Jump to content


Photo
- - - - -

Bang/Crunch Revisited


  • This topic is locked This topic is locked
121 replies to this topic

#1 Michael Mooney

Michael Mooney

    Suspended

  • Members
  • PipPipPipPipPipPip
  • 629 posts

Posted 26 April 2009 - 04:20 PM

Just for openers, here is a piece on "The Oscillating Universe" from the PBS link at "Frequently Asked Questions in Cosmology
Frequently Asked Questions in Cosmology
under "What about the oscillating Universe?"
(First that intro):

If the Universe recollapses, then there is another singularity at the time of the Big Crunch. A singularity means that the laws of physics break down, so we have no way to predict whether the Big Crunch will connect to another cycle of expansion. Even if the density were high enough to cause a recollapse, there would be no guarantee that the Universe would oscillate. But the current evidence is strongly against any recollapse, which would rule out the oscillating Universe. See PBS or Ask an Astronomer about this.


Note: I will be debating the latter assertion.

The PBS blurb on Oscillating Universe:

One of the implications of the big-bang theory is that the universe will one day end, or at least any life in the universe will come to an end. If the universe is either open or flat, meaning that it expands forever, it will survive for an infinite period of time. But eventually all the material in all the generations of stars will be exhausted, and the universe will grow cold and dark. In a closed universe, in which the expansion eventually stops and a contraction follows, the end is far from cold and dark—as the Big Crunch approaches, the universe grows hotter and brighter until it implodes into a singularity and gets crushed out of existence.

But is that what would really happen? Some scientists speculate that the Big Crunch would not signal the end. Perhaps another Big Bang would follow the Big Crunch, giving rise to a new universe of possibilities. The idea that Bangs follow Crunches in a never-ending cycle is known as an oscillating universe. Though no theory has been developed to explain how this could ever happen, it has a certain philosophical appeal to people who like the idea of a universe without end.

I know this topic has been addressed in other threads, but I'd like a fresh start here if I may.
Michael
BTW, I have critiqued Lynde's model on a site I forgot, but "time reversal" is not an option for me, as per my repetitive critique of time in my "spacetime thread."
But I have have a similar model that doesn't require a sci-fi rendering of time.

Our cosmic event horizon is just a small bubble of visibility *within* the thickness of the "rubber" of the good old cosmic expanding balloon. This mini-cosmos within the maxi-cosmos, the Whole Balloon, is cycling through bangs and crunches even as the whole balloon keeps expanding.... *Yes*... out into the infinity of space.

Anyway, we can't even "see out of the rubber" (the visible cosmos) let alone see the *yes* empty space within or beyond the bubble.

Well, this should stir up some more trouble.
BTW, I ask all respondents to refrain from starting with "expanding space" as an established fact. I know "stuff expanding out into empty space" is usually called a "misconception"... but I see it as a viable contender as a cosmology.

Nuff for now.
Michael

#2 lemit

lemit

    Creating

  • Members
  • PipPipPipPipPipPipPip
  • 1115 posts

Posted 26 April 2009 - 05:33 PM

Since this isn't science in the observable/quantifiable/knowable sense, I'll take a shot at it, although any discussion like this suggests a similarity to the question, "If parallel lines meet in infinity, where do they go after that?"

An oscillating universe gives those lines somewhere to go and is therefore appealing to me. Of course I'm more of an arts type than a science type, so I like symmetry.

I would love to see any math that could support or refute the oscillating universe theory. Once I'd seen the math, I'd need to have it explained to me (several times), but I would try to be as patient as the explainer would have to be.

--lemit

#3 maddog

maddog

    Cybernetic Quantum Alchemist

  • Members
  • PipPipPipPipPipPipPip
  • 1293 posts

Posted 27 April 2009 - 11:10 AM

Since this isn't science in the observable/quantifiable/knowable sense, I'll take a shot at it, although any discussion like this suggests a similarity to the question, "If parallel lines meet in infinity, where do they go after that?"

