Why is there a 'crisis' in cosmology?

[Admin]

Since 2014, there have been over 300 proposals for solutions to the "crisis in cosmology." None of these proposals is universally agreed upon by cosmologists, and the crisis just keeps getting worse.

Why is there a 'crisis' in cosmology? : Read more

 

[rod]

I use these cosmology calculators to check H0 and other variables that show up, like the Hubble time for the age of the universe or size of the universe when the CMBR appeared vs. size of the universe today (very different).

Cosmology Calculators (caltech.edu)
Cosmology calculator | kempner.net

Just tweaking a few parameters will create a *crisis in cosmology*

 

[rod]

Here is another cosmology calculator, LAMBDA - Calculators (nasa.gov)

A tweak here and there, we have a crisis

 

[rod]

Here is another example of why cosmology is in crisis mode. Physicists Set a Record by Measuring Time Distortion Across a Single Millimeter, https://www.msn.com/en-us/news/tech...e-millimeter/ar-AAQ8uVr?ocid=msedgdhp&pc=U531

My observation. The report here says, "More importantly, that seamless sheet of spacetime curving ever so gracefully for general relativity would be a fuzzy mess under a quantum microscope because of the problem with less precise properties we mentioned earlier. This would create a nightmare for anybody looking for a way to mesh the two ideas together." My note. The *fuzzy mess* adds to the vacuum energy density or cosmological constant in GR for expanding 3D space. This is a serious conflict between QM and GR where our universe should not exist today. Is Inflation physics as well tested as GR and gravity redshift as reported here? How can I test that 3D space expanded some 10^20 or more times faster than c velocity *in the beginning*, just after the postulated BB event? Consider the tests reported here. What is going in cosmology? Is it a science or something else?

Reference paper cited, Resolving the gravitational redshift within a millimeter atomic sample, https://arxiv.org/abs/2109.12238, 24-Sep-2021

The 27 page arXiv paper link, https://arxiv.org/ftp/arxiv/papers/2109/2109.12238.pdf

 

[Helio]

It might be that we are discovering that the Hubble Constant isn’t a fixed constant for all the prior 13.8 billion years.

It‘s now called the Hubble-Lemaitre Constant and a few points are worth noting:

Edwin Hubble gave us advanced values for both redshifts and distances, but he never would state redshifts were velocity related.

Lemaitre used the first redshifts known (Slipher’s) and Hubble’s distance estimates to support his 1927 GR model, which became the BBT. This model, IIRC, included an acceleration period, hence variable rates.

Here’s an article that finds variances in rates from SN redshifts that correlate with distance. The two “constants” might be correct - the slower one (62) from the distant past and before acceleration, and the current rate (74).

 

[rod]

From Helio post #5. "The two “constants” might be correct - the slower one (62) from the distant past and before acceleration, and the current rate (74)."

LAMBDA - Calculators (nasa.gov)

Using the LAMBDA calculator, plugging these values into H0 and z = 0 provides illumination here concerning how a crisis can be shown to the public using plain language . The age of the universe using 62 is 15.403 billion years old, 74 results in a universe 12.906 billion years old. We have stars and various clusters dated older than this. Other parameter tweaks will result in more variations for the answers

 

[Helio]

From Helio post #5. "The two “constants” might be correct - the slower one (62) from the distant past and before acceleration, and the current rate (74)."

LAMBDA - Calculators (nasa.gov)

Using the LAMBDA calculator, plugging these values into H0 and z = 0 provides illumination here concerning how a crisis can be shown to the public using plain language . The age of the universe using 62 is 15.403 billion years old, 74 results in a universe 12.906 billion years old. We have stars and various clusters dated older than this. Other parameter tweaks will result in more variations for the answers

So the average rate for a non-linear expansion rate will be between the 62 and 74, hence an age between 12.9 billion and 15.4 billion years. Thus, 13.8 billion years is looking about right.

 

[rod]

Helio, your post #7 I will call the *Helio reconciliation method* If folks use those calculators I provided in these posts, small variations in DM, DE, or open vs. flat universe will alter more than a little, including a universe that is less than 11 billion years old.

 

[Helio]

Helio, your post #7 I will call the *Helio reconciliation method* If folks use those calculators I provided in these posts, small variations in DM, DE, or open vs. flat universe will alter more than a little, including a universe that is less than 11 billion years old.

Yep, it can quickly get tricky. Far more observations with extreme accuracy are needed.

Lemaitre made what he knew was a crude estimate of ~ 600 kps/Mpc, based on Slipher’s ~ 2 dozen red shifts of only close galaxies, I assume.

Later, when Hubble found his first extragalactic Cepheid, his data put the age of the universe of only 2 billion years. [Soon, another type of Cepheid was determined to exist, which was the one he found in Andromeda.]

Stars were known at the time to be older, so this may be one reason Hubble avoided making any theoretical claims.

 

[David-J-Franks]

From the article;

"And it assumes that there's another substance, called dark energy (that's the "Lambda"), that maintains a constant density as the universe expands."

Does anyone know what it is that's being kept at constant density?

 

[Helio]

From the article;

"And it assumes that there's another substance, called dark energy (that's the "Lambda"), that maintains a constant density as the universe expands."

Does anyone know what it is that's being kept at constant density?

That's a good question. I think they meant something else, like "critical density", which is dependent on changing density as the Universe expands.