Question Cyclical Universe

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But there are regions (closer ones) we can observe that are already moving away from us > C.

GR demonstrates that any one point can be treated as not moving. So from many outer regions were moving faster than C.

It's held that Dark Energy is gaining the upper hand over gravity as the density of the universe decreases with time. So, it will continue to accelerate and not stop.
Only moving at faster than C relative to us but not at C relative to the center of the universe..
As soon as it does matter converts to radiation and it can't go faster than C so conversion happens inward.
Got to be some interesting math for that :)

Same problem with dark energy creating something for nothing.
If it's part of reality then it will eventually becomes infinite energy.
Gets more each day and more than that day the next day.
Energy has mass so no matter what it is converted into it becomes infinite in a finite area.

Dark energy is an interesting idea but makes the original big bang problematic to have in the first place.
Difficult to imagine how we got mass to create a universe size black hole with
dark energy in the mix at the start.

Dark energy multiplying E and pushing the universe apart.
Or external universes with greater G influence than the mass of our universe puling our universe apart.
What math and E law is easier?

Certainly agree with Helio on this. Playing around with a recycling universe was just for fun. What really happens is anybody's guess.

That long, slow ever-expanding heat death is too ugly to inspire, and harder still to accept.

But, as they say, entropy rules!
I think the answer is cyclic for 1 reason, we are here to see it and for it to be in needs a beginning..
Just got to fill in the missing details and find out if nature is weird or mankinds thinking is :)

No, I just checked!

Anyway, Definitely cyclical.
Check math, might have errors :)

IMO probably cyclic for a number or reasons.
If not the universe sure is a weird place starting from nothing and just happening once.
Who says nature has to make mankind happy, it just needs to do whatever it does and follow the most simple self induced rules doing it.
 
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rod

Oct 22, 2019
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Okay, some interesting points raised in #51 post. In 1984, Alan Guth et al said this about the origin of the universe. "There are only 3 options for the origin of this universe: 1) it has always existed 2) it suddenly appeared from nothing 3) it was created supernaturally -“It is then tempting to go one step further and speculate that the entire universe evolved from literally nothing.” - Guth & Steinhardt, May 1984, Scientific American"

It seems the cyclical universe view is similar to option 1, similar to the steady state model with no beginning and no end :) The problem is the outline from the 1982 Fed court ruling defining science. One critical component of science is testing using the empirical world. In BB cosmology, the current radius of the universe is said to be 46.5E+9 light-years distance, https://www.livescience.com/how-big-universe.html, How Big Is the Universe?, August 2019.

This radius using the formula for a 3D sphere, shows the volume could be 4.2E+32 cubic light-years. How many astronomical objects surveyed in this volume of space supports the universe we see today is cyclical? We have a new survey report for some 4 million objects now measuring the Hubble constant, ranging 67.4 to 69 km/s/Mpc. See https://skyandtelescope.org/astronomy-news/new-3d-map-universe-growing-cosmological-debate/

The redshifts surveyed range 0.6 to 3.5 (arxiv reports). The 4 million targets viewed were not reported as showing a cyclical universe and the volume of space surveyed, much smaller than 4.2E+32 cubic light-years. I am still looking for the test(s) that show the universe observed and documented in astronomy today is cyclical vs. a universe that had a distinct beginning in the unobserved past. My post here in #52, now defines some specific volume and target numbers to test against, including perhaps, the much larger volume of space postulated in BB cosmology to show the universe observed today is cyclical.
 
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Well, that's the point, we don't know. We don't know yet. But, as far as astronomers observations go, dark energy remains constant. And, if it really remains that constant, a heat death is inevitable. One day, all the quarks in the universe will be so far from each other that even gravity won't be able to make them join together again. And with that, the cyclic universe theory is falsified.
You may be right, but we don't know enough to say what the distant future holds for our universe regarding DEs behavior, especially given we don't know at all what it is, only that it's the label we put on whatever it is causing acceleration.

If a cyclical "supposition" suggests that DE will do a reverse Inflationary model trick, then full collapse would be likely. So we can't falsify these ideas, though it's hard to falsify suppositions.
 
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Well, that's the point, we don't know.
And Helio beat me to the punch. Seems to be happening a bit lately.

That is the whole game regarding what happens to the universe:

"we don't know"

There is likely more to "our" story than meets the eye, or the model, or whatever.

Even at that, can it be shown that a "beginning and end" of it all is any more acceptable or provable than a "cycle"? Seems unlikely.
 
