6
$\begingroup$

There are a lot of claims, on YouTube at least, that the James Webb space telescope have found too many to old/highly redshifted normal looking galaxies to fit easily into the Big Bang model.

One such claim from a physicist by the name Eric Lerner can be found here. He claims that according to this article, that is supposedly soon to be published in Nature, they have found 100 000 more galaxies than expected at a redshift of z>10. I could not locate that particular number in the article

I wonder what part, if any, have to be adjusted in the current / "pre-James Webb" Big Bang model of the development of the universe due to the findings of James Webb. Claims are both that there are "too many" highly redshifted galaxies and that the "morphology distribution" of the highly redshifted galaxies are not as expected but that question is perhaps more suited for another question.

Question: What parameters, if any, of the standard Big Bang model will have to be adjusted in order to explain that the James Webb telescope (supposedly) has found that there are more highly redshifted galaxies than "pre-James Webb" cosmology had projected?

Improve this question
$\endgroup$
5
  • 3
    $\begingroup$ Could you give a reference to one of these videos that gives such a claim? $\endgroup$
    – Justin T
    Sep 11, 2022 at 19:54
  • 3
    $\begingroup$ Could you give a reference that isn't a youtube video? $\endgroup$
    – ProfRob
    Sep 13, 2022 at 12:59
  • 1
    $\begingroup$ As far as I know, there are more "red blobs" in the images than expected. But so far (still as far I know) there has been no full analysis of the noise background in the images, e.g. subtraction of hot pixels or inhomogenities in spectral filters and there has been no full and calibrated spectrometer analysis of the spectrum which is the only way to tell if these are red-shifted or just appearing red, e.g. due to dust. $\endgroup$
    – asdfex
    Sep 13, 2022 at 16:44
  • 3
    $\begingroup$ It's obvious that whoever made that video knows nothing about cosmology. I think the source of all of these stories may be this article by Eric Lerner, a long-time advocate of steady-state cosmologies whose 1991 book "The Big Bang Never Happened" was debunked by Ned Wright. I think Lerner's article would be a much better source than that video. $\endgroup$
    – benrg
    Sep 13, 2022 at 20:58
  • $\begingroup$ @benrg The number of found galaxies at high redshifts by James Webb are exactly as expected from the big bang model without changing any parameters? $\endgroup$
    – Agerhell
    Sep 14, 2022 at 13:09

1 Answer 1

Reset to default
13
+50
$\begingroup$

The big-bang model does not have much to say about the redshift-dependence of the galaxy mass function (NB It is really the luminosity function that is being probed), other than that at some high redshift we ought to encounter the regime before the first galaxies formed and therefore high-mass galaxies should be rare beyond those redshifts.

A summary of the paper (which has not been accepted for publication yet I think) by Labbe et al. is that they have found 14 candidate high-redshift, high-mass galaxies; a handful (4) of these have redshift of $z \sim 10$ and they would not (by extrapolating the mass functions at lower redshifts) have expected to see any (well, much $<1$).

If these findings are correct$^{\dagger}$ and these candidate high-redshift objects turn out to be bona fide, then in the context of the $\Lambda$CDM model, it would mean that the assembly of the cores of the most massive galaxies must take place very quickly - but this could be in accord with existing observations of supermassive black holes that are already present in the universe at $z \sim 7.6$ just six hundred million years after the big-bang (Wang et al. 2021). It isn't clear to me that this would require any modification to the big bang model.

Incidentally - these galaxies look nothing like the big galaxies in the present-day universe (e.g. they have very small core radii $<0.5$ kpc) and therefore, if their redshifts are correct they provide yet more evidence (as if any more is needed) against any "steady state" model for the universe.

$^\dagger$ I am a bit disappointed that there are not more details and consideration of the uncertainties in the data. The results are based on photometric redshifts, which can have strange and certainly non-gaussian error distributions. If I were to find 14 unusual objects in a parent sample of $\sim$40,000 objects (which is the case here), I would want to be very sure that these objects could not simply be the extrema of a broad uncertainty distribution. i.e. Even in a normal distribution you expect about this many 4-sigma outliers and the number of outliers might be greater if the uncertainty distribution is non-Gaussian.

Improve this answer
$\endgroup$
3
  • $\begingroup$ Well, they either tend to have a very small core radii or the expression connecting the redshift to the distance is wrong and they have a normal radii but resides further away... $\endgroup$
    – Agerhell
    Sep 22, 2022 at 6:51
  • $\begingroup$ @Agerhell you should back that up with a calculation. How big would they be? $\endgroup$
    – ProfRob
    Sep 22, 2022 at 12:01
  • $\begingroup$ Eric Lerner comes with a lot of statements like this one: "Put another way, the galaxies that the JWST shows are just the same size as the galaxies near to us, assuming that the universe is not expanding and redshift is proportional to distance." I do not know if that is corrects. I might ask a question based on Lerners assertations that people can refute. $\endgroup$
    – Agerhell
    Sep 22, 2022 at 15:47

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .