"Prime Mover" wrote in message
...
|
| As Tom Van Flander has said, gravitational potential and gravitational
| force are
| two distinct concepts and as such their speeds does not have to be the
| same.
| As many published experiments have demonstrated, gravitational forces
| can not possibly
| propagate at c. I consider this as a scientific fact, indeed.

It's as silly as jumping into a swimming pool and asking how fast the
water pressure propagates.

Are you saying, for example, that what this astronomer is saying in
this discussion (speed of gravity) is based on fraud? Are you saying
that all experiments that this astronomer has conducted on speed of
gravity measurements are a fraud? If so, it is just your opnion and I
must say that no one can take you seriously unless you can show
evidence for your accusations. Accusing a scientist of fraud without
any proof just show us your anti-scientific posture.

By the way, I read his papers on the subject and I saw no apparent
fraud, quite the contrary. They were fairly conducted, in my opnion.

On 16 abr, 08:56, "Dirk Van de moortel" dirkvandemoor...@ThankS-NO-
SperM.hotmail.com wrote:
Prime Mover wrote in message

*





On 15 abr, 17:15, "DirkVande moortel" dirkvandemoor...@ThankS-NO-
SperM.hotmail.com wrote:
wrote in message


[This replies to "Koobee Wublee", Steve Carlip, andTomRoberts.]

"Koobee Wublee" writes:

[Wublee]: Claiming the speed of gravity exceeding the speed of light in
free space violates relative simultaneity as demanded by the Lorentz
transform and thus SR. Since GR is built on top of SR, GR is falsified in
the process.

Special relativity (SR) has now been falsified in favor of Lorentzian
relativity (LR). See Ref. [1] at end for a primer on LR:

Ref [1]:
http://metaresearch.org/solar%20syst...iles/proof.asp

Dirk Vdm

What does the mentioned link has to do with this discussion?

Fraud, mental condition, incompetence... take your pick.

Dirk Vdm- Ocultar texto entre aspas -

- Mostrar texto entre aspas -

Prime Mover wrote in message

On 16 abr, 08:56, "Dirk Van de moortel" dirkvandemoor...@ThankS-NO-
SperM.hotmail.com wrote:
Prime Mover wrote in message







On 15 abr, 17:15, "DirkVande moortel" dirkvandemoor...@ThankS-NO-
SperM.hotmail.com wrote:
wrote in message


[This replies to "Koobee Wublee", Steve Carlip, andTomRoberts.]

"Koobee Wublee" writes:

[Wublee]: Claiming the speed of gravity exceeding the speed of light in
free space violates relative simultaneity as demanded by the Lorentz
transform and thus SR. Since GR is built on top of SR, GR is falsified in
the process.

Special relativity (SR) has now been falsified in favor of Lorentzian
relativity (LR). See Ref. [1] at end for a primer on LR:

Ref [1]:
http://metaresearch.org/solar%20syst...iles/proof.asp

Dirk Vdm

What does the mentioned link has to do with this discussion?

Fraud, mental condition, incompetence... take your pick.

Dirk Vdm- Ocultar texto entre aspas -

- Mostrar texto entre aspas -

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.
What he is saying in
http://redshift.vif.com/JournalFiles...F/V10N1TVF.pdf
between pages 78 and 83 shows that he doesn't even understand
the basics of special relativity.
What he is saying in
http://users.telenet.be/vdmoortel/di...TVFSeries.html
shows that he has no idea about basic mathematics.

Take your pick - and stop top-posting.

Dirk Vdm




Are you saying
that all experiments that this astronomer has conducted on speed of
gravity measurements are a fraud? If so, it is just your opnion and I
must say that no one can take you seriously unless you can show
evidence for your accusations. Accusing a scientist of fraud without
any proof just show us your anti-scientific posture.

By the way, I read his papers on the subject and I saw no apparent
fraud, quite the contrary. They were fairly conducted, in my opnion.

Cosmik de Bris wrote on Wed, 16 Apr 2008 08:59:58 +1200:

You make bold statements without any explanation,

That is not true. But i repeat main points below.

you leave the
newsgroup when challenged on anything

That is not true.

I am not following open threads (except this one until its dead) on
sci.physics.relativity but, as said, i will continue posting research
stuff on sci.physics.research and sci.physics.foundations and, probably,
some informative poster. E.g. I promised to post a message about second
law of thermodynamics and evolution time ago and i will post when ready.

and you avoid answering Tom's
question.

Finally, that is also not true.

Tom did a very bold statement, he said that one cannot measure
gravitational forces. I did not asked him for a proof (i know Tom cannot
give one), but i asked him for something more simple: I asked Tom to
write the expression for the gravitational force.

If anyone here is making strong claims about electromagnetic forces i
wait from the same person to be able to write the force at least.

Is this such one unrealistic requirement for you?

Tom is just unable to write the gravitational force, because he never
studied a non-geometrical formulation to gravity. As usual, Tom Roberts
is doing strong claims about theories and he never studied nor even heard
about.

