The sea of galaxies comes slowly into view

In article , jacobnavia
writes:

Because we have been told by big bang proponents that the early galaxies
were quite small!

Assuming this is true, it was a guess, but IS RELATED TO GALAXY
FORMATION AND NOT TO THE BIG BANG PER SE.

Even if there are surprises, problems, whatever with galaxy formation,
why do you then conclude that the idea of the big bang is wrong?

At what z we will still accept that the theory has not been rejected by
observations?

When a DEFINITIVE prediction has been convincingly falsified.

I suppose that when we find old and dusty galaxies at z=7 the bang will
(hopefully) go away.

Why hopefully? Do you have an axe to grind?

So, the authors arrive at the conclusion that in a few hundred million
years the massive galaxies appear out of the blue. That is quite a
bitter pill to swallow... how can those massive galaxies appear almost
instantaneously?

A few hundred million years is not instantaneous, not even within the
context of galaxy formation.

You (may) know that any frontal attack of big bang theory provokes a
banning of the concerned astronomer.

Some see it that way, but it is usually not true. Halton Arp wrote a
book where he challenges conventional cosmology, including the big bang,
in a quite aggressive manner. The dust-jacket flap said "He is on the
staff of the Max Planck Institute for Astrophysics". I'm sure any
astronomer would be perfectly happy at being banned to a Max Planck
Institute.

Plese note that a single OLD galaxy at z=8 or 9 suffices to disprove big
bang theory.

[[Mod. note -- Actually, a single OLD galaxy at z=8 or 9 *might*
(a) disprove big bang theory, and/or
(b) it might disprove whatever combination of theoretical models
and observation that were used to infer that the galaxy was "old".

Given our poor state of knowledge about early-universe galaxy
formation/evolution, (b) doesn't seem implausible to me.
-- jt]]

Or it could falsify some theory of galaxy formation.

In article ,
"Robert L. Oldershaw" writes:

1.How can one say that "Dark matter is a firm prediction" if one
does not have any idea of what it specifically is, far less any
shred of empirical evidence for any member of the zoo of pop
candidates?

Read up on the history of dark matter. THAT it exists is pretty firm.
In what exact form is an open question.

2. It is quite incorrect to say that only those interested in fractal
modeling have investigated inhomogeneity in the cosmological context.
If you do a search at arXiv.org on "cosmological inhomogeneity" or
"large-scale inhomogeneity" you will find many papers, and most are
not specifically linked to fractal modeling.

Not all large-scale inhomogeneity is concerned with inhomogeneity on a
scale so large that it challenges the idea of a universe which is
homogeneous on large scales, whereas fractal ideas by definition do.

On 11/27/2015 7:28 AM, jacobnavia wrote:
Le 26/11/2015 09:34, Jos Bergervoet a e(C)crit :
On 11/25/2015 1:11 AM, jacobnavia wrote:
Le 23/11/2015 19:37, jacobnavia a e(C)crit :
So how do we know that 750 My isn't enough time?

Dust. That needs billions of years to be

a) Produced in stars
Why? It was produced 3 minutes after the big bang (look up
nucleosysnthesis). Only after that material was used up,
the need arose for more dust created by stars.

...
According to popular legend (wikipedia)
...
No word of DUST, I am sorry. Hydrogen and Helium aren't dust!

Why not? Gas or dust, it's fine to condense into stars,
and stars will form your galaxies (how exactly is not known,
so you can't say they won't!) It is up to you to prove that
in a universe loaded with gas, you will *not* have extremely
fast galaxy formation. Others explicitly say they do not
fully understand galaxy formation, you are the one making
claims about it.

--
Jos

http://www.eso.org/public/archives/r...5/eso1545a.pdf

In article ,
jacobnavia writes:
By the way, the mass of our galaxy is around 6.42*10^42 Kg. Twice that
is around 1.3*10^43 Kg.

5E10 solar masses is about 1E41 kg. Simpler to use units of Msun and
years.

Each second that galaxy must accrete around 10^27 Kg, around a solar
mass per 20 minutes... And that rate must be sustained without stop!

The original article doesn't estimate star formation rates unless I
missed it. Other _observed_ high-z galaxies typically have SFRs in
the range 10-1000 Msun/yr. Readers can work out how long it would
take at those rates to form a galaxy with 2E11 solar masses.

There's also a question of redshift accuracy. Readers should have a
close look at Table 3 of the article and also the text justifying the
claim of z5, which doesn't seem entirely convincing to me.

And the problem is not even there. The problem is that the article says
that there are MORE galaxies BEHIND!!!!

A subsequent post repeats this position, but I think it's a mis-
reading of the article. Readers can decide for themselves.

I remember the times when Big Bang proponents said that all far away
galaxies were small...

I don't know about "all," but most high-z galaxies have small linear
sizes. Masses have a wide range, but measurements are reliable only
for the most massive galaxies.

--
Help keep our newsgroup healthy; please don't feed the trolls.
Steve Willner Phone 617-495-7123
Cambridge, MA 02138 USA

[[Mod. note -- ((The author surely knows this, but others may not.))
It's important not to confuse the rate at which new stars are formed
in a galaxy which already exist (this is usually called the galaxy's
"star formation rate", and of course varies with time and across
galaxies) with the rate or timescale in which a new galaxy forms.
-- jt]]

I wrote:
No word of DUST, I am sorry. Hydrogen and Helium aren't dust!

Le 27/11/2015 20:27, Jos Bergervoet a écrit :
Why not?

Because dust is formed by two types of material: silicates and
carbonaceous dust particles, not H or He!