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One critical component of science is testing using the empirical world. In BB cosmology, the current radius of the universe is said to be 46.5E+9 light-years distance, https://www.livescience.com/how-big-universe.html, How Big Is the Universe?, August 2019.
The radius used is simply our observational range from our point of view. GR argues that there is no center since any point in the universe can be treated as a center. [It may be that GR simply has no way to see if there is some absolute point or region. The Hubble Flow makes this idea interesting.]

I am still looking for the test(s) that show the universe observed and documented in astronomy today is cyclical vs. a universe that had a distinct beginning in the unobserved past. My post here in #52, now defines some specific volume and target numbers to test against, including perhaps, the much larger volume of space postulated in BB cosmology to show the universe observed today is cyclical.
What tests are you suggesting that would help us argue for or against a cyclical model?
 

rod

Oct 22, 2019
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The radius used is simply our observational range from our point of view. GR argues that there is no center since any point in the universe can be treated as a center. [It may be that GR simply has no way to see if there is some absolute point or region. The Hubble Flow makes this idea interesting.]

What tests are you suggesting that would help us argue for or against a cyclical model?

FYI. I do not argue for a cyclical universe so do not have any tests for this discussion. I would think those that propose the cyclical universe, will present the tests using the empirical universe to support it. My post in #52, demonstrates we have plenty of space and many objects documented now to test against (as seen from Earth's frame of reference). My opinion, the discussion of a cyclical universe presented without testing using the empirical world, i.e. the universe astronomy observes today, seems suspect and more likely conjecture or efforts to avoid unpleasant philosophical implications in post #52, e.g. the 1984 quote provided.
 
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To me it is not that hard to imagine DE and gravity co-existing in an expanding universe. The huge void between galaxies allows for plenty of expansion. Gravity is strongest close in where there is an abundance of matter. It is really the immensity of the universe that allows so many things to happen at the same time, which causes confusion with our limited understanding.
 
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To me it is not that hard to imagine DE and gravity co-existing in an expanding universe. The huge void between galaxies allows for plenty of expansion. Gravity is strongest close in where there is an abundance of matter. It is really the immensity of the universe that allows so many things to happen at the same time, which causes confusion with our limited understanding.
A very succinct and outstanding overview, Dexter101, especially your closing comment - "confusion with our limited understanding."

Nothing could define the "issue" better than our limited understanding. And we have no idea whatsoever as to how limited it really is. And that is the real kicker!

Anyone who claims to know where the universe came from and/or is going might consider serious counseling for mental stability, or else ascend to some celestial throne and rule over all of the mortals who don't have a clue.
 
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My post in #52, demonstrates we have plenty of space and many objects documented now to test against (as seen from Earth's frame of reference). My opinion, the discussion of a cyclical universe presented without testing using the empirical world, i.e. the universe astronomy observes today, seems suspect and more likely conjecture or efforts to avoid unpleasant philosophical implications in post #52, e.g. the 1984 quote provided.
Ok, so by "test"you mean that if an empirical test comes along for a cyclical universe, that there is considerable data to assist if that test suggests something special, say, for galaxy distributions. My guess is that such things won't matter in a cyclical model. The big problem today is it will be hard to get this universe to collapse given that it is accelerating.
 
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A very succinct and outstanding overview, Dexter101, especially your closing comment - "confusion with our limited understanding."

Nothing could define the "issue" better than our limited understanding. And we have no idea whatsoever as to how limited it really is. And that is the real kicker!
Agreed.

Anyone who claims to know where the universe came from and/or is going might consider serious counseling for mental stability, or else ascend to some celestial throne and rule over all of the mortals who don't have a clue.
That's a strange comment. Are you suggesting those that argue for a cold death for a universe that is accelerating in expansion needs counseling? Where it came from is easily addressed by religion and philosophy, which is outside the purview of science, of course.
 
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Where it came from is easily addressed by religion and philosophy, which is outside the purview of science, of course.
And where it is headed could be addressed in the same manner, which would be outside the purview of science, of course.


Again, pardon any redundancies that the below may represent, but it must be included to make a point.

