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Author Topic:   Cosmological Constant and Dark Energy has been in the news for months.
LamarkNewAge
Member
Posts: 2497
Joined: 12-22-2015


Message 1 of 53 (917477)
04-09-2024 12:52 AM


But the last week, it has been reported widely.
The largest survey of the sky, reported back in January, showed that there was probably only a 5% chance Dark Energy had the numbers that matched up with a supposed value of the "Cosmological Constant".
I always preferred a 100% flat universe, as it was seen as the most consistent cosmological topography which was consistent with the Many Worlds Theory.
But I doubted the Dark Energy was very good proof of the perfect "cosmological constant".
I dont feel a 100% flat universe is needed for the Many Worlds Theory to be possible.
(Copenhagen is still about to get buried overnight, when psychic studies are finally released
The relevant study, released in January (But the developing results have been leaked for years).
quote:
Will We Ever Know the True Nature of Dark Energy? | NOVA | PBS
Astronomers discovered dark energy in 1998, but are we any closer to understanding what it really is?
MONDAY, JANUARY 27, 2014 THE NATURE OF REALITY
....
Future observations should help narrow down the possibilities. Dark energy’s behavior over time, which is measured by the ratio of its pressure and energy density (called its equation of state, or w) is measured to a precision of about 5% today. But in the next five years, new observations, including those with a special camera fitted onto a telescope in Chile called the Dark Energy Survey , will increase the precision to 2% or 3%, says Mortonson. Future ground- and space-based missions, including a planned European space mission called Euclid and a possible US probe called WFIRST , could make even finer measurements.
These missions will not only probe the expansion history of the universe but also chronicle how the distribution of matter has changed over time. One way to do this is with a method called weak gravitational lensing, which looks for distortions in the light from distant galaxies due to any mass that the light passes on its way to a telescope. If dark energy changes over time or if gravity behaves unexpectedly at large scales, we might see evidence of it in the changing “clumpiness” of matter over space and time.
But Eisenstein points out that there are always going to be exotic dark energy models that behave just like the cosmological constant. “The worry is that if we do all these very accurate measurements, and it still looks like a cosmological constant, then we haven’t actually ruled out a lot of the models,” he says. “I think we have a major challenge on the theory side to try to understand what else we can look for.”
“[To understand] dark energy, we will probably require more time, and I would say not less than 10 years,” says Pettorino.
But it’s worth trying to get to the bottom of the mystery, say the researchers. “We thought we had four forces of nature: gravity, electromagnetism, and the weak and strong nuclear forces. Dark energy is either some new force, or some substantial modification to gravity,” says Eisenstein. “It’s a major actor in cosmology and in the history of the universe.”
Then
quote:
Dark energy survey result dims hope for cosmological constant
January 10,2024
A dark energy survey 10 years in the making has made a surprise finding, suggesting that the theory of the expansion of the universe might not be correct.
The final Dark Energy Survey (DES) measurement was released at the 243rd American Astronomical Society meeting in New Orleans and published on pre-print server arXiv.
Dark energy is dark matter’s even more elusive cousin. Studies have suggested that dark energy is estimated to make up almost 70% of the observable Universe and is immensely important for measurements of the acceleration of the Universe’s expansion. But, scientists also have no idea what it is.
One theory is that this dark energy should fit nicely into something called the ‘cosmological constant’ which Einstein added, and then removed, from his calculations into general relativity.
Although Einstein tossed it, it was later revived when it was realised that the universe was expanding at an accelerating rate.
Supernova ‘standard candles’ not so standard after all
“Einstein’s concept of the cosmological constant could actually explain dark energy if it had a positive value (allowing it to conform to the accelerating expansion of the cosmos),” said Professor Robert Nichol, a member of the DES collaboration in a piece for The Conversation. Nichol is also a Pro Vice Chancellor at the University of Surrey.
If dark energy is the cosmological constant, the “equation of state” of dark energy would equal -1. The DES used the best space object we have to try and measure this equation of state – Type Ia supernovae or ‘standard candles’. These are stellar explosions which release consistently bright flashes, allowing researchers to measure how far away they are in the Universe.
“It is very exciting times to see this innovative technology to harness the power of large astronomical surveys”, says one of the researchers, Dr Anais Möller from Swinburne University of Technology.
“Not only we are able to obtain more type Ia supernovae than before, but we tested these methods thoroughly as we want to do more precision measurements on the fundamental physics of our universe.”
An international team of more than 100 scientists mapped an area almost one-eighth of the sky using the 570-megapixel Dark Energy Camera. They took data for 758 nights across six years.
But the results, weren’t what they were expecting. Instead of an equation of state of -1, the end result from the DES was -0.8.
That’s a pretty large difference in astronomy terms, and would suggest that the cosmology constant is wrong. But scientists aren’t so sure yet.
First there’s the error bars – about plus or minus 0.18. Combined with data from the ESA’s Plank telescope the uncertainty is large enough that there’s still a 5% chance of -1.
That’s only a 1 in 20 odds, not ideal, but the results aren’t sure enough for researchers to confirm either way.
“As usual, scientists want more data,” said Nichol.
“The DES results suggest that our new techniques will work for future supernova experiments with ESA’s Euclid mission (launched July 2023) and the new Vera Rubin Observatory in Chile.”
[ Originally published by Cosmos as Dark energy survey result dims hope for cosmological constant ]

