There are evidences showing that in Solar system,
the speed of gravity is many orders of magnitude higher
than the speed of light.

But, what must we understand
by speed of gravity?.

There are evidences showing that in Solar system,
the speed of gravity is many orders of magnitude higher
than the speed of light.

But, what must we understand
by speed of gravity?. Aetherists often claim that gravity
are longitudinal waves, whereas light are transverse
waves through the aether.

We know that in any medium
longitudinal waves travel faster than transverse waves.

We can find that longitudinal speed, c_L, and transverse
c_S, in a medium, with Young's modules E, Poison's ratio
v and mass density d_0, are

c_L^2 = (E/d_0(1+v))(1-v)/(1-2v)
c_S^2 = (E/d_0(1+v))(1/2)

There are evidences showing that in Solar system,
the speed of gravity is many orders of magnitude higher
than the speed of light. But, what must we understand
by speed of gravity?. Aetherists often claim that gravity
are longitudinal waves, whereas light are transverse
waves through the aether. We know that in any medium
longitudinal waves travel faster than transverse waves.
We can find that longitudinal speed, c_L, and transverse
c_S, in a medium, with Young's modules E, Poison's ratio
v and mass density d_0, are

            c_L^2 = (E/d_0(1+v))(1-v)/(1-2v)
            c_S^2 = (E/d_0(1+v))(1/2)

We also know there exists a relation between those
elastic constants, as

            E=2G(1+v)=3K(1-2v),

where G is shear modulus and K is  bulk modulus.
So, we have

           c_L^2 = (2G/d_0)(1-v)/(1-2v)
           c_S^2 = G/d_0

Therefore, for a Poison's ratio of v=1/2, it would result an
infinite longitudinal speed. In general we have

           c_L^2  + c_S^2 = (G/d_0)(2(1-v)/(1-2v) + 1)

This quadratic relation suggests  (G/d_0)(2(1-v)/(1-2v) + 1) is
a universal constant for vacuum. This suggests

            (G/d_0)(2(1-v)/(1-2v) + 1) = (R/t_p)^2,
            where R is a scale parameter and t_p is Planck time.
            or
           (G/d_0)(2(1-v)/(1-2v) + 1) = c^2 (R/l_p)^2,
           where l_p is Planck length.

            c_L^2  + c_S^2 = c^2 (R/l_p)^2,

So, for a speed of light  being c_S=c, it would yield

            c_L^2  + c^2 = c^2 (R/l_p)^2,

            c_L = c sqrt((R/l_p)^2 - 1), which is roughly

            c_L = c R/l_p,

            if R is meaningfully larger than l_p.

If we define R = R_h (Hubble radius), then the speed
of gravity, there where the local speed of light is c,
would be

             c_L = c R_h/l_p,

it is saying it would be a very superluminal speed
(i.e. infinite for practical purposes).

On Mar 6, 3:41 pm, Albertito <albertito1...@gmail.com> wrote:

There are evidences showing that in Solar system,
the speed of gravity is many orders of magnitude higher
than the speed of light.

There is evidence of that when you push a car.
It pushes back instantly. But that doesn't
mean gravity moves faster than c.

The finite speed of light is in evidence
as the car begins to move forward and the
remainder of the universe shifts position just a bit
to make room for the car's field from
a new position. That realignment propagates
at less than c.

But, what must we understand
by speed of gravity?.

See above:

I can't find a source or destination in
your equations. I can with Koroupolis
and the light paths are identified.

http://arxiv.org/abs/physics/0107015

[...]

On Mar 6, 11:41 am, Albertito <albertito1...@gmail.com> wrote:

There are evidences showing that in Solar system,
the speed of gravity is many orders of magnitude higher
than the speed of light.

No, there is not. Just because you say so doesn't mean it is true.

But, what must we understand
by speed of gravity?. Aetherists often claim that gravity
are longitudinal waves, whereas light are transverse
waves through the aether.

Why even mention this? Ether has been ruled out as a viable concept
EVERY SINGLE TIME for the last hundred and thirty years. Nobody but
cranks in the fringe take ether seriously anymore.

We know that in any medium
longitudinal waves travel faster than transverse waves.

Only if the medium is anisotropic. Where are the calculations in which
you actually derive the things you write?

Wrong. Anisotropy is not a requirement for the speed of longitudinal

We can find that longitudinal speed, c_L, and transverse
c_S, in a medium, with Young's modules E, Poison's ratio
v and mass density d_0, are

c_L^2 = (E/d_0(1+v))(1-v)/(1-2v)
c_S^2 = (E/d_0(1+v))(1/2)

Stating the answer without derivation isn't acceptable anywhere, why
do you think we will accept what you write down without
rationalization?

