Bang/Crunch Revisited

[Michael Mooney]

Maddog,

The sub-topic was on cosmic origin... clapping membranes (M-Theory) or singularity (all cosmic "stuff" originally in a "point of zero volume.")

 

Hawking abandon the latter in favor of the former. Whether or not my debunking of "infinite matter density in a point of zero volume" had anything to do with this particular change of his mind was a side issue and only a chronological sequence of events, not a debate between us, as I clarified before.

 

Another sub-issue was about the existence (or not) of "singularities" (plural... in general... of all sizes) in black holes. The list of similar links addresses that question.

 

Modest asked what I was talking about and requested links.

 

My post answered him honestly and to the best of my ability short of composing and extensive paper on the subject.

 

Do you have an unresolved problem with me personally which ensures that your every reply will be framed as a personal attack?

 

Michael

[modest]

Hawking wrote an intro endorsing Endless Universe by Neil Turok and Paul Steinhardt on M-theory cosmology, and I assumed this meant he was abandoning his singularity model of cosmic origin. This a few months after my criticism of the singularity quote (above) in Myspace. I doubt he or his team saw my posts there, but never the less....

 

Ok. I think I see what happened. When you mentioned Turok it clicked. Hawking bet Turok that the Plank satellite would find relic gravitational waves from inflation supporting a more classical type singularity over a M-theory / colliding brane scenario (which Turok's model is). The exchange is described in the book you mention (page 213):

 

Endless universe: beyond the Big Bang - Google Books

 

I don't know if the bet has been settled, but I doubt it because Plank has only just been launched in May.

 

It certainly has *not* been established by any stretch of the imagination that inflation did not happen while colliding branes did happen. These are very much open questions. The thing you should realize is that the big bang singularity is where general relativistic physics breaks down. So, we need some kind of new physics to understand what (if anything) came before the big bang.

 

What that new physics will be is a very open question in cosmology and it is certainly not possible as of yet to say conclusively if inflation vs. M-Theory is correct (if indeed either are).

 

Here Turok talks about his theory and some discussion of the bet with Hawking:

 

It's a strange idea, though Turok would say it's no stranger than the standard explanation of the Big Bang: a singular point that defies our laws of physics, where all equations go to infinity and "all the properties we normally use to describe the universe and its contents just fail." That inconsistency led Turok to see if the Big Bang could be explained within the framework of string theory, a controversial and so-far untested explanation of the universe as existing in at least 10 dimensions and being formed from one-dimensional building blocks called strings. Within a school of string theory known as m-theory, Turok said, "the seventh extra dimension of space is the gap between two parallel objects called branes. It's like the gap between two parallel mirrors. We thought, What happens if these two mirrors collide? Maybe that was the Big Bang...

 

Turok: "If the universe sprung into existence and then expanded exponentially, you get gravitational waves traveling through space-time. These would fill the universe, a pattern of echoes of the inflation itself. In our model, the collision of these two branes doesn't make waves at all. So if we could measure the waves, we could see which theory is right.

 

Stephen Hawking bet me that we'll see the signal from inflation. I said that we won't, and he can take it for any amount of money at even odds. So far he hasn't named an amount. He's richer than me, so he's being nice. "

 

Physicist Neil Turok: Big Bang Wasn't the Beginning

 

~modest

[Michael Mooney]

modest;270582]Ok. I think I see what happened. When you mentioned Turok it clicked. Hawking bet Turok that the Plank satellite would find relic gravitational waves from inflation supporting a more classical type singularity over a M-theory / colliding brane scenario (which Turok's model is). The exchange is described in the book you mention (page 213):

 

Endless universe: beyond the Big Bang - Google Books

 

I don't know if the bet has been settled, but I doubt it because Plank has only just been launched in May.

 

The "Hawking Loses Bet" link was about another bet.

Bottom lines of link:

"He sent a note saying `I have solved the black hole information paradox and I want to talk about it,"' Cutler said.

