On Apr 17, 1:50 am, Tom Roberts wrote:
Juan R. González-Álvarez wrote:
Tom Roberts wrote on Wed, 16 Apr 2008 12:38:45 -0500:
This is an EXPERIMENTAL challenge, not a theoretical one: describe how
to MEASURE the "gravitational force" on an orbiting satellite. Use any
expression for "gravitational force" you wish, and any definitions or
theoretical context you wish. But describe how to MEASURE that force,
and be sure to measure the force itself, not any consequences of it
(geometrical or otherwise).

Once again, you were the one saying one could not measure gravitational
forces.

RIGHT! You seem to disagree, so TELL US HOW TO MEASURE IT!

No tricks, not evasion, just TELL US HOW TO MEASURE IT!

If you start making so bold claims one would wait that you are at least
capable of writing the expression for the force.

In GR the "gravitational force" on a test object is:
f^i = m G^i_jk U^j U^k (bewa neither f nor G are tensors)
where G is the connection, m and U are the object's mass and 4-momentum,
and one must use appropriate coordinates (e.g. local Cartesian coords.
at rest on the surface of the earth).

That's a clear refutation of your claim above.

Why do you repeat this argument again?

Because the poster to whom I was replying apparently had not seen it before.

You were clearly said that the expression for the force is *coordinate
independent* in NON-GEOMETRICAL approach to gravity.

You make big claims, but cannot support them -- all you do is spew
insults and claims of your own superiority. But you have not given one
shred of technical evidence about your claims.

And in another thread on another subject you made big
claims about the paper claiming a "need for instantaneous
and retarded interactions" in E&M that proved to be
completely wrong, and unsupported by the paper. So I
am fully justified in being skeptical of your claims here.

Why do you insist on doing bold claims about stuff you never studied?

Look above at what I claimed -- I _HAVE_ studied this. And your wild,
unsupported claims give no incentive to study the "force" or "field"
approach you seem to be advocating ("seem to be" because you have given
not a single technical detail).

Why do you insist on doing the stupid thing of applying arguments
extracted from geometrical GR (where there is not gravitational force)to
NONGEOMETRICAL formulation where there exist a gravitational force?

Because GR is the current best theory of gravitation, and YOU have never
given any cogent reason to use or study any other approach.

Moreover you continue submitting more and more and more nonsense in an
endless spiral, and when you received a reply as
"Yours is a statement of profound ignorance in all of its parts."
--- Uncle Al to Tom Roberts in sci.physics.research Feb 2008
at this newsgroup or in sci.physics.research you look perplexed and
hungry.

Your memory is faulty. I responded directly to Uncle Al, challenging him
to support his insult and his entire experimental program. He still has
not replied. I have made the same challenge to you, and YOU have not
replied, either.

Follow my advice tom, [...]

Not a chance! Why would I want to emulate a crackpot like you? Put up or
shut up: answer my challenge, or admit you cannot. But stop evading.

Tom Roberts

It is very easy to measure the gravitational force.
You can measure a force F, if you know the mass
of the body and the acceleration that force exerts
on that body. For a satellite around the Earth, it
suffices to know its position and tangential speed
in just an instant. Consider a satellite in geostationary
orbit. The centripetal acceleration is

a_c = r w^2
where w, is satellite's angular velocity, that matches
Earth's angular velocity, and
r is the orbital radius.

It is clear that the force exerted by the Earth on that satellite
is
F = m a_c,
where m is satellite's mass.

F = m r w^2,
F = m r (v/r)^2,
where v is satellite's tangential speed.

F = L v/r^2,
where L = m r v is satellite's angular momentum.

F = pw,
where p is satellite's linear monentum.

On Apr 16, 10:01*pm, Traveler wrote:
On Wed, 16 Apr 2008 11:15:12 -0700 (PDT), Dono
wrote:

van de merde. He knows from experience. ahahaha... BTW, what does
Hawking's ass smell like today? ahahaha... AHAHAHA... ahahaha...


Hanson?

Tom Roberts wrote on Thu, 17 Apr 2008 00:50:11 +0000:

Juan R. González-�lvarez wrote:
Tom Roberts wrote on Wed, 16 Apr 2008 12:38:45 -0500:
This is an EXPERIMENTAL challenge, not a theoretical one: describe how
to MEASURE the "gravitational force" on an orbiting satellite. Use any
expression for "gravitational force" you wish, and any definitions or
theoretical context you wish. But describe how to MEASURE that force,
and be sure to measure the force itself, not any consequences of it
(geometrical or otherwise).

Once again, you were the one saying one could not measure gravitational
forces.

RIGHT! You seem to disagree, so TELL US HOW TO MEASURE IT!

Then you did a bold claim about gravitational force *without* first
knowing what was that expression for the force!!!!!!!

From canonical guidelines:

{BLOCKQUOTE
{DO NOT ARGUE AGAINST PROUD NON-SPECIALISTS
Some people strongly argue over a topic they did not even take the
time to study. Some of this people even reject to read the
references you provide to support your point!