I am preparing a complete literature review of dust, dust formation, and
the corresponding time scales. As far as I can see, the dust argument is
not going to go away. Until I send a literature review here however, I
will abstain from further comments about dust.

jacob

On Friday, November 27, 2015 at 2:27:07 PM UTC-5, Phillip Helbig (undress t=
o reply) wrote:

=20
Read up on the history of dark matter. THAT it exists is pretty firm. =20
In what exact form is an open question.
=20

So are you saying that we have good reason to believe that most of
the matter of the cosmos is in a form that can be detected via
gravitational effects, unless there is something about matter,
gravitation or fundamental modeling assumptions that we are not
aware of, but we have no idea what it is, and a history of 40 years
of failure to find the most fashionable candidates?

That is your idea of a "firm prediction"? I would say it is more
of an indication that our understanding of the cosmos is extremely
limited. Not to mention grossly over-hyped.

I have studied all aspects of dark matter physics in great detail
-especially its history, thank you very much.

RLO
Fractal Cosmology

[[Mod. note -- ###
we have good reason to believe that most of
the matter of the cosmos is in a form that can be detected via
gravitational effects, unless there is something about matter,
gravitation or fundamental modeling assumptions that we are not
aware of

Yes.


but we have no idea what it is

Not quite -- we have some constraints on what it might be
(e.g., it's not "stuff that would emit visible light that would have
been detected by now")

and a history of 40 years
of failure to find the most fashionable candidates?

Yes.
-- jt]]

On Tuesday, November 24, 2015 at 5:11:44 PM UTC-7, jacobnavia wrote:
....
By the way, the mass of our galaxy is around 6.42*10^42 Kg. Twice that
is around 1.3*10^43 Kg.

From the rotation curve, the velocity is about 220 km/sec at 30 kpc.
From M = r*v^2/G, I get 6x10^41 kg. Of course, that depends on what
we use for r. The curve is still pretty flat beyond 50 kpc, but to get
your number, it would have to be flat to 300 kpc.
Did I make an order of magnitude mistake or did you?

Gary

Le 28/11/2015 19:47, Gary Harnagel a écrit :
On Tuesday, November 24, 2015 at 5:11:44 PM UTC-7, jacobnavia wrote:
....
By the way, the mass of our galaxy is around 6.42*10^42 Kg. Twice that
is around 1.3*10^43 Kg.

From the rotation curve, the velocity is about 220 km/sec at 30 kpc.
From M = r*v^2/G, I get 6x10^41 kg. Of course, that depends on what
we use for r. The curve is still pretty flat beyond 50 kpc, but to get
your number, it would have to be flat to 300 kpc.
Did I make an order of magnitude mistake or did you?

Gary



Mmmm see:
http://www.universetoday.com/22790/m...the-milky-way/

That number is based on the SDSS data...

Interesting.

Why does your method say 10 times less??????

I do not know.

jacob

On Saturday, November 28, 2015 at 3:35:57 PM UTC-7, jacobnavia wrote:

Le 28/11/2015 19:47, Gary Harnagel a =E9crit :

On Tuesday, November 24, 2015 at 5:11:44 PM UTC-7, jacobnavia wrote:
....
By the way, the mass of our galaxy is around 6.42*10^42 Kg. Twice th=
at
is around 1.3*10^43 Kg.

From the rotation curve, the velocity is about 220 km/sec at 30 kpc.
From M =3D r*v^2/G, I get 6x10^41 kg. Of course, that depends on what
we use for r. The curve is still pretty flat beyond 50 kpc, but to get
your number, it would have to be flat to 300 kpc.
Did I make an order of magnitude mistake or did you?

Gary
=20
Mmmm see:
http://www.universetoday.com/22790/m...the-milky-way/
=20
That number is based on the SDSS data...
=20
Interesting.
=20
Why does your method say 10 times less??????
=20
I do not know.
=20
jacob

For one thing, they took a radius of 300k light years and I only used
100K. There's a factor of three, although I'm not sure how they found
enough normal matter out there to confirm its velocity. The uncertainty
in the velocity of the Magellanic clouds is quite significant, for
example, the LMC at about 150,000 L-yrs is 281 +/- 41 km/sec:

http://arxiv.org/pdf/astro-ph/0404192v1.pdf

which is higher than the 220 km/sec of the disc at 100,000 l-yrs. Perhaps
the Universe Today quoted a number based on the velocities of other
satellite galaxies beyond the LMC. 300,000 L-yrs is one sixth of the way
to Andromeda. Ii may be that significant matter exists well beyond that
distance, perhaps bridging the gap between Andromeda and the Milky Way so
that there is no cutoff for size (other than where the velocities of
objects are circling Andromeda rather than the MW).

Gary

On Thursday, November 26, 2015 at 12:34:56 AM UTC-8, Jos Bergervoet wrote:
On 11/25/2015 1:11 AM, jacobnavia wrote:
Le 23/11/2015 19:37, jacobnavia a =E9crit :
there wasn't any "creation moment" 13.7 Gy ago.
=20
But if we go backwards in time we see galaxies receding
towards each other, so what kind of singularity do you
think there was, if it wasn't the concordance big bang?

Personally, I think that some other brane crashed into ours, and
some of the impact energy got transferred inside our brane as the
initial, early state of matter that quickly decayed down to the
current state of matter.

(And no, I don't understand the state of matter decay concept.)

=3D=3D=3D

Side note: From what I've read/understood, one of the tests to
distinguish a big-bang universe, where space actually expands as
matter spreads out, from a "Brane impact" universe, where space has
already existed as matter spreads out, is the density of the residual
gravity waves -- big bang would have more. So once we can actually
measure them accurately, this should become a testable idea.