Register | Sign In


Understanding through Discussion


EvC Forum active members: 65 (9162 total)
3 online now:
Newest Member: popoi
Post Volume: Total: 915,815 Year: 3,072/9,624 Month: 917/1,588 Week: 100/223 Day: 11/17 Hour: 0/0


Thread  Details

Email This Thread
Newer Topic | Older Topic
  
Author Topic:   Did a 5-D black hole brane event horizon make the universe?
RAZD
Member (Idle past 1405 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 1 of 18 (710236)
11-03-2013 2:00 PM


I came across this article from Banoosh
Goodbye Big Bang, Hello Black Hole? A New Theory Of The Universe’s Creation
Now I find Banoosh to be a resource of questionable trustworthyness (a lot of conspiracy theories for instance) so I looked up their links
quote:
You can read more about their research on this prepublished Arxiv paper. The Arxiv entry does not specify if the paper has been submitted to any peer-reviewed scientific journals for publication.
Source: Nature
The Arvix link is short:
quote:
Out of the White Hole: A Holographic Origin for the Big Bang
Razieh Pourhasan, Niayesh Afshordi, Robert B. Mann
(Submitted on 5 Sep 2013 (v1), last revised 22 Sep 2013 (this version, v2))
While most of the singularities of General Relativity are expected to be safely hidden behind event horizons by the cosmic censorship conjecture, we happen to live in the causal future of the classical big bang singularity, whose resolution constitutes the active field of early universe cosmology. Could the big bang be also hidden behind a causal horizon, making us immune to the decadent impacts of a naked singularity? We describe a braneworld description of cosmology with both 4d induced and 5d bulk gravity (otherwise known as Dvali-Gabadadze-Porati, or DGP model), which exhibits this feature: The universe emerges as a spherical 3-brane out of the formation of a 5d Schwarzschild black hole. In particular, we show that a pressure singularity of the holographic fluid, discovered earlier, happens inside the white hole horizon, and thus need not be real or imply any pathology. Furthermore, we outline a novel mechanism through which any thermal atmosphere for the brane, with comoving temperature of 20% of the 5D Planck mass can induce scale-invariant primordial curvature perturbations on the brane, circumventing the need for a separate process (such as cosmic inflation) to explain current cosmological observations. Finally, we note that 5D space-time is asymptotically flat, and thus potentially allows an S-matrix or (after minor modifications) AdS/CFT description of the cosmological big bang.
Comments: 16 pages, 3 figures
That is just the abstract, but there is a link to download the PDF version -- note this is on the technical side ...
The other link is to the Nature article: Did a hyper-black hole spawn the Universe?
quote:
Big Bang was mirage from collapsing higher-dimensional star, theorists propose.
It could be time to bid the Big Bang bye-bye. Cosmologists have speculated that the Universe formed from the debris ejected when a four-dimensional star collapsed into a black hole a scenario that would help to explain why the cosmos seems to be so uniform in all directions.
In a paper posted last week on the arXiv preprint server(1), Afshordi and his colleagues turn their attention to a proposal(2) made in 2000 by a team including Gia Dvali, a physicist now at the Ludwig Maximilians University in Munich, Germany. In that model, our three-dimensional (3D) Universe is a membrane, or brane, that floats through a ‘bulk universe’ that has four spatial dimensions.
In our Universe, a black hole is bounded by a spherical surface called an event horizon. Whereas in ordinary three-dimensional space it takes a two-dimensional object (a surface) to create a boundary inside a black hole, in the bulk universe the event horizon of a 4D black hole would be a 3D object a shape called a hypersphere. When Afshordi’s team modelled the death of a 4D star, they found that the ejected material would form a 3D brane surrounding that 3D event horizon, and slowly expand.
The picture has some problems, however. Earlier this year, the European Space Agency's Planck space observatory released data that mapped the slight temperature fluctuations in the cosmic microwave background the relic radiation that carries imprints of the Universe’s early moments. The observed patterns matched predictions made by the standard Big Bang model and inflation, but the black-hole model deviates from Planck's observations by about 4%. Hoping to resolve the discrepancy, Afshordi says that his is now refining its model.
Despite the mismatch, Dvali praises the ingenious way in which the team threw out the Big Bang model. The singularity is the most fundamental problem in cosmology and they have rewritten history so that we never encountered it, he says. Whereas the Planck results prove that inflation is correct, they leave open the question of how inflation happened, Dvali adds. The study could help to show how inflation is triggered by the motion of the Universe through a higher-dimensional reality, he says.
And then the "Bulk Universe" is a "bulk brane" around a black hole in a mega-bulk universe ... and it's turtles all the way down ... or you can think of it as a shell game where each universe is a "russian doll" inside another "russian doll" ...
Enjoy