It makes no sense i waste time explain something about *measurements of
F* waiting a lot of misunderstanding and trivial queries from the other
part.

For instance, Tom gave an 'argument' (see two HINTs in his message of day
14) about why gravitational force cannot be measured. But his argument is
plain wrong.

I already waited misunderstanding of that kind becoming from Tom. Tom was
not aware that the force that some astronomers are working actually is
"coordinate independent".

Their famous 'challenges' are so boring...


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

Prime Mover wrote on Wed, 16 Apr 2008 05:00:07 -0700:

As Tom Van Flander has said, gravitational potential and gravitational
force are
two distinct concepts and as such their speeds does not have to be the
same.

That is right.

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

It has been theoretically also.

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.

That is right.



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

Prime Mover wrote on Wed, 16 Apr 2008 07:22:20 -0700:

Are you saying, for example, that what this astronomer is saying in this
discussion (speed of gravity) is based on fraud? Are you saying that all
experiments that this astronomer has conducted on speed of gravity
measurements are a fraud? If so, it is just your opnion and I must say
that no one can take you seriously unless you can show evidence for your
accusations. Accusing a scientist of fraud without any proof just show
us your anti-scientific posture.

Usual attacks here to Tom van Flandern belong to two categories:

(Technical)

E.g. publishing a rebuttal paper. Carlip submitted a paper about
aberration. But Carlip wrong paper was invalidated in more recent
publications (by Van Flandern and others) which have received no formal
reply neither from Carlip not from nobody else.

(Ad hominem)

That is, avoiding the central scientific topic and then just attacking
the man with a bunch of unrelated arguments. This is the case with the
poster who you are replying now.


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

Juan R. González-�lvarez wrote in message

Prime Mover wrote on Wed, 16 Apr 2008 07:22:20 -0700:

Are you saying, for example, that what this astronomer is saying in this
discussion (speed of gravity) is based on fraud? Are you saying that all
experiments that this astronomer has conducted on speed of gravity
measurements are a fraud? If so, it is just your opnion and I must say
that no one can take you seriously unless you can show evidence for your
accusations. Accusing a scientist of fraud without any proof just show
us your anti-scientific posture.

Usual attacks here to Tom van Flandern belong to two categories:

(Technical)

E.g. publishing a rebuttal paper. Carlip submitted a paper about
aberration. But Carlip wrong paper was invalidated in more recent
publications (by Van Flandern and others) which have received no formal
reply neither from Carlip not from nobody else.

(Ad hominem)

That is, avoiding the central scientific topic and then just attacking
the man with a bunch of unrelated arguments. This is the case with the
poster who you are replying now.


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

Juanita follows guidelines:
http://users.telenet.be/vdmoortel/di...uidelines.html

Dirk Vdm

--
This message is brought to you by Androcles
http://www.androcles01.pwp.blueyonder.co.uk/

"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?

Yes.


| Are you saying
| that all experiments that this astronomer has conducted on speed of
| gravity measurements are a fraud?

Yes.

| If so, it is just your opnion and I
| must say that no one can take you seriously unless you can show
| evidence for your accusations. Accusing a scientist of fraud without
| any proof just show us your anti-scientific posture.


That's just your opinion and I must say that no one can take you seriously
unless you can show evidence for your accusations. Accusing a whistle blower
of false accusations without any proof just show us your illogical posture.

Juan R. González-�lvarez wrote:
Tom did a very bold statement, he said that one cannot measure
gravitational forces. I did not asked him for a proof (i know Tom cannot
give one), but i asked him for something more simple: I asked Tom to
write the expression for the gravitational force.

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).

Why is it you cannot do this, and only give objections, evasions, and
insults?

[Underlying this is the knowledge that if it were possible to
actually measure this, then GR could not possibly model
gravitation as geometry. That is, if Juan R. or anybody
else could actually meet this challenge, that would completely
undermine the foundations of GR. To date nobody has ever done
that. Juan R. is full of big words and insults, but somehow
has not been able to actually support his own claims.]


BTW in the context of GR there is indeed a simple proof that
"gravitational force" cannot be measured:

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). Inherently, any measurement is an
invariant (i.e. is independent of any coordinate choice). The above
"gravitational force" is NOT invariant, and thus cannot be identified
with any measurement.

Note that real forces, such as electromagnetism, can
always be expressed in an invariant way:
f_i = q F_jk U^k
where F is the Faraday 2-form, q and U are the charge and
4-velocity of the object. Unlike the above equation, this
is a tensor equation, and here f is a 4-vector (and thus
invariant).


Cosmik de Bris wrote to Juan R.:
and you avoid answering Tom's
question.

Juan R. replied:
Finally, that is also not true.

This is TRIVIALLY false, which anybody can easily verify: nowhere in
this thread have you answered my question/challenge, and you have
clearly "avoided" answering by replying only with objections, delays,
evasions, and insults.

Please answer it.


Tom Roberts

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.


Tom Roberts