Continuation Why James Webb Telescope rewrites/doesn't the laws of Physics/Redshifts (2)

[hecd2]

Oh, and I’ll just add this, in the absurdly unlikely event that 30 orders of magnitude is insufficient: we observe a CMB dipole. The Gibbons Hawking radiation has no dipole and the same temperature is observed by all free-falling observers.

[Steve]

Originally Posted by hecd2

We don’t know how much of the Universe lies beyond the observable region, but let’s say it’s 99.99 recurring percent. So what?

Well, if no one knows then that gives Mike Helland freedom to incorporate it into Helland physics in whatever manner he sees fit. And you cannot dispute his opinion because you "don't know".

[Ziggurat]

Originally Posted by hecd2

We don’t know how much of the Universe lies beyond the observable region, but let’s say it’s 99.99 recurring percent. So what?

He thinks this means you can treat the universe as being approximately mass-free since very little fraction is within the visible universe. Of course, to no one's surprise, it doesn't work that way.

[hecd2]

Originally Posted by Steve

Well, if no one knows then that gives Mike Helland freedom to incorporate it into Helland physics in whatever manner he sees fit. And you cannot dispute his opinion because you "don't know".

Yes, but he’d have to incorporate it in a way that is physically correct, not in any way he sees fit, and I have no idea where he’s going with this. Anyway, we genuinely have no idea how much of the universe lies outside our observable region, but what lies outside the observable universe can have no influence on what observe - by definition.

[hecd2]

Originally Posted by Ziggurat

He thinks this means you can treat the universe as being approximately mass-free since very little fraction is within the visible universe. Of course, to no one's surprise, it doesn't work that way.

Is that what he thinks? He raised it as a response to my pointing out the the Gibbons-Hawking radiation can’t explain the CMB.

[Mike Helland]

Originally Posted by hecd2

I can’t believe you wrote that. Have you any idea how big a discrepancy of 30 orders of magnitude is?

It's about the difference between the radius of a smallish black hole and the radius of the universe.

The 30 orders of magnitude figure seems to be for the "future" horizon in an expanding universe.

https://physics.stackexchange.com/qu...sitter-horizon

Quote:

The future cosmic Event horizon is the source of de Sitter (aka cosmic Hawking) radiation, also characterised by a specific temperature, the de Sitter temperature T (as per the OP). It is the minimum possible temperature of the universe.

I'm talking about what's beyond the galaxies we see. So I would assume that's the past horizon.

[Mike Helland]

Originally Posted by hecd2

Is that what he thinks? He raised it as a response to my pointing out the the Gibbons-Hawking radiation can’t explain the CMB.

The idea I had in mind is something like a reverse Schwarzschild situation, where all the mass in the universe is at infinity.

[Steve]

Originally Posted by Mike Helland

The idea I had in mind is something like a reverse Schwarzschild situation, where all the mass in the universe is at infinity.

Does that include your own personal mass?

[Mike Helland]

Originally Posted by Steve

Does that include your own personal mass?

Does your own personal mass exist in the Schwarzschild metric?

[Steve]

Originally Posted by Mike Helland

Does your own personal mass exist in the Schwarzschild metric?

If mine does not then there is no me (or you) to ponder the mysteries of the Schwarzchild metric . Which makes the entire line of thought as meaningless as Helland physics.

[Mike Helland]

Originally Posted by Steve

If mine does not then there is no me (or you) to ponder the mysteries of the Schwarzchild metric .

That doesn't answer the question.

ETA, FWIW, I don't know for sure. I think that all the mass in the system is put at the origin. But then, I think, you place a test particle in there and compute some geodesics, which would require the particle's initial momentum, so I think the mass is included there?

[Mike Helland]

FWIW, here's my version of what's developed here:

https://mikehelland.github.io/hubbles-law/

We're at the bottom part now. The sections are:

Observation
Conjecture
An ad hoc hypothesis
-Compared to data
A geometrical solution
Cosmological implications
-The CMB
-Other cosmological phenomena

[hecd2]

Originally Posted by Mike Helland

It's about the difference between the radius of a smallish black hole and the radius of the universe.

The 30 orders of magnitude figure seems to be for the "future" horizon in an expanding universe.

30 orders of magnitude is the discrepancy between the observed CMB temperature and the temperature of cosmic Gibbons-Hawking radiation in a de Sitter Universe expanding with H=~2.2e-18 s^-1 =~ 70km s^-1Mpc^-1.

Quote:

I'm talking about what's beyond the galaxies we see. So I would assume that's the past horizon.

And you’re making zero sense as usual. What does this have to do with Gibbons-Hawking radiation?

[hecd2]

Originally Posted by Mike Helland

The idea I had in mind is something like a reverse Schwarzschild situation, where all the mass in the universe is at infinity.

Wut? All the mass of the Universe is not at infinity (what does that even mean?) and what the devil is a “reverse Schwarzschild situation”?

[Mike Helland]

Originally Posted by hecd2

Wut? All the mass of the Universe is not at infinity (what does that even mean?) and what the devil is a “reverse Schwarzschild situation”?

Couldn't tell ya.

But reading Einstein and de Sitter's 1917 papers gives the impression that they were not really concerned with a theory of the universe, but how GR acts at the boundary conditions, out at infinity. I thought one of the scenarios considered back then was putting all the mass out at infinity. Though I can't find the reference, so I probably imagined it.

[hecd2]

Originally Posted by Mike Helland

Couldn't tell ya.

That figures.

Quote:

But reading Einstein and de Sitter's 1917 papers gives the impression that they were not really concerned with a theory of the universe, but how GR acts at the boundary conditions, out at infinity.

You don’t have, by about 30 orders of magnitude, the mathematical chops to understand Einstein and de Sitter’s 1917 papers. Einstein was concerned with developing a theory of gravity which would apply universally. The term “boundary conditions” does not mean what you think it means. What does all this have to do with the Gibbons-Hawking cosmic radiation?

Quote:

I thought one of the scenarios considered back then was putting all the mass out at infinity. Though I can't find the reference, so I probably imagined it.

That figures.

[hecd2]

Originally Posted by Mike Helland

FWIW, here's my version of what's developed here:

https://mikehelland.github.io/hubbles-law/

We're at the bottom part now. The sections are:

Observation
Conjecture
An ad hoc hypothesis
-Compared to data
A geometrical solution
Cosmological implications
-The CMB
-Other cosmological phenomena

The link leads to a piece of appallingly bad journalism where the author of the piece displays a fundamental lack of knowledge of the subject matter, and extreme bias in favour of a crackpot idea.

[Steve]

Originally Posted by hecd2

The link leads to a piece of appallingly bad journalism where the author of the piece displays a fundamental lack of knowledge of the subject matter, and extreme bias in favour of a crackpot idea.

That kind of writing seems quite familiar.

[Mike Helland]

Originally Posted by hecd2

That figures.

You don’t have, by about 30 orders of magnitude, the mathematical chops to understand Einstein and de Sitter’s 1917 papers. Einstein was concerned with developing a theory of gravity which would apply universally. The term “boundary conditions” does not mean what you think it means. What does all this have to do with the Gibbons-Hawking cosmic radiation?
That figures.

The issue seems to be what happens when time approaches infinity or negative infinity.

LCDM/FLRW and its quasi-absolute cosmic time is incompatible with the equivalence principle and not totally relativistic.

De Sitter's system B is entirely relative, compatible with EEP, and has time dilation and redshift at a distance from the observer.

If my model could be rejected because you thought it was incompatible with relativity, then so should LCDM/FLRW.

De Sitter's system B is safe though.

[W.D.Clinger]

Originally Posted by Ziggurat

"Apes don't read philosophy."
"Yes they do, Otto, they just don't understand it."

I stand corrected.

Originally Posted by hecd2

You don’t have, by about 30 orders of magnitude, the mathematical chops to understand Einstein and de Sitter’s 1917 papers.

Confirming hecd2's diagnosis, the author and sole proponent of Helland physics wrote:

Originally Posted by Mike Helland

LCDM/FLRW and its quasi-absolute cosmic time is incompatible with the equivalence principle and not totally relativistic.

De Sitter's system B is entirely relative, compatible with EEP, and has time dilation and redshift at a distance from the observer.

If my model could be rejected because you thought it was incompatible with relativity, then so should LCDM/FLRW.

De Sitter's system B is safe though.

As has already been explained within just the past couple of days:

1. FLRW is entirely compatible with general relativity, as is the "cosmic time" coordinate that is customarily used when describing an FLRW model.
   
   
2. De Sitter's system B is a specific example of an FLRW model, so it too is entirely compatible with general relativity.
   