For someone who does not consider himself very knowledgeable in ways of science, I find
you quite perceptable at picking up the nuances enough to make a good argument.
I would quite agree with you the similarity between Michael's "arguments" for/against
BBT are very much like trying to qualify the "straightness" of lines past infinity. :)

An oscillating universe gives those lines somewhere to go and is therefore appealing to me. Of course I'm more of an arts type than a science type, so I like symmetry.

So do a lot of other Theoretical Physicists.

maddog

#4 maddog

maddog

    Cybernetic Quantum Alchemist

  • Members
  • PipPipPipPipPipPipPip
  • 1293 posts

Posted 27 April 2009 - 11:15 AM

BTW, I have critiqued Lynde's model on a site I forgot, but "time reversal" is not an option for me, as per my repetitive critique of time in my "spacetime thread."
But I have have a similar model that doesn't require a sci-fi rendering of time.

No, it requires Greek Mythology instead... :)

Our cosmic event horizon is just a small bubble of visibility *within* the thickness of the "rubber" of the good old cosmic expanding balloon. This mini-cosmos within the maxi-cosmos, the Whole Balloon, is cycling through bangs and crunches even as the whole balloon keeps expanding.... *Yes*... out into the infinity of space.

Making this conjecture doesn't make it so. There have been other theories about the
"universe" being bigger (larger) than the "observable universe". No as yet "observable"
evidence either for/against.

maddog

#5 Michael Mooney

Michael Mooney

    Suspended

  • Members
  • PipPipPipPipPipPip
  • 629 posts

Posted 27 April 2009 - 12:24 PM

Maddog:

Making this conjecture doesn't make it so. There have been other theories about the
"universe" being bigger (larger) than the "observable universe". No as yet "observable"
evidence either for/against.


True, but then cosmology is mostly theoretical, and evidence to back up each theory the more rare commodity.
As you know, I keep hammering on String/M-theory with its 11 to 26 "dimensions" and clashing membranes/imaginary "universes for this very reason.

And I'd rather not even go into "time reversal" again. I don't see time as an entity.
Space either. So "expanding space," (if it really is the empty volume in which all things move, expand, etc. will be a cosmology dependent on the reification of space, which topic we all beat to death in the spacetime thread.

Agreed, no one knows what lies beyond the cosmic event horizon. Could be the Whole Balloon tho, the rubber of which our little bubble of expanding cosmos lies within. This would account for the homogeneity of the isotropic cosmos we observe with galaxies moving apart from each other as the membrane expands. But that could still leave empty space (get over it!:)) within the balloon and beyond the whole thing.

There simply can be no "boundary" to space. What... a wall... of...?... and beyond that... hey, more space... no matter what may be out there floating around in it. (More Big Balloons with zillions of little expanding bubble/cosmi like ours as the "rubber molecules?")
Michael

#6 Moontanman

Moontanman

    Unobtainium...

  • Members
  • PipPipPipPipPipPipPip
  • 9029 posts

Posted 27 April 2009 - 01:42 PM

The big bang/big crunch is soooo last century dude! Colliding branes is where it's at!

#7 Michael Mooney

Michael Mooney

    Suspended

  • Members
  • PipPipPipPipPipPip
  • 629 posts

Posted 27 April 2009 - 01:50 PM

Moontanman:

The big bang/big crunch is soooo last century dude! Colliding branes is where it's at!

Please explain and document (this is a formal request) how seven of the eleven "dimensions" in String/M-theory (after 3-D space and "elapsed time for all movement"... 4-d) are derived and what there referents in the observable cosmos are.

Or are you just here to heckle?... in which case... hey modertors... this is a formal complaint.

Michael

#8 Michael Mooney

Michael Mooney

    Suspended

  • Members
  • PipPipPipPipPipPip
  • 629 posts

Posted 27 April 2009 - 01:52 PM

Moontanman:

The big bang/big crunch is soooo last century dude! Colliding branes is where it's at!

Please explain and document (this is a formal request) how seven of the eleven "dimensions" in String/M-theory (after 3-D space and "elapsed time for all movement"... 4-d) are derived and what there referents in the observable cosmos are.

Or are you just here to heckle?... in which case... hey moderators... this is a formal complaint.

