Distribution of observed galaxies in early universe

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Lou

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May 23, 2022, 3:48:51 AMMay 23
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There is one very big question that Big Bang theorists do not seem to
have addressed. And if I could get some feedback on this point. Look at
galaxy distribution in our local universe. Now compare it to the very
earliest universe we can image in the Hubble deep field observations.
They seem to have the same distance between galaxies that we have
locally? And the galaxies seem to,be the same size and maturity as those
seen locally.

How is this possible? If galaxies are said to spread apart with
expansion then galaxy distribution observed now,...and reversed 13
billion years should give us an image of galaxies that should be much
closer together in the Hubble deep field. Seeing as the space between
them has supposed to have expanded for 13 billion years since the BB.

Phillip Helbig (undress to reply)

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May 23, 2022, 2:23:57 PMMay 23
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In article <4fce0bdc-eb71-4473...@googlegroups.com>, Lou
<noeltu...@live.co.uk> writes:

> There is one very big question that Big Bang theorists do not seem to
> have addressed. And if I could get some feedback on this point. Look at
> galaxy distribution in our local universe. Now compare it to the very
> earliest universe we can image in the Hubble deep field observations.
> They seem to have the same distance between galaxies that we have
> locally?

How do you judge this? Distance between galaxies in units of galaxy
size? But what if both were smaller? Or both larger?

Also, keep in mind projection effects. Typical photos of nearby
galaxies usually show several all at more or less the same distance,
which is not the case in the Hubble Deep Field.

> And the galaxies seem to, be the same size and maturity as those
> seen locally.

You need to quantify this. Most experts would disagree.

> How is this possible? If galaxies are said to spread apart with
> expansion then galaxy distribution observed now,...and reversed 13
> billion years should give us an image of galaxies that should be much
> closer together in the Hubble deep field. Seeing as the space between
> them has supposed to have expanded for 13 billion years since the BB.

Gravitationally bound objects do not expand with the expansion of the
Universe. (It's complicated, but to first order there is no effect.)
For example, the size of the Solar System doesn't increase with the
expansion of the Universe. Neither does the Earth.

Eric Flesch

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May 25, 2022, 7:48:58 PMMay 25
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On 23 May 2022 08:48:49 +0100 (BST), Lou <noeltu...@live.co.uk>
wrote:
> If galaxies are said to spread apart with expansion
> then galaxy distribution observed now,...and reversed 13 billion
> years should give us an image of galaxies that should be much
>closer together in the Hubble deep field.

Remembering that we see back 13 billion years in every direction, your
point boils down to that we should see those early galaxies as larger
on the sky. But their surface brightness is very faint at the
distance so we would be seeing their brightest cores only. I'm not
defending the BB model, but I'm pretty sure it accomodates your point.

However, way back in 1993, Nilsson et al (ApJ 413,453) showed in their
Figure 5 that the apparent size of radio lobes decreases linearly with
redshift, as though the universe is endless flat space. Nilsson
commented about this: "The crucial assumption here is that the linear
size-redshift correlation, if it exists, can be neglected". To my
knowledge, this linear correlation has not been refuted
observationally to the present day.

Phillip Helbig (undress to reply)

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May 26, 2022, 9:00:48 AMMay 26
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In article <628ddeb3....@news.aioe.org>, er...@flesch.org (Eric
Flesch) writes:

> On 23 May 2022 08:48:49 +0100 (BST), Lou <noeltu...@live.co.uk>
> wrote:
> > If galaxies are said to spread apart with expansion
> > then galaxy distribution observed now,...and reversed 13 billion
> > years should give us an image of galaxies that should be much
> >closer together in the Hubble deep field.
>
> Remembering that we see back 13 billion years in every direction, your
> point boils down to that we should see those early galaxies as larger
> on the sky.

Not sure what you are referring to hear. In general, angular size is
not inversely proportional to distance. In some cosmological models it
has a minimum (i.e. the angular-size distance has a maximum).

> But their surface brightness is very faint at the
> distance so we would be seeing their brightest cores only.