we are limited in our ability to understand
by our ability to understand
Rebel American Zen Deist
... to learn ... to think ... to live ... to laugh ...
to share.


Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click)

Replies to this message:
 Message 18 by taiji2, posted 09-15-2014 3:50 AM RAZD has seen this message but not replied

  
AdminNosy
Administrator
Posts: 4754
From: Vancouver, BC, Canada
Joined: 11-11-2003


(1)
Message 2 of 18 (710238)
11-03-2013 2:19 PM


Thread Copied from Proposed New Topics Forum
Thread copied here from the Did a 5-D black hole brane event horizon make the universe? thread in the Proposed New Topics forum.

  
Son Goku
Inactive Member


(1)
Message 3 of 18 (711132)
11-15-2013 10:15 AM


5D Black Holes
I read the paper. It's actually a cool idea. Basically they studied in detail the dynamics of what happens when very heavy stars collapse to form black holes in a universe with four dimensions*.
In three-dimensions, when a star collapses, the outer layers get blown out into space and the inner layers collapse to form a black hole. The black hole being surrounded by the two-dimensional surface know as the event horizon. The surface past which light cannot escape.
However the authors have found that this isn't what happens in four-dimensions. The inner layers collapse into a black hole and are surrounded by a three-dimensional event horizon. However all of the outer layers don't explode out randomly into space like they do in three dimensions.
Some of the outer layers form a thin-sheet, a three dimensional sheet, that looks like an extra layer on top of the event horizon. This sheet then expands slowly away from the star, as it has enough momentum to escape the collapse.
It turns out that this sheet, when taken as an object on its own, is identical to the Big Bang solution of General Relativity in three-dimensions. So an entity living on this sheet would see data consistent with there being no fourth dimension and everything originating from a point in the distant past.
Usually the singularity in General Relativity is taken to mean some approximation or assumption is breaking down. This model would say that as we rewind time we eventually reach a point before the star collapsed and our universe merges with the other layers of the star and can no longer be considered an independent object.
In essence, this model says our universe is "really" a slowly expanding bubble of stellar material, one of the mid layers of a hyperstar** that went supernova. The gravity of the black hole that that star collapsed into keeps the layer compressed and effectively three-dimensional, but the energy of the supernova blast gives it enough velocity to slowly escape from the black hole and so it expands. Living inside this sheet, we perceive this expansion as the cosmological expansion of a three-dimensional universe.
I think the idea is in too early a stage to comment on. The author wants to do better simulations to see if it matches current cosmological data. The model currently matches some observations, but the three-dimensional universe this model produces is scale invariant. Basically its Cosmic Microwave Background (CMB) has an equal number of photons of each energy. Where as our universe shows slightly more photons at some energies.
However it's possible this model does produce a universe like ours, but the current methods of analyzing it are too weak to demonstrate this, or perhaps depending on the conditions in the hyperstar the three-dimensional universe has different CMBs.
*I'm ignoring time in this post.
**Hyperstar refers to the four-dimensional star.
Edited by Son Goku, : No reason given.

Replies to this message:
 Message 4 by AZPaul3, posted 11-15-2013 3:02 PM Son Goku has replied

  
AZPaul3
Member
Posts: 8513
From: Phoenix
Joined: 11-06-2006
Member Rating: 5.3


(1)
Message 4 of 18 (711195)
11-15-2013 3:02 PM
Reply to: Message 3 by Son Goku
11-15-2013 10:15 AM


Re: 5D Black Holes
This sheet then expands slowly away from the star, as it has enough momentum to escape the collapse.
Thanks, Son. This is good stuff. One question if I may, and this may also be too early to discuss.
Does, or how could, this model explain the accelerated expansion we see in the supernovae data? Dark energy still or some other mechanism?

This message is a reply to:
 Message 3 by Son Goku, posted 11-15-2013 10:15 AM Son Goku has replied

Replies to this message:
 Message 5 by Son Goku, posted 11-16-2013 8:52 AM AZPaul3 has seen this message but not replied

  
Son Goku
Inactive Member


(2)
Message 5 of 18 (711238)
11-16-2013 8:52 AM
Reply to: Message 4 by AZPaul3
11-15-2013 3:02 PM


Re: 5D Black Holes
Well the interesting thing is that accelerating expansion and Dark Energy naturally fall out of the model.
Our universe, which according to this is simply a "sphere" of material slowly escaping from a dead hyperstar's black hole, has its size increase as it escapes the black hole.
The interesting thing is that this expansion naturally accelerates. The basic laws of physics in the higher dimensional universe dictate that a spherical shock wave of material accelerates as it moves away from the black hole.
To beings living inside the shock wave (i.e. us), the only way they could model this expansion without reference to the higher dimensions is by introducing an additional Dark Energy term into General Relativity.
In essence in this model, there is no mechanism for the accelerating expansion besides basic kinematics. Spherical shells of supernova debris simply naturally accelerate away from a four-dimensional black hole.
Edited by Son Goku, : No reason given.
Edited by Son Goku, : No reason given.

This message is a reply to:
 Message 4 by AZPaul3, posted 11-15-2013 3:02 PM AZPaul3 has seen this message but not replied

Replies to this message:
 Message 6 by Diomedes, posted 11-18-2013 10:25 AM Son Goku has replied

  
Diomedes
Member
Posts: 995
From: Central Florida, USA
Joined: 09-13-2013


Message 6 of 18 (711399)
11-18-2013 10:25 AM
Reply to: Message 5 by Son Goku
11-16-2013 8:52 AM


Re: 5D Black Holes
Our universe, which according to this is simply a "sphere" of material slowly escaping from a dead hyperstar's black hole, has its size increase as it escapes the black hole
I am curious: does this imply that our universe is, in and of itself, a 'bubble' within another four dimensional universe of some type?
I'm also a little confused with regards to three dimensional universes versus four dimensional universes. Is the 'fourth dimension', as implied in this case, not the dimension of time but something else? And a final question: since space-time is a fundamental construct of our universe, isn't our universe already a four dimensional universe?

This message is a reply to:
 Message 5 by Son Goku, posted 11-16-2013 8:52 AM Son Goku has replied

Replies to this message:
 Message 7 by Son Goku, posted 11-19-2013 11:45 AM Diomedes has replied

  
Son Goku
Inactive Member


Message 7 of 18 (711478)
11-19-2013 11:45 AM
Reply to: Message 6 by Diomedes
11-18-2013 10:25 AM


Re: 5D Black Holes
I am curious: does this imply that our universe is, in and of itself, a 'bubble' within another four dimensional universe of some type?
If his theory is correct, then yes that is exactly what it implies.
I should say that what interests me most here is that the author derived explicit predictions from his model. Things we can check over the next few years. Unlike a lot of models which try to explain the Big Bang which often simply paint some vague idea with some mathematics without any solid predictions.
I'm also a little confused with regards to three dimensional universes versus four dimensional universes. Is the 'fourth dimension', as implied in this case, not the dimension of time but something else?
It's an extra spatial dimension.
And a final question: since space-time is a fundamental construct of our universe, isn't our universe already a four dimensional universe?
In my post I said that I wouldn't include time, as it wasn't necessary to understand this model. However correctly our universe is 3+1-dimensional. This model says we might be a bubble in a 4+1 dimensional universe.
The 3+1 notation is often used to indicate that we have four dimensions but one of them is different to the others.

