More trouble for big bang theory

Le 05/11/11 11:09, Phillip Helbig---undress to reply a écrit :
In , "Robert L.
writes:

Perhaps the simplest and most direct test of the conventional Big Bang
scenario would be the presence or absence of galaxies at z 10.


UDFj-39546284 is at z = 10 already...
480 million years after the big bang.

In their discovery article the astronomers mention a candidate at
z=10.3.

Luckily for BB Theory, the JWST is in danger... A monster scope
like that could detect galaxies at distances even farther away!

In article , jacob navia
writes:

Le 05/11/11 11:09, Phillip Helbig---undress to reply a écrit :
In , "Robert L.
writes:

Perhaps the simplest and most direct test of the conventional Big Bang
scenario would be the presence or absence of galaxies at z 10.


UDFj-39546284 is at z = 10 already...
480 million years after the big bang.

In their discovery article the astronomers mention a candidate at
z=10.3.

It's important to keep in mind that in terms of time, the difference
between z=10 and z=11 is much less than between z=0 and z=1. Also,
element synthesis depends on time but not on redshift (i.e. the size of
the universe). (In the very early universe, it depends on density which
of course depends on the size of the universe, but then again in the
very early universe there is a simple relation between density, redshift
and time regardless of the values of the cosmological parameters (since
in the very early universe the behaviour is very close to Einstein-de
Sitter).)

The correct thing to do is to set a lower limit for the AGE of the
universe for a certain metallicity to be obtained then convert this into
the corresponding redshift for the appropriate values of the
cosmological parameters.

On Nov 8, 7:31*am, Phillip Helbig---undress to reply
wrote:
In article , jacob navia

writes:
Le 05/11/11 11:09, Phillip Helbig---undress to reply a écrit :
In , "Robert L.
*writes:

Perhaps the simplest and most direct test of the conventional Big Bang
scenario would be the presence or absence of galaxies at z *10.

UDFj-39546284 is at z = 10 already...
480 million years after the big bang.

In their discovery article the astronomers mention a candidate at
z=10.3.

It's important to keep in mind that in terms of time, the difference
between z=10 and z=11 is much less than between z=0 and z=1. *Also,
element synthesis depends on time but not on redshift (i.e. the size of.......
---------------------------------------------------------------------------------

Let me try one last time to squeeze a definitive prediction out of
standard cosmology proponents.

At some value of z, the standard cosmological model should comfortably
and definitively predict that no galaxies should exist. Allowing a
reasonable amount of wiggle room, there should be a *lowest* z value
for the non-existence of galaxies.

I remember a time galaxies at z = 8 were surprising.
Now the lowest z must be 10.

Where is the "line in the sand" beyond which the existence of galaxies
would require major rethinking of cosmological assumptions?

RLO
Fractal Cosmology

Le 06/11/11 10:46, eric gisse a écrit :
jacob wrote in news:mt2.0-6983-1320480432
@hydra.herts.ac.uk:

Le 04/11/11 07:03, eric gisse a ecrit :
Steve wrote in
:

In ,
jacob writes:
"metal" rich galaxies incompatible with any bing bang
that would have happened only 1.7 billion years earlier.


http://www.eso.org/public/archives/r...s/eso1143/eso1
143.pdf

There's a big difference between "a surprise" on the one hand and
"incompatible" on the other. As Thomas mentioned, the timescale for
one generation of stars is 10-100 Myr, so there's plenty of time for
enrichment, especially if the IMF is top-heavy.

Its' gotta be.

Sure, if not, BB is doomed Oh catastrophe :-)

Maybe if the subject wasn't so foreign to you, the notion of stars being
more massive in the past wouldn't be so surprising?


Yes, I am aware of that. I am even aware that stars have an upper mass
limit of around 150 M0 can you imagine that?

http://www.nature.com/nature/journal...050310-04.html

For *some* reason, stars will not go beyond that even if the conditions
would allow for stars around 500 M0.

You postulate however that in the "young" universe this limit doesn't
apply?


What happened?

We are looking essentially at a random sample of galaxies 12 billion
years ago. At that time a quasar happened to exist that pointed
exactly in the direction where 12 billion years later a star would
pass, that had a small rocky planet that happened to have the right
position at the end of northern summer so that the light of that
quasar hits the CCD of the VLT after all those billion years of
journey.

There are SO many factors that happen to collaborate in making that
CCD point to that quasar (not only astronomical but also political,
the EU decided many years ago to build that VLT, those humans decided
to study astronomy etc) that it s essentially random.

And we hit two galaxies very rich in heavy elements. Just like that.

If we assume that having more heavy elements than our own sun would be
NORMAL for galaxies 12 billion years ago then ALL galaxies NOW should
have even MORE heavy elements since those elements do not go away but
accumulate with time. What would be extraordinary would be to find
heavy elements poor galaxies!!!

Did you know that different stars have different lifetimes and different
galaxies have different masses and all that together means there's a
wide spectrum of metalicity for galaxies?

Solar metalicitity, for example, only requires a few generations of
stars to generate. It isn't that hard to kick past that.


