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Posted

ok so I just bought of that and I was wondering if such theory was already proposed or if its just a ridiculous idea.

 

Basicaly its on what was there before the big bang. We know that when star dies it usually implodes then explodes. Now what if we think of a black hole as a star. It does emit gamma rays which is basicaly a high energy light. And I basicaly acts like a star. And some stars become black holes which can be thought of as the next step in the evolution of the star rather then its death.

 

Now what if the black holes have some point if "critical mass" where it acts the same as the star? It explodes. Wouldnt that mean that all the elements which got absorbed into the cingularity would be blown out. If the process of spaghettification applies to atoms it means by the time it reaches cingularity point its disassembled into quarks. Therefore it can form the universal atoms of helium, hydrogen, etc. So now when his critical mass is attained and black holes go boom all these elements are ejected into vacuum and begin forming basic elements.

 

So it seems that it all works and the previous universe surrounding the whole would blown away by the energy it emits which should be far beyond the energy of gamma rays.

 

Now tell me what u think be kind please LOL

Posted

I'm not an expert on this stuff (Martin, who is, will probably be stopping by soon enough), but I'm pretty sure there's no theoretical basis for black holes reaching "critical mass." If anything, it's the opposite: if they're smaller than a certain mass, they "evaporate" faster than they grow, and they emit more and more radiation until they "flare out" at the very end, when they're very small.

 

More importantly, though, I don't think it's accurate to compare the singularity at the big bang with the singularity of a black hole. A black hole is a compression of matter, but the big bang was a compression of the entirety of space itself. That's why it wasn't really an explosion like how you're talking about it, since there would be nothing for it to explode into. It's not as if there was a tiny ball of everything in the middle of a big empty space. It was a tiny ball of space. Except that's inaccurate also, since a "ball" has an inside and an outside, and this only had an inside. If you can't picture what I'm talking about, don't worry: nobody can. It can exist in reality and in mathematics, but not in our imaginations.

Posted

I don't think there's any evidence for a critical mass, or any reason for one, but to understand this fully and talk about it fully we'd need a theory of quantum gravity, which we don't have, so there might be a critical mass, but it'd be larger than the mass of the largest supermassive black hole that has been detected, 1010 solar masses!

 

There is a hypothesis of universes inside 'black holes', but I can't find the url right now :\ I'll have a better look tomorrow!

Posted (edited)

I've read of very small universes being created from black holes. Baby universes, to use Hawking's words, but they are much, much smaller than our own. And presumably, they can merge right back into our own.

 

As for black holes creating universes like ours, I don't think so.

 

Basicaly its on what was there before the big bang. We know that when star dies it usually implodes then explodes. Now what if we think of a black hole as a star. It does emit gamma rays which is basicaly a high energy light. And I basicaly acts like a star. And some stars become black holes which can be thought of as the next step in the evolution of the star rather then its death.

 

A black hole doesn't emit much of anything though. If anything falls into it, the material will emit high energy radiation as it falls into the black hole. But the hole itself doesn't.

 

Now what if the black holes have some point if "critical mass" where it acts the same as the star? It explodes.

 

Black holes are theorized to explode, but not in the manner that you are describing. Black holes, even though they absorb any and all radiation (because it's escape velocity is greater than that of the speed of light), still have an entropy. Overtime, they shrink, until when they are small enough they will explode, releasing high energy gamma radiation. But that takes a very long time. Certainly much longer than the lifetime of the universe.

Edited by Deja Vu
multiple post merged
Posted (edited)

Sisyphus, Klaynos, and DV thanks so much for responding. I am in a rush today and can't think of anything to add beyond what's already been said.

May be able to get back later tonight or tomorrow.

 

 

So it seems that it all works and the previous universe surrounding the whole would blown away by the energy it emits which should be far beyond the energy of gamma rays.

 

 

What you are proposing is your own homegrown version of an idea that has been around at least since before 1993 (when Lee Smolin wrote it up in a reseearch article) but probably way earlier. Because the great physicist John Wheeler is said to have advocated it---Smolin says he got it from him.

 

The idea is that a black hole can make a new universe.

 

Smolin has a book about this, written around 1999, called The Life of the Cosmos.

 

The idea will be included as a chapter in a new book to appear in April 2009 called Beyond the Big Bang.

 

It is a very strange idea, and it has been attacked, but so far it is still standing up and it is hanging in there. So we will see how it goes.

 

If you want technical papers about it, I can get you links. But the only popular non-math treatment I know of is The Life of the Cosmos, which I didn't read.