It was only a matter of time until the numbers did not match up.
I have mixed feelings :
I feel it is a blow to see the absolutely perfect critical density Dark Energy number miracle fall apart.
But, the (um)clue is a fortunate one, if one values science. It is actually scary to think that a pure coincidence could have caused us to assume all of the expansion of space was due to a "cosmological constant" when our perfect number inflation observation was more of an artifact fluke.
(The more logical heads always knew that the number match value, per the Ia supernova observations, could be just a coincidence, as coincidences can and do happen all the time. Not all observations carry the same weight. This 25 year old - now obsolete - "cosmological constant" is an example of an observation that always could have been interpreted differently)
(A good example of a non-coincidence example would be the hypothetical VHS tape of an alternate universe 1983 AFC Championship game featuring John Elway & the L.A. Raiders defeating Dan Marino's Baltimore Colts at Memorial Stadium in early 1984, then a tape of the Raiders beating the Redskins in the Superbowl with Van McCelroy winning the MVP after intercepting a pass and making 6 tackles. A piece of evidence for a Quantum Tuner, it would be! If only...)

Replies to this message:
 Message 3 by Tanypteryx, posted 04-09-2024 9:31 AM LamarkNewAge has replied
 Message 4 by Percy, posted 04-09-2024 9:40 AM LamarkNewAge has replied
 Message 5 by Taq, posted 04-09-2024 1:03 PM LamarkNewAge has replied

  
LamarkNewAge
Member
Posts: 2497
Joined: 12-22-2015


Message 6 of 53 (917492)
04-09-2024 2:18 PM
Reply to: Message 3 by Tanypteryx
04-09-2024 9:31 AM


quote:
"(Copenhagen is still about to get buried overnight, when psychic studies are finally released

The relevant study, released in January (But the developing results have been leaked for years)."

Really? Psychic studies?
The relevant study had to do with what I quoted. The Chilean observatory DES study.
The other issue:
Copenhagen has a theoretical "COLLAPSE" of the wave function. Undefined numbers of particle get "observed" and the quantum superposition (in Hibbert space) of these particles (however many and in what conglomeration?) collapses, and then classical physics kicks in (at some undefined size boundary, when the quantum object world becomes a classical object.
The Many Worlds Interpretation also has an undefined particle number problem in the first field issue of play, but the conglomeration field is much cleaner: There exists a UNIVERSAL wave function with NO COLLAPSE from Hibbert Space. Instead the entire Universe doubles, perhaps trillions of times - per each individual particle (?) - in a fraction of a second.
(Yes, that means each individual rat, eating cheese in China, has many trillions of particles in which each little quark - on a single rat hair - creates trillions of copies of YOU per FRACTION OF A SECOND.)
Physicist Donnie Deutch feels that the very early stage of the universe splitting is not yet a complete separation into a totally isolated into its self contained, internally consistent isolation. Interactions are still going on, while Sean Carroll defines the complete split slightly earlier.
Quantum Reports | Free Full-Text | Many-Worlds: Why Is It Not the Consensus?
Quantum Reports | Special Issue : The Many-Worlds Interpretation of Quantum Mechanics
MDPI - Publisher of Open Access Journals
quote:
So, I think it's interesting that the microwave background observations indicate a different expansion rate for the Universe than the observations of Type 1A supernovae, but it seems clear that they must not be measuring the exact same thing, one or the other, or both, have some unknown factors that are skewing the results.
The early universe, at 379,000 years old, is clearly "flat". Per CMB.
I dont think there is debate on the first 380,000 years.
The expansion rate of the universe, per Type 1A SUPERNOVAE observations, never has had exactly identical numbers per observation. My way of saving a flat universe (my excuse) was to consider the tiny percentage of the universe containing galaxies as a type of hypothetical gravity trap which stalls the creation of space, per some unknown physical property of gravity. And the effects of the conglomerated gravity radiate outward (some unknown distance) an manipulate the dark energy (whatever it is exactly) in a way the changed the amount of space created.
quote:

I'm not sure what you want to discuss, or if you really meant psychic studies and miracles, or if it's your personal feelings about cosmology as if you have a stake in the final explanation?
What is magic to one generation is science to another.
What is a miracle to one generation is part of the known physical laws of the universe to another.
Stephen Hawking said something - once controversial - that became part of the lyrics of a 1990s song. He said FOR MILLIONS OF YEARS MAN LIVED WITH THE DINOSAURS. Birds, indeed.

