Big Bang Singularity: What Prevents Universe from Becoming Black Hole?

[Alan McDougal]

Hi

We know that a black hole is a dense object so dense that it gravitational makes it vanish from the universe.

Now at the moment of the big bang creation event the ultimate in density and gravity was experienced, so what prevented the universe from going the way of black holes. Is it a white hole spewing out from another universe, or what do you guys think?

Regards

Alan

 

[gendou2]

Clearly the universe did not behave like a black hole, because here we are!
The prediction of a singularity tells us that general relativity alone fails to explain what happened.
The Inflationary Model attempts to solve our problem by getting rid of the singularity.

P.S.: You sneak the word "creation" in when labeling the big bang event. Was that a creationist Freudian slip?

 

[marcus]

Now at the moment of the big bang creation event...

You need some help getting up to speed on current research. The research area that focuses most on modeling the big bang is called quantum cosmology.
The field is going thru a period of rapid growth and change.

Here are the papers published since 2005 with Stanford-data-base keyword "quantum cosmology"

 

[Alan McDougal]

gendoo2,

Maybe all universes are black holes some existing for one blindingly brief moment and others like our own for almost an eternity. The absolute density of our universe might be considered a void or empty space in another. universe

Just wild speculation, but man! it can be fun.

Alan

 

[Freezeezy]

Hi Alan,

I do believe that there is something wrong with what you are saying. This could be due to my own beliefs, which I will relate in short order. But back to your statement, Black holes appear "invisible" because light cannot escape. This is how we detect them. They make "black holes" in light that is behind them (from our perspective).

So forward. The universe could have been a massive black hole at one point. All the matter and energy of the universe (including the universal-powers of Gravity, Strong Nuclear, Weak Nuclear, and Electromagnetic) was in one "ball" of mass and condenced at extremely high temperatures and density. Something sparked (don't ask what) and that all exploded. The idea right now is that all the universal-powers (mentioned above) were still in their "super-power" state (not separated like the rest of the matter and energy). This is what explains the extreme distances between the clusters of matter (galactic neighborhoods) and the lack of energy residue. Gravity separated first, then Electromagnetics, then the Nuclear forces. Galaxies, stars, planets, and moons form afterward. Then there are the Dimentions and the 11th dimension/Supergravity, but that is irrelevant (but could define your "another universe" concept)

What I am trying to say is that it is a little bit more complex.

 

[marcus]

EDIT I got interrupted and couldn't finish typing earlier, here is the rest of the post

Alan,
You need some help getting up to speed on current research. The research area that focuses most on modeling the big bang is called quantum cosmology.
The field is going thru a period of rapid growth and change.

Here are the papers published since 2006 with Stanford-data-base keyword "quantum cosmology"
http://www.slac.stanford.edu/spires/find/hep/www?rawcmd=DK+quantum+cosmology+and+date+%3E+2005&FORMAT=WWW&SEQUENCE=citecount%28d%29

Have a brief glance at the list. None of the papers you are likely to see here assume that the big bang event was the beginning of the universe, or the beginning of time, or any such thing. These are mainstream professional research papers. They go back before the big bang and model smoothly up thru it to the beginning of expansion. It is peer-reviewed published stuff, not popularizations.

I have set the keyword search up so that the most highly cited papers are listed first. The number of times a research paper is cited by other experts in the field, as a reference in their own papers, is a rough measure of expert opinion about it---how important or useful it is, how significant the results are. So the top 10 or 20 papers that you see on the list would represent the dominant mainstream thought at the present time. That doesn't mean it's right, it means it is worth knowing about.

Your question about black hole has to be referred to some mathematical model. Classical General Relativity is insufficient because it breaks down at the beginning of expansion. That means it is wrong. But right afterwards, even just with classic GR, the universe is expanding too rapidly for black holes to form. Black holes form in the classical GR model only where the expansion is not too rapid. So there is no reason to worry about black holes at the beginning of expansion, even just using vintage 1915 GR.

There is even less reason to worry about black holes if you use the modern quantum improved version, mainstream quantum cosmology (QC), as your model. QC models predict a bounce. When gravity is quantized, spatial geometry acquires a certain "springiness". The prior collapse phase leads to conditions of extreme density where quantum corrections make gravity repel instead of attract. This rather surprising result comes out of the math when classical General Relativity is quantized. So there is a period of very rapid expansion and the formation of black holes is out of the question.

