Something is wrong with Einstein's theory of gravity

[Admin]

Albert Einstein's theory of general relativity has been remarkably successful in describing the gravity of stars and planets, but it doesn’t seem to apply perfectly on all scales.

Something is wrong with Einstein's theory of gravity : Read more

 

[Helio]

The ‘tension” caused by the difference between the two H-L constants does not seem to mention that, with acceleration, the expansion rate will always (100% of the time) prodeuce an increase in any “constant”. The 67.4 rate from 13.8 Gyrs. ago, and the recent times rate of 73.4 rate looks like acceleration is a very simple answer to the “tension”. But math isn’t a weakness for cosmologists, so what am I missing?

 

[Unclear Engineer]

I think what you are missing is that there seems to be a lack of understanding for the reason that the universe is accelerating its expansion. Especially since it is theorized to have expanded extremely rapidly in the past, then slowed down, then accelerated again. The BBT just puts those speeds into the theory without any explanation of how the physics work to cause it. Even the GRT doesn't explain the causes, it just describes the effects in a predictable way. Getting an equation that accurately describes something that we don't have physical process insights about often leads to new discoveries that provide those insights. But, so far, that is not happening with the BBT. We see that gravity alone does not explain the behavior of stars in galaxies nor the behavior of galaxies in the universe, but all we have done is attribute that to an unknown force that we named "dark energy" for the expansion and "dark matter" for the unexplained apparent attraction. And, it seems that the BBT explanation for the expansion of space due to dark energy violates our understanding of the physical law of conservation of (energy + mass).

So, there is a lot missing from the BBT in the way of explanation about how all of those assumed things actually work.

 

[Helio]

So, there is a lot missing from the BBT in the way of explanation about how all of those assumed things actually work.

Yes, but I’m asking a math question, IMO.

You can’t have acceleration with a constant velocity (H-L “Constant”).

[My lengthy prior post here was voided because it claimed I needed to accept cookies.]

iPhone

 

[Unclear Engineer]

I think you are saying that the "math" is inconsistent to have a "constant" that is changing with time. But, theorists who embrace the idea that the expansion of the universe is accelerating already have changed their language from "Hubble constant" to verbiage like "Hubble factor" or "Hubble expansion" to be compatible with their opinion that it is not a constant factor over time.

But, I still wonder about that. When scientists perform uncertainty analyses, they can only assess the uncertainty in the factors that they understand. My experience with uncertainty estimates that can be compared to later knowledge is that they are very often underestimates of the amount of uncertainty. And, there seems to be a lot we don't understand in cosmology.

From what I understand, the major "tension" is between the data on supernovas and the cosmologic microwave background radiation. So, how certain are we that we know what we need to know about the CMBR? Do we really understand its "age" and its "expansion" factor so well that we know that the expansion of the universe slowed down after the BBT inflation period and then started speeding up again? If that is the case, why do the 3 graphs of the different measures of the Hubble factor over different distances look like straight lines that join end-to-end without a curve or inflection point?

I look at the BBT as a lot of speculation about how what we see might be explained, but without any real proof that it is actually the way it had to happen. The argument in its favor seems to be only that there isn't any other theory currently believed by more people. And we all know that astronomy/cosmology comes from a long line of theories that were believed by most people until somebody came up with a better testable theory.

 

[rod]

The article does briefly mention the cosmological constant problem in BB too, something not well known apparently today concerning the BB model and expansion of space.

"Quantum theory predicts that empty space, the vacuum, is packed with energy. We do not notice its presence because our devices can only measure changes in energy rather than its total amount. However, according to Einstein, the vacuum energy has a repulsive gravity – it pushes the empty space apart. Interestingly, in 1998, it was discovered that the expansion of the universe is in fact accelerating (a finding awarded with the 2011 Nobel prize in physics(opens in new tab)). However, the amount of vacuum energy, or dark energy as it has been called, necessary to explain the acceleration is many orders of magnitude smaller than what quantum theory predicts. Hence the big question, dubbed “the old cosmological constant problem”, is whether the vacuum energy actually gravitates – exerting a gravitational force and changing the expansion of the universe."

Here is an interesting report on the topic. The Cosmological Constant Is Physics’ Most Embarrassing Problem, https://www.scientificamerican.com/...onstant-is-physics-most-embarrassing-problem/

"The problem with vacuum energy is that there's not enough of it. When scientists first started thinking about the concept, they calculated that this energy should be huge—it should have expanded the universe so forcefully and quickly that no stars and galaxies ever formed. Because that is clearly not the case, the vacuum energy in the universe must be very small—about 120 orders of magnitude smaller than what quantum theory predicts. That's like saying that something weighing five pounds should really weigh five-with-120-extra-zeros-after-it pounds. The discrepancy has prompted some scientists to call vacuum energy “the worst theoretical prediction in the history of physics.” Vacuum energy is thought to be the main ingredient in the “cosmological constant,” a mathematical term in the equations of general relativity. The enormous discrepancy between the predicted amount of vacuum energy and the measured amount is often called the cosmological constant problem."

My note. The cosmological constant is the Greek letter Lambda in GR equations attempting to show how the vacuum energy of empty space can expand space or create a static universe. The NASA ADS Abstract has a number of papers on this problem, e.g., Interrogating the Legend of Einstein's "Biggest Blunder" https://ui.adsabs.harvard.edu/abs/2018PhP....20..318O/abstract, December 2018.

One hundred years of the cosmological constant: from "superfluous stunt" to dark energy, https://ui.adsabs.harvard.edu/abs/2018EPJH...43...73O/abstract, April 2018.

There is more going on now with BB model than just the Hubble constant. I collected various reports on the Hubble Constant and found values ranging from 500 km/s/Mpc in the early 1930s and values ranging 67 km/s/Mpc to 75.4, some 80+ range now. Currently the cosmology calculators use this as a constant and the age of the universe bounces all around too.

 

[Helio]

From what I understand, the major "tension" is between the data on supernovas and the cosmologic microwave background radiation.

Yes, that's my understanding as well.

So, how certain are we that we know what we need to know about the CMBR? Do we really understand its "age" and its "expansion" factor so well that we know that the expansion of the universe slowed down after the BBT inflation period and then started speeding up again?

There are a number of variables that must fit to get a precise understanding of the CMBR, including the amount of baryonic and dark matter density.

But I think these current estimates are assumed to be reasonably accurate, hence the slower expansion rate from the CMBR data is considered quite accurate.

But given those higher densities, why isn't a slower expansion rate not a solid given? It seems too obvious so that any discussion on "tension" should at least address this circumstance, yet it's not. And it may be that both values are correct due to the very likely slower rate from 13.8 billion years ago.

I recall seeing a graph from Lemaitre showing a slight variable rate (i.e. acceleration to modern times). Recall that it was he, not Hubble, that introduced the first expansion rate, though he knew that the data he had was too rough to argue accuracy.

 

[Helio]

There is more going on now with BB model than just the Hubble constant. I collected various reports on the Hubble Constant and found values ranging from 500 km/s/Mpc in the early 1930s and values ranging 67 km/s/Mpc to 75.4, some 80+ range now. Currently the cosmology calculators use this as a constant and the age of the universe bounces all around too.

The early high values are due to Hubble's use of the wrong Cepheid variable data. This had the effect of claiming the universe was younger than the age of many stars. So quite a mess.

Once it was discovered that Cepheids are not all the same in their Period-luminosity relationship, then Andromeda, and other galaxies suddenly were determined to be much farther away than the original estimates by Hubble.

 

[rod]

"I recall seeing a graph from Lemaitre showing a slight variable rate (i.e. acceleration to modern times). Recall that it was he, not Hubble, that introduced the first expansion rate, though he knew that the data he had was too rough to argue accuracy."

That is a problem. When you use the cosmology calculators, the universe diameter when the CMBR appears as light is about 80-82 million light years. Today it is 93 billion light years diameter (CMBR z = 1100 and comoving radial distance from Earth). For space to expand from a size near or smaller than the Planck length and Planck time to some 80 million light years across when the CMBR forms (380,000 years), is much faster than c velocity. If H0 is a variable for different times in the BB model, the cosmology calculators need to be modified to show this and what impact that will have like on the age of the universe along with other changes too like distances and sizes.