   
3. The reason de Sitter's system B "has time dilation and redshift at a distance from the observer" is because it is an FLRW model for an expanding universe. (Because that universe is devoid of matter and has a nonzero cosmological constant, that universe expands at an exponential rate.)
   
   
4. The reason "de Sitter's system B is safe" (in the sense of being consistent with relativity) is because it is an FLRW model.
   
   
5. Mike Helland's model is not at all the same as de Sitter's system B. Mike Helland's model postulates a non-expanding universe, whereas de Sitter's system B describes a universe that expands at an exponential rate.
   
   
6. Mike Helland's model is rejected for many reasons, not least because it is incompatible with relativity.
   
   
7. In particular, Mike Helland has been unable and will forever be unable to describe any solution of the Einstein field equations that allows cosmological redshift to occur within a non-expanding universe.

[Mike Helland]

Originally Posted by W.D.Clinger

[*]FLRW is entirely compatible with general relativity, as is the "cosmic time" coordinate that is customarily used when describing an FLRW model.

Not according to this:

Quote:

Problem 8: ΛCDM is inconsistent with Einstein’s equivalence principle

As his grand finale, Melia presents a fundamental inconsistency in ΛCDM: its choice to use the Friedmann equations in the first place to describe the universe during periods of exponential expansion. In standard use, the Friedmann equations arise by assuming isotropy and homogeneity for the universe, and are then derivable from the Einstein field equations, where the time-time component of the metric (g_tt) is related to the overall Einstein stress-energy tensor. In particular, the second Friedmann equation, which describes how the expansion rate changes with time, is derived after already assuming the validity of the cosmological principle, and therefore: after assuming isotropy and homogeneity. While this simplifies the metric coefficients greatly, it ignores the important fact that the metric coefficients depend on the chosen stress-energy tensor, which changes as the universe evolves through phases of deceleration (when matter and radiation dominate) and acceleration (when dominated by inflation and dark energy).

And yet, in ΛCDM the time-time component of the metric, g_tt, is set at 1 at all times and stages of cosmic evolution, even under conditions where it may not be mathematically robust to do so. Given that the Hubble flow – the motion of galaxies due to the universe’s expansion – is not inertial in ΛCDM, i.e., the galaxies don’t experience “freefall,” why should we be comfortable applying free-fall conditions during phases of accelerated expansion? Melia then goes on to prove that when the universe accelerates, an observer must see their time being dilated relative to local free-falling frames, so that g_tt can by no means be 1. And yet, because the condition g_tt = 1 is always imposed, we arrive at an inherent inconsistency: ΛCDM is inconsistent with Einstein’s equivalence principle.

de Sitter says this in 1917:

Quote:

The system A satisfies the "material postulate of relativity of inertia," but it restricts the admissible transformation to those for which at infinity t' = t, and thus introduces a quasi-absolute time, as has been explained in art. 2. In B and C the time is entirely relative, and completely equivalent to the other three co-ordinates. In A there is a world-matter, with which the whole world is filled, and this can be in a state of equilibrium without any internal stresses or pressures, if it is entirely homogeneous and at rest. In B there may, or may not, be matter, but if there is more than one material particle these cannot be at rest, and if the world were filled homogeneously with matter this could be at rest without internal pressure or stress; for if it were, we would have the system A, with g₄₄ = 1 for all values of the four co-ordinates. The system B satisfies the "mathematical postulate" of relativity of inertia, which does not appear to admit of a simple physical interpretation.

So you claim coordinates don't matter. Map, territory.

And then you choose a coordinate system that's incompatible with relativity.

It seems your claims are false.

[Mashuna]

Originally Posted by Mike Helland

Not according to this:

Quote:

Problem 8: ΛCDM is inconsistent with Einstein’s equivalence principle

As his grand finale, Melia presents a fundamental inconsistency in ΛCDM: its choice to use the Friedmann equations in the first place to describe the universe during periods of exponential expansion. In standard use, the Friedmann equations arise by assuming isotropy and homogeneity for the universe, and are then derivable from the Einstein field equations, where the time-time component of the metric (gtt) is related to the overall Einstein stress-energy tensor. In particular, the second Friedmann equation, which describes how the expansion rate changes with time, is derived after already assuming the validity of the cosmological principle, and therefore: after assuming isotropy and homogeneity. While this simplifies the metric coefficients greatly, it ignores the important fact that the metric coefficients depend on the chosen stress-energy tensor, which changes as the universe evolves through phases of deceleration (when matter and radiation dominate) and acceleration (when dominated by inflation and dark energy).