 

If Hawking succeeds in making his case, he will lose a bet that he and theoretical physicist Kip Thorne of the California Institute of Technology made with John Preskill, also of Caltech.

 

The terms of the bet were that "information swallowed by a black hole is forever hidden and can never be revealed."

 

Ironically he did "succeed in making his case" about information retrieval from black holes (from interpretation of BH "radiation"... No longer "forever hidden" as he earlier theorized), and therefore "lost his (and Thorne's) bet" with Preskill.

Quite convoluted... but I respect his willingness to change his mind as new evidence comes to "light."

 

It certainly has *not* been established by any stretch of the imagination that inflation did not happen while colliding branes did happen. These are very much open questions. The thing you should realize is that the big bang singularity is where general relativistic physics breaks down. So, we need some kind of new physics to understand what (if anything) came before the big bang.

 

"Colliding branes" are of course quite imaginary, as is the "expanding space*" required for "inflation" after all cosmic "stuff" magically appears out of nothing... whether from a "point of zero volume" or a Plank-length sized volume of super-concentrated primordial cosmos.

(*The ontology of what is expanding remains unanswered!)

 

What I already "realize" is that a "Singularity" "containing"

"all-there-is" in the cosmos" (first) was not "contained in zero volume" and (second) did not just magically appear out of "nothing."

 

Further, I don't think we need to re-invent physics for a Bang/Crunch model as I have presented it. Please review before engaging "auto-pilot" standard criticism precluding extremely large supernova-like *explosions* (see "cosmic juggling act" model) of actual, incoming, "crunching" cosmic stuff... mostly super,super "supermassive black holes" becoming even more "super" as they crunch together. If such super balls of extremely condensed matter can not explode, per se, maybe they can "spew out jets" of the "stuff" of new born cosmi as per the BH/neutron star/pulsar models.

 

And, yes, this is in total contradiction of the standard dictum that the above (stuff exploding out into empty space) is now a thoroughly debunked cosmology.

 

 

What that new physics will be is a very open question in cosmology and it is certainly not possible as of yet to say conclusively if inflation vs. M-Theory is correct (if indeed either are).

 

I am glad to hear that you see it as an "open question." "How open" is yet another question. Open enough to entertain the possibilities I have again outlined above? I doubt it.

 

Michael

[maddog]

Now that this thread has apparently hit a stride that is more scientifically based I think it is worthwhile to remind all concerned that nomenclature here is paramount. There is an extreme difference between Quantum Gravity theories and Loop Quantum Gravity theories, somewhat analagous to the boost that Ed Witten gave String theory with supersymmetry resulting in M Theory.

In general, Quantum Gravity theories is the melding of QM with GR. Yes, LQG attempt is

an extension coming from GR; whereas String Theories (all types: Superstring, M-Theory, etc) are derived from Particle physics. What I found interesting in your link

to the presentation was the LQG is a QM quantization of spacetime that involve Spin Networks

similar to Twistor Theory. Ed Witten has already been considering Twistor Theory in

adjunct to String Theory (M-Theory).

 

It isn't that Quantum Gravity has just led directly to Loop Quantum Gravity after the former "hit a wall" in 2004, it's that the "crash" branched out into many theories, with some saying LQG being the most simple, elegant and well-developed.

 

It is said that Quantum Gravity replaces the Big Bang with the Big Bounce but Loop Quantum Gravity does not require it. So this thread goes on, soon to be "quantum leaped" by several new experiments and instruments as divers as LHC and numerous new space telescopes, some at LaGrange points, such as Herschel-Planck. This is a very exciting time!

Yes, a very exciting time it definitely is ! :eek_big: :hyper: :hyper:

 

maddog

[maddog]

Oh yeah and only very slightly OT but this thread could benefit greatly from some humour

 

This was hilarious! :hyper: I do think though that the main character was a bit snobbish, even

if both sides could see the other's point of view.