This message is a reply to:
 Message 6 by Diomedes, posted 11-18-2013 10:25 AM Diomedes has replied

Replies to this message:
 Message 8 by Diomedes, posted 11-19-2013 12:08 PM Son Goku has not replied

  
Diomedes
Member
Posts: 995
From: Central Florida, USA
Joined: 09-13-2013


Message 8 of 18 (711481)
11-19-2013 12:08 PM
Reply to: Message 7 by Son Goku
11-19-2013 11:45 AM


Re: 5D Black Holes
In my post I said that I wouldn't include time, as it wasn't necessary to understand this model. However correctly our universe is 3+1-dimensional. This model says we might be a bubble in a 4+1 dimensional universe.
That clears things up. I appreciate the clarification.
I have no idea how another spatial dimension would manifest, but then again, I am not a four dimensional being!
It makes me wonder: if our universe (3+1) is essentially a 'bubble' within another, larger (4+1) universe, are there other (3+1) universe bubbles also in existence and if so, can they interact? i.e. collide?

This message is a reply to:
 Message 7 by Son Goku, posted 11-19-2013 11:45 AM Son Goku has not replied

Replies to this message:
 Message 9 by jar, posted 11-19-2013 12:40 PM Diomedes has replied
 Message 10 by New Cat's Eye, posted 11-19-2013 2:44 PM Diomedes has not replied

  
jar
Member (Idle past 394 days)
Posts: 34026
From: Texas!!
Joined: 04-20-2004


Message 9 of 18 (711482)
11-19-2013 12:40 PM
Reply to: Message 8 by Diomedes
11-19-2013 12:08 PM


Re: 5D Black Holes
Have you read Flatland?

Anyone so limited that they can only spell a word one way is severely handicapped!

This message is a reply to:
 Message 8 by Diomedes, posted 11-19-2013 12:08 PM Diomedes has replied

Replies to this message:
 Message 11 by Diomedes, posted 11-19-2013 2:49 PM jar has seen this message but not replied

  
New Cat's Eye
Inactive Member


Message 10 of 18 (711489)
11-19-2013 2:44 PM
Reply to: Message 8 by Diomedes
11-19-2013 12:08 PM


Re: 5D Black Holes
I have no idea how another spatial dimension would manifest, but then again, I am not a four dimensional being!
The best way I found to get a grip on it is to go the other way, dimension reductions, see what that entails, and then try to imagine rewinding that until you get back past three dimensions into the fourth. You're never really going to be able to "picture" 4 spatial dimensions though, because our brains just don't work that way.
Anyways, here we go:
A cube is three dimensions. If you reduce a cube by one dimension, then you get a square. A square is like looking straight at one side of a cube. If you hold a dice just right in front of you so you can only see one side of it, then it will look like a square.
A square is two dimensions. If you reduce a square by one dimension, then you get a line. A line is like looking straight at one edge of a square. If you hold a piece of paper just right in front of you so you can only see one edge of it, then it will look like a line
A line is one dimension. If you reduce a line by one dimension, then you get a point. A point is like looking straight down the length of a line. If you hold a pencil just right in front of you so you can only see it pointing at you, then it will look like a point.
A point is zero dimensions.
Now, what about a four dimension object, a hyper-cube. Well that is the object that if you reduce it by one dimension then you will get a cube. If you look down one section of the hyper-cube, then you will see a cube.
So imagine how you can take a point, and drag it into one dimension to create a line. Then you can drag that line into a second dimension to create a square. Then you can drag that square into a thrid dimension to make a cube. Then you could drag that cube into a fourth dimension to make a hyper-cube.
Like I said, that's not really going to help you "picture" it in your head, but hopefully you can get what it means to have one.