 

[g33kski11z]

...Black holes appear "invisible" because light cannot escape. This is how we detect them. They make "black holes" in light that is behind them (from our perspective)..

Really..? I thought black holes were detected by the gravitational effects they have on orbiting stars.

...The universe could have been a massive black hole at one point.

That statement is false.

...The idea right now is that all the universal-powers (mentioned above) were still in their "super-power" state (not separated like the rest of the matter and energy).This is what explains the extreme distances between the clusters of matter (galactic neighborhoods) and the lack of energy residue...

Are you sure about that? I'm not positive, but I don't think the separation of forces caused the differences in temperature and density we see in the WMAP images.
I'm trying to find the thread that mentioned this.

 

[Alan McDougal]

Freezeesy,

I do believe that there is something wrong with what you are saying. This could be due to my own beliefs, which I will relate in short order. But back to your statement, Black holes appear "invisible" because light cannot escape. This is how we detect them. They make "black holes" in light that is behind them (from our perspective).

So forward. The universe could have been a massive black hole at one point. All the matter and energy of the universe (including the universal-powers of Gravity, Strong Nuclear, Weak Nuclear, and Electromagnetic) was in one "ball" of mass and condenced at extremely high temperatures and density. Something sparked (don't ask what) and that all exploded.

This ball of colossal energy could be the "spark" that gave it sufficient push to enter our universe from a greater universe in the form of a white hole. (the term enter is of course wrong)

Marcus

Your question about black hole has to be referred to some mathematical model. Classical General Relativity is insufficient because it breaks down at the beginning of expansion. That means it is wrong. But right afterwards, even just with classic GR, the universe is expanding too rapidly for black holes to form. Black holes form in the classical GR model only where the expansion is not too rapid. So there is no reason to worry about black holes at the beginning of expansion, even just using vintage 1915 GR

It is news to me that Classical General Relativity might be wrong! But physics always moves on towards the theory of everything T.O.E.


The rate of Expansion is problematic to me! But elimination the singularity brings us back to Fred Hoyles static universe. Of course the universe might not have an alpha point moment or beginning and be infinite and eternal and indeed be all that is, in other words Existence.

The universe is decidedly not static but this does not eliminate the possibility that it is infinite. Expansion can happen in an eternal infinite universe .

The "bounce" you mentioned would make the universe finite as entropy must eventually stop this cyclic phenomenon.

 

[marcus]

...But elimination the singularity brings us back to Fred Hoyles static universe...

I don't think so. Instead of putting yourself up against the acknowledged mainstream experts in this field, why don't you read the abstracts of the top ten or so recent publications and get an idea of what they are saying.

About entropy, your objection doesn't make sense. You talk about a "cyclic phenomenon".
I said nothing about a cyclic phenomenon. In a common QC picture there is one bounce.

Ashtekar, one of the experts in this field, just posted a paper on the Bousso covariant entropy bound in Loop Quantum Cosmology. It is at the preprint archive. If you are interested in entropy you might like to look at it. Say, and I'll get the link for you.

 

[Freezeezy]

...The universe could have been a massive black hole at one point...

That statement is false.

Well the general consensus is that the before the Big Bang the universe was a massive clump of matter and energy and was very dense. Isn't that what a black hole is? A large collection of matter and energy that is super dense... right? Tell me if I'm wrong to say that there is a HUGE common similarity between the two and the fact of the matter is this: I said "could have been" and I have found no satisfactory source that says that my speculation is wrong.

Now thank you for being rude and not taking in the fact that I was being very vague.


Now Alan... Think of this: What if it isn't a plethora of universes (please stop making that plural from now on... use the term Multiverse), just a specific amount of dimensions. As of right now we postulate there to be anywhere from 5 to 24 to an infinite number of dimensions. I will look into this a bit further before pushing this issue.

Thanks for the entertaining thread Alan.

 

[marcus]

Well the general consensus is that the before the Big Bang the universe was a massive clump of matter and energy and was very dense...

But that simply is not true, Freezeezy.
How can you support such a statement about a general consensus? Do you have a source?

Isn't that what a black hole is? A large collection of matter and energy that is super dense... right?