 

IMHO, I think the answer lies with both theories being merged in some way we don't forsee

yet. Maybe Penrose was right after all and Twistor theory is also involved ! :eek_big:

 

maddog

[maddog]

Do you have an unresolved problem with me personally which ensures that your every reply will be framed as a personal attack?

Nothing of the kind. I have no personal vendetta against any member of Hypography. That

includes you. No animosity whatsoever.

 

I do phrase questions when I feel the post wasn't being clear. In this post you added a lot of

links while discussing none of the points. I misunderstood your "innuendo" of how you

"bested" Hawking. Since I wasn't present to that debate I will refrain further of what I

might really think. As it would be unfair of me.

 

Going with the clashing of branes is the fashionable thing to do today in M-Theory whether

it is wrong or right. To me, I am still hedging my bets as M-Theory is directly untestable.

 

I am interested in what inroads that Ed Witten has done in last few years integrating

Twistor Theory with various variations of String Theories. I see this may have some

future. As well as considering using the group F12.

 

maddog

[maddog]

Ok. I think I see what happened. When you mentioned Turok it clicked. Hawking bet Turok that the Plank satellite would find relic gravitational waves from inflation supporting a more classical type singularity over a M-theory / colliding brane scenario (which Turok's model is). The exchange is described in the book you mention (page 213):

 

Endless universe: beyond the Big Bang - Google Books

 

I don't know if the bet has been settled, but I doubt it because Plank has only just been launched in May.

Ohh. I see where I had goofed. I was thinking of the bet Hawking made with Berkenstein about information getting out of Black Holes. That one was resolved. I didn't

know of one made to Turok. My apologies to Michael Mooney. Oops! :eek_big:

 

maddog

[maddog]

"Colliding branes" are of course quite imaginary, as is the "expanding space*" required for "inflation" after all cosmic "stuff" magically appears out of nothing... whether from a "point of zero volume" or a Plank-length sized volume of super-concentrated primordial cosmos.

(*The ontology of what is expanding remains unanswered!)

Yes, these are still theoretical (and as yet, directly untestable). It is symantic, yet somewhat

inaccurate to say they are "imaginary" (maybe ok to you). Both M-Theory and Inflation

are so far to date internally consistent yet unproven theories. This does not make a theory

imaginary. Mathematically, even make no sense. The imaginary number [math]i = sqrt(-1)[/math]

is even though not "real" does exist! I would consider this a poor use of the word. Maybe

what you mean is that these theories are as yet untestable.

 

What I already "realize" is that a "Singularity" "containing"

"all-there-is" in the cosmos" (first) was not "contained in zero volume" and (second) did not just magically appear out of "nothing."

This is another fallacy. The volume is not "0" [zero]. It is called a "limit" from Calculus.

One approaches 0 yet does not reach it (Zeno paradox).

 

Further, I don't think we need to re-invent physics for a Bang/Crunch model as I have presented it. Please review before engaging "auto-pilot" standard criticism precluding extremely large supernova-like *explosions* (see "cosmic juggling act" model) of actual, incoming, "crunching" cosmic stuff... mostly super,super "supermassive black holes" becoming even more "super" as they crunch together. If such super balls of extremely condensed matter can not explode, per se, maybe they can "spew out jets" of the "stuff" of new born cosmi as per the BH/neutron star/pulsar models.

This spewing does happen according to the Blandford-Znajek method which I have discussed at

length with Pluto.

And, yes, this is in total contradiction of the standard dictum that the above (stuff exploding out into empty space) is now a thoroughly debunked cosmology.

Here we go again. What particular Cosmology got debunked, when and by whom ???

 

maddog

 

ps: enorbet2 -> I am not sure how that happened. I was totally cutting & pasting off of Michael's Quote. :eek:

[enorbet2]

psssst! Maddog! I didn't say that stuff you quoted as mine, not even one of three. Please fix.

[Michael Mooney]

Assuming you have sorted out who said what as requested by enorbet2...