====================

 

The old universe doesnt necessarily get blown away in these scenarios. The new universe forms OUT THE BOTTOM so to speak and creates new space along with new matter and doesnt interfere with the old.

 

The new universe doesn't necessarily have to be SMALL because it is a new expanding space and is not limited by the size or mass of the black hole that formed it. In these scenarios something gets around the energy requirement----somehow falling down a gravity well regenerates the energy needed for a new big bang and a new universe.

 

I am not an expert on this and I can't evaluate or judge these scenarios. All I can do is report what I see. The idea has been around for over 10 years and more papers are being written about it, and it has been attacked but has stood up, and it is being included in scholarly books----like one published by Cambridge University Press in the UK last year, called Universe or Multiverse which had chapters by Nobel laureates and all that. And the new one due out April 2009 which also has top people contributing. It is a very strange idea but it is too early to rule it out.

 

Dont worry about blowing the old universe away. There is no theory about massive black holes exploding at some critical mass. Holes can evaporate and the little ones evaporate quicker and maybe you could call the rapid evaporation of a very tiny BH an explosion. but it is not analogous to supernova explosion of stars. Reproductive cosmology with holes producing new bangs doesn't need to have the old cleared away. The old one just stays there and expands and burns out gradually, while its black holes spawn new space and matter, not intersecting with the old.

 

Also remember that this idea is still speculative and unproven. It gets included as a chapter in this or that book. It gets published in a research paper every few months, at least a couple of time a year. But it hasn't been proven. It is just surviving out there on the table for discussion. A wait-and-see thing.

Edited by Martin
multiple post merged
Posted

If you want technical papers about it, I can get you links. But the only popular non-math treatment I know of is The Life of the Cosmos, which I didn't read.

 

I would appreciate it if you posted links to technical papers please, so that I can see the details and the mathematics behind it.

Posted (edited)

If you want technical papers about it, I can get you links...

 

I would appreciate it if you posted links to technical papers please, so that I can see the details and the mathematics behind it.

 

Great! I will get some links to relevant papers of various levels of technicality.

Glad someone is interested in looking at this at a critical nuts and bolts level.

Some of it, like the quantum gravity black hole bounce papers are work in progress. they are by other people and are intended to figure out what happens, not necessarily to fit in with Smolin's reproductive cosmology idea---but in some cases they turn out to lend at least tentative support to the idea.

A. some Smolin papers

http://arxiv.org/abs/hep-th/0612185

The status of cosmological natural selection

Authors: Lee Smolin

(Submitted on 18 Dec 2006)

 

Abstract: The problem of making predictions from theories that have landscapes of possible low energy parameters is reviewed. Conditions for such a theory to yield falsifiable predictions for doable experiments are given. It is shown that the hypothesis of cosmological natural selection satisfies these conditions, thus showing that it is possible to continue to do physics on a landscape without invoking the anthropic principle. In particular, this is true whether or not the ensemble of universes generated by black holes bouncing is a sub-ensemble of a larger ensemble that might be generated by a random process such as eternal inflation.

A recent criticism of cosmological natural selection made by Vilenkin in hep-th/0610051 is discussed. It is shown to rely on assumptions about both the infrared and ultraviolet behavior of quantum gravity that are very unlikely to be true.

 

Comments: 25 pages

 

http://arxiv.org/abs/hep-th/0407213

Scientific alternatives to the anthropic principle

Authors: Lee Smolin

(Submitted on 26 Jul 2004 (v1), last revised 29 Jul 2004 (this version, v3))

 

Abstract: It is explained in detail why the Anthropic Principle (AP) cannot yield any falsifiable predictions, and therefore cannot be a part of science. Cases which have been claimed as successful predictions from the AP are shown to be not that. Either they are uncontroversial applications of selection principles in one universe (as in Dicke's argument), or the predictions made do not actually logically depend on any assumption about life or intelligence, but instead depend only on arguments from observed facts (as in the case of arguments by Hoyle and Weinberg). The Principle of Mediocrity is also examined and shown to be unreliable, as arguments for factually true conclusions can easily be modified to lead to false conclusions by reasonable changes in the specification of the ensemble in which we are assumed to be typical.

We show however that it is still possible to make falsifiable predictions from theories of multiverses, if the ensemble predicted has certain properties specified here. An example of such a falsifiable multiverse theory is cosmological natural selection. It is reviewed here and it is argued that the theory remains unfalsified. But it is very vulnerable to falsification by current observations, which shows that it is a scientific theory.

The consequences for recent discussions of the AP in the context of string theory are discussed.

 

Comments: Contribution to "Universe or Multiverse", ed. by Bernard Carr et. al., to be published by Cambridge University Press

http://www.amazon.com/Universe-Multiverse-Bernard-Carr/dp/0521848415

==========================

B. some papers relevant to black hole bounce (favoring, disfavoring, or inconclusive---still being investigated)

 

http://arxiv.org/abs/0805.1187

Black holes in loop quantum gravity: the complete space-time

Authors: Rodolfo Gambini, Jorge Pullin

(Submitted on 8 May 2008)

 

Abstract: We consider the quantization of the complete extension of the Schwarzschild space-time using spherically symmetric loop quantum gravity. We find an exact solution corresponding to the semi-classical theory. The singularity is eliminated but the space-time still contains a horizon. Although the solution is known partially numerically and therefore a proper global analysis is not possible, a global structure akin to a singularity-free Reissner--Nordstrom space-time including a Cauchy horizon is suggested.

 

 

http://arxiv.org/abs/0709.2129

Loop Quantum Dynamics of the Schwarzschild Interior

Authors: Christian G. Boehmer, Kevin Vandersloot

(Submitted on 13 Sep 2007 (v1), last revised 8 Oct 2007 (this version, v2))

 

Abstract: We examine the Schwarzschild interior of a black hole, incorporating quantum gravitational modifications due to loop quantum gravity. We consider an improved loop quantization using techniques that have proven successful in loop quantum cosmology. The central Schwarzschild singularity is resolved and the implications for the fate of an in-falling test particle in the interior region is discussed. The singularity is replaced by a Nariai type Universe. We discuss the resulting conformal diagram, providing a clear geometrical interpretation of the quantum effects.

 

Phys.Rev. D76 (2007) 104030

 

http://arxiv.org/abs/hep-th/0701239

Loop quantum gravity and black hole singularity

Authors: Leonardo Modesto

(Submitted on 25 Jan 2007)

 

Abstract: In this paper we summarize "loop quantum gravity" (LQG) and we show how ideas developed in LQG can solve the black hole singularity problem when applied to a minisuperspace model.

 

Comments: 17 pages, 7 figures, LaTex. Proceedings of the XVII SIGRAV Conference, Turin, September 4-7, 2006

=====================

 

at the end of the last one, by Modesto, you find some words like this:

"An important consequence of the quantization is that, unlike the classical evolution, the quantum

evolution does not stop at the classical singularity and the “other side” of the singularity corresponds to

a new domain where the triad reverses its orientation...

It is interesting to recall that beyond the classical singularity the eigenvalue µE is negative and so

we can suggest a new universe was born from the black hole formation process."

 

in the first one, by Gambini-Pullin you get a reference to a bounce (they put it in quotes) and a white hole developing on the other side.

 

I think all this stuff is inconclusive but one can't rule it out at least as yet

========================

 

the Smolin papers do not delve into what the mechanics of the bounce might be. What they say is that a hole->bang reproductive cosmology where black holes produce new universes slightly different from the parent would PREDICT EVOLUTION to where the parameters of a typical universe would favor abundant black holes. Because such universes would have more more offspring and greater reproductive success. So he says reproductive cosmology is TESTABLE and falsifiable because to falsify it all you have to show is that some parameters of the standard cosmology and particle physics models are not optimal for producing black holes.

 

He doesnt argue that BH -> BB reproductive cosmology is right. He argues that it can be tested.

And in a sense it is being tested and has survived testing since he proposed it in 1993. Because there are ongoing astronomical observations which he pointed out could disprove optimality if they came up with, for instance, too big a neutron star mass. So far no one has proven that the universe is not finely adjusted to make a lot of (stars and then by collapse) black holes.

 

So it kind of a sleeper. A theory that has been around for while but so far not enough people have worked hard to disprove it. And which has survived whatever tests have happened to come up.

Edited by Martin
Posted
Great! I will get some links to relevant papers of various levels of technicality.

Glad someone is interested in looking at this at a critical nuts and bolts level.

Some of it, like the quantum gravity black hole bounce papers are work in progress. they are by other people and are intended to figure out what happens, not necessarily to fit in with Smolin's reproductive cosmology idea---but in some cases they turn out to lend at least tentative support to the idea.

 

 

This is way cool but I am very confused.

 

When the term multiverse is used, is this is the same sense as the many worlds version?

 

Also, would that make then for the classical world to emerge somehow from this as is?

 

I think that its neat to see evolutionary biology being used in cosmology, I mean if life can occur as is naturally, that has to be able to aid somehow if studied physically.