No that is an unsupported statement. We don't know what is actually there in Nature, in reality, at the pit of a black hole. We have mathematical models, both classic GR models and quantum models. They predict different things happen, at the pit.
As far as I know in neither case can you make that general statement based on the prevailing models.

I certainly don't mean to be rude. I am just telling you that you are making unsubstantiated statements and don't seem to know what you are talking about. It would be a big help if you would sample the current peer-review mainstream literature and see what kind of things people are talking about these days. Revise your idea of what the consensus is, etc. Alan too, could use some help getting up to speed.

 

[Alan McDougal]

Marcus,

I said nothing about a cyclic phenomenon. In a common QC picture there is one bounce

Ah! common QC picture but is it truth? By Cyclic bouncing universe expands ,contracts back to second singularity and expands again a little less in each expansion/ contraction, like a rubber ball bouncing until it finally comes to rest. Entropy will do the trick for this mode of
universe or cause the heat death of a universe expanding outward forever, as ours might be.

Freezeesy

Now Alan... Think of this: What if it isn't a plethora of universes (please stop making that plural from now on... use the term Multiverse), just a specific amount of dimensions. As of right now we postulate there to be anywhere from 5 to 24 to an infinite number of dimensions. I will look into this a bit further before pushing this issue

I like that "Multiverse" What about "Super Universe"

gee33ksj11z

Originally Posted by Freezeezy View Post

...The universe could have been a massive black hole at one point...

Originally Posted by g33kski11z View Post

"That statement is false".

Come on be polite , how do you know it is false, once people were so sure that the Earth was the center of everything that if anyone differed this thinking the person who did not recant would promply be burned at the stake, Freezeesy just might be correct you know.

Alan

 

[marcus]

...Ah! common QC picture but is it truth?

Who knows? We don't know the truth. We know what models the experts are working on, and which ones have fallen by the wayside. We know who the experts are and what they currently find most interesting, and who is getting the most new results along which lines.

In this forum we are normally not interested in philosophy and religion. Or in people's personal cosmic systems. We normally focus on mainstream cosmology models that are part of the professional literature. So the most efficient thing for you to do, if you want to discuss, is to sample the current peer-review literature, find articles that appeal to you pursuing approaches you like, and present the ideas, with links.

Get familiar with the Spires and ArXiv database search tools. And familiar with current mainstream ideas.

Here is Spires
http://www.slac.stanford.edu/spires/
Here is ArXiv
http://arxiv.org/find

Here is the ArXiv menu laid out for browsing
http://arxiv.org

Good luck and have fun!

Right now, no disrespect intended, you come across to me as someone who has read some faintly religious stuff by Frank J. Tipler from, like, before 1995. Singularity-mysticism. But in the real science world the effort since 2001 or so has been towards resolving the cosmological singularity. Improving the model so it doesn't break down.
Great conference at Santa Barbara last year about that. Three week workshop with all types, string, loop, classical, etc.
Videos of many of the talks, which you can sample if you want

Have a look if you want:
http://online.kitp.ucsb.edu/online/singular_m07/
You can click on links there and get PDF of the speaker's slides and then watch him/her present the talk.

Try to stick to recent sources, like since 2004 or later. There's been a lot of change in how people think.

 

[Alan McDougal]

I registered on this forum to escape religious dogma

Alan

 

[Freezeezy]

...In this forum we are normally not interested in philosophy and religion. Or in people's personal cosmic systems. We normally focus on mainstream cosmology models that are part of the professional literature. So the most efficient thing for you to do, if you want to discuss, is to sample the current peer-review literature, find articles that appeal to you pursuing approaches you like, and present the ideas, with links...

If we are to only talk about "current peer-review literature" we would be failing at the number one goal of science: Curiosity. We must try and look at things differently or be doomed to make the mistakes of the past.

I understand that knowledge of current ideas is important... but to formulate your own ideas is a far greater prerogative.

As my best friend always says (with the enthusiasm of an evangelical preacher):

"Knowledge hinders; Liberates. Knowing something only gives you foresight. Knowing when to know and when not to know is Wisdom."

The reason I relate this is that right now, in the original context of Alan's proposition, we don't need to know the main-stream ideas. All we need to know is what we believe and think. We need to toy with the standards of thought to conclude this conversation.

Thank you,
Freezeezy

P.S. Alan, I love your "Super Universe" idea... Why not call it the "Superverse"? ;-)

 

[g33kski11z]

...Now thank you for being rude and not taking in the fact that I was being very vague.

Freezeezy, I was not trying to be rude. But the fact is that your statements are past vague, they show a lack of understanding, and that's why we are here at PF, to learn. Now, please, do not take this as if I am acting to know everything about cosmology {notice my avatar comment?} I definitely do not, but I do not make unsupported statements. I hope this can help clear up some of your misconceptions about the Big Bang, http://www.astro.princeton.edu/~aes/AST105/Readings/misconceptionsBigBang.pdf

...All we need to know is what we believe and think.

Believe... interesting choice of words. I prefer to know based on fact and observations.

how do you know it is false

Which comment are you specifically talking about:

...Black holes appear "invisible" because light cannot escape. This is how we detect them. They make "black holes" in light that is behind them (from our perspective)..

-or-

...The idea right now is that all the universal-powers (mentioned above) were still in their "super-power" state (not separated like the rest of the matter and energy).This is what explains the extreme distances between the clusters of matter (galactic neighborhoods) and the lack of energy residue...

.. as Marcus and I stated, these remarks are incorrect.

 

[marcus]

... but to formulate your own ideas is a far greater prerogative.
...

But not here in Cosmology forum. There is a special subforum at PhysicForums set up exactly for this purpose. It is called "Individual Research"
https://www.physicsforums.com/forumdisplay.php?f=146

the mainstream forums are for learning about and discussing professionally reasearched ideas. Individual Research was set up a couple of years back for people to formulate their own ideas. (as you say).

It was set up because too many people were formulating their own personal theories in the regular forums. (often without even taking the trouble to understand the current research models first)

 

[Alan McDougal]

Marcus

It was set up because too many people were formulating their own personal theories in the regular forums. (often without even taking the trouble to understand the current research models first)

Yes Marcus ignorance of the basics of physical science can be frustrating to us who are debating present progress.

I would not like to see this forum descend into wild conjecture and speculation. We should state what is known by present modalities and then try to move further on. We should attempt original thought within the confines of common sense,

 

[yuiop]

The "bounce" you mentioned would make the universe finite as entropy must eventually stop this cyclic phenomenon.

I assume you are talking about finite time. Thermodynamics does not forbid reversible processes as long as the net entropy change is zero. Perhaps that is the case with the universe as a whole. Although "time's arrow" goes in the direction of increasing entropy, it just might be possible that the net change in entropy of the universe as it expands is zero. If that was the case, thermodynamics would not forbid the universe expanding and collapsing repeatedly forever. An example of a reversable process is a black hole forming and then evaporating again. No has seen that happen yet, but no one has said it can not happen in principle on thermodynaic grounds.

 

[gendou2]

gendoo2,

Maybe all universes are black holes some existing for one blindingly brief moment and others like our own for almost an eternity. The absolute density of our universe might be considered a void or empty space in another. universe

Just wild speculation, but man! it can be fun.

Alan

This is not the sort of attitude one may bring to a scientific debate!
1. Many-universe theory is not a valid scientific theory.
2. You are not using proper punctuation.
3. Wild speculation may be fun for you, but it can insult other people's intelligence.

I would not like to see this forum descend into wild conjecture and speculation. We should state what is known by present modalities and then try to move further on. We should attempt original thought within the confines of common sense,

I agree, and caution you to avoid being hypocritical.

 

[Allday]

my 2

Without even getting into the realm of quantum GR, It is unclear to me that a BH would form in the early dense universe. Here is my thinking. One of the major misconceptions about the Big Bang is that there was this super dense nugget of stuff early on. What happens in a flat Universe is that the density is the same everywhere, there is not ball of matter. This density increased as you run time backwards from the present.

Now there is a critical density for collapse into a black hole. You can do a simple classical derivation by setting the escape velocity of a parcel of matter equal to the speed of light. Even if the density of the Universe crosses this threshold at some point, it has this density everywhere and so the curvature is still flat. I would guess that even a non-expanding, but infinite Universe would not form a black hole.

Of course there are quantum effects that need to be take into account in an exact theory, but simplistically from a smooth classical GR perspective I wouldn't expect a black hole to form. If you have pertubations in this density field then individual black holes could form at the overdense sites, but this would still not mean the whole Universe becoming a black hole.