 

Yes, these are still theoretical (and as yet, directly untestable). It is symantic, yet somewhat

inaccurate to say they are "imaginary" (maybe ok to you). Both M-Theory and Inflation

are so far to date internally consistent yet unproven theories. This does not make a theory

imaginary. Mathematically, even make no sense. The imaginary number [math]i = sqrt(-1)[/math]

is even though not "real" does exist! I would consider this a poor use of the word. Maybe

what you mean is that these theories are as yet untestable.

 

How are membranes not imaginary? My version is not yet testable either, but seems much more likely, reasonable and possible than absurd "points" with little or no volume... originating from nowhere, or membranes made of one dimensional strings vibrating in lots of very speculative "dimensions" based on extremely esoteric math... and not much else.

 

This is another fallacy. The volume is not "0" [zero]. It is called a "limit" from Calculus.

One approaches 0 yet does not reach it (Zeno paradox).

 

Please refer to the direct Hawking quote above from his website. Again, he said that a singularity is "infinite matter density in a point of zero volume." If you want to correct him, write to him and tell him how he said it in error.

 

 

This spewing does happen according to the Blandford-Znajek method which I have discussed at

length with Pluto.

 

Of course "it happens!" We have pictures of it! The question here at hand is, "on what scale might it happen?" Might "it" work on the scale of cosmic origin?

 

It might help if you would review the supernova model. The explosion disperses "supernova remnants" (SNR) and the stuff that did not "launch" falls back into a "compact body of matter" (of whatever technical name.) From such bodies, "jets of near- light- speed plasma are often "spewed out" into the *empty space* around the epicenter of the explosion... and will eventually cool into elements known as "matter." This dynamic happening on cosmic scale makes mor sense that the nonsense of singularities and the metaphysical membranes of M-Theory.

 

The same model might work for cosmic origin if "incoming" and "outgoing" matter( and plasma/dust/gas/energy) are phased implosion/explosions. The scale might be one tiny "bubble" deep within a "greater cosmic expanding balloon."

 

Do you want evidence and supporting math? Don't we all, including the major "players!'

Here we go again. What particular Cosmology got debunked, when and by whom ???

 

Well that is an "easy one." The traditional "Bang/Crunch" cosmology based on all cosmic "stuff" perpetually exploding and imploding out into the infinite emptiness of space and then back to crunch and explode again... is said to have been debunked. Look up a few sites on Bang/Crunch Cosmology and save me the trouble of doing your research for you.

I've been there already. My version is officially off the the list of favored cosmologies. Singularities and clashing membranes are much more *popular*....

 

And... sorry to say, it seems to me that cosmology has become more of a popularity contest than unbiased inquiry into possible origins. ... i.e., science which might still have a shred of reason and observable evidence to back it up... without re-inventing physics!!

 

Michael

[maddog]

How are membranes not imaginary? My version is not yet testable either, but seems much more likely, reasonable and possible than absurd "points" with little or no volume... originating from nowhere, or membranes made of one dimensional strings vibrating in lots of very speculative "dimensions" based on extremely esoteric math... and not much else.

Being "imaginary" and imagined (as fictional) are quite different. Being imagined as being

fictional questions it's existence. Being imaginary only addresses it not being real. Very

different. Not being real can still have existence. Look at any image in a mirror.

Please refer to the direct Hawking quote above from his website. Again, he said that a singularity is "infinite matter density in a point of zero volume." If you want to correct him, write to him and tell him how he said it in error.

I don't need to correct Hawking as I don't see he made the error. You made it I think by

not including that a limit was involved. Makes all the difference. I can't imagine Hawking

not including it [even if he didn't even say it]. Thus I would error on simplicity and say

you didn't include limit of such.

Of course "it happens!" We have pictures of it! The question here at hand is, "on what scale might it happen?" Might "it" work on the scale of cosmic origin?