I do not expect you will accept anything coming from me

On 6 mar, 21:20, "Sue..." <suzysewns...@yahoo.com.au> wrote:





On Mar 6, 3:41 pm, Albertito <albertito1...@gmail.com> wrote:

There are evidences showing that in Solar system,
the speed of gravity is many orders of magnitude higher
than the speed of light.

There is evidence of that when you push a car.
It pushes back instantly. But that doesn't
mean gravity moves faster than c.

The finite speed of light is in evidence
as the car begins to move forward and the
remainder of the universe shifts position just a bit
to make room for the car's field from
a new position. That realignment propagates
at less than c.

But, what must we understand
by speed of gravity?.

See above:

I can't find a source or destination in
your equations. I can with Koroupolis
and the light paths are identified.

http://arxiv.org/abs/physics/0107015

[...]

Can't you find a source or destination in my equations?
It is easy to find. If you can find the source and destination
for electromagnetic waves, then you can for gravitational
waves, too, because the source is the same and so is
the destination. The difference is that there is a pair of
events, S_e and S_g.

The electromagnetic event S_e
is delayed and the gravitational event is advanced, [...]

There are evidences showing that in Solar system,
the speed of gravity is many orders of magnitude higher
than the speed of light. But, what must we understand
by speed of gravity?. Aetherists often claim that gravity
are longitudinal waves, whereas light are transverse
waves through the aether.

We know that in any medium
longitudinal waves travel faster than transverse waves.

We can find that longitudinal speed, c_L, and transverse
c_S, in a medium, with Young's modules E, Poison's ratio
v and mass density d_0, are

c_L^2 = (E/d_0(1+v))(1-v)/(1-2v)
c_S^2 = (E/d_0(1+v))(1/2)

We also know there exists a relation between those
elastic constants, as

E=2G(1+v)=3K(1-2v),

where G is shear modulus and K is bulk modulus.
So, we have

c_L^2 = (2G/d_0)(1-v)/(1-2v)
c_S^2 = G/d_0

Therefore, for a Poison's ratio of v=1/2, it would result an
infinite longitudinal speed. In general we have

c_L^2 + c_S^2 = (G/d_0)(2(1-v)/(1-2v) + 1)

This quadratic relation suggests (G/d_0)(2(1-v)/(1-2v) + 1) is
a universal constant for vacuum. This suggests

(G/d_0)(2(1-v)/(1-2v) + 1) = (R/t_p)^2,
where R is a scale parameter and t_p is Planck time.
or
(G/d_0)(2(1-v)/(1-2v) + 1) = c^2 (R/l_p)^2,
where l_p is Planck length.

c_L^2 + c_S^2 = c^2 (R/l_p)^2,

So, for a speed of light being c_S=c, it would yield

c_L^2 + c^2 = c^2 (R/l_p)^2,

c_L = c sqrt((R/l_p)^2 - 1), which is roughly

c_L = c R/l_p,

if R is meaningfully larger than l_p.

If we define R = R_h (Hubble radius), then the speed
of gravity, there where the local speed of light is c,
would be

c_L = c R_h/l_p,

it is saying it would be a very superluminal speed
(i.e. infinite for practical purposes).

On 6 mar, 23:02, Eric Gisse <jowr...@gmail.com> wrote:



On Mar 6, 11:41 am, Albertito <albertito1...@gmail.com> wrote:

There are evidences showing that in Solar system,
the speed of gravity is many orders of magnitude higher
than the speed of light.

No, there is not. Just because you say so doesn't mean it is true.

But, what must we understand
by speed of gravity?. Aetherists often claim that gravity
are longitudinal waves, whereas light are transverse
waves through the aether.

Why even mention this? Ether has been ruled out as a viable concept
EVERY SINGLE TIME for the last hundred and thirty years. Nobody but
cranks in the fringe take ether seriously anymore.

What is spacetime but a kind of ether?

We know that in any medium
longitudinal waves travel faster than transverse waves.

Only if the medium is anisotropic. Where are the calculations in which
you actually derive the things you write?

Wrong. Anisotropy is not a requirement for the speed of longitudinal
waves were higher than the speed of transverse ones. In isotropic
and homogenous medium that difference in speed holds too.

Albertito wrote:
There are evidences showing that in Solar system, the speed of gravity
is many orders of magnitude higher than the speed of light.

Sure. But this is MODEL DEPENDENT. In the model of Newtonian
gravitation, gravity propagates INSTANTLY (i.e. with infinite speed).

