On Friday, March 17, 2023 at 2:51:10=E2=80=AFAM UTC-4, Jacob Navia wrote:
> Le mardi 7 mars 2023 =C3=A0 23:18:50 UTC+1, edpr...@gmail.com a =C3=A9crit=C2=A0:
> > On Thursday, March 2, 2023 at 3:54:17=E2=80=AFAM UTC-5, Jacob Navia wrote:
> > []
> > > Our sun is 5Gy old. The chemical composition of the cloud that
> > > formed the sun was the chemical composition at 13.7 - 5Gyr =3D 8.7Gyr.
> > > It took then more than 8Gyr to our galaxy to accumulate "metals"
> > > to build the sun. The fact that a galaxy appears that is chemically
> > > equivalent implies that it also needed 8Gyr to accumulate metals,
> > This is an assumption that a galaxy needs 8Gyr to reach the metallicity
> > of the Milky Way.
> > > but it is only 1.4 Gyrs from the Big Bang. That doesn't fit, so
> > > something must be wrong. Then, we start putting into question the
> > > star formation theories and NOT the Big Bang, of course.
> > >
> > > The fact that the old galaxies that we are seeing just 0.6Gyr after
> > > the supposed bang are impossible
> > Not impossible, just not yet understood.
> Excuse me, but you are proposing a new theory of metallicity formation
> in galaxies: a FAST one, that arrives at the same metallicity of
> the Mily Way in just 1,400 million years. Without providing ANY
> justification for it. Metals are built by stars in a long process
> in their cores. Then, when the supernovas explode, they disseminate
> their metals into the void, where they will be used by the new stars
> that start with more metals, etc etc. That is a VERY slow process.

You made the assertion that such galaxies to exist " just 0.6Gyr after
the supposed bang are impossible."
I merely reminded you that they have been observed and
therefore are clearly not impossible.
>
> And why are you proposing this "fast track" metallicity process?
> Have you any REAL DATA behind your new theory?

I did not propose a theory. Why are you being so impatient in
wanting an explanation so soon after this new discovery?
Science doesn't work that way.
>
> No, you just want to save the big bang theory.
> > > unless... we say that the galaxy
> > > formation theories are wrong without advancing anything to explain
> > > how and old galaxy can happen in just 0.6 Gyr. If you say that star
> > > formation theory is wrong, you must come with ANOTHER star formation
> > > theory to explain the facts.
> > Precisely. This is how we learn and REFINE the models and theories
> > we use to explain the universe.
> No
>
> There is another process. When a theory acquires too many problems
> it must be discarded entirely. That is why we do not add more
> epicycles to theories that put the earth at the center of the
> Universe. We DISCARDED the whole theory and built a new, better
> one.

Sorry, but both types of refinement have happened throughout history:
development of complete new theories and revisions of established theories.
It is too early to determine which must happen here.

However, given the large amount of other evidence supporting the Big Bang theory,
I expect we may find this observation to be a new refinement. It may point the way
to some new physical process.

>
> Problem: there isn't now any theory to replace the big bang theory.
> So, you, and many astronomers also, try to save the big bang theory
> against all evidence.

I'm not trying to save anything "at all costs". I just point out that
this ONE observation is not the death knell you are looking for.
> > >
> > > Obviously the Big Bang theory has a lot of momentum and will try
> > > to save something for some time. But it is a LOST fight... and
> > > everyone sees it now. It would be more productive if we try to see
> > > what stands after this earthquake.
> > I don't think the Big Bang is in much of a fight. There isn't any
> > strong contender around.
> You are right. There is no alternative theory right now.
Agreement. Yeah!
> > >
> > > The assumption that the red shift is due to a Doppler effect is
> > > proved wrong. What are the alternatives? That is the scientific
> > > question now.
> > >
> > > jacob
> > But red shift is NOT just due to Doppler. It is also due to cosmic
> > expansion.
> We assume that the red-shift is caused by cosmic expansion, i.e. a
> Doppler effect. Then, we need an origin because if space is expanding,
> in the past it was just a point with infinite density at 13,700
> million years ago.
>
> This is not what is observed. There is no hint to a big bang in the
> photographs of the JWST. Just more galaxies like our own.