Good question! I see nothing directly prevent such an occurrence. Though you will likely

have to differential geometry into account. As more mass is taken into account, will cause

the local geometry to deform somewhat. In fact the whole initial bang can be thought

of a jet forming this bubble universe from another universe; at least in theory... ;)

Do you want evidence and supporting math? Don't we all, including the major "players!'

I always like supporting mathematical derivation backing up theory. :hihi:

Well that is an "easy one." The traditional "Bang/Crunch" cosmology based on all cosmic "stuff" perpetually exploding and imploding out into the infinite emptiness of space and then back to crunch and explode again... is said to have been debunked. Look up a few sites on Bang/Crunch Cosmology and save me the trouble of doing your research for you.

I've been there already. My version is officially off the the list of favored cosmologies. Singularities and clashing membranes are much more *popular*....

There has no "debunking" of BBT or "Bang/Crunch" per se. Any sites you found were not

of the credible variety. The papers you mentioned do question some of the hypotheses

of BBT [i have yet to finish them all]. This was my point in the first place. You post a

link and think it does the work for you. No, it does not.

 

If that were allowed in giving a PhD Thesis, we would just list the citations be done with it.

You have to make a case.

And... sorry to say, it seems to me that cosmology has become more of a popularity contest than unbiased inquiry into possible origins. ... i.e., science which might still have a shred of reason and observable evidence to back it up... without re-inventing physics!!

On your highlighted comment -- sad to say -- I agree with. To me Cosmology has sunk

to a new low, allowing any old idea to get some merit... :shrug:

 

maddog

[modest]

Well that is an "easy one." The traditional "Bang/Crunch" cosmology based on all cosmic "stuff" perpetually exploding and imploding out into the infinite emptiness of space and then back to crunch and explode again... is said to have been debunked. Look up a few sites on Bang/Crunch Cosmology and save me the trouble of doing your research for you.

 

Can you find me a science source describing the big bang or a bang/crunch where stuff "explodes... out into the infinite emptiness of space"? The reason I ask is because you will find no such source, and perhaps by looking for it you will discover the misconception that it is.

 

Big bang theory does *not* claim that stuff explodes *out into empty space*. No credible description of the theory would ever claim such a thing.

The Big Bang is not an explosion of matter moving outward to fill an empty universe. Instead, space itself expands with time everywhere and increases the physical distance between two comoving points.

 

Big Bang - Wikipedia, the free encyclopedia

 

~modest

[Michael Mooney]

Can you find me a science source describing the big bang or a bang/crunch where stuff "explodes... out into the infinite emptiness of space"? The reason I ask is because you will find no such source, and perhaps by looking for it you will discover the misconception that it is.

 

Big bang theory does *not* claim that stuff explodes *out into empty space*. No credible description of the theory would ever claim such a thing.

 

~modest

 

There must be some misunderstanding here.

I already said above that the bang/crunch model I favor is said to have been debunked.

 

The traditional "Bang/Crunch" cosmology based on all cosmic "stuff" perpetually exploding and imploding out into the infinite emptiness of space and then back to crunch and explode again... is said to have been debunked. Look up a few sites on Bang/Crunch Cosmology and save me the trouble of doing your research for you.

 

In summary, as I already said... and you seem to have missed:

And, yes, this is in total contradiction of the standard dictum that the above (stuff exploding out into empty space) is now a thoroughly debunked cosmology.

 

As I said above, the standard inflation model which requires "expanding space" does *not* address the ontology of what it is that is posited as "expanding." Obviously as things move away from each other... stuff moving in outward trajectory from the bang... the "expanding universe"... there is more and more space between them. This is different than positing that "space itself expands"... as an entity of some sort. We have been through this dozens of times in the "spacetime" thread already, and the ontology of what the "space" component is is still in hot debate... as noted and linked many times in that thread.

Here is another Wiki link on the Bang/Crunch model:

Big Crunch - Wikipedia, the free encyclopedia

 

In physical cosmology, the Big Crunch is one possible scenario for the ultimate fate of the universe, in which the metric expansion of space eventually reverses and the universe recollapses, ultimately ending as a black hole singularity.