And yet, in ΛCDM the time-time component of the metric, gtt, is set at 1 at all times and stages of cosmic evolution, even under conditions where it may not be mathematically robust to do so. Given that the Hubble flow – the motion of galaxies due to the universe’s expansion – is not inertial in ΛCDM, i.e., the galaxies don’t experience “freefall,” why should we be comfortable applying free-fall conditions during phases of accelerated expansion? Melia then goes on to prove that when the universe accelerates, an observer must see their time being dilated relative to local free-falling frames, so that gtt can by no means be 1. And yet, because the condition gtt = 1 is always imposed, we arrive at an inherent inconsistency: ΛCDM is inconsistent with Einstein’s equivalence principle.

Ooh, can I play Google physics too?

Quote:

The so-called impossibly early galaxy problem, first identified via the Hubble Space Telescope’s observation of galaxies at redshifts z > 10, appears to have been exacerbated by the more recent JWST discovery of galaxy candidates at even higher redshifts (z ∼ 17) which, however, are yet to be confirmed spectroscopically. These candidates would have emerged only ∼230 Myr after the big bang in the context of Lambda cold dark matter (ΛCDM), requiring a more rapid star formation in the earliest galaxies than appears to be permitted by simulations adopting the concordance model parameters. This time-compression problem would therefore be inconsistent with the age–redshift relation predicted by ΛCDM. Instead, the sequence of star formation and galaxy assembly would confirm the timeline predicted by the Rh = ct universe, a theoretically advanced version of ΛCDM that incorporates the ‘zero active mass’ condition from general relativity. This model has accounted for many cosmological data better than ΛCDM, and eliminates all of its inconsistencies, including the horizon and initial entropy problems. The latest JWST discoveries at z ≳ 14, if confirmed, would add further support to the idea that the Rh = ct universe is favoured by the observations over the current standard model.

[W.D.Clinger]

The author and sole proponent of Helland physics continues to supply evidence in support of hecd2's observation that he doesn't have, "by about 30 orders of magnitude, the mathematical chops to understand" any serious discussion of general relativity and cosmology:

Originally Posted by Mike Helland

Originally Posted by W.D.Clinger

[*]FLRW is entirely compatible with general relativity, as is the "cosmic time" coordinate that is customarily used when describing an FLRW model.

Not according to this:

As I explained two days ago:

Originally Posted by W.D.Clinger

Although a nonzero cosmological constant is compatible with FLRW models, FLRW models are not compatible with a time-varying value for the cosmological constant (or with any other time-varying dark energy). If someone interprets "ΛCDM" to mean a constant value for Λ combined with rigid insistence upon pure FLRW models, then "ΛCDM" is not fully consistent with cosmic inflation.

So what I wrote is quite true: "FLRW is entirely compatible with general relativity, as is the "cosmic time" coordinate that is customarily used when describing an FLRW model."

But Mike Helland "dunno" that.

Helland physics is cargo cult pseudoscience. Its author and sole proponent searches the World-Wide Web for anything he can find that can be misinterpreted to support his own misconceptions. He doesn't understand what he reads, but that doesn't stop him from citing and even quoting sources that aren't actually saying what he thinks they're saying.

In this instance, the cargo cultist has found someone saying it's a mistake to assume the Friedmann equations continue to hold when the so-called cosmological constant Λ is not actually a constant. That's a technical error, which should have a straightforward technical fix. Today's mainstream cosmology (insofar as I myself understand it) attempts to fix that problem by assuming a piecewise approximation to the evolution of the universe, in which Λ remains constant within each era. That's a plausible way to deal with the problem of retrofitting an inflationary epoch (lasting about 10^-32 seconds) into the pre-Guth version of ΛCDM theory, but that approach can be and has been questioned.

But no one who understands any of the above is questioning the success of ΛCDM or its use as a starting approximation for some more refined theory. In particular, the article Mike Helland is failing to understand goes on to say this:

Originally Posted by Ethan R. Siegal

....And this is a perfect starting point for ΛCDM: when inflation ends and the hot Big Bang begins, the onset of living in a matter- and radiation-rich universe causes a tremendous increase in entropy within our cosmic horizon, and that entropy has been increasing monotonically ever since – exactly as required....

