sci.physics.relativity

On Feb 21, 1:43 am, "Juan R." Gonz=E1lez-=C1lvarez
wrote:
> Eric Gisse wrote on Thu, 21 Feb 2008 01:59:50 -0800:
>
> A) Note that i am not following guidelines in this thread (see bottom
> part of of my messages).

Note that I have always ignored your guidelines and will continue to
do so.

>
> B) Note i am just replying you for fun *now* (see point A). I am working
> hard on a paper since last week and i need some diversion.
>
> C) Note i will not reply your usual nonsenses in a future when I was
> again following guidelines and just waiting sensical answers.
>
> D) I am clever enough to know you will fail to understand this.

Do you ever worry about overflow when you are that full of yourself?

>
> >> 1) Explicit expression for non-geometrical "coordinate forces" [#] in
> >> terms of gravitational potentials for the specific case of time-
> >> orthogonal system of coordinates.
>
> > Reformulate your question to a more meaningful expression.
>
> > In pure GR, there are no "non-geometrical 'coordinate force' " since all=

> > the effective forces are geometric in nature.
>
> A) "pure GR" is written zero (0) times on 1). You start doing
> assumptions. Bad start...

Why? My statement isn't true in general.

>
> B) "1)" contains a note labelled [#]. Usually this mean reader would go
> to an endnote and read it. You did not. I copy and paste it here
>
> [#] This is usual name in literature, including that by celestial
> mechanicists and astronomers. Therefore do not repeat the old mistake
> of blaming about geometry...
>
> C) "This is usual name in literature" . You never read, ok. But then do
> not reply something where you are a clear ignorant

I did read it...

>
> D) The note also says "do not repeat the old mistake of blaming about
> geometry..." but you ignored and repeat the mistake.

=2E..but I didn't care.

Look, all the quantities that can be called "forces" in GR are results
of the geometry. There is no avoiding that. If you want to clump
everything that affects the motion of a particle, take everything
other than d^2x^i / d\tau^2 in the geodesic equation and call it
"force". Just be prepared to deal with the eventual complaint that
those are not real forces just like the Coriolis force isn't an actual
force.

>
> >> 2) What experiments confirm geometric GR and invalidates
> >> non-geometrical GR? some time ago Roberts tried to convince us that
> >> curved spacetime had been measured...
>
> > Your question is nebulous enough to be meaningless. There are dozens of
> > non-GR theories of gravitation - you have to be more specific. If you
> > want an explanation of why a certain CLASS of theories are excluded by
> > observation while confirming GR, be more specific.
>
> Clear like pure water: "What experiments confirm geometric GR and
> invalidates non-geometrical GR?"

What part of my request to be more specific confuses you? "non-
geometrical GR" is too broad of a subject.

>
> >> 3) Write the *full* relativistic N-body equation of motion for bodies
> >> under gravity.
>
> > G_uv =3D R_uv - 1/2 R g_uv =3D 8piG/c^2 sum n=3D1...N m U_u U_v [where t=
here
> > is a sum over m_i masses].
>
> ha, ha, ha, ha, ha, ha, this was very good one.
>
> I repeat again: "Write the *full* relativistic N-body equation of motion
> for bodies under gravity."

I did. The field equations determine the system.

>
> >> 4) Equation of motion in field GR and differences with geometric GR. By=

> >> commodity works on weak fields.
>
> > GR is a geometric field theory. There is no difference.
>
> And if had one you would not notice it, therefore may a correct reply
> from your personal perspective. I will be benevolent with this one.
>
> >> 5) Non-relativistic limit of GR geodesic. Or more easy geodesic
> >> equation for linearized GR.
>
> > Open up Wald and look - you have referenced Wald before so I know you
> > have it. OTOH, you didn't understand Wald the last time you referenced
> > Wald, so I dunno.
>
> and close it and then ask again. "Non-relativistic limit of GR geodesic.
> Or more easy geodesic equation for linearized GR."

Open it up and look. Why do you ask questions whose answers are within
easy reach? Writing the geodesic equation for linearized GR is only a
test of someone's knowledge if you ask them to derive it in front of
you.


>
> >> 6) What is the 'speed' of gravity (and why?).
>
> > Open up Wald, MTW, Carroll, D'Inverno, etc and look. Perturbations
> > propagate at c. If you want a non-perturbative answer, you'll have to
> > re-formulate your question since it isn't meaningful to ask how "fast"
> > gravity goes.
>
> "6) What is the 'speed' of gravity (and why?)."

c - because that's how fast perturbations propagate.

>
> >> > David A. Smith
>
> >> In advance, thanks by all clever knowledge we will receive from you.
>
> >> [#] This is usual name in literature, including that by celestial
> >> mechanicists and astronomers. Therefore do not repeat the old mistake
> >> of blaming about geometry...