This message is a reply to:
 Message 8 by Diomedes, posted 11-19-2013 12:08 PM Diomedes has not replied

  
Diomedes
Member
Posts: 995
From: Central Florida, USA
Joined: 09-13-2013


Message 11 of 18 (711490)
11-19-2013 2:49 PM
Reply to: Message 9 by jar
11-19-2013 12:40 PM


Re: 5D Black Holes
Have you read Flatland?
Have not read it, but I know of it. They actually indirectly referenced the concept in one of the episodes of the Big Bang Theory.
That reminds me: I recall reading a sci fi short story years ago about a vacuum instability event (I think that is what they called it) where the universe's inherent 'energy state' actually shifted. (Like an electron changing energy states) This changed the fundamental laws of physics in the universe and most advanced devices stopped working. Interesting take on a theoretical premise, although I believe even a minor shift in any of the fundamental forces would basically negate all current life and drastically change the nature of the universe as a whole.

This message is a reply to:
 Message 9 by jar, posted 11-19-2013 12:40 PM jar has seen this message but not replied

Replies to this message:
 Message 12 by RAZD, posted 11-20-2013 2:56 PM Diomedes has not replied

  
RAZD
Member (Idle past 1405 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 12 of 18 (711583)
11-20-2013 2:56 PM
Reply to: Message 11 by Diomedes
11-19-2013 2:49 PM


Re: 5D Black Holes
http://www.geom.uiuc.edu/~banchoff/Flatland/
I've also written a spoof
Enjoy

we are limited in our ability to understand
by our ability to understand
Rebel American Zen Deist
... to learn ... to think ... to live ... to laugh ...
to share.


Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click)

This message is a reply to:
 Message 11 by Diomedes, posted 11-19-2013 2:49 PM Diomedes has not replied

Replies to this message:
 Message 13 by TryingToBeLogical, posted 06-16-2014 6:53 AM RAZD has seen this message but not replied

  
TryingToBeLogical
Junior Member (Idle past 3563 days)
Posts: 10
From: Clermont, Florida, USA
Joined: 06-12-2014


Message 13 of 18 (729628)
06-16-2014 6:53 AM
Reply to: Message 12 by RAZD
11-20-2013 2:56 PM


Something to chew on...
Here's something that's been bugging me about the Big Bang. Where did the energy that caused it come from? And don't try telling me it was already there. The current theory is that it was all compressed to a ball of near-nothingness; logic dictates that, as temperature tends to decrease with mass, this sphere must have been at pure Absolute Zero. There WAS no energy for it to do anything; it was simply there. But all that pressure reduced the atoms to nothingness, still pushing to be freed from nonexistent bounds. So where did the energy come from? Where did the mass originate?
The answer, as it turns out, might lie in gravity and dark matter. Gravitational potential energy is a negative value; if it wasn't, we'd all be pushed AWAY. But this means that this is actually 'anti-energy', as it might be termed, and therefore, is a negative value in the gigantic equation of the Universe. Averaging out the gravitational potential energy with every positive and negative energy value in the universe may very well result in Absolute Zero; thus, there is a loophole in the Law of Conservation of Energy. The same applies to matter; anti- or dark matter could well be a negative value to 'regular' forms of matter, and thus, average out to Nothing once the equation is complete. The implications are troubling.
Therefore, thanks to this little loophole, it's entirely possible that all of existence - no matter how impressive or enormous - may simply be the twin complex roots in a quadratic or cubic equation of truly mind-bending proportions. It's the mathematical concept of redefining zero, where you get around the lack of actual roots in a quadratic equation by completing the square with equal positive-negative values. We may be simply +42-42.
Makes you think, doesn't it?

Logic is the ultimate argument; for none can refute logic with anything but logic. Thus, you will always walk away satisfied if you stay logical, knowing either you're right, or you're wrong.