Concerning the early appearance, growth, and evolution of stars, galaxies, and supermassive black holes, there are many studies suggesting that the nonlinear growth of structure can accelerate gravitational collapse and trigger the formation of the first stars in under 200 million years, and that the second generation of stars, rich in heavy elements that enable rapid cooling, requires virtually no time at all (in cosmic terms) to subsequently form. Many studies provide plausible pathways and mechanisms for galaxies to form and grow much more quickly than Melia contends.

....These difficult problems exist but cannot possibly detract from the extraordinary string of successes that have accompanied the standard ΛCDM model of cosmology.

Originally Posted by Mike Helland

So you claim coordinates don't matter. Map, territory.

And then you choose a coordinate system that's incompatible with relativity.

It seems your claims are false.

It seems Mike Helland, as usual, doesn't know what he's talking about.

He doesn't understand that the so-called "cosmic time" coordinate is compatible with relativity, and he doesn't understand that it is preferred because any other choice of time coordinate would obscure the homogeneity and isotropy of the model.

As I wrote two days ago:

Originally Posted by W.D.Clinger

As was clearly explained by two of the papers Helland cited, quoted, and copy/pasted, de Sitter's original coordinates fail to reconcile cosmological redshift with a static (non-expanding) universe. Amusingly, the incorrect idea that de Sitter's coordinates might reconcile cosmological redshift with a static universe came about because those coordinates present a misleading map of the expanding de Sitter universe, much as the TDP coordinates of Helland physics present a misleading map of the static Minkowski universe in which cosmological redshift cannot possibly occur.

Even more amusingly, the author and sole proponent of Helland physics has begun to cite a criticism of ΛCDM that is based upon the fact that FLRW models with a constant Λ are insufficiently non-static. He "dunno" that such criticism is an even more damning criticism of the static universe postulated by Helland physics.

[Mike Helland]

Originally Posted by W.D.Clinger

FLRW is entirely compatible with general relativity, as is the "cosmic time"

Not according to the sources I've given.

After your recent series of fabrications, you can understand why I'm not inclined to simply take your word over theirs.

[Mashuna]

Originally Posted by Mike Helland

Not according to the sources I've given.

After your recent series of fabrications, you can understand why I'm not inclined to simply take your word over theirs.

If only you could perform the calculations. . .

[Mike Helland]

Originally Posted by Mashuna

If only you could perform the calculations. . .

I'll bite.

What are you referring to?

If you have any question about the data I used, or equations I used, it's all documented in the github repo.

eg,

https://github.com/mikehelland/hubbl.../other/sse.htm

ETA, you can use this bit right here to get a data object with the Pantheon+SH0ES data:

    fetch("https://mikehelland.github.io/hubbles-law/data/Pantheon+SH0ES_z_mu.csv").then(res => res.text()).then(text => {
        //console.log(text)

        var lines = text.split("\n")
        for (var i = 1; i < lines.length; i++) {
            var line = lines[i].split(",")
            if (line[0]) {
                snData.push({"dm": parseFloat(line[2]), "z": parseFloat(line[0]), "derr": parseFloat(line[0])})
            }
            
        }
        calculateDistances()

        drawData()

        calculateLCDMErrors()
        
    })

[Mashuna]

I can’t see any part of that link that relates to the ‘Problem 8’ you’ve googled above, not W. D. Clingers addressing of the issues discussed there.

So for you to decide you’re going to accept one over the other, you must have solid logic - it’s not an issue of having to ‘take your word over theirs’

[Mike Helland]

Originally Posted by Mashuna

I can’t see any part of that link that relates to the ‘Problem 8’ you’ve googled above, not W. D. Clingers addressing of the issues discussed there.

So for you to decide you’re going to accept one over the other, you must have solid logic - it’s not an issue of having to ‘take your word over theirs’

13.8 is a fairly popular column by Adam Frank, and he's doing a series on the problems with LCDM. That's where this came from. People are talking about it. I don't have to go looking for it.

You might have to look outside the skeptics forum tho.

[W.D.Clinger]

The author and sole proponent of Helland physics advertises his mathematical chops by denying, on the record, that FLRW models are compatible with general relativity.