 

[yuiop]

Without even getting into the realm of quantum GR, It is unclear to me that a BH would form in the early dense universe. Here is my thinking. One of the major misconceptions about the Big Bang is that there was this super dense nugget of stuff early on. What happens in a flat Universe is that the density is the same everywhere, there is not ball of matter. This density increased as you run time backwards from the present.

Now there is a critical density for collapse into a black hole. You can do a simple classical derivation by setting the escape velocity of a parcel of matter equal to the speed of light. Even if the density of the Universe crosses this threshold at some point, it has this density everywhere and so the curvature is still flat. I would guess that even a non-expanding, but infinite Universe would not form a black hole.

Of course there are quantum effects that need to be take into account in an exact theory, but simplistically from a smooth classical GR perspective I wouldn't expect a black hole to form. If you have pertubations in this density field then individual black holes could form at the overdense sites, but this would still not mean the whole Universe becoming a black hole.

Assuming an universe of infinite mass would indeed prevent the universe being a black hole or nugget at any time. However, the concept of infinite mass is not one to be used lightly. When you evaluate the true meaning of infinite, the concept of infinite mass is very hard to take seriously. The concept of a universe with infinite volume is not too hard to imagine, but if the density of the universe is isotropic and homogenous everywhere on large scales then even finite density implies infinite mass in a universe of infinite volume.

A second difficulty is this. It is known that in an earlier epoch of the universe, the expansion of the universe actully slowed down, as if it was going to collapse but later the cosmological constant kicked in and started accelerating the expansion. Now the slow down in expansion in the earlier epoch was put down to gravitational collapse. That would not be possible in a universe with infinite mass and volume for the same reasons that it would not be possible to have a black hole at the beginning of the universe in a universe that was always infinite.

That means we cannot explain the initial slow down of expansion by gravity, so we would have to postulate that the cosmological constant changes over time taking on negative values early on in the history of the universe and changing to positive later on. I am not sure a pulsating cosmological constant is the current accepted view. That means an infinite universe is ruled out by the accepted view.

 

[Alan McDougal]

Gendou2,

This is not the sort of attitude one may bring to a scientific debate!
1. Many-universe theory is not a valid scientific theory.
2. You are not using proper punctuation.
3. Wild speculation may be fun for you, but it can insult other people's intelligence.

So the forum needs protection from my exotic mind! By wild speculation I meant "scientific wild speculation" of the kind Einstein (imagined himself riding on a beam of light) or Newton, (what is gravity).I do not equate myself with these great minds ,but please allow me to think
in my own unique manner which is outside apparently of your "boxed"" in mind

If great minds like this did not indulge in speculation that would be considered "wild" in their time frame we might still be living in the stone age. Some of them were even burned at the stake. Heck I hope you don't want the forum to give me the same punishment!


I don't like your rhetoric and will punctuate just like I want to. I do not like admonishment << personal insult removed by berkeman >>, and "just one more unfortunate comment like this will see me leaving this forum"

Alan

 

[Allday]

Assuming an universe of infinite mass would indeed prevent the universe being a black hole or nugget at any time. However, the concept of infinite mass is not one to be used lightly. When you evaluate the true meaning of infinite, the concept of infinite mass is very hard to take seriously. The concept of a universe with infinite volume is not too hard to imagine, but if the density of the universe is isotropic and homogenous everywhere on large scales then even finite density implies infinite mass in a universe of infinite volume.

A second difficulty is this. It is known that in an earlier epoch of the universe, the expansion of the universe actully slowed down, as if it was going to collapse but later the cosmological constant kicked in and started accelerating the expansion. Now the slow down in expansion in the earlier epoch was put down to gravitational collapse. That would not be possible in a universe with infinite mass and volume for the same reasons that it would not be possible to have a black hole at the beginning of the universe in a universe that was always infinite.

That means we cannot explain the initial slow down of expansion by gravity, so we would have to postulate that the cosmological constant changes over time taking on negative values early on in the history of the universe and changing to positive later on. I am not sure a pulsating cosmological constant is the current accepted view. That means an infinite universe is ruled out by the accepted view.