Michael

#9 Moontanman

Moontanman

    Unobtainium...

  • Members
  • PipPipPipPipPipPipPip
  • 9029 posts

Posted 27 April 2009 - 02:04 PM

Complain all you want Mooney, I'm alwasy ready to back up my BB.

We propose a cosmological scenario in which the hot big bang universe is produced by the collision of a brane in the bulk space with a bounding orbifold plane, beginning from an otherwise cold, vacuous, static universe. The model addresses the cosmological horizon, flatness and monopole problems and generates a nearly scale-invariant spectrum of density perturbations without invoking superluminal expansion (inflation). The scenario relies, instead, on physical phenomena that arise naturally in theories based on extra dimensions and branes. As an example, we present our scenario predominantly within the context of heterotic M-theory. A prediction that distinguishes this scenario from standard inflationary cosmology is a strongly blue gravitational wave spectrum, which has consequences for microwave background polarization experiments and gravitational wave detectors.


[hep-th/0103239] The Ekpyrotic Universe: Colliding Branes and the Origin of the Hot Big Bang

COLLIDING BRANES AND ITS APPLICATION TO STRING COSMOLOGY

Ekpyrotic - Wikipedia, the free encyclopedia

many links in this one

Science - Physics - Cosmology - Branes - Brane-Storm Challenges Big Bang Theory, A Recycled Universe, Cosmology in a Brane Universe ...

The ID Report - Darwinian Universes And Colliding Branes: Eschewing A Cosmic Singularity

The list is long and often argumentative but colliding branes is indeed as much a theory as your musings are.

#10 Michael Mooney

Michael Mooney

    Suspended

  • Members
  • PipPipPipPipPipPip
  • 629 posts

Posted 27 April 2009 - 07:29 PM

OK man,
Them there's a lot 'o links, so you escape the fierce sword of failing to comply with request for documentation. I'll study the ones I have not yet seen, but I've been on string theory since there were five or six contending and the once debunked 11th dimension was brought back (and its author turned from whacko to hero) to save it as a unified "M-theory," finally endorsed by Hawking after he gave up on his primordial Singularity... several months after i debunked him on Myspace.

So... meanwhile... a new request: In your own words explain even one of those 11 dimensions after the familiar four I mentioned above...
and if you can explain all seven extras you will win the prize as the only one through several forums of my asking, to explain them.
Thanks ahead. Or maybe you will just cite more links and a bunch of math without world-reference meaning behind it. That however will not win you any prizes.

Michael

#11 Moontanman

Moontanman

    Unobtainium...

  • Members
  • PipPipPipPipPipPipPip
  • 9029 posts

Posted 27 April 2009 - 07:34 PM

Well Michael, lots of words can accurately be used to describe me but "fool" isn't one of them. If you know more about this than Hawking does then I would be a fool to dispute you wouldn't I? I bow to your superior intellect.

#12 Michael Mooney

Michael Mooney

    Suspended

  • Members
  • PipPipPipPipPipPip
  • 629 posts

Posted 27 April 2009 - 10:32 PM

Moontanman:

Well Michael, lots of words can accurately be used to describe me but "fool" isn't one of them. If you know more about this than Hawking does then I would be a fool to dispute you wouldn't I? I bow to your superior intellect.


Don't just settle for being a smart ***. I think your comment above is disingenuous. If you think M-theory is a viable cosmology, explain in your own words how those 11 dimensions make sense to *you.* If they don't, then don't bs me about it.

It is a fact that I knew better than Hawking that " infinite mass density in zero volume" (a direct quote describing his singularity as the origin of the cosmos) was nonsense. I have a "gift of genius" for seeing nonsense and calling it as such. The Myspace archives will show, chronologically at least, the truth of the above. It has been a few years since he "recanted" and endorsed the latest (at the time) M-theory book. So I would not know where to find those particular Myspace posts. And he would never acknowledge my input anyway. It is the way of celebrity to ignore those not in the inner circle... and then just admit they were wrong as if it came to them from their own genius muse.