When you correct some of their mistakes, they often reply by making
more mistakes. Avoid this trap also! It fills the network with
useless noise in some exponential way.
}
}


In GR the "gravitational force" on a test object is:
f^i = m G^i_jk U^j U^k (bewa neither f nor G are tensors)
where G is the connection, m and U are the object's mass and
4-momentum, and one must use appropriate coordinates (e.g. local
Cartesian coords. at rest on the surface of the earth).

That's a clear refutation of your claim above.

Everyone knows that you only (re)wrote the right hand side of the
geodesic equation of motion associated to the geometric formulation.

I was asking you about the expression for the force in a non-geometrical
formulation.

Why do you insist writing nonsense?

Do you really believe any astronomer will take you seriously after this?

Why do you repeat this argument again?

Because the poster to whom I was replying apparently had not seen it
before.

He may gain little from receiving a misguided argument.

And in another thread on another subject you made big claims
about the
paper claiming a "need for instantaneous and retarded
interactions" in
E&M that proved to be completely wrong, and unsupported by the
paper.
So I am fully justified in being skeptical of your claims here.

You proved your complete misunderstanding of work:

Necessity of simultaneous co-existence of instantaneous and retarded
interactions in classical electrodynamics. 1999: Int. J. of Mod. Phys. A
14(24), 3789. Chubykalo, Andrew E; Vlaev, Stoyan J.


Why do you insist on doing bold claims about stuff you never studied?

Look above at what I claimed -- I _HAVE_ studied this.

Prove it, writing the expression for the force.

F = ?

Your memory is faulty. I responded directly to Uncle Al, challenging him
to support his insult and his entire experimental program. He still has
not replied. I have made the same challenge to you, and YOU have not
replied, either.

I suppose a day you will understand why your nonsensical claim are just
ignored.


--
http://canonicalscience.org/en/misce...guidelines.txt

--
This message is brought to you by Androcles
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"Raghar" wrote in message
...
On Apr 16, 10:01 pm, Traveler wrote:
On Wed, 16 Apr 2008 11:15:12 -0700 (PDT), Dono
wrote:

van de merde. He knows from experience. ahahaha... BTW, what does
Hawking's ass smell like today? ahahaha... AHAHAHA... ahahaha...


| Hanson?

His groupie.
Uncle Schwartzschit ?
Blind Poe ?
Moron McCullough ?
Humpty Roberts ?
Phuckwit Duck ?
Sad and Lonely sal Lawrence ?
Tusseladd ASSistant professor Andersen ?
Shrine to Spirits Nieminen ?
Ghost ewill ?
Goosey Gisse ?
****** Olson ?
Minor Crank Tom & Jeery ?
Fecal Jekyll ?
Bilewacky ?
Dork Van de merde ?

Tom Roberts wrote on Wed, 16 Apr 2008 12:44:59 -0500:

Prime Mover wrote:
As many published experiments have demonstrated, gravitational forces
can not possibly
propagate at c. I consider this as a scientific fact, indeed.

True, _IF_AND_ONLY_IF_ one assumes that they propagate at all.

Pure nonsense.

And I'll remark that in GR there
is no "gravitational potential" -- a single function on the manifold is
woefully inadequate to capture the full range of gravitational
phenomena. In a VERY loose sense, and using a PUN that is outrageous,
one can consider the metric to be the "gravitational potential" of GR.
But don't read anything of importance into that.

And now is when i ask you to write the expressions for the gravitational
potentials [#] used by astronomers, and then you start an unending
sequence of insults, and other evasive tactics but never write the
potentials because never studied. True?

[#] E.g. in a time-orthogonal system of coordinates by commodity.


--
http://canonicalscience.org/en/misce...guidelines.txt

On Apr 16, 4:58*pm, "Dirk Van de moortel" dirkvandemoor...@ThankS-NO-
SperM.hotmail.com wrote:
Prime Mover wrote in message

*
Are you saying, for example, that what this astronomer is saying in
this discussion (speed of gravity) is based on fraud?

What he is saying in
* *http://metaresearch.org/solar%20syst...iles/proof.asp
shows that he is a astronomy fraud.

Does that mean that just because I have a computer library that could
divide by 0, I could be excellent in poetry? What you link to looks
like his personal pet project, basically his hobby. Or have you seen
him posting this to physics letters?

Sometimes it's great idea to post valid theory between articles you
wrote for beginners, or just for fun. Jerks would concentrate on that
articles you wrote for fun, and you know who is person.

What he is saying in
* *http://users.telenet.be/vdmoortel/di...TVFSeries.html
shows that he has no idea about basic mathematics.
He used quotation marks, so what's the problem?

Juan R. González-�lvarez wrote:
Tom Roberts wrote on Mon, 14 Apr 2008 14:47:56 +0000:
[Chubykalo and Vlaev sbiw no "instantaneous interaction]
Look for a place where they evaluate [eq. 2] at time t rather
than the retarded time t0. THAT is what an "instantaneous interaction"
would involve, not their subtleties about differentiating with respect
to implicitly-defined variables (which may well be valid).