Originally Posted by Mike Helland

Originally Posted by W.D.Clinger

FLRW is entirely compatible with general relativity, as is the "cosmic time"

Not according to the sources I've given.

After your recent series of fabrications, you can understand why I'm not inclined to simply take your word over theirs.

ETA: It so happens that the archives of this forum record an unusually detailed mathematical proof that an entire family of FLRW models are compatible with general relativity:

• FLRW solutions for a flat, expanding universe
• corrections, part 1
• corrections, part 2

To simplify that proof, I assumed flat space, a zero cosmological constant, and positive mass/energy density. Those assumptions already imply space is either expanding or contracting. For generalizations of that proof to FLRW models with non-flat space, nonzero cosmological constant, and/or zero mass/energy density, consult standard textbooks (where the proofs are usually far less detailed).

[Mashuna]

Originally Posted by Mike Helland

13.8 is a fairly popular column by Adam Frank, and he's doing a series on the problems with LCDM. That's where this came from. People are talking about it. I don't have to go looking for it.

You might have to look outside the skeptics forum tho.

I’m not denying you’ve found a link, I’m questioning your understanding of the ink.

[Mike Helland]

Originally Posted by Mashuna

I’m not denying you’ve found a link, I’m questioning your understanding of the ink.

And I'm saying just because Clinger says something over and over doesn't mean it's true, or that the context in which it is true is relevant.

[Steve]

Originally Posted by Mike Helland

And I'm saying just because Clinger says something over and over doesn't mean it's true, or that the context in which it is true is relevant.

OTOH there are stacks of reliable evidence that Mike Helland saying something over and over has no connection whatsoever to the truth.

[steenkh]

Originally Posted by Mike Helland

And I'm saying just because Clinger says something over and over doesn't mean it's true, or that the context in which it is true is relevant.

Correct, but then you should be able to point to where he is wrong. Until you can do that, you need to assume that he is right, considering his vastly better understanding of the subject.

[Mike Helland]

Originally Posted by steenkh

Correct, but then you should be able to point to where he is wrong. Until you can do that, you need to assume that he is right, considering his vastly better understanding of the subject.

Maybe Clinger could explain how de Sitter is wrong about system A having a quasi-absolute time and system B being entirely relative.

De Sitter seems pretty clear. Clinger can claim otherwise, but without an argument there isn't a reason to accept that as the truth.

[hecd2]

Helland is in no position to understand anything whatsoever to do with general relativity, and does not have the mathematical knowledge to understand the discussion which is taking place between respected cosmologists. It is the sign of a crackpot to find some idea by a respected physicist that he thinks supports his silly ideas, and to give that view 100% credibility while completely discounting the fact that dozens of other equally respected physicists have a different view. Helland is also notorious for ignoring proofs that his ideas are garbage, either through bias or because he doesn’t understand the proofs. It’s a simple fact that FLRW solutions are exact solutions to the Einstein equations under well understood conditions and are therefore entirely compatible with general relativity. As for accusing WDC of “fabrications”, that’s the height of projection, as it’s Helland who stumbles from one misunderstood and silly idea to the next.

[hecd2]

Originally Posted by Mike Helland

The issue seems to be what happens when time approaches infinity or negative infinity.

What issue?

Quote:

LCDM/FLRW and its quasi-absolute cosmic time is incompatible with the equivalence principle and not totally relativistic.

Gibberish. I don’t know what you’ve read and misunderstood, but this is gibberish.

Quote:

If my model could be rejected because you thought it was incompatible with relativity, then so should LCDM/FLRW.

Except the FLRW solutions are exact solutions to the field equations, so they are, by definition, compatible with GR.

[W.D.Clinger]

Originally Posted by Mashuna

Originally Posted by Mike Helland

13.8 is a fairly popular column by Adam Frank, and he's doing a series on the problems with LCDM. That's where this came from. People are talking about it. I don't have to go looking for it.

You might have to look outside the skeptics forum tho.

I’m not denying you’ve found a link, I’m questioning your understanding of the [l]ink.