Posted (edited)

Thank you Martin, for providing the articles :) . It will take a while to read through them, as I don't always have the time, but they all seem interesting. The one that caught my eye in particular is the article on Reproductive Cosmology (does it have any connection whatsoever to biological reproduction?). I'll dive into them when I get the chance.

 

When the term multiverse is used, is this is the same sense as the many worlds version?

 

Sort of. The many worlds interpretation mostly applies to quantum mechanics, in that it is proposed that for every possible quantum state or phenomenon or path, there is a parallel world/universe in which each and every one of those histories play out. Either branching off of this universe, or they exist separately. Personally, I'm not a fan of this interpretation, but that's for another thread.

 

A multiverse, on the other hand, refers to the existence of multiple universes in general, not always having to be related or connected to each other, or have the same physical laws as our own.

 

Also, would that make then for the classical world to emerge somehow from this as is?

 

I don't see how this would follow from the previous statements.

Edited by Deja Vu
multiple post merged
Posted
Thank you Martin, for providing the articles :) . It will take a while to read through them, as I don't always have the time, but they all seem interesting. The one that caught my eye in particular is the article on Reproductive Cosmology (does it have any connection whatsoever to biological reproduction?). I'll dive into them when I get the chance.

...

 

I'm not urging you read any of the articles. I just provided the links because you asked. Most is awfully technical. Plus they haven't got it nailed down whether or not a black hole can lead to a big bang (out the bottom, a new region of spacetime not intersecting ours) within that particular theoretical framework.

 

Reproductive cosmology is my term for a cosmology where each region of spacetime (like ours) can form stars some of which then collapse to form black holes and bud off to make new expanding regions of spacetime.

 

I don't like the term "multiverse" which sounds kind of Madison Avenue slick to me. I would look on it as one big universe that has a kind of branching structure.

 

You ask about biological comparisons and there is obviously a similarity.

 

Smolin takes this a step further and points out that if the physical constants are allowed to change slightly during the budding process (the BH->BB transition) then something very much like biological evolution would occur.

Branches of the universe that were good at branching would produce more branches. Some brances would have such bad constants they would never even form stars and they would have no offspring.

Eventually almost the whole tree would consist of branches where the physical constants were optimized for producing black holes and thereby having lots of offspring.

In that case, he observes, we could TEST to see if the constants in our fundamental physical laws are optimized for black hole production or not.

If we could find some obvious improvement resulting from a small adjustment of some parameter that would tend to shoot down the idea---invalidate the theory.

It's always good to have a test for some idea.

 

So he carries the evolution idea over from biology and calls his picture Cosmological Natural Selection---and he definitely draws the parallel to Darwin.

 

I'm just responding to your question---you asked about how much analogy to biology there is here.

 

From my immediate perspective, I would guess that there is more to be gained by learning about Ambjorn and Loll's research that they give a popularized account of in July Scientific American. I put the link in my signature. Another time I might find Smolin's evolutionary cosmology idea exciting but at the moment it is Ambjorn and Loll's work---they simulate the emergence of little quantum universes in the computer. Get uncertainty and quantum fluctuations in the geomety. Can freeze one of the little universes and get inside with a probe, do a random walk in it etc etc. Really fascinating.

 

Evolutionary reproductive cosmology does have some interest though, and still might provide explanations for some things. Like why the values of the fundamental physical constants are what they are.

  • 2 weeks later...
Posted

Just to add...

Basicaly its on what was there before the big bang. We know that when star dies it usually implodes then explodes.

Thats only for stars with a mass of greater than or equal to 8 solar masses. Otherwise, a supernova will not occur.

Posted

 

You ask about biological comparisons and there is obviously a similarity.

 

Smolin takes this a step further and points out that if the physical constants are allowed to change slightly during the budding process (the BH->BB transition) then something very much like biological evolution would occur.

Branches of the universe that were good at branching would produce more branches. Some brances would have such bad constants they would never even form stars and they would have no offspring.

Eventually almost the whole tree would consist of branches where the physical constants were optimized for producing black holes and thereby having lots of offspring.

In that case, he observes, we could TEST to see if the constants in our fundamental physical laws are optimized for black hole production or not.

If we could find some obvious improvement resulting from a small adjustment of some parameter that would tend to shoot down the idea---invalidate the theory.

It's always good to have a test for some idea.

 

So he carries the evolution idea over from biology and calls his picture Cosmological Natural Selection---and he definitely draws the parallel to Darwin.

 

I'm just responding to your question---you asked about how much analogy to biology there is here.