This message is a reply to:
 Message 3 by Tanypteryx, posted 04-09-2024 9:31 AM Tanypteryx has replied

Replies to this message:
 Message 9 by Tanypteryx, posted 04-09-2024 3:10 PM LamarkNewAge has replied

  
LamarkNewAge
Member
Posts: 2497
Joined: 12-22-2015


Message 7 of 53 (917495)
04-09-2024 2:40 PM
Reply to: Message 4 by Percy
04-09-2024 9:40 AM


quote:
Can't tell where you're going with this, but the big cosmological questions of our time are:

What is dark energy?
What is dark matter?
Are all studies and experiments forever doomed to validate the Standard Model?
Dark Energy being understood has just about the same chance of us finding a complete cure to every single type of cancer, a complete cure to hardening arteries, a completely safe & cheap prevention pill for blood clots, and a discovery of a medicine that stalls and then reverses aging.
We better hope those quantum computers, we are developing, can tune into & receive signals from a parallel universe that is already millions of years into the future, so we can get all these things downloaded.
As for the majority view of particle physics:
The biggest question is whether one can solve the two totally different sets of physical laws that divide the quantum world from the classical world. Per Copenhagen, the quantum world has different physical laws than classical physics. But the size barrier is undefined.
Many Worlds proponents say the problem is already solved. We are all living in the quantum world. There is no size barrier that divides a classical object from a quantum object.
You are a quantum pea.
It is all a grand unified quantum physics.
(String Theory has its critics, like Bret/Eric Weinstein, and problems abound, granted)

This message is a reply to:
 Message 4 by Percy, posted 04-09-2024 9:40 AM Percy has seen this message but not replied

  
LamarkNewAge
Member
Posts: 2497
Joined: 12-22-2015


Message 8 of 53 (917496)
04-09-2024 3:02 PM
Reply to: Message 5 by Taq
04-09-2024 1:03 PM


quote:
The cosmological constant was thrown out a long time ago once we observed that the universe was expanding. The CC was something Einstein threw in because he thought the universe was eternal and static, so there had to be something that perfectly balanced the universe between expanding and contracting. Once we understood that the universe wasn't static then there was no need for the CC.
One has to know the composition of the universe, the rough age of the universe, and many other physical properties, forces, fields, etc. to even come close to understanding the inflation of the universe and the results of its interactions.
Einstein was at even more of a disadvantage than we are in. He lived the vast majority of his life before 1950.
He could not help but be wrong, whether he accepted a CC or not.
quote:
Could the CC make a comeback? Maybe. That's what the article you quoted was suggesting. However, the CC isn't a part of modern Big Bang models, so it isn't a problem if the CC is not brought back.
A Cosmological Constant DID make a comeback - in 1998, and it is not a stretch to say that most cosmologists felt that Dark Energy was proof of the Cosmological Constant, especially when the observations produced results that backed up a completely flat universe at exactly 100% the critical density needed for a 100% flat universe.
The 2024 story is that the newer Dark Energy version of the Cosmological Constant had a life that spanned from 1998-2024, then it died.
Dark Energy exists but there could be literally 100 different drivers that constitute its total value.
(Some sort of constant might make up a certain percentage of its total whole, but good luck sorting that one out)
And its total value is not certain, though there is a range.

This message is a reply to:
 Message 5 by Taq, posted 04-09-2024 1:03 PM Taq has replied

Replies to this message:
 Message 10 by Taq, posted 04-09-2024 3:12 PM LamarkNewAge has replied

  
LamarkNewAge
Member
Posts: 2497
Joined: 12-22-2015


Message 11 of 53 (917503)
04-09-2024 3:30 PM
Reply to: Message 9 by Tanypteryx
04-09-2024 3:10 PM


quote:
Really? I couldn't find anything related to "psychic studies."
I thought is said that was a "hypothetical" study and/or an unreleased study.
I started talking about Many Worlds because many have long speculated that Hibbert Space takes the UNIVERSAL UNCOLLAPSING macro-particle (entire universe) conglomeration "ray" to the hypothetical multiverse real-estate.
In a flat universe, with both early ​(first fraction of a second) Inflation, plus (separately) physical laws brought by an infinite local universe expansion (via Dark Energy), there is a place for these ever duplicating macro-particles (our duplicating universe!) to go.
quote:
Well, it wasn't the cosmic microwave background when it was emitted. And we are trying to compare observations made here and now on Earth of events that occurred in the distant past.