Right.

> I'm not
> defending the BB model, but I'm pretty sure it accomodates your point.

Indeed. "The size of a galaxy" is not very well defined, certainly not
in any way which can be valid at greatly different redshifts.

> However, way back in 1993, Nilsson et al (ApJ 413,453) showed in their
> Figure 5 that the apparent size of radio lobes decreases linearly with
> redshift, as though the universe is endless flat space. Nilsson
> commented about this: "The crucial assumption here is that the linear
> size-redshift correlation, if it exists, can be neglected". To my
> knowledge, this linear correlation has not been refuted
> observationally to the present day.

Kellerman claimed around the same time that he saw the minimum in the
angular size. Several papers showed that his analysis was flawed. With
regard to Nilsson et al., that conclusion---even if it holds
up---depends on the lack of evolution; in other words, one needs a
"standard rod".

In any case, several lines of evidence have converged on what is now
known as the concordance model of cosmology. We know the parameters
well enough that we can calculate the dependence of observable
quantities on redshift. If something deviates from that, we can be
pretty sure that evolution is involved, not that the concordance model
is wrong.

Eric Flesch

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May 27, 2022, 5:00:50 AMMay 27
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On Thu, 26 May 2022 06:00:43 PDT, hel...@asclothestro.multivax.de
(Phillip Helbig (undress to reply)) wrote:
>er...@flesch.org (Eric Flesch) writes:
>> To my knowledge, this linear correlation has not been refuted
>> observationally to the present day.
>
> With regard to Nilsson et al., that conclusion---even if it holds
> up---depends on the lack of evolution; in other words, one needs a
>"standard rod".

Not at all, it's purely observational, no models involved.

>In any case, several lines of evidence have converged on what is now
>known as the concordance model of cosmology. We know the parameters
>well enough that we can calculate the dependence of observable
>quantities on redshift. If something deviates from that, we can be
>pretty sure that evolution is involved, not that the concordance model
>is wrong.

If the concordance model requires evolution to replicate a simple
inverse angular size - redshift relationship which is observationally
supported, then surely that is evidence against the model.

Phillip Helbig (undress to reply)

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May 27, 2022, 1:59:02 PMMay 27
to
In article <62907f14....@news.aioe.org>, er...@flesch.org (Eric
Flesch) writes:

> On Thu, 26 May 2022 06:00:43 PDT, hel...@asclothestro.multivax.de
> (Phillip Helbig (undress to reply)) wrote:
> >er...@flesch.org (Eric Flesch) writes:
> >> To my knowledge, this linear correlation has not been refuted
> >> observationally to the present day.
> >
> > With regard to Nilsson et al., that conclusion---even if it holds
> > up---depends on the lack of evolution; in other words, one needs a
> >"standard rod".
>
> Not at all, it's purely observational, no models involved.

If you say "just like in flat space", then that flat space is a model.
If you observe the expectation for flat space, then that expectation
depends on the objects being standard rods, i.e. the intrinsic size
doesn't depend on redshift. Even assuming that the angular size
decreases linearly with redshift, what does that prove? It can't be
consistent with any expectation unless one has a model for the evolution
(which might be evolution) and a model for spacetime (which might be
Minkowski space).

> >In any case, several lines of evidence have converged on what is now
> >known as the concordance model of cosmology. We know the parameters
> >well enough that we can calculate the dependence of observable
> >quantities on redshift. If something deviates from that, we can be
> >pretty sure that evolution is involved, not that the concordance model
> >is wrong.
>
> If the concordance model requires evolution to replicate a simple
> inverse angular size - redshift relationship which is observationally
> supported, then surely that is evidence against the model.

Why? It would be evidence against it only if we had independent
evidence that there is no evolution, and also independent evidence of
what the expectation is. Also, when several different tests converge on
the same result (hence the term "concordance cosmology"), it takes a
huge leap of faith to assume that one contradictory test rules out that
model. Yes, that one test might be correct and all the others wrong,
but then one has to explain why they were wrong and why they were all
wrong in the same way.
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