This message is a reply to:
 Message 12 by RAZD, posted 11-20-2013 2:56 PM RAZD has seen this message but not replied

Replies to this message:
 Message 14 by NoNukes, posted 06-16-2014 9:28 AM TryingToBeLogical has replied

  
NoNukes
Inactive Member


Message 14 of 18 (729635)
06-16-2014 9:28 AM
Reply to: Message 13 by TryingToBeLogical
06-16-2014 6:53 AM


Re: Something to chew on...
The current theory is that it was all compressed to a ball of near-nothingness; logic dictates that, as temperature tends to decrease with mass, this sphere must have been at pure Absolute Zero.
Temperature decreases with mass? That is complete nonsense. Whatever caused you to say that?
Wow. That's some really bad physics.
And why introduce a concept of anti-energy? I understand what you are getting at when you suggest that the total energy in the universe might be zero. But dark matter is not anti-matter. Not sure why you said that. And redefining zero?
There is a grain of truth in what you posted but the majority of it seems to be wrong. Even your completing the square stuff, which is basic algebra is misguided nonsense. Quadratic equations always have roots even if those roots are doubled, or are complex, or are zero.
In any event, there is a pretty long thread about the possibility that the total energy of the universe is actually zero, and the key is Gravitational potential energy as you did mention. It might be interesting for you to see how a Creationist argues in that thread.

Under a government which imprisons any unjustly, the true place for a just man is also in prison. Thoreau: Civil Disobedience (1846)
I have never met a man so ignorant that I couldn't learn something from him. Galileo Galilei
If there is no struggle, there is no progress. Those who profess to favor freedom, and deprecate agitation, are men who want crops without plowing up the ground, they want rain without thunder and lightning. Frederick Douglass

This message is a reply to:
 Message 13 by TryingToBeLogical, posted 06-16-2014 6:53 AM TryingToBeLogical has replied

Replies to this message:
 Message 15 by TryingToBeLogical, posted 06-16-2014 1:50 PM NoNukes has replied

  
TryingToBeLogical
Junior Member (Idle past 3563 days)
Posts: 10
From: Clermont, Florida, USA
Joined: 06-12-2014


Message 15 of 18 (729659)
06-16-2014 1:50 PM
Reply to: Message 14 by NoNukes
06-16-2014 9:28 AM


Re: Something to chew on...
Frack, sorry. I messed up big time, didn't I?
Anyway, as it is, thermal energy would increase as the mass it was contained in decreased, correct? Thus, the Big Bang contained the absolute energy of the universe, right? But the key is that that energy couldn't have come into existence on its own. The problem is where all this matter and energy originated.
Also, we don't know a damn thing about dark matter. It's just a theory, and antimatter, well, we all know the destruction that can cause.
The point being, based on the theory of relativity, isn't it entirely possible that you could transform a negative energy value into a negative mass value? Therefore, it is also possible that mass can exist as a negative. The logical conclusion as to the identity of this (keeping in mind that this is all just postulation) anti-matter would be the single most mysterious form of matter in the known universe. Hence, dark or anti matter.
Does that clear things up a bit? I don't know WHAT I was thinking with the Absolute Zero thing. Sorry...

Logic is the ultimate argument; for none can refute logic with anything but logic. Thus, you will always walk away satisfied if you stay logical, knowing either you're right, or you're wrong.

This message is a reply to:
 Message 14 by NoNukes, posted 06-16-2014 9:28 AM NoNukes has replied

Replies to this message:
 Message 16 by NoNukes, posted 06-16-2014 2:23 PM TryingToBeLogical has not replied
 Message 17 by Modulous, posted 06-16-2014 5:21 PM TryingToBeLogical has not replied

  
Newer Topic | Older Topic
Jump to:


Copyright 2001-2023 by EvC Forum, All Rights Reserved

™ Version 4.2
Innovative software from Qwixotic © 2024