The concept of infinite mass and infinite volume is exactly what the Friedman Robertson Walker metric implies for a flat Universe. This is a well accepted model and observations from WMAP have been narrowing in on a flat Universe each time new results come out.

It is indeed possible for an infinite Universe with infinite mass to go through a period of deceleration and then acceleration in expansion. The effect comes from the change in the ratio of the density of the components of the Universe. Specifically the matter density drops as a^-3 and the energy density of the cosmological constant remains ... well ... constant (a is the scale factor). The matter causes contraction the cosmological constant causes expansion and eventually takes over.

 

[Wallace]

That means we cannot explain the initial slow down of expansion by gravity, so we would have to postulate that the cosmological constant changes over time taking on negative values early on in the history of the universe and changing to positive later on. I am not sure a pulsating cosmological constant is the current accepted view. That means an infinite universe is ruled out by the accepted view.

Allday is correct, there is nothing in the current 'deceleration followed by acceleration' model of the Universe that prohibits an infinite Universe. In an infinite homogeneous Universe, within any spherical sub section we can observe that the gravitational effect of matter outside that sphere cancels and we need only consider the matter within the sphere. Mathematically this works fine. You can derive the Friedman equations (that come formally from the Einstein Field Equations) simply by considering a finite sphere of matter and working out how its radius changes with time. As the initial radius of the ball is taken to infinity you get an infinite Universe.

 

[yuiop]

The concept of infinite mass and infinite volume is exactly what the Friedman Robertson Walker metric implies for a flat Universe. This is a well accepted model and observations from WMAP have been narrowing in on a flat Universe each time new results come out.

It is indeed possible for an infinite Universe with infinite mass to go through a period of deceleration and then acceleration in expansion. The effect comes from the change in the ratio of the density of the components of the Universe. Specifically the matter density drops as a^-3 and the energy density of the cosmological constant remains ... well ... constant (a is the scale factor). The matter causes contraction the cosmological constant causes expansion and eventually takes over.

Allday is correct, there is nothing in the current 'deceleration followed by acceleration' model of the Universe that prohibits an infinite Universe. In an infinite homogeneous Universe, within any spherical sub section we can observe that the gravitational effect of matter outside that sphere cancels and we need only consider the matter within the sphere. Mathematically this works fine. You can derive the Friedman equations (that come formally from the Einstein Field Equations) simply by considering a finite sphere of matter and working out how its radius changes with time. As the initial radius of the ball is taken to infinity you get an infinite Universe.

In that case, if matter density can contract the expansion in a inifinite universe then the fact that the universe is infinite cannot prevent the universe being a black hole when the density was sufficient at the early stages. As Wallace says, "gravitational effect of matter outside that sphere cancels and we need only consider the matter within the sphere"

 

[Wallace]

Right, that's why the Universe required some as yet unknown mechanism that inflated the early Universe. As marcus detailed earlier in this thread (and others) the search for the mechanism of inflation if one of the hot research topics of today.

 

[yuiop]

Right, that's why the Universe required some as yet unknown mechanism that inflated the early Universe. As marcus detailed earlier in this thread (and others) the search for the mechanism of inflation if one of the hot research topics of today.

Perhaps they need look no further than GR and the Schwarzschild solution to see how a finite mass confined to considerably less than the Schwarzschild radius of the mass would inflate rapidly at superluminal velocities as detailed in this post: https://www.physicsforums.com/showpost.php?p=1769733&postcount=137

 

[gendou2]

... Please allow me to think in my own unique manner which is outside apparently of your "boxed-in" mind.

If pointing out gaping holes in an attempt at logical argument is having a "boxed-in" mind, then I am guilty of this. I am perfectly willing to hear any radical idea regarding the fascinating field of cosmology. Please don't blame me for your failure to back up your ideas with a coherent argument.

You are free to think whatever you want. Your are not free to harass members of this forum who disagree with your unsupported theories by accusing them of being closed minded. This is abusive behavior and will be reported.

Still, if I have seemed unfriendly to you, I apologize. This was not my intention.

 

[Alex48674]

Right, that's why the Universe required some as yet unknown mechanism that inflated the early Universe. As marcus detailed earlier in this thread (and others) the search for the mechanism of inflation if one of the hot research topics of today.

I thought that mechanism was a supercooled higg's field causing a negative pressure. Is this wrong, or do you mean what caused it to supercool?