The light of that GRB passed through clouds of material in two galaxies
at high red shift. "A few generations" are required yes, but then you
need more time to disperse the material into those clouds. And you need
enough material to enrich them in Zinc more than the solar
concentration.


But they exist those metal poor galaxies not THAT far away from my
home. For instance I Zw 018, (UGCA 166) at only 20.98 Mpc.

Why?

If already 12 billion years ago a random sample of two galaxies
has more heavy elements than our own sun why hasn't this galaxy gotten
more of that?

Because this galaxy isn't as rich of a star former as other, more
massive, galaxies.

[snip quotemining]


With that "quotemining" I proved that many astronomers thought that
low "metallicity" meant younger galaxies since it was asked how did
I justify my belief that there was an association between low
metallicity and galaxy age.

I brought those citations to prove that astronomers expected lower
"metall" content in youger galaxies.


Here again we have the association of low metallicity with young
galaxies

So, it is not that fair to say now that there is no association of
low "metallicity" (what a terminology) and age of a galaxy.

You not understanding what the word means does not make it an odd word.


Well, if you speak to any chemist and treat carbon as a "metall" you
will get bad marks... I am a biochemist by training, sorry.

I understand in astronomy you call all elements heavier than helium
"metalls", it was that it collides with chemistry where that word is
used differently as you may know.

But this is just a distraction, let's close it.


Since all galaxies at 12 billion years are very young (less than
1Gy) it would be normal that a stupid layman like me would assume
that a high metallicity would be a surprise.

The article I quoted says:

quote
The column density NZn II = 1013.57±0.04 cm−2 in G1 is also among
the
highest ever inferred, with other systems of comparable density all
residing at z 2.9. The large column densities in G1 would indicate
the
galaxy to be massive and/or metal rich. At this high redshift, this
would make G1 a rare object.
end quote

"A RARE OBJECT" indeed. In a scientific paper you just do not use
words
like "unthinkable" as in the press release. But it is THE SAME of
course.

I note how you completely disregarded the other possibility...


Well, even in the abstract the authors speak about a
quote
We report on the surprisingly high metallicity measured ...
end quote

That is the FIRST SENTENCE of the abstract.

The other possibility, that the authors thought this was expected
but speak about "unthinkable" in the press release and "surprising"
and "rare" in their paper is too strange to contemplate.



All other comparable systems reside at z 2.9. The two galaxies
observed are at z 3.57.


Do you have a point beyond complaining for the sake of it?

My point is that as the scopes go deeper and deeper in the "young"
universe we see more and more objects like the ones we find in
our own local universe.

This means more trouble to this "big bang" theory.

Nothing else, I am not "complaining" about anything, and I do
know my limitations having studied biochemistry instead of
astronomy.

But now it is too late to return to my twenties, even
if I would like to.

:-(

jacob

jacob navia wrote in news:mt2.0-27602-1320753865
@hydra.herts.ac.uk:

Le 05/11/11 11:09, Phillip Helbig---undress to reply a écrit :
In , "Robert L.
writes:

Perhaps the simplest and most direct test of the conventional Big Bang
scenario would be the presence or absence of galaxies at z 10.


UDFj-39546284 is at z = 10 already...
480 million years after the big bang.

In their discovery article the astronomers mention a candidate at
z=10.3.

Neat, but what does this have to do with falsifying the big bang theory?

What it seems to come down to is you Just Can't Understand(tm) how there
can be meaningful amounts of star formation a full half billion years after
the big bang.

Are you going to do this every time something old is discovered?

Robert Oldershaw has tried a variation on this tactic, and it did not work
for him.

Luckily for BB Theory, the JWST is in danger...A monster scope
like that could detect galaxies at distances even farther away!

The JWST didn't get axed.

In article ,
jacob navia wrote:
Yes, I am aware of that. I am even aware that stars have an upper mass
limit of around 150 M0 can you imagine that?

http://www.nature.com/nature/journal...050310-04.html

That is, stars in our Galaxy that formed a few tens of millions of
years ago in a metal-rich cloud (I think the publications reference
the Arches cluster) don't get so big.

For *some* reason, stars will not go beyond that even if the conditions
would allow for stars around 500 M0.

You postulate however that in the "young" universe this limit doesn't
apply?

Yes; in the young universe the stars are composed of basically pure
hydrogen. So the radiation production is less efficient as a function
of mass because you don't have carbon for the CNO cycle; also, you
don't get absorption by metals of the light coming out of the stars,
so there's less opacity, and less radiation pressure.

Tom

Le 08/11/11 19:39, eric gisse a écrit :
jacob wrote in news:mt2.0-27602-1320753865
@hydra.herts.ac.uk:

Le 05/11/11 11:09, Phillip Helbig---undress to reply a écrit :
In , "Robert L.
writes:

Perhaps the simplest and most direct test of the conventional Big Bang
scenario would be the presence or absence of galaxies at z 10.


UDFj-39546284 is at z = 10 already...
480 million years after the big bang.

In their discovery article the astronomers mention a candidate at
z=10.3.