Michael

#13 Michael Mooney

Michael Mooney

    Suspended

  • Members
  • PipPipPipPipPipPip
  • 629 posts

Posted 27 April 2009 - 10:45 PM

WOW! I just got another "infraction" for telling the truth about my firsthand lifelong experience of GNOSIS.
I probably will soon be banned. If science can not even let a mystic/gnostic speak his truth...

And I always add the disclaimer that this source of knowing (the omnipresent NOW in this case) is not presented as "science."
Maybe if my every comment acknowledging this gnosis were posted in the theology forum...
Like... not allowed to say this here, so here is the link to the proper forum....

Quite an inconvenience... and seems absurd... but scientists disdain mystics, and they have the "power over' here to ban us at their whim... or as violating the rules against honest expression of gnostic knowing.
I can see the trend here. I don't even know hoe many "infractions" a guy gets before he is banned. I've lost count. If anyone has anything besides smart *** remarks, this is probably the time for serious science. Mostly my whole life this IQ thing has made people use whatever "credentials" they have to get the upper hand and try to "slay me."

this place is no different. One in ten million. Am I lying? Does the guy who accused me of lying get an "infraction."
I'll tune in tomorrow to find out. Waht a drama.
Waht about serious cosmology. The old Bang/Crunch is not dead yet, and my intention in this thread is to make an *intelligent argument* to resurrect it from the dumpster designated by the 'expanding space' theorists.
Michael
Michael

#14 Boof-head

Boof-head

    Suspended

  • Members
  • PipPipPipPip
  • 213 posts

Posted 27 April 2009 - 11:40 PM

This possibly has a chance of being ignored, but Ashtekar is a name that should be familiar to someone here (I hope):

Loop quantum cosmology ...
Abhay Ashtekar and Edward Wilson-Ewing

Loop quantum cosmology (LQC) [4, 5] is constructed by applying methods of LQG to mini-superspaces obtained by a symmetry reduction of general relativity. In the homogeneous, isotropic cosmological models with a massless scalar field, quantum geometry effects of LQG have been shown to create a new repulsive force in the Planck regime. The force is so strong that the big bang is replaced by a specific type of quantum bounce.


Detailed and viable quantum theories were constructed in the homogeneous, isotropic case using the so-called “[math]\bar{\mu}[/math]” scheme. A key open question has been whether or not the qualitative features of their Planck scale physics will persist in more realistic situations in which these strong symmetry assumptions do not hold exactly. A first step in this direction is to retain homogeneity and extend the “improved dynamics” of [10] to anisotropic situations.

In the isotropic case, there is only one non-trivial curvature invariant, the (space-time) scalar curvature (or, equivalently, matter density). In anisotropic situations Weyl curvature is non-zero and it too diverges at the big bang. Therefore, now one can enter the Planck regime in several inequivalent ways which suggests that the Planck scale physics would now be much richer.



#15 lemit

lemit

    Creating

  • Members
  • PipPipPipPipPipPipPip
  • 1115 posts

Posted 28 April 2009 - 02:14 AM

Well Michael, lots of words can accurately be used to describe me but "fool" isn't one of them. If you know more about this than Hawking does then I would be a fool to dispute you wouldn't I? I bow to your superior intellect.


I missed the "fool" reference. Is it in this thread?

May I volunteer to be the fool so we can go on with a relatively adult discussion? It doesn't mean that much to me, but apparently, Moontanman, it means a lot to you.

Michael, I might owe you an apology, since I can readily see that you didn't start the name-calling this time. I hope I do have a chance to apologize. I always like both the giving and receiving of apologies. They facilitate so much more than the self-conscious avoidance of them ever will.

--lemit

p.s. I do have the feeling of being a small child trying to get the adults to stop fighting. In that vein:

Hey! I'm down here!

Thanks for noticing.

#16 Pluto

Pluto

    Suspended

  • Members
  • PipPipPipPipPipPip
  • 601 posts

Posted 30 April 2009 - 03:56 AM

G'day from the land of ozzzzz

These links are interesting reading.