Overview:

 

If the universe is finite in extent and the cosmological principle (not to be confused with the cosmological constant) does not apply, and the expansion speed does not exceed the escape velocity, then the mutual gravitational attraction of all its matter will eventually cause it to contract. Because entropy continues to increase in the contracting phase, the contraction would appear very different from the time reversal of the expansion. While the early universe was highly uniform, a contracting universe would become increasingly clumped. Eventually all matter would collapse into black holes, which would then coalesce producing a unified black hole or Big Crunch singularity.

 

The Hubble Constant measures the current state of expansion in the universe, and the strength of the gravitational force depends on the density and pressure of the matter and in the universe, or in other words, the critical density of the universe. If the density of the universe is greater than the critical density, then the strength of the gravitational force will stop the universe from expanding and the universe will collapse back on itself. Conversely, if the density of the universe is less than the critical density, the universe will continue to expand and the gravitational pull will not be enough to stop the universe from expanding. This scenario would result in the 'Big Freeze', where the universe cools as it expands and reaches a state of entropy.[1] Some theorize that the universe could collapse to the state where it began and then initate another Big Bang, so in this way the universe would last forever, but would pass through phases of expansion (Big Bang) and contraction (Big Crunch)[2]

 

Recent experimental evidence (namely the observation of distant supernova as standard candles, and the well-resolved mapping of the cosmic microwave background) have led to speculation that the expansion of the universe is not being slowed down by gravity but rather accelerating. However, since the nature of the dark energy that drives the acceleration is unknown, it is still possible that it might eventually reverse sign and cause a collapse.[3]

 

You will notice the standard phrasing right up front, to which I object on the above ontological grounds: "...metric expansion of space..."

 

We have previously debated the "entropy" question as a possible spoiler for a perpetually cycling Bang/Crunch cosmology, and we have likewise discussed the "missing matter" objection and the open question of the cosmic density required for a reversal and implosion back into a "crunch."

 

I simply suggest a model of actual cosmic plasma, energy, matter (of all kinds)... "stuff" for short... expanding outwardly into empty space, which is endless/infinite. The dynamic is open for debate. My model has it as a super-duper supernova kind of explosion or sequence of explosions (or "jetting out plasma form an axis of spin) as more incoming "stuff" crunches and then bangs (or "jets stuff out.) For me, the alternative makes no sense, as above.... that "space itself expands"... whatever "it" is supposed to be, and this is after somehow stuff magically appears as The Singularity... of whatever size... or no volume at all.

 

All of the above is why I asked you to avoid engaging the "auto-pilot" of standard mainstream cosmology... and its denial outright of the bang/crunch model I advocate.

 

If you object to "stuff" either exploding or jetting out from a primordial body of extremely compacted matter into infinite, empty space (having imploded after reversal of the expansion phase) please give specific reasons why that model will not work... and is no longer considered a viable model. Just saying that modern cosmology now rejects the model (which it does!) is not enough.

And wile you are at it, please address the unresolved ontological question of what this "expanding space" actually is.

Michael

Ed: Here's another link on cyclical cosmology:

http://en.wikipedia.org/wiki/Cyclic_model

 

It raises again the entropy objection which I addressed in the "entropy..." thread spun off from "spacetime." It also presents the M-theory version, including the following (my bold):

 

One new cyclic model is a brane cosmology model of the creation of the universe, derived from the earlier ekpyrotic model. It was proposed in 2001 by Paul Steinhardt of Princeton University and Neil Turok of Cambridge University. The theory describes a universe exploding into existence not just once, but repeatedly over time.[3][4] The theory could potentially explain why a mysterious repulsive form of energy known as the "cosmological constant", and which is accelerating the expansion of the universe, is several orders of magnitude smaller than predicted by the standard Big Bang model.