I would consider the question to be the accuracy of the measuring technique and the resolution of the image. Do have any comments on how recent the CMB data brings us to a clear picture, and how clear would you call the picture?
On the Type IA Supernovae observations, and the never matching values in the light shift measurements:
quote:
I think that can be said for any scientific observations. Exactly identical numbers per observation would be a clue that you might have a problem with your equipment or your analysis.
CMB and Type IA Supernova observations are clearly different techniques.
Both are trying to see what speed the inflation of the universe was moving at and at what time.
CMB has a great ability to let us look at the topography an spatial dimensions

This message is a reply to:
 Message 9 by Tanypteryx, posted 04-09-2024 3:10 PM Tanypteryx has replied

Replies to this message:
 Message 21 by Tanypteryx, posted 04-09-2024 6:08 PM LamarkNewAge has replied

  
LamarkNewAge
Member
Posts: 2497
Joined: 12-22-2015


Message 12 of 53 (917505)
04-09-2024 3:38 PM
Reply to: Message 10 by Taq
04-09-2024 3:12 PM


quote:
The accelerating expansion of the universe is the evidence for dark energy. It is no different than watching two masses being attracted to one another and calling it gravity. I don't understand why CC even has to be brought into the conversation because dark energy already encompasses what is being observed.
You seem to be saying there is no practical value to knowing what Dark Energy comes from.
I massively disagree, especially if it is relevant to alternate universes.
Inflation is 100% relevant to the multiverse ( whether alternate universes exist or not), as all can agree.
String Theory is highly relevant to the early cosmic inflation.
Dark Energy is also relevant to whether you get crushed like a quantum bug.

This message is a reply to:
 Message 10 by Taq, posted 04-09-2024 3:12 PM Taq has replied

Replies to this message:
 Message 13 by Taq, posted 04-09-2024 3:56 PM LamarkNewAge has replied

  
LamarkNewAge
Member
Posts: 2497
Joined: 12-22-2015


Message 14 of 53 (917514)
04-09-2024 4:17 PM
Reply to: Message 13 by Taq
04-09-2024 3:56 PM


Dark Energy has a measurable value.
What is your opinion on the average number value of Dark Energy?

This message is a reply to:
 Message 13 by Taq, posted 04-09-2024 3:56 PM Taq has replied

Replies to this message:
 Message 15 by Taq, posted 04-09-2024 4:35 PM LamarkNewAge has replied

  
LamarkNewAge
Member
Posts: 2497
Joined: 12-22-2015


Message 16 of 53 (917517)
04-09-2024 4:40 PM
Reply to: Message 15 by Taq
04-09-2024 4:35 PM


Re: Dark Energy has a measurable value.
I dont think there is a controversy when one measures the speed of light.
Would a hypothetical controversy related to the speed of light, be important?

This message is a reply to:
 Message 15 by Taq, posted 04-09-2024 4:35 PM Taq has replied

Replies to this message:
 Message 17 by Taq, posted 04-09-2024 4:55 PM LamarkNewAge has replied

  
LamarkNewAge
Member
Posts: 2497
Joined: 12-22-2015


Message 18 of 53 (917524)
04-09-2024 5:13 PM
Reply to: Message 17 by Taq
04-09-2024 4:55 PM


Re: Dark Energy has a measurable value.
The age of the universe is affected by this probable change in the (now very disputed) number value of Dark Energy, for one thing.
You seem to feel that the number value of Dark Energy is unimportant.
One thing that should possibly scare you is there is now the possibility that the value could change suddenly, and the difference between a positive and negative number value could - if extreme enough possibilities are considered - in theory, possibly cause the whole universe to collapse in our lifetimes.
Now there is the possibility for Dark Energy to change across time and space.
Infact, most will reach just such an interpretation.
So what is the cosmic trigger?

This message is a reply to:
 Message 17 by Taq, posted 04-09-2024 4:55 PM Taq has replied

Replies to this message:
 Message 19 by Taq, posted 04-09-2024 5:21 PM LamarkNewAge has replied

  
LamarkNewAge
Member
Posts: 2497
Joined: 12-22-2015


Message 20 of 53 (917529)
04-09-2024 5:36 PM
Reply to: Message 19 by Taq
04-09-2024 5:21 PM


Re: Dark Energy has a measurable value.
But has the speed of light ever changed?
(distant light is spatially further away from us than its very physical speed due to, ironically, Dark Energy)
The spatial dimensions of our universe have probably changed to some extent (or could) depending on what Dark Energy has been doing all along the way. I hope everything is flat and stays flat, if we aren't a bunch of cut off bubble universes.
Michio Kaku feels that the multiverse is made up of separate round bubbles (for universes), which keep splitting off when inflation creates a, perhaps, never ending number of universes.
Kaku says the bubble universes actually bump into each other and actually can and do destroy each other. I hope not!
Inflationary forces seem to very much have the possibility of changing, though Dark Energy might possibly be unchanging ( increasingly unlikely, now, it seems)
EDIT; Kaku is one of the Many World Interpretation proponents who do not regard a flat universe as important to the MWI, but he is a minority, I feel.

This message is a reply to:
 Message 19 by Taq, posted 04-09-2024 5:21 PM Taq has replied

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 Message 22 by Taq, posted 04-09-2024 6:24 PM LamarkNewAge has not replied

  
LamarkNewAge
Member
Posts: 2497
Joined: 12-22-2015


Message 23 of 53 (917538)
04-09-2024 6:58 PM
Reply to: Message 21 by Tanypteryx
04-09-2024 6:08 PM


quote:
LamarkNewAge in Message 11 writes:

I started talking about Many Worlds because many have long speculated that Hibbert Space takes the UNIVERSAL UNCOLLAPSING macro-particle (entire universe) conglomeration "ray" to the hypothetical multiverse real-estate.

In a flat universe, with both early ​(first fraction of a second) Inflation, plus (separately) physical laws brought by an infinite local universe expansion (via Dark Energy), there is a place for these ever duplicating macro-particles (our duplicating universe!) to go.
Tanypteryx in message 21:
I don't understand anything you are saying here.
I was saying the real issue of the quantum wave function NOT collapsing means the particles (such as trillions of duplicates of YOU per second) have to go somewhere, and Dark Energy AND early cosmic Inflation are an have been highly relevant for decades. Brian Greene wrote a book around 12 (?) years ago, and fairly early on, he referenced dark energy as highly relevant to Many Worlds, and he spent alot of pages on showing what objects in our life (whether television screens, pinpong tables, etc.) were shaped in a "finite" verses "infinite" dimension.
The multiverse has often been seen as something completely apart and different from the alternate universes, Sean Carroll had his epiphany in 2011.
quote:
Are Many Worlds and the Multiverse the Same Idea?
95 Comments / Science
When physicists are asked about “parallel worlds” or ideas along those lines, they have to be careful to distinguish among different interpretations of that idea. There is the “multiverse” of inflationary cosmology, the “many worlds” or “branches of the wave function” of quantum mechanics, and “parallel branes” of string theory. Increasingly, however, people are wondering whether the first two concepts might actually represent the same underlying idea. (I think the branes are still a truly distinct notion.)
At first blush it seems crazy — or at least that was my own initial reaction. When cosmologists talk about “the multiverse,” it’s a slightly poetic term. We really just mean different regions of spacetime, far away so that we can’t observe them, but nevertheless still part of what one might reasonably want to call “the universe.” In inflationary cosmology, however, these different regions can be relatively self-contained — “pocket universes,” as Alan Guth calls them. When you combine this with string theory, the emergent local laws of physics in the different pocket universes can be very different; they can have different particles, different forces, even different numbers of dimensions. So there is a good reason to think about them as separate universes, even if they’re all part of the same underlying spacetime.
The situation in quantum mechanics is superficially entirely different. Think of Schrödinger’s Cat. Quantum mechanics describes reality in terms of wave functions, which assign numbers (amplitudes) to all the various possibilities of what we can see when we make an observation. The cat is neither alive nor dead; it is in a superposition of alive + dead. At least, until we observe it. In the simplistic Copenhagen interpretation, at the moment of observation the wave function “collapses” onto one actual possibility. We see either an alive cat or a dead cat; the other possibility has simply ceased to exist. In the Many Worlds or Everett interpretation, both possibilities continue to exist, but “we” (the macroscopic observers) are split into two, one that observes a live cat and one that observes a dead one. There are now two of us, both equally real, never to come back into contact.
These two ideas sound utterly different. In the cosmological multiverse, the other universes are simply far away; in quantum mechanics, they’re right here, but in different possibility spaces (i.e. different parts of Hilbert space, if you want to get technical). But some physicists have been musing for a while that they might actually be the same, and now there are a couple of new papers by brave thinkers from the Bay Area that make this idea explicit.
Physical Theories, Eternal Inflation, and Quantum Universe, Yasunori Nomura
The Multiverse Interpretation of Quantum Mechanics, Raphael Bousso and Leonard Susskind
Related ideas have been discussed recently under the rubric of “how to do quantum mechanics in an infinitely big universe”; see papers by Don Page and another by Anthony Aguirre, David Layzer, and Max Tegmark. But these two new ones go explicitly for the “multiverse = many-worlds” theme.
After reading these papers I’ve gone from a confused skeptic to a tentative believer. This happened for a very common reason: I realized that these ideas fit very well with other ideas I’ve been thinking about myself! So I’m going to try to explain a bit about what is going on. However, for better or for worse, my interpretation of these papers is strongly colored by my own ideas. So I’m going to explain what I think has a chance of being true; I believe it’s pretty close to what is being proposed in these papers, but don’t hold the authors responsible for anything silly that I end up saying.
There are two ideas that fit together to make this crazy-sounding proposal into something sensible. The first is quantum vacuum decay.
Are Many Worlds and the Multiverse the Same Idea? – Sean Carroll
(I am glad I knew what keywords to type. Carrolls article was totally unfinable when I put "sean carroll many worlds interpretation" into google. Alot is said about Carroll on the net. Awsome. I put this search term to find the article: sean carroll many worlds interpretation hibbert space multiverse 2011)
Next
quote:
LamarkNewAge in Message 11 quotes
Tanypteryx from Message 9:

"Well, it wasn't the cosmic microwave background when it was emitted. And we are trying to compare observations made here and now on Earth of events that occurred in the distant past."

​LamarkNewAge
I would consider the question to be the accuracy of the measuring technique and the resolution of the image. Do have any comments on how recent the CMB data brings us to a clear picture, and how clear would you call the picture

Tanpteryx
I don't understand what kind of answer you are asking for here either.
I suppose I wanted to see what value people placed on the CMB.
Then compared it to other pictures from other observation techniques.
quote:
OK, I am really confused now, are you asking here why the supernovae results don't agree with eachother in some way, or why the supernovae and CMB data disagree?
All of the above
(yes and yes)
I was quote as saying:
quote:
LamarkNewAge in Message 11 writes:

CMB and Type IA Supernova observations are clearly different techniques.

Both are trying to see what speed the inflation of the universe was moving at and at what time.
You responed:
quote:
Obviously different measurement techniques, one giving data on the temperature of different regions of the Universe when it was ~380,000 years after the Big Bang and the other measuring the distance of different supernovae at different times in the past to measure the expansion rate.

I thought "inflation" referred specifically to a brief period of very rapid expansion right after the Big Bang. Are you using "inflation" and "expansion" interchangeably?
I was asking about the broad sweep, but you don't need to address the first fraction of a second of the universe (light was not even visible until 379,000 years later (CMB!) so the Supernovae observations wont ever be relevant to that).
I did not specifically mention Dark Energy, perhaps due to the fact that it can possibly be used in way too overgeneralized of a fashion, when describing the expansion from all time periods. But, the use of the term Dark Energy is taken to be a synonym for expansion in general. So just assume I was talking about Dark Energy.

This message is a reply to:
 Message 21 by Tanypteryx, posted 04-09-2024 6:08 PM Tanypteryx has replied

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LamarkNewAge
Member
Posts: 2497
Joined: 12-22-2015


Message 27 of 53 (917850)
04-18-2024 7:35 PM


Space.com article by Robert Lea argues Big Crunch is back
I hope a Big Crunch is not back.
But:
quote:
Dark energy could be getting weaker, suggesting the universe will end in a 'Big Crunch'
News
By Robert Lea published 2 days ago
"The discovery of evolving dark energy would be as revolutionary as the discovery of the accelerated expansion of the universe itself, if confirmed."
The current "standard model" of the cosmos, its history, and its evolution is called the Lambda Cold Dark Matter (LCDM) model — but the supremacy of this model, in which lambda represents the cosmological constant and dark energy, may now be under serious threat.
In short, that is because new observations of the cosmos have suggested that dark energy, the force causing our universe to expand faster and faster, seems to be weakening. That may not sound like much in and of itself, but this finding actually has the potential to cause the first major paradigm shift in cosmology since the discovery of the accelerated expansion of the universe just over 25 years ago. It could even suggest out universe won't end in a "Big Rip," or a "Big Chill," but rather a "Big Crunch." More on that shortly, first, let's dive into these fascinating results.
Related: Largest 3D map of our universe could hint that dark energy evolves with time
....
"The release of these results was a great day for cosmology, pointing to a 'decreasing' effect of the dark energy over time, meaning it is evolving and, therefore, not constant after all," Luz Ángela García Peñaloza, former DESI team member and a cosmologist at the Universidad ECCI in Columbia, told Space.com. "The discovery of evolving dark energy would be as revolutionary as the discovery of the accelerated expansion of the universe itself, if confirmed with future data."

Replies to this message:
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LamarkNewAge
Member
Posts: 2497
Joined: 12-22-2015


Message 30 of 53 (917854)
04-18-2024 8:16 PM
Reply to: Message 29 by ChatGPT
04-18-2024 8:07 PM


Re: Space.com article by Robert Lea argues Big Crunch is back
The link first:
Dark energy could be getting weaker, suggesting the universe will end in a 'Big Crunch' | Space
(This "bad news" came just before I started my thread, 2 weeks ago)
(This is not the other "bad" news, which I have been discussing - Supernova results)
The Supernova results came in early January
I immediately thought of the implications for the (hypothetical) multiverse, and the (very controversial) Quantum Many Worlds.
Sean Carroll, every month, has a three hour question and answer program. Usually, it is mostly about the Many Worlds Theory. He did not get any questions about whether the collapse of the Cosmological Constant could also sink the Many Worlds Theory. I fear it could bring down my favorite theories. 

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 Message 29 by ChatGPT, posted 04-18-2024 8:07 PM ChatGPT has not replied

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LamarkNewAge
Member
Posts: 2497
Joined: 12-22-2015


Message 46 of 53 (917925)
04-20-2024 2:14 AM
Reply to: Message 45 by ChatGPT
04-19-2024 10:39 AM


Back to the Big Bounce (Loop Quantum Gravity is a theory)
https://www.youtube.com/watch?v=P1iA8haPBe0
In this weekly science news, from May 2023, we see an institution made news by conducting an experiment, which supports Quantum Loop Gravity.
The CMB is somewhat consistent with some aspects of Loop Quantum Gravity.
The physicist in the video shoots this news story down, a bit.
On that note, a roundtable in London, will be looking at Dark Energy and the ailing Cosmological Constant
quote:
Cosmologists convene to question accepted view of the universe - Thred Website
Cosmologists convene to question accepted view of the universe
TECH
SCIENCE
Posted 15 April, 2024
By Jamie Watts
London, UK
Some of the world’s top cosmologists are meeting at London’s Royal Society to scrutinise an accepted theory on the universe’s formation. The view, formed in 1922, suggests that the universe is a vast, even expanse with no notable features.
....
In recent years, though, a backlog of astronomical observations has cast doubt on the accepted science and raised the question of whether humanity’s current cosmology model needs revising – or perhaps throwing out entirely.
‘The theoretical basis is past its sell-by date,’ declares Oxford University cosmologist Professor Subir Sakar, who is co-organising a crunch meeting including some of the field’s biggest brains at London’s Royal Society.
....
Many of the conference’s attendees are ready to posit alternative views with file-binders of evidence in-hand. ‘More and more people are saying the same thing and these are respected astronomers,’ Sakar clarified.
These anomalous findings include observations that suggest the universe is expanding quicker in certain regions than others, evidence of cosmic flows – huge celestial tracks where the universe should be smooth and featureless – and a ‘lopsided’ view of the cosmos that could undermine the basis for dark energy.
Cosmological Constant in trouble, unless gravitational clusters are reason for differing speeds:
quote:
Top Astronomers Gather to Confront Possibility They Were Very Wrong About the Universe
TOP ASTRONOMERS GATHER TO CONFRONT POSSIBILITY THEY WERE VERY WRONG ABOUT THE UNIVERSE
A number of researchers have found evidence that the universe may be expanding more quickly in some areas compared to others, raising the tantalizing possibility that megastructures could be influencing the universe's growth in significant ways.
Sarkar and his colleagues, for instance, are suggesting that the universe is "lopsided" after studying over a million quasars, which are the active nuclei of galaxies where gas and dust are being gobbled up by a supermassive black hole.
The team found that one hemisphere actually hosted slightly more of these quasars, suggesting one area of the night sky was more massive than the other, undermining our conception of dark energy, a hypothetical form of energy used to explain why the universe is expanding at an accelerated rate.
....
Other researchers have suggested that the cosmological constant, which has been used for decades as a way to denote the rate of the universe's expansion, actually varies across space, which would contradict the standard model of physics.
Daily Star Lebanon gives details:
quote:
Cosmologists poised to challenge universe-viewing standards
....
At this conference, taking place from April 15th to 16th, leading cosmologists will explore the implications of recent astronomical discoveries that suggest inconsistencies in this long-held assumption. Professor Subir Sarkar from the University of Oxford, one of the conference’s organizers, noted in The Guardian that new high-profile observations indicate the universe might expand at different rates in different areas and contain massive structures that defy existing theories.