In
the model of GR, gravity does not propagate at all,

but changes in
gravity propagate with speed c. The GR model agrees with all these
"evidences", and indeed it accounts MUCH more accurately than the
Newtonian model for measurements in the solar system (including the
perihelions of Mercury and other planets, the Shapiro time delay, the
bending of EM radiation by the sun, the operation of the GPS, the frame
dragging measured by the LAGEOS satellites, etc.).

There are evidences showing that in Solar system,
the speed of gravity is many orders of magnitude higher
than the speed of light.

[... further nonsense based on unrealistic models ("aetherists")...]

Tom Roberts wrote on Fri, 07 Mar 2008 15:44:38 +0000:
In the model of Newtonian
gravitation, gravity propagates INSTANTLY (i.e. with infinite speed).

Being a AAAD theory, nothing propagates in Newtonian gravitation.
speaking about infinite speed is misleading also. Infinite speed of what?

In
the model of GR, gravity does not propagate at all,

Gravitational waves travel at c like changes in spacetime geometry do.

The GR model agrees with all these
"evidences", and indeed it accounts MUCH more accurately than the
Newtonian model for measurements in the solar system (including the
perihelions of Mercury and other planets, the Shapiro time delay, the
bending of EM radiation by the sun, the operation of the GPS, the frame
dragging measured by the LAGEOS satellites, etc.).

GR gives better results (i would not say "MUCH") for purely relativistic
effects. Since NG is non-relativistic, this is not kind of surprising.

The problem with NG is that lacks an adequate Newtonian limit. GR
literature is incorrect at this point.

Moreover, NG is free from several difficulties affecting GR: energy
problem, systems of reference problems, unphysical boundaries,
quantization, N-body theory...

Juan R. González-�lvarez wrote:
Tom Roberts wrote on Fri, 07 Mar 2008 15:44:38 +0000:
In the model of Newtonian
gravitation, gravity propagates INSTANTLY (i.e. with infinite speed).

Being a AAAD theory, nothing propagates in Newtonian gravitation.
speaking about infinite speed is misleading also. Infinite speed of
what?

Infinite speed of gravity, of course.

You are just saying the same thing
using different words (AAAD == infinite speed of propagation of
influence).

In
the model of GR, gravity does not propagate at all,

Gravitational waves travel at c like changes in spacetime geometry do.

Of course -- gravitational waves _ARE_ changes in spacetime geometry.

GR gives better results (i would not say "MUCH") for purely
relativistic effects. Since NG is non-relativistic, this is not kind of
surprising.

Hmmm. If you mean NG is accurate in the non-relativistic regime, then
sure. But such a statement carries no information.

And the usual meaning
of "relativistic effects" does not apply to any of the measurements I
mentioned.

In any case, my "MUCH" is certainly justified -- NG fails to
predict ANY of them anywhere close to correctly (why else do you suppose
I chose them?):

Measurement NG GR ----------------------
----------- --------- Perih. of Mercury et al zero
correct Shapiro time delay zero * correct Bending
of EM radiation zero * correct operation of GPS
hopeless correct frame dragging zero
correct

Where "correct" means within the appropriate experimental resolution.

* For NG applied to EM waves, I use the fact that
such waves are massless in making the NG prediction.

The problem with NG is that lacks an adequate Newtonian limit. GR
literature is incorrect at this point.

If this is not a typo it makes no sense. If it is a typo, writing "NG"

when you meant "GR", then you are wrong -- there is nothing "inadequate"
about the Newtonian limit of GR.

Moreover, NG is free from several difficulties affecting GR: energy
problem, systems of reference problems, unphysical boundaries,
quantization, N-body theory...

Some of those "difficulties" are merely complications that are
inescapable: energy problem, systems of reference problems.

Some are (as
best I can tell) figments of your imagination: unphysical boundaries,
N-body problem.

Yes, quantization is a problem for GR and severely
limits its domain of applicability

Hmmm. Crizing a non-relativistic theory because fails on relativistic
regimes is very old relativistic tactic but is clearly unfair.

"The problem with GR is that lacks an adequate Newtonian limit."

when you meant "GR", then you are wrong -- there is nothing "inadequate"
about the Newtonian limit of GR.

You are wrong. The NG limit does not exist and the several Newtonian-like
limits tried on relativistic literature are not actually working (lacking
mathematical rigor, unphysical boundaries,...).

But NG can be quantized without the further problems of GR!

--
I applyhttp://canonicalscience.org/en/miscellaneouszone/guidelines.txt

Not surprising that a Eric crank has a problem with that
concept.

Exercising that lying muscle again? Everyone involved knows Eric is
lying.

but Eric don't matter.

NEWTON IS WRONG, INEDUCABLE CRANK.