Early galaxies weren't mystifyingly massive after all, James Webb Space Telescope finds

[Admin]

Black holes may be behind why the newborn universe appeared to possess more huge galaxies than scientists could explain, a new study finds.

Early galaxies weren't mystifyingly massive after all, James Webb Space Telescope finds : Read more

 

[rod]

'The bottom line is, there is no crisis in terms of the standard model of cosmology.'

Okay, nothing to see hear folks, cosmology and BBT, all is well. The paper cited shows z=4-8 for galaxies studies. Using cosmology calculators like Ned Wright, z=4, comoving radial distance is some 23.873 Gly

Using z = 8, comoving radial distance is some 29.823 Gly

From earth, we cannot see what those galaxies evolved into today or what mass they may or may not have. Small issues like this show up when interpreting observations of redshifts and expanding universe modeling.

 

[Unclear Engineer]

It is no surprise to me that the BBT cosmologists can "explain" practically anything we are currently capable of observing, even if it was not what their model predicted before the observations were made. There are just so many unconstrained assumptions in the model that it is extremely malleable.

But, it seems that there is still a question about how such large black holes developed so quickly.

Frankly, if the universe was many hundreds of times more dense with matter back when the light was emitted from which these observations were now made, it would not surprise me if the star formation rate was higher than we see today. And, if central supermassive black holes tend to suppress star formation in their galaxies, then perhaps the galaxies grew quite rapidly until they could produce black holes large enough to suppress growth.

But, it still bothers me that the assumption seems to be that atoms then are the same size as atoms now, rather than they too got larger as the space around them and inside them became larger. In terms of cross sectional areas for interactions, and thus reaction rates for frictional heating, chemical reactions, etc., that seems like an important assumption when trying to figure out the dynamics of early galaxy formation.

 

[Torbjorn Larsson]

Possibly other groups can criticize that almost all the "red dot" galaxies are excluded due to problems with estimating their masses. But that just points to how they are likely accretion disk controlled as a recent model explaining early black hole growth with magnetic rigidity allowing for super-Eddington growth rates says [references added below to answer a specific question].

The remaining high star rate formation is ironic, since ten years ago models had problems turning the natural rate down to match late universe galaxy counts. But that discrepancy was a factor 10, now it is merely a factor 2 in the other direction.

It is no surprise to me that the BBT cosmologists can "explain" practically anything we are currently capable of observing, even if it was not what their model predicted before the observations were made. There are just so many unconstrained assumptions in the model that it is extremely malleable.

But, it seems that there is still a question about how such large black holes developed so quickly.

It is a fact that the cosmological models are still somewhat malleable, but it is also a fact that the surveys agree on most general parameters. Full star formation models are auxiliary (and complicated) models that only show up in cosmological simulations, not in plain vanilla BBT models of hot big bang universe expansion.

Here is how an astrophysicist describes it, when writing on the same topic:

Theoretically, our picture of the Universe isn’t particularly malleable, at least on cosmic scales. We already have a suite of observations that cannot be ignored; everything else that we learn has to be explained within the same context as what we already know.

https://bigthink.com/starts-with-a-bang/jwst-galaxies-didnt-break-cosmology/

Regarding supermassive black hole early growth (and coincidentally, red dots), a recent first complete model may have explained it in a series of papers (but the first paper suffice here): https://astro.theoj.org/article/947...on-disks-from-cosmological-initial-conditions , https://astro.theoj.org/article/930...on-disks-from-cosmological-initial-conditions , https://astro.theoj.org/article/93065-an-analytic-model-for-magnetically-dominated-accretion-disks.

It has recently become possible to zoom-in from cosmological to sub-pc scales in galaxy simulations to follow accretion onto supermassive black holes (SMBHs). However, at some point the approximations used on ISM scales (e.g. optically-thin cooling and stellar-population-integrated star formation [SF] and feedback [FB]) break down. We therefore present the first cosmological radiation-magnetohydrodynamic (RMHD) simulation which self-consistently combines the FIRE physics (relevant on galactic/ISM scales where SF/FB are ensemble-averaged) and STARFORGE physics (relevant on small scales where we track individual (proto)stellar formation and evolution), together with explicit RMHD (including non-ideal MHD and multi-band M1-RHD) which self-consistently treats both optically-thick and thin regimes. This allows us to span scales from ~100 Mpc down to <100 au (~300 Schwarzschild radii) around a SMBH at a time where it accretes as a bright quasar, in a single simulation. We show that accretion rates up to ∼10−100M⊙yr−1 can be sustained into the accretion disk at ≪103Rschw, with gravitational torques between stars and gas dominating on sub-kpc scales until star formation is shut down on sub-pc scales by a combination of optical depth to cooling and strong magnetic fields. There is an intermediate-scale, flux-frozen disk which is gravitoturbulent and stabilized by magnetic pressure sustaining strong turbulence and inflow with persistent spiral modes. In this paper we focus on how gas gets into the small-scale disk, and how star formation is efficiently suppressed.

[Nice to see how STARFORGE - the model that first self consistently explained star formation rates - and RMHD naturally seem to explain growth rates and magnetic field aggregation in disks right from the start!]

But, it still bothers me that the assumption seems to be that atoms then are the same size as atoms now, rather than they too got larger as the space around them and inside them became larger.

Spectra are the same after accounting for cosmological expansion redshift, so it is the same atom physics.

Atoms are cohesive systems, also helping by way of molecular forces in building cohesive stars and planets and organisms, so they easily resist the cosmological expansion from general relativity.

In fact, gravity suffice to resist space expansion up to the scale of our Local Group, which seems to be bound and hence see no space expansion within. The cosmological space expansion in between galaxy clusters is locally very slow at currently a 10^-10 rate in space and time or in other words 1 nanometer per meter and per year.

 

[Unclear Engineer]

Torbjorn, Trying to think about your model and also think "outside your box", the thing that seems inconsistent between the expansion of space and quantum mechanics is how space expansion seems to affect some "waves" but not other "waves" in space. The whole astronomical red shift phenomenon is predicated on the assumption that space expands and electromagnetic waves we call photons expand with it. But, quantum mechanics gives wave properties to everything in their respective "fields". So, my question is really why doesn't everything expand the same way that photons expand?

Arguing that other things are bound by forces that are stronger than dark energy so that they are "bound" by electromagnetic, gravity, and the strong and weak nuclear forces is the usual "answer". But, that really doesn't address why their fields are not stretched in such a manner that it does not really affect what is being bound. For instance, if space expands by a factor of 2 and a photon's wavelength is thus stretched by a factor of 2 because its field is stretched, why isn't an atom also stretched by a factor of 2, since it is also "waves" in "fields"?

The "answer" provided is usually that fields that have association with mass are not stretched because they are "bound". The "Higgs Field" that somehow creates the effect of mass is theorized to be "sticky" in ways that I have not seen explained coherently for laypeople to understand.

But, getting back to my question, if space expansion can pull galaxies away from each other (unless they are pulled close to each other faster by gravity), then it seems that 'dark energy" is acting on mass to move it apart. Why doesn't that apply to electrons "orbiting" atomic nuclei?

Just saying that it doesn't because some fields are sticky and others are not seems to just be circular logic to me. It seems like the rules are made to fit the observations, but then the differing rules for different "fields in space" are not required to be consistent with each other.

This seems to me to be a fundamental gap between astrophysics models and quantum mechanics models. And, that really isn't surprising, given the problems acknowledged in combining the laws of gravity with the laws of the other forces.

 

[Pearlman YeC]

Pearlman SPIRAL cosmology was already on record predicting overall, starting at SPIRAL light year radius i, fewer, smaller, stellar objects, as we see from light that departed them when they were much closer to us. at radius i.
In addition, if SPIRAL, the entire universe approximating the visible universe (the approximate sphere we the Earth-sun elliptic) are the approximate center of) the radius of which is 4B light years maximum, but more likely 1B light years rounded based on the current CMB temperature and distribution and it's attaining gravitational bound equilibrium relatively very early in history.
radius i = distance to nearest light year departure point of any light arriving here and now at standard light speed that has ever been subjugated to any cosmic expansion.
reference at ResearchGate MVP hypothesis and Pearlman vs Hubble.

 

[Unclear Engineer]

I saw an explanation of the Higgs Field that is somewhat better than I had seen before:
https://www.quantamagazine.org/how-...-gives-mass-to-elementary-particles-20240903/ .

But, it still seems to have some unexplained effects, such as it "suddenly turning on" as the universe was evolving. And, it "stiffening" other fields by unexplained interactions to cause mass. There are some other issues such as massless particles like photons being ripples in electric fields and electrons being ripples in (?) "electron fields". So, not the same "field"?! Does every elementary particle have its own field in which it is the resonant frequency? And, what happens when we find that what we thought was an elementary particle turns out to be made of even smaller particles? Did a "proton field" become an interaction of multiple "quark fields". Will those become even more complex interactions of even more "fields" if we discover quarks are made of "axions"?

The whole thing seems to me reminiscent of the old mythologies where anthropomorphized forces named "Zeus" and "Apollo" etc. did the things that we observed but did not understand. Now it is non-anthropomorphized "fields" that "did" and "do" things without explanation of why or how during the evolution of the universe.