I suspect the author and sole proponent of Helland physics is referring to a series that begins with these four articles:

1. 6 major cracks have appeared in the standard model of cosmology. Is it wrong?
2. Our standard model of cosmology is both a triumph and a jumbled mess
3. Our best models of the Universe have a troubled past
4. Some scientists speak of a "crisis in cosmology." They have a good reason

Although the titles of those articles are clickbait, the articles themselves are reasonable. Here's a summary of the situation, from the end of that fourth article:

Originally Posted by Adam Frank

The Big Bang model of cosmology shows us a Universe that is evolving rather than static and eternally unchanging. It is not under question in any serious way....What these new JWST results do throw into question is the story about that evolution that the standard model of cosmology tells us. That is what Melia says needs a big update, and the new data certainly provide a compelling clue that something might be amiss. The real question facing us is how much of an update is needed.

The following spoiler gives Mike Helland's cargo-cult silliness more attention than it really deserves, but it has some genuine historical interest.

Originally Posted by Mike Helland

Maybe Clinger could explain how de Sitter is wrong about system A having a quasi-absolute time and system B being entirely relative.

De Sitter seems pretty clear. Clinger can claim otherwise, but without an argument there isn't a reason to accept that as the truth.

Mike Helland is expressing his own misunderstanding of a paper by Willem de Sitter, published in 1917. That paper is of historical interest because it includes (what I believe to be) the first published description of what we now call de Sitter space. We now recognize de Sitter space as an FLRW model, but Friedmann (the F in FLRW) didn't publish his equations until 1922 and 1924, Lemaître (the L) didn't publish until 1927 (and wrote in Dutch, so his contributions weren't generally recognized until several years later), and Robertson and Walker (the RW) didn't publish until the 1930s. In short, de Sitter's understanding of these models circa 1917 was somewhat more confused than his understanding of these same models circa 1930.

As I noted two days ago, the "system A" of de Sitter's 1917 paper is Einstein's static universe. When de Sitter said "It should be pointed out that this relativity of inertia is in the system A only realised by making the time practically absolute", what de Sitter was really saying is that the relativity of inertia in Einstein's static universe would be obscured if that universe were to be described using any time coordinate other than the cosmic time coordinate by which Einstein's static universe is most naturally and most reasonably described. (Whether de Sitter understood that in 1917 is open to question, but he certainly understood that by the 1930s.)

As I noted two days ago, the "system B" of de Sitter's 1917 paper is an inelegant presentation of what we now call de Sitter space. As I noted above, de Sitter space is an FLRW model. That de Sitter space is most naturally and most reasonably described using a cosmic time coordinate, but de Sitter didn't understand that in 1917. In keeping with the prejudices of that time, de Sitter preferred a coordinate system that gave the misleading impression of describing a static universe, even though that misleading coordinate system came at the cost of making de Sitter space appear to be inhomogeneous and anisotropic. (It appears unlikely that de Sitter understood that in 1917, but he certainly had come to understand that by the 1930s.)

[Mike Helland]

Originally Posted by hecd2

What issue?

Gibberish. I don’t know what you’ve read and misunderstood, but this is gibberish.

Except the FLRW solutions are exact solutions to the field equations, so they are, by definition, compatible with GR.

And the equivalence principle? And the principle of relativity?

If so, why does de Sitter call it quasi-absolute? Why do the other authors say g_tt=1 breaks the equivalence principle?

[hecd2]

Originally Posted by hecd2

Except the FLRW solutions are exact solutions to the field equations, so they are, by definition, compatible with GR.

Don’t want to take my word for it? Try a standard textbook, for example Ciufolini and Wheeler Gravitation and inertia. Turn to section 4.2 on pages 193 - 220. First the metric is formally derived by applying the formalism of the Lie derivative of a tensor field with respect to a vector field. The derivation proceeds to define the homogeneity and isotropy of the manifold in terms of an isometry group of the Killing vector fields. Once the familiar metric is formally and rigorously derived, it can be formally shown that the origin can be translated freely anywhere and the metric has the same form with the new coordinates as it had with the original ones. The expression for the Gaussian curvature is derived and from that the Ricci curvature and the Einstein curvature tensor, to show formally that the curvature is constant over the manifold. Ciufolini and Wheeler then go on to formally derive the distance versus redshift relationship, and then the dynamics of the model - ie how it evolves over time. This is all perfectly compatible with, and indeed derived from the concepts of general relativity.

[hecd2]

Originally Posted by Mike Helland

And the equivalence principle? And the principle of relativity?

What about them?

Quote:

If so, why does de Sitter call it quasi-absolute? Why do the other authors say g_tt=1 breaks the equivalence principle?

Why do they?

I want you to state in your own words what you think the problem is.