From Wiki*:

"The accelerated expansion of the universe is thought to have begun since the universe entered its dark-energy-dominated era roughly 4 billion years ago. Within the framework of general relativity, an accelerated expansion can be accounted for by a positive value of the cosmological constant Λ, equivalent to the presence of a positive vacuum energy, dubbed "dark energy". While there are alternative possible explanations, the description assuming dark energy (positive Λ) is used in the current standard model of cosmology, which also includes cold dark matter (CDM) and is known as the Lambda-CDM model."

end quote

Apparently expansion began by some mechanism we cannot see, and do not understand, and have called it "dark energy". This is because we have no real idea what could be driving the acceleration. But because it is accelerating the expansion of a rather large amount of debris from the BB, it must be in some form of energy.

Since we really have no clue about what is going on with the Hubble Flow, why should we believe that the acceleration will not be reversed in the future by some other form of energy? Certainly this acceleration came as a big surprise to more than a few cosmologists.

So an energy form that reverses this expansion surely cannot be ruled out. How could it be when we aren't there, when it might occur, yet? As Dexter101 noted, concepts of the current state of the universe could be mistaken due to our limited understanding.

For all we know, cosmologists 30 billion years from now will see a second "dark ages", where the universe begins to slow down 5 billion years from now. And everyone will be modeling what is going to happen next, with many predicting a cosmic collapse.


* https://en.wikipedia.org/wiki/Accelerating_expansion_of_the_universe
 
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Agreed.

Cosmologists, however, that argue we are headed for a cold death vs. a hot one have demonstrable evidence from SN data alone that puts their claim, IMO, within mainstream science.

Claims made by philosophers or theologians regarding the origin of the universe are quite valid in their magisteria.
 
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We do have a bit of evidence that our universe is not alone, dark flow.
No mechanism other than external gravity source can explain dark flow.
Forever as 1 universe with an external gravity source can't exist, but forever as infinite universes can exist.
That in itself gives possibilities for cyclic universes.big bangs, creation from nothing and universes that collide and interact.

Maybe we are just looking at what the universe is the wrong way.
The universe could simply be fluctuation and everything else in it just byproducts of it.
 
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The universe could simply be fluctuation and everything else in it just byproducts of it.
I really like the fluctuation idea. It seems that whenever the physicists have a problem, the fall back explanation is that it is caused by a "quantum fluctuation". Can't count how many times I have read this. It almost seems like crying "WOLF" too many times.

All the universe is presumed to result from a quantum fluctuation, so why can't everything else?

There is your theory of everything!
 
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Fluctuation, of course, implies movement. How can something be still (without motion) in space? Stationary relative to what? In the good old resuscitated M 'n M aether? Did you miss it?

So motion is the key to all. The key to planets not falling into their stars. There you have it! The key to the Universe. Perpetual motion!

(C) Cat 2020 :)
 
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Either I don't have the capability to understand your deep statement. Or, that was a sarcastic sentence. Sir, can you please tell me what you mean to say?
No Sir! It was entirely serious. Please do not let us fall into the Sun.
You have more than the necessary capability to understand.

And, as I believe that you deserve that form of address, so shall it be.

Cat :)
 
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Let us now discuss the cyclical Universe, wherein the two major forces are motion and gravity. The two great forces which oppose one another. The black and the white chess pieces and, please, do not fall guilty to anthropomorphism and bring some none existent player into the game.

Cat :)
 
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(C) Cat 2020 :) Well I did get a UK patent for cleaning that nasty resinous residue from wood-burning chimneys by spraying them (from below) with a zwitterionic based detergent.

To keep on topic, I have to say that the claims did not, specifically, include the cleaning of cyclic chimneys. Still, I have not renewed that (granted) patent, so I am not too worried about that all too obvious omission.
 
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I think the answer is cyclic for 1 reason, we are here to see it and for it to be in needs a beginning..
Am going to guess you were not in on the "Anthropic Principle" thread.

I will refer you to the anthropo-master Catastrophe to fill you in the notion of " it to be in needs a beginning."

(He also fools around with the significant and difficult complexities of surface-active molecular agents, and other such balderdash.)
 
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No Sir! It was entirely serious. Please do not let us fall into the Sun.
You have more than the necessary capability to understand.

And, as I believe that you deserve that form of address, so shall it be.

Cat :)
Okay then.

Um, now when I try to think of it, it seems that I perfectly know what that means. I was a little busy in another work when I made the reply. Sorry for disturbing you, sir.
 
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(C) Cat 2020 :) Well I did get a UK patent for cleaning that nasty resinous residue from wood-burning chimneys by spraying them (from below) with a zwitterionic based detergent.
The thought of chimney sweeps and things zwitterionic are making me dizzy. Wait, not dizzy, Disney.;)

What a cool label.
 
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