torstai 11. toukokuuta 2023 klo 0.22.05 UTC+3 Chris M. Thomasson kirjoitti:
> On 5/3/2023 10:31 PM, Hannu Poropudas wrote:
> > keskiviikko 3. toukokuuta 2023 klo 18.56.17 UTC+3 Tom Roberts kirjoitti:
> >> On 5/3/23 5:58 AM, Hannu Poropudas wrote:
> [...]
> > Please take a look two analytic General Relativity solutions of
> > S2-star orbits ( SgrA* Black Hole) mine from above mentioned posting chain.
> > (Maple 9 program codes (two solutions are primitive functions in parametric form)
> > and they can be copy pasted into Maple and run in Maple programs and
> > see this REAL GR PROBLEM.)
> What about the great attractor?

I do not know definition of this great attactor you asked, but
if you meant center of Metagalaxy ?

I do not know where is the center of the Metagalaxy (= center of the space?)?
Center of the Universe does not exist but center of the space exist and it is well
hidden as I have understood. This is not accepted in the standard cosmology.

I have made analytic solution of Freedmann's equation of the standard cosmology,
but there is no center of the space accounted due assumptions made of our
standard cosmology.

I have posted this analytic solution also in this sci.physics. relativity
Google Groups some years ago.

I used in that analytic solution Planck Satellite 2013 results as numerical
values of initial parameters.

Best Regards,
Hannu Poropudas

On 5/11/2023 5:39 AM, Hannu Poropudas wrote:
> torstai 11. toukokuuta 2023 klo 0.22.05 UTC+3 Chris M. Thomasson kirjoitti:
>> On 5/3/2023 10:31 PM, Hannu Poropudas wrote:
>>> keskiviikko 3. toukokuuta 2023 klo 18.56.17 UTC+3 Tom Roberts kirjoitti:
>>>> On 5/3/23 5:58 AM, Hannu Poropudas wrote:
>> [...]
>>> Please take a look two analytic General Relativity solutions of
>>> S2-star orbits ( SgrA* Black Hole) mine from above mentioned posting chain.
>>> (Maple 9 program codes (two solutions are primitive functions in parametric form)
>>> and they can be copy pasted into Maple and run in Maple programs and
>>> see this REAL GR PROBLEM.)
>> What about the great attractor?
>
> I do not know definition of this great attactor you asked, but
> if you meant center of Metagalaxy ?
>
> I do not know where is the center of the Metagalaxy (= center of the space?)?
> Center of the Universe does not exist but center of the space exist and it is well
> hidden as I have understood. This is not accepted in the standard cosmology.
>
> I have made analytic solution of Freedmann's equation of the standard cosmology,
> but there is no center of the space accounted due assumptions made of our
> standard cosmology.
>
> I have posted this analytic solution also in this sci.physics. relativity
> Google Groups some years ago.
>
> I used in that analytic solution Planck Satellite 2013 results as numerical
> values of initial parameters.

The great attractor in our local group:

https://en.wikipedia.org/wiki/Great_Attractor

On 5/9/23 3:28 PM, Volney wrote:
> On 5/7/2023 12:04 PM, Tom Roberts wrote:
>> Bottom line: 'r' and 't' are just LABELS, and the "switch" you
>> mention is merely due to the way the coordinates happened to be
>> labeled.
>
> So r and t inside cannot be the same as r and t outside?

Hmmm. The geometry of the Schw. manifold differs greatly between inside
and outside the horizon. So "the same" does not hold at all, no matter
how you label the coordinates.

> My thought experiment [...]

No instrument ever measures a coordinate, it measures some physical
distance, some physical time, or some other physical value. You can
choose to use coordinates corresponding to what various instruments
measure, but that is quite different from what you said.

>> For the usual Schw. coordinates on Schw. spacetime: Outside the
>> horizon: d/dt is a future pointing timelike coordinate axis d/dr is
>> spacelike, as are d/dtheta and d/dphi Inside the horizon: -d/dr is
>> a future pointing timelike coordinate axis
>
> Yes meaning you're heading to the singularity no matter what, no r
> away from the singularity. Is it just timelike or is it really like
> the time coordinate outside the hole?

Inside the horizon, in the usual Schw. coordinates, r is timelike. It is
nothing like the usual time coordinate, which we usually select so it
corresponds to a Killing vector (because the manifolds we consider are
usually static, and virtually always stationary). But inside the
horizon, Schw. spacetime is neither static nor stationary.

stationary = there is a timelike Killing vector
static = stationary and there is a 3-d space
orthogonal to the timelike Killing vector

>> At the horizon: these coordinates are invalid and cannot be used
>
> What happens upon crossing? Does the clock explode? :-)

No. A clock simply continues ticking off its proper time. There is no
local experiment that can determine the location of the horizon;
observations of distant stars can do so. Because no clock is measuring
the Schw. time coordinate, it is measuring its own proper time.

Tom Roberts

On Friday, 12 May 2023 at 22:09:02 UTC+2, Tom Roberts wrote:
> On 5/9/23 3:28 PM, Volney wrote:
> > On 5/7/2023 12:04 PM, Tom Roberts wrote:
> >> Bottom line: 'r' and 't' are just LABELS, and the "switch" you
> >> mention is merely due to the way the coordinates happened to be
> >> labeled.
> >
> > So r and t inside cannot be the same as r and t outside?
> Hmmm. The geometry of the Schw. manifold differs greatly between inside
> and outside the horizon. So "the same" does not hold at all, no matter
> how you label the coordinates.
>
> > My thought experiment [...]
>
> No instrument ever measures a coordinate

Wrong, poor halfbrain. If your clock indicates
2023-05-13 17:49 - what do you think it is?