Neat, but what does this have to do with falsifying the big bang theory?


A galaxy at only 480 My after the supposed bang... I am waiting for more
information on this object, but forming a galaxy in just 480 million
years seems to me like too little time.

But I was answering to:

Perhaps the simplest and most direct test of the conventional Big Bang
scenario would be the presence or absence of galaxies at z 10.

That is already proved that galaxies exist at that time.

What it seems to come down to is you Just Can't Understand(tm) how there
can be meaningful amounts of star formation a full half billion years after
the big bang.


Not only star formation but full blown galaxies.

Are you going to do this every time something old is discovered?


Well, I am doing this since quite a while. I saw the "limit" of
clusters of galaxies go from 7-8 Gy to 11 when a cluster of galaxies
was discovered at that distance.

True, galaxy formation is maybe not well understood, there could be
"seeds" in the big bang already, and many other "explanations" being
tried, but the fact that stars need to interact, concentrate into
a galaxy in less than 480 million years is quite a stretch.


Robert Oldershaw has tried a variation on this tactic, and it did not work
for him.

I do not know what do you mean by "tactic". I am not playing
games, trying to "win" whatever that means.

And, as I have said many times, I do NOT have any theory
explaining the Universe in my pocket. I am absolutely
NOT qualified to propose how the Universe came into
being excuse me.

I just do not see why this "big bang" is maintained against
all evidence, that's all.


Luckily for BB Theory, the JWST is in danger...A monster scope
like that could detect galaxies at distances even farther away!

The JWST didn't get axed.

I hope not of course, it will bring down BB theory when we start
seeing that the further we look, nothing changes, we still find
galaxies, quasars, GRBs, supernovae...

And that it goes forever as far as our scopes will see.

jacob navia wrote in news:mt2.0-13243-1320777505
@hydra.herts.ac.uk:

Yes, I am aware of that. I am even aware that stars have an upper mass
limit of around 150 M0 can you imagine that?

http://www.nature.com/nature/journal...050310-04.html

For *some* reason, stars will not go beyond that even if the
conditions
would allow for stars around 500 M0.

What bearing does this have on the conditions of the early universe
where the star material density was just so much higher? There's no
fundamental limitation on the mass of a star, regardless of what you
think the above implies.


You postulate however that in the "young" universe this limit doesn't
apply?

No, I postulate that the observation is irrelevant.

[...]


With that "quotemining" I proved that many astronomers thought that
low "metallicity" meant younger galaxies since it was asked how did
I justify my belief that there was an association between low
metallicity and galaxy age.

I brought those citations to prove that astronomers expected lower
"metall" content in youger galaxies.

This has already been discussed elsewhere. Metallicity is not that good
of a clock.

A star cluster with lots of low mass but long lived members will have
low metallicity compared to a cluster with lots of high mass but short
lived members.

Using metalicity as a clock could tell you that the former is younger
than the latter when that could be exactly wrong or with them being the
same age.

[snip]


My point is that as the scopes go deeper and deeper in the "young"
universe we see more and more objects like the ones we find in
our own local universe.

This means more trouble to this "big bang" theory.

No, it does not. The reason why this is has been explained multiple
times.

[...]

[Mod. note: quoted text trimmed -- mjh]

In article ,
Steve Willner wrote:
In article ,
Martin Hardcastle writes:
nobody has figured out a way of measuring meaningful
whole-galaxy elemental abundances even in the local universe.

I'm not sure I agree with this, though, depending on how strict you
are about "meaningful." We have H II regions, planetary nebulae, the
integrated starlight (both whole-galaxy and maps), and (for the
nearest galaxies) individual stars. I'd call that meaningful, though
no doubt people can disagree on exactly how to translate any given
result into a whole-galaxy average.

Agreed: I should have been clearer. It's hard to get an absolutely
calibrated, properly weighted whole-galaxy average, even with all
those indicators (to which you might add, for example, the metallicity
of the hot phase via X-rays). It's certainly possible to use all those
indicators (a) to get a pretty good idea of what's going on and (b) to
carry out comparisons between different types of galaxy.

Martin
--
Martin Hardcastle
School of Physics, Astronomy and Mathematics, University of Hertfordshire, UK
Please replace the xxx.xxx.xxx in the header with herts.ac.uk to mail me

In article ,
Robert L. Oldershaw wrote:
Where is the "line in the sand" beyond which the existence of galaxies
would require major rethinking of cosmological assumptions?

Perhaps you missed the posting, in response to the last time you asked
this question, where I said that the current best models put the start
of star formation at z ~ 30-20?

If you see galaxies much above those redshifts, then the current best
models are wrong. (Does that mean that the BB is wrong? -- no, for the
reasons other people have given earlier. It means that either the BB
is wrong, or the complicated numerical models needed to derive that
20-30 figure are wrong; people will almost certainly start by looking
at the models first if galaxies at z30 are ever found.)

Martin
--
Martin Hardcastle
School of Physics, Astronomy and Mathematics, University of Hertfordshire, UK
Please replace the xxx.xxx.xxx in the header with herts.ac.uk to mail me