[0711.1824] From Big Crunch to Big Bang with AdS/CFT
From Big Crunch to Big Bang with AdS/CFT

Authors: Neil Turok, Ben Craps, Thomas Hertog
(Submitted on 12 Nov 2007 (v1), last revised 27 Dec 2007 (this version, v3))

Abstract: The AdS/CFT correspondence is used to describe five-dimensional cosmology with a big crunch singularity in terms of super-Yang-Mills theory on R times S^3 deformed by a potential which is unbounded below. Classically, a Higgs field in the dual theory rolls to infinity in finite time. But since the S^3 is finite, the unstable mode spreads quantum mechanically and the singularity is resolved when self-adjoint boundary conditions are imposed at infinity. Asymptotic freedom of the coupling governing the instability gives us computational control and the quantum spreading provides a UV cutoff on particle creation. The bulk interpretation of our result is a quantum transition from a big crunch to a big bang. An intriguing consequence of the near scale-invariance of the dual theory is that a nearly scale-invariant spectrum of stress-energy perturbations is automatically generated in the boundary theory. We comment on implications for more realistic cosmologies.



and

[0712.4180] Quantum Resolution of Cosmological Singularities using AdS/CFT
Quantum Resolution of Cosmological Singularities using AdS/CFT

Authors: Ben Craps, Thomas Hertog, Neil Turok
(Submitted on 27 Dec 2007 (v1), last revised 9 Apr 2008 (this version, v4))

Abstract: The AdS/CFT correspondence allows us to map a dynamical cosmology to a dual quantum field theory living on the boundary of spacetime. Specifically, we study a five-dimensional model cosmology in type IIB supergravity, where the dual theory is an unstable deformation of $N=4$ supersymmetric SU(N) gauge theory on $Rbartimes S^3$. A one-loop computation shows that the coupling governing the instability is asymptotically free, so quantum corrections cannot turn the potential around. The big crunch singularity in the bulk occurs when a boundary scalar field runs to infinity, in finite time. Consistent quantum evolution requires that we impose boundary conditions at infinite scalar field, {it i.e.} a self-adjoint extension of the system. We find that quantum spreading of the homogeneous mode of the boundary scalar leads to a natural UV cutoff in particle production as the wavefunction for the homogeneous mode bounces back from infinity. Translating back to the bulk theory, we find that a quantum transition from a big crunch to a big bang is the most probable outcome of cosmological evolution, for a specific parameter range. Intriguingly, the instability and approximate scale-invariance of the boundary theory lead to the generation of an approximately scale-invariant spectrum of stress-energy perturbations on the boundary, whose amplitude is naturally small. We comment on qualitative differences with holographic descriptions of large black holes, on four-dimensional generalizations and on implications for cosmological perturbations.



#17 maddog

maddog

    Cybernetic Quantum Alchemist

  • Members
  • PipPipPipPipPipPipPip
  • 1293 posts

Posted 06 May 2009 - 08:46 AM

True, but then cosmology is mostly theoretical, and evidence to back up each theory the more rare commodity.

Theory with attempts to back-up by evidence as it comes.
Sometimes (if not often) Theory gets ahead of Experimentation & Validation.

As you know, I keep hammering on String/M-theory with its 11 to 26 "dimensions" and clashing membranes/imaginary "universes for this very reason.

I empathize with on this subject. Though I do love the elegance of M-Theory, aside
from struggling to understand it. I find it hard to consider it credible when no current
corroboration is available (if even attainable).

And I'd rather not even go into "time reversal" again. I don't see time as an entity.

The notion "time reversal" [is] not an entity as you say. This "reversal" of time is a
thing you [can] do to any model as though running a movie in reverse to understand
what is going on. It is the Model which is run backwards Only.

There simply can be no "boundary" to space. What... a wall... of...?... and beyond that... hey, more space... no matter what may be out there floating around in it. (More Big Balloons with zillions of little expanding bubble/cosmi like ours as the "rubber molecules?")

Wheeler has theorized of a "Multiverse" where what is "outside" or observable universe
is "whole" other "bubble" universes in a higher (> 3 or 4) dimension vector space.

maddog