 

As you know, the membranes have no referents in the observable cosmos (being imaginary) and this theory's extra "dimensions" beyond the 3-D space (and time) we all know and love are purely metaphysical speculation. But an "exploding" cosmos is basic to the theory, and an explosion throws "stuff" into an outward trajectory... into space... as we do observe in this expanding universe.

[Michael Mooney]

More on Bang/Crunch from:

Apologetics Press :: Sensible Science

“Big Bang” or “Big Crunch"?

by Bert Thompson, Ph.D.

(The site is religious... sorry... but Thomson seems to be looking at cosmologies as a scientist.)

The Big Bang model replaced the Steady State theory by postulating that all the matter/energy in the observable Universe was condensed into a particle smaller than a single proton (the famous “cosmic egg”). The Big Bang model, however, suffered from at least two major problems. First, it required that the “cosmic egg” be eternal—a concept clearly at odds with the Second Law of Thermodynamics. John Gribbin, a highly regarded evolutionary cosmologist, voiced the opinion of many when he said: “The biggest problem with the Big Bang theory of the origin of the Universe is philosophical—perhaps even theological—what was there before the bang?” (1976, pp. 15-16).

 

Second, the expansion of the Universe could not go on forever; it had to end somewhere. The Universe had a beginning, and would have an ending. Robert Jastrow has addressed both of these points: “And concurrently there was a great deal of discussion about the fact that the second law of thermodynamics, applied to the Cosmos, indicates the Universe is running down like a clock. If it is running down, there must have been a time when it was fully wound up” (1978, pp. 48-49). Matter could not be eternal, because eternal things do not run down. Furthermore, there was going to be an end at some point in the future.

 

Such a scenario is unacceptable to evolutionists. Jastrow himself admitted: “Astronomers try not to be influenced by philosophical considerations. However, the idea of a Universe that has both a beginning and an end is distasteful to the scientific mind” (1977, p. 31). To avoid any vestige of a beginning, or any hint of an ending, evolutionists invented the Oscillating Universe model (also known as the Big Bang/Big Crunch model, the Expansion/ Collapse model, etc.). Dr. Gribbin suggested: “[T]he best way around this initial difficulty is provided by a model in which the Universe expands from a singularity, collapses back again, and repeats the cycle indefinitely” (1976, pp. 15-16).

 

That is to say, there was a Big Bang; but there also will be a Big Crunch, at which time the matter of the Universe will collapse back onto itself. There will be a “bounce,” followed by another Big Bang, which will be followed by another Big Crunch, and this process will be repeated ad infinitum. In the Big Bang model, there is a permanent end; not so in the Oscillating Universe model, as Dr. Jastrow explained:

 

But many astronomers reject this picture of a dying Universe. They believe that the expansion of the Universe will not continue forever because gravity, pulling back on the outward-moving galaxies, must slow their retreat. If the pull of gravity is sufficiently strong, it may bring the expansion to a halt at some point in the future.

 

What will happen then? The answer is the crux of this theory. The elements of the Universe, held in a balance between the outward momentum of the primordial explosion and the inward force of gravity, stand momentarily at rest; but after the briefest instant, always drawn together by gravity, they commence to move toward one another. Slowly at first, and then with increasing momentum, the Universe collapses under the relentless pull of gravity. Soon the galaxies of the Cosmos rush toward one another with an inward movement as violent as the outward movement of their expansion when the Universe exploded earlier. After a sufficient time, they come into contact; their gases mix; their atoms are heated by compression; and the Universe returns to the heat and chaos from which it emerged many billions of years ago (1978, p. 118).

 

Again, all this banging and crunching requires a theater of activity, a volume to expand/explode into and back again. Since there can be no "end of space" (no wall or boundary but in man's finite mind) space must be infinite, not a finite, expandable, contractable entity. The "stuff in space" does the exploding and imploding, not "space itself.)

 

So "bang!"... out into space... then "crunch" back to whnce it came.

For me this is the only cosmology which makes sense... and it still doesn't require that space be an entity which expands.

Michael

[modest]

There must be some misunderstanding here.