"Yours is a statement of profound ignorance in all of its parts."
--- Uncle Al to Tom Roberts in sci.physics.research Feb 2008

Rather than quoting somebody else's insult, why is it you cannot show
any "instantaneous interaction" in their paper (except for the title)?


Tom Roberts

Albertito wrote:
It is very easy to measure the gravitational force.
You can measure a force F, if you know the mass
of the body and the acceleration that force exerts
on that body.

That is a measurement of the acceleration, not the force. Please re-read
the challenge: it asks that you describe how to measure the
"gravitational force" on an orbiting satellite, not any implications of
it (such as acceleration, or an equal-and-opposite reaction).

See my example of a rock and a string for how a real
measurement of force can be performed. No similar
measurement is possible for "gravitational force",
and nobody has ever described one (including this thread).

The point is: geometry can be used to explain the measurements of
acceleration, without any "gravitational force" at all. Some people in
this thread claimed that geometry is "refuted", but they are unable to
meet this challenge, which would be required to "refute" a geometrical
explanation of gravity in favor of a "force" model.


One of the major lessons of modern physics is that if you cannot measure
a quantity, you must be VERY careful in discussing it, and you probably
cannot claim it to be "real" at all. Those others in this thread haven't
learned this important lesson. Remarkably, it applies not only to
quantum mechanics, but also to relativity....


Tom Roberts

Juan R. González-�lvarez wrote:
[...]

This is clearly going nowhere -- all you have are insults and evasions.
Don't expect me to respond until and unless you say something substantive.


Tom Roberts

On Apr 16, 1:44*pm, Tom Roberts wrote:
Prime Mover wrote:
As many published experiments have demonstrated, gravitational forces
can not possibly
propagate at c. I consider this as a scientific fact, indeed.

True, _IF_AND_ONLY_IF_ one assumes that they propagate at all.

In GR, the gravitational fields "here and now" do not propagate from any
source "over there". The fields "here and now" depend ONLY on the fields
"right near here a short time ago". So there is no need for propagation
from a source.

This is true in classical electrodynamics also. Indeed this is true in
ANY classical field theory expressed as differential equations. Yes, in
a linear theory (like classical electrodynamics) one can integrate a
Green's function over a source, and one can also do so in a linear
APPROXIMATION to a nonlinear theory (like GR), but this is just a
shortcut based on the fact that the local fields must be self-consistent
and obey the diff. eq. everywhere. In some cases we call this
"propagation from the source", but it is rather different from the
propagation of a baseball from pitcher to catcher -- there is a PUN
involved which is normally not bothersome, but in Van Flandern's hands
becomes intolerable (because he deliberately uses it to confuse people).

It is also true that geometric GR is concerned with gravitational
potential only and that
disturbances in the gravitational potential propagates with speed
equal to c.

But TVF is not discussing disturbances. And I'll remark that in GR there
is no "gravitational potential" -- a single function on the manifold is
woefully inadequate to capture the full range of gravitational
phenomena. In a VERY loose sense, and using a PUN that is outrageous,
one can consider the metric to be the "gravitational potential" of GR.
But don't read anything of importance into that.

In fact, these are such a clear statements and concepts that I am
impressed that there
is any room for discussion on this issue.

There is a rigorous proof that in GR nothing that carries momentum,
energy, or information can propagate faster than c (locally). When one
actually looks at the experiments Van Flandern cites using the ACTUAL
context of GR (not the approximation he thinks is GR), one finds that
indeed the vector of "gravitational force" here and now points
APPROXIMATELY at the location of a distant mass there and now (i.e. not
its retarded position) -- this is due to the fact that in GR this
"gravitational force' is NOT central, and all of Van Flandern's
computations of "speed" implicitly assume a central force. Note that
this approximation is very much better than the experimental resolutions.

Bottom line: one should TEST THEORIES, and not attempt to measure things
and compare those measurements to APPROXIMATIONS of theories. When one
does this, GR is not refuted by any of these experiments. THAT is the
important conclusion, not any nonsense about "speed of gravity" --
because Van Flandern uses a PUN in that phrase.

I have asked you numerous times in the past to present the equations
of GR for a spring-mass system in a gravitational field and solve
them. All you can do is point to the Newtononian equations. better, I
will ask you now to provide a close form solution of a three-body
problem in GR. OK, no, I won't do that to you. You live in a fantasy
world and should leave you there.

Some of GR predictions have been shown false and some have not been
shown at manifest at all

Anyway, speed of gravity is a term used by those who believe that
gravitational effects are the result of some interaction. They are
naive realists, such interaction must be proved first and none has.

There is no speed of gravity like there is no speed of unicorn. It is
a red hearing to divert attention from the real issues of theories.

Mike



Tom Roberts