....
One of the intriguing presentations will be by Dr. Nathan Secrest from the US Naval Observatory, who will discuss findings from over 1 million quasars. His research suggests a slight asymmetry in the distribution of these quasars across the universe’s hemispheres, a potential challenge to the concept of dark energy which accounts for two-thirds of the universe.
Additionally, Dr. Konstantinos Migkas from Leiden University will present data suggesting that the Hubble constant— the rate of the universe’s expansion—varies in different parts of space, contradicting predictions based on the standard model.
PhD student Alexia Lopez from the University of Central Lancashire will introduce discoveries of cosmic megastructures like the Big Ring and Giant Arc, which exceed the scale at which the universe is expected to be homogeneous and featureless. These findings prompt questions about the fundamental assumptions underpinning all cosmological theories.
....
In conclusion, as cosmology faces potentially paradigm-shifting evidence, Professor Wendy Freeman points out the “tantalising threads” revealed by the James Webb Space Telescope that necessitate further investigation to determine where the standard model might fall short. This conference promises to be a significant event in the ongoing exploration of our universe’s mysteries.
In light of all this, here is a recent study which, on reflections, seems amusing.
https://phys.org/news/2024-03-precise-dark-energy-ai.html
Not at all what the really big 2024 studies have been showing us. Amazing contradictions, no? Crazy.
Back to the avalanche:
Here is yet another study that contradicts what was thought about Dark Energy
quote:
The Universe
Surprise! The universe's expansion rate may vary from place to place
News
By Mike Wall published April 9, 2020
The new results challenge a core tenet of modern cosmology.
The universe may not be the same in every direction after all.
The expansion rate of the universe appears to vary from place to place, a new study reports. This finding, if confirmed, would force astronomers to reassess just how well they understand the cosmos.
"One of the pillars of cosmology — the study of the history and fate of the entire universe — is that the universe is 'isotropic,' meaning the same in all directions," study lead author Konstantinos Migkas, of the University of Bonn in Germany, said in a statement. "Our work shows there may be cracks in that pillar."
....
It's possible that this result has a relatively prosaic explanation. For example, perhaps galaxy clusters in the anomalous areas are being pulled hard gravitationally by other clusters, giving the illusion of a different expansion rate.
Such effects are seen at smaller spatial scales in the universe, the researchers said. But the new study probes clusters up to 5 billion light-years away, and it's unclear if gravitational tugs could overwhelm expansion forces over such vast distances, they added.
If the observed expansion-rate differences are indeed real, they could reveal intriguing new details about how the universe works. For instance, maybe dark energy itself varies from place to place throughout the cosmos.
"It would be remarkable if dark energy were found to have different strengths in different parts of the universe," study co-author Thomas Reiprich, also of the University of Bonn, said in the same statement. "However, much more evidence would be needed to rule out other explanations and make a convincing case."
The new study appears in the April 2020 issue of the journal Astronomy and Astrophysics. You can read it for free at the online preprint site arXiv.org.
Surprise! The universe's expansion rate may vary from place to place | Space
Above was just amazing.
Here is another study based on a study published December 2023 in the Journal of Cosmology and Astroparticle Physics, in which researchers from the University of Copenhagen and the Tokyo Institute of Technology, which challenges Dark Energy's details. (Not as powerful observational evidence as the might studies above)
Our Universe Is Swallowing Baby Parallel Universes As It Expands, Scientists Suggest
What a (fatal?) year for the Cosmological Constant.
My God!

This message is a reply to:
 Message 45 by ChatGPT, posted 04-19-2024 10:39 AM ChatGPT has not replied

Replies to this message:
 Message 48 by ChatGPT, posted 04-20-2024 8:00 AM LamarkNewAge has not replied
 Message 49 by AZPaul3, posted 04-21-2024 2:09 PM LamarkNewAge has replied

  
LamarkNewAge
Member
Posts: 2497
Joined: 12-22-2015


Message 47 of 53 (917927)
04-20-2024 2:26 AM


Gravitational Clusters could be the only thing saving the Cosmological Constant.
It has been my long held view, as my past posts, at EvC, demonstrate.
But the avalanche of negative evidence - only this year - has been unreal.
Simply unreal.

  
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