I already said above that the bang/crunch model I favor is said to have been debunked.

 

The traditional "Bang/Crunch" cosmology based on all cosmic "stuff" perpetually exploding and imploding out into the infinite emptiness of space and then back to crunch and explode again... is said to have been debunked. Look up a few sites on Bang/Crunch Cosmology and save me the trouble of doing your research for you.

 

In summary, as I already said... and you seem to have missed:

And, yes, this is in total contradiction of the standard dictum that the above (stuff exploding out into empty space) is now a thoroughly debunked cosmology.

 

You're not following. It has never been the case that big bang theory was described as stuff exploding out into space. It has never been "traditional Bang/Crunch cosmology". The very first rendition of big bang cosmology was Friedmann's and Lemaître's in the 1920's which is pretty-much indistinguishable from the theory today. No exploding stuff moving out into empty space.

 

As I said above, the standard inflation model which requires "expanding space" does *not* address the ontology of what it is that is posited as "expanding."

 

There is nothing special about inflation as far as expanding space. Big bang theory requires the metric expansion of space today just as it did during inflation. The only significant difference is the speed at which space expanded.

 

I simply suggest a model of actual cosmic plasma, energy, matter (of all kinds)... "stuff" for short... expanding outwardly into empty space, which is endless/infinite. The dynamic is open for debate. My model has it as a super-duper supernova kind of explosion or sequence of explosions (or "jetting out plasma form an axis of spin) as more incoming "stuff" crunches and then bangs (or "jets stuff out.)

 

The universe is isotropic.

 

For me, the alternative makes no sense, as above.... that "space itself expands"

 

Yes, I can tell it doesn't make sense to you.

 

If you object to "stuff" either exploding or jetting out from a primordial body of extremely compacted matter into infinite, empty space (having imploded after reversal of the expansion phase) please give specific reasons why that model will not work...

 

The universe is isotropic. Read the first 3 paragraphs of this link:

 

Robertson-Walker Metric

 

Just saying that modern cosmology now rejects the model (which it does!) is not enough.

 

It's not that modern cosmology *now* rejects the model. What you are describing has never been a working model. It has always been a misconception. You'll find it corrected on every "common misconceptions about the big bang" website... and I've given you links to several over this issue.

 

And wile you are at it, please address the unresolved ontological question of what this "expanding space" actually is.

 

It's expanding distance. I've told you that a dozen times. Cosmological distances expand over time in a manner roughly proportional to the distance itself. It's Hubble's law.

 

I know we have our disagreements, Michael. But, I think that what I'm about to recommend would help tremendously. With the best intentions I offer this. Read the whole tutorial:

 

Ned Wright's Cosmology Tutorial - Part 1

 

~modest

[Boerseun]

Michael, I think one of your biggest problems with the current understanding of the Big Bang is that you envision the universe to be a bubble with a defined border.

 

Yes, the universe has a border. But that border exist in time, not in space. If it was ten minutes after the Big Bang, you'd have a border to the universe of ten minutes - but you will never, try as you might, reach that border - because it's ten minutes in time. You will have to outfly light to get there - which is impossible. This "edge" of the universe is expanding away from you at the speed of light, and with the space between you and the border expanding as well, the furthest reaches will expand away from you at what would appear to you to be faster than the speed of light.

 

There is no way for you to reach it.

 

It's not a "balloon" with a "border" or "edge" in space.

 

The space in which we exist is bordered in time.

 

I don't know how else to explain this to you. But I can clearly see where your problem lies.

[enorbet2]

Yes...please google "background independent cosmology". It is the biggest problem w/ String Theories and the reason so much focus is on Gravity, it's weakness relative to the other 3 forces, and it's possible coherence within QM. The answers may lead to discovering if SpaceTime is truly a "fabric" possibly at Planck Scale, or whether that concept is just a useful construct. In any case one cannot begin to understand BBT unless one understands "from nothing" really means "no thing" as in nada... no enclosure required.