 

This is such a fascinating idea. One can imagine universes in which the physical constants are unfit for black hole production, universes (like ours) fit to produce multiple black holes, and most interestingly, universes which instantly collapse into a giant black hole and "reproduce" only once and give birth to another universe that does the exist same thing, ad infinitum.

 

BTW, Martin, do you know if there are any theories (or even vague notions) as to what constants might govern the whole of the multiverse (to use a term you hate)? Obviously all of our physical constants would be arbitrary to it, and it seems that conservation of energy is also right out the window. I would imagine that every individual universe would be bound by some sort of conservation law, and that Newton's 2nd law would apply to them as well, but what about at the multiverse level?

 

Kind of puzzling to imagine that, at the grandest scale, there may be no real order.

Posted (edited)
This is such a fascinating idea. One can imagine universes in which the physical constants are unfit for black hole production, universes (like ours) fit to produce multiple black holes, and most interestingly, universes which instantly collapse into a giant black hole and "reproduce" only once and give birth to another universe that does the exist same thing, ad infinitum.

...

 

You sound reasonably up on this and able to pursue lines of reasoning on your own, about it. I'm reluctant to speculate. there are two kinds of test that it must survive.

 

to be legitimate science a theory should be testable---roughly speaking falsifiable, it should predict something that might not turn out.

 

this Smolin idea predicts that you can't find a small adjustment of OUR OWN physical constants which would make astrophysical black holes more abundant. So far nobody has, but maybe they haven't looked hard enough.

 

Another thing to ask is whether quantum gravity models of a black hole show a bounce and re-expansion. The models havent been confirmed but that would be supportive anyway. Well some papers by Gambini Pullin and some by Modesto suggest that might happen but it wasn't conclusive, the theory is actually just work in progress, still under construction. The latest paper was by Vandersloot and Boehmer

http://arxiv.org/abs/0807.3042

and to me the analysis looked good and solid and the conclusion was CONTRARY to what Smolin's idea needs. There was indeed another universe coming out of the bottom of the black hole but it was a degenerate thing called a NARIAI universe which nobody would mistake for one like ours and nobody in his right mind would want to live in. A Nariai universe only expands in one direction and is crippled in other directions.

They have to go where the math leads them. Some people have suggested that a Nariai universe would immediatly decay into one like ours. Or explode, if you prefer. The expansion could not be contained in one dimension but would seep into other dimensions and the thing would pop open into full-blown. But

Vandersloot and Boehmer argue that it would not do that. They argue that the Nariai configuration is stable. They are young smart secondgeneration Loop people---Vandersloot is an Ashtekar PhD now doing postdoc. I have watched him for 4 years. I've got respect for him so I have to pay attention.

 

Nothing is settled yet but if they win the argument then Smolin's idea is dead in the context of Loop Quantum Cosmology (LQC). Though some other QC model might conceivably be developed in which the earlier expected stuff does happen.

 

For me, i'm putting this on a back burner until the quantum picture of black hole collapse gets better developed. It is too early in the game to speculate on past that. Basic issues have to be more resolved first (that's my feeling about it.)

Edited by Martin
  • 3 weeks later...
Posted
ok so I just bought of that and I was wondering if such theory was already proposed or if its just a ridiculous idea.

 

Basicaly its on what was there before the big bang. We know that when star dies it usually implodes then explodes. Now what if we think of a black hole as a star. It does emit gamma rays which is basicaly a high energy light. And I basicaly acts like a star. And some stars become black holes which can be thought of as the next step in the evolution of the star rather then its death.

 

Now what if the black holes have some point if "critical mass" where it acts the same as the star? It explodes. Wouldnt that mean that all the elements which got absorbed into the cingularity would be blown out. If the process of spaghettification applies to atoms it means by the time it reaches cingularity point its disassembled into quarks. Therefore it can form the universal atoms of helium, hydrogen, etc. So now when his critical mass is attained and black holes go boom all these elements are ejected into vacuum and begin forming basic elements.

 

So it seems that it all works and the previous universe surrounding the whole would blown away by the energy it emits which should be far beyond the energy of gamma rays.

 

Now tell me what u think be kind please LOL

 

of course you assume that " blackholes " exist in the first place based on GR ( general realivity )

 

I don't

Posted
of course you assume that " blackholes " exist in the first place based on GR ( general realivity )

 

I don't

 

Would you care to explain where gr is incorrect (this should be mathematical) and cite experimental evidence why this is the case (again this should include some mathematical analysis of the data)?

 

If not this comment is unscientific and you should not make such things here.

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