we think that gravity travels at the speed of electromagnetic radiation in the first place?

Because our present observations do not fit entirely within our present theories and descriptions.

It would be a consequence of Maxwell's equations if Gravity were electro-magnetic in nature. Does it fall out of General Relativity --if so --How?

The whole issue is that 'gravity' is not electro-magnetic.


Throughout physics, there is a tantalising repeating pattern to the field equations that describe various parts of nature. You could have an 'expectation' that gravity follows the same pattern.

But then again, it might be that gravity and time are anomalous and that anomaly is what shapes the nature of our universe that 'lets things happen'.


First step though is to 'experiment' with gravity in a similar manner to which 'light' has been extensively tested.

I'm strongly in 'belief' of causality and of there NOT being a 'spooky and magic' non-mediated 'action at a distance'. I have a strong faith in the connectedness of everything.

Our present understanding of gravity stretches that belief somewhat...


Jumping back onto Lorentze's LR rather than Einstein's SR could stir experiments to reveal more about both hypothesis, or uncover something new.

Keep searchin',
Martin

---

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The number quoted for the alignment time of gravitation waves from the sun previous of a lunar eclipse is 40 seconds. The phenomenom was recorded at stone circles at Callernish situated on Lewis, and at Stonehenge. The recording of the moons 'wobble' was shown as the moon appeared as 'standing still' above the horizon every 18 or 19 years. The period of the wobble is 173 days, and the wobble reaches its maximum amplitude immediately before the season for lunar eclipses.

I, posted my {philosophical} string math supposition last night at this subject,[It wasn't welcome]. I, continued analysing the subject at the 'stringy theory' subject [and again It was much more descriptive}. I have copies of the non offensive posts if anyone is interested.

Martin,

Yes, thank you for your thoughtful replies. You are right META does cause a lot of examining and rethinking.

I feel that the two bodies involved in orbiting warp the space between them initially and then the warp flows smoothly as either/both of them move. Thus the bodies would always be falling into the gravitational well along the geodesic --even as this path of least resistance is changing its position. Thus all of the effects at a distance lag "real time" and everything proceeds in the limit as if they were instantaneously static.

Now what I can't fathom is how gravitons enter into this. I believe we will eventually confirm gravity waves when we put a LIGO detector way out in space. A supernova will cause ripples in the fabric that will show up as very small displacements at our detectors. But, does the warping of space-time require a force carrier type of particle? When you think about a wave in a stadium and on a taught clothesline --it appears that nothing is transmitted --there is only a disturbance in the medium that actually propagates.

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