The CMB was the last nail in the coffin of a static universe, along with
observations of receding galaxies, the current chemical composition
of the universe. The JWST observations are not inconsistent with BB theory.
> >
> > This is not the knockout discovery for the Big Bang that you claim.
> I have been arguing against that theory since quite a number of
> years in this group. The "impossible galaxy" problem was there
> already BEFORE the JWST was started. A few days before JWST took
> off from Kouru I posted a message here predicting that the JWST
> will see more galaxies without end without any trace of a big bang.
> This has been confirmed.
>
> But I haven't any new theory of the Universe in my suitcase. I just
> see that the big bang theory is wrong, without being able to explain
> to you anything. I do not even know what the red-shift is. OK. It
> is not a Doppler effect, space is not expanding. But then... what
> is it?
>
> I DO NOT KNOW.
Yeah! You are in the same position as every astrophysicist.

there is one concept of science to keep in mind:
-----All our theories are wrong, but some are useful.-----

>
> Acknowledging your ignorance is the first step in the way of
> knowledge. You try to understand what is there ONLY when you see
> that you do not know what it is.When you see that your theories are
> wrong you try to see reality as it is.

Yes, but until a more useful theory of the evolution of the universe is proposed,
then the Big Bang theory is the most useful model we have.
>
> What is the red-shift? It is the red-shift that was discovered
> by Hubble that gave impetus to a theory of the "Big Bang" that
> "created" the Universe 13,700 Million years ago. And now we have
> to return to the start: What is the red-shift?
>
> That is the scientific question to ask now.
>
> jacob

Red shift is currently understood as due to three effects:
Doppler Red shift due to motion relative to the observer
Gravitational Red shift due to light traversing a gravitational potential
Cosmological Redshift due to the expansion of space itself.

I suspect you doubt the Cosmological Redshift. But it has fit
observations of galaxies prior to JWST.
>
> [[Mod. note --
> 1. That "1,400 million years" is calculated assuming a big-bang cosmology.
> 2. > Metals are built by stars in a long process
> > in their cores. Then, when the supernovas explode, they disseminate
> > their metals into the void, where they will be used by the new stars
> > that start with more metals, etc etc. That is a VERY slow process.
> This whole process depends STRONGLY on the mass of the star.
> Relatively low-mass stars (e.g., solar-mass or below) have lifespans
> of 10 billion years or more, and never do supernova. Very high-mass
> stars do indeed end their lives in a supernova, but this happens very
> fast (well under 10 million years). So the timescale on which metals
> build up in a galaxy depends STRONGLY on the distribution of stellar
> masses.
>
> We think that "population III" stars (those forming from essentially
> hydrogen/helium only, as would be the case for the first stars formed
> after the big bang) will tend to be highly massive. But we have
> zero direct observational data for this, so there's some uncertainty
> about the details.
>
> So, there's substantial uncertainty about just what metal abundance
> a galaxy developes at a a given (young) age. And given that, maybe
> it's not quite so surprising that our first observations probing
> this are not quite what we expected?
> -- jt]]

I'm glad, Jacob, that you agree that these new observations may require
a new explanation which we do not have yet. But at least I (and
possibly others) do not assume that the BB Theory will be totally
replaced when that explanation comes. As the moderator points out,
we should not be surprised that these observations are not what we expected.

You and others may find this video enlightening
https://youtu.be/hmkyF1tNFc4
from Dr Becky Smethurst, an astrophysicist at the University of Oxford
titled:
JWST has found MASSIVE galaxies in the early Universe which we can't explain
(Note, she does not say "impossible")

Ed