Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: Nimrod on 07/04/2009 03:25:37
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Allthough I've read we know little about what goes on inside of black holes, is it possible that the Universe exists inside one? If we were, how might we know?
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From what I've read it seems that if enough matter congregates in a small enough area or surpasses a certain threshold, a black hole must result. If this is true and we rewind the universe to its beginning, then all the matter and energy in the known universe were in a singular point, would this not be a black hole? Is it possible that inside this Singularity exist all that we have or need in this Universe, i.e. energy/matter, space/time and allow for the expanion of space?
any information or opinions on this would be Greatly Appreciated :)
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Take a trip and see :)
http://www.thinktechnologies.com/portfolio/demos/Blackhole.html
Some say we could be in a 'white hole'?
http://news.softpedia.com/news/What-is-a-White-Hole-75335.shtml
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Thanks Yor_On for the links, but alas I've seen this kind of info before.
you and some others I've seen post here obviously know more (much more)about physics than I and hoped for some informed opinion.
below I've included a link to a site I though was interesting.
couldn't understand all (OK most) of the math but the lower section on life in a black hole was interesting
http://members.cox.net/jhaldenwang/black_hole.htm
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Some say we could be in a 'white hole'?
http://news.softpedia.com/news/What-is-a-White-Hole-75335.shtml
This thought has occured to me more than once. It has also crossed my mind more than once, that quite possibly, our universe is an exploding black hole in an infinite space. The universe we observe may only be the result of a local event, namely, an exploding black hole. Imagine for one minute if you will, a black hole having a limit to it's size, beyond which it must return it's matter and energy back into the surrounding space. Depending upon the value of this structure, we may not be aware of the true size of the universe. This local event I speak of may be so large, we may not be privileged to ever observe another such happening. It may just be that the universe is filled with a multitude of such explosions so far removed from each other by time and space that we will never be able to observe the history of these events.
....................Ethos
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Below I have pasted the part of the article I found so interesting
this link has a good illustration to go with this and alot more additional info if anyones interested or can understand it :)
http://members.cox.net/jhaldenwang/black_hole.htm
Spacetime Geometry Inside a Black Hole
by Jim Haldenwang
written Nov. 12, 2004
revised May 28, 2008
Life Inside the Black Hole
Some have speculated that our universe might exist inside a gigantic black hole. Let’s explore this idea further, in order to gain more insight into what the interior of a black hole is really like (and for the fun of it). If our universe is really inside a giant black hole, one might ask where the event horizon is. Is there any path we can take that will bring us closer to the event horizon? According to GRT, if our universe is inside a black hole, every point in our universe is moving closer to the center of this black hole, and away from the event horizon. There is no (spatial) direction that will bring us closer to the event horizon. As it is difficult to visualize a four-dimensional curved surface (one needs to think in five dimensions to be able to do this), subtracting a dimension or two makes it easier. Imagine a giant sphere, and a point on the interior surface of this sphere. This point detaches from the inner surface and moves toward the center, at the same time expanding into a disk. This expanding disk represents our universe expanding in space as it moves through time. In this model let's suppose that our universe formed on the event horizon of the giant black hole, represented by the surface of the sphere. We suppose that the Big Bang occurred at the event horizon of the black hole. See figure 5. The expanding disk is a two-dimensional representation of the three spatial dimensions of our universe. (We could label these spatial dimensions q, j and t. Note that the disk represents an unimaginable curved 3-D hypersurface.) Every point in our universe (the disk) is moving away from the inner surface of the sphere (the event horizon) toward the center of the sphere (the singularity of the giant black hole). The dimension through which this disk is moving is a timelike dimension (let’s label it r). For every point on the disk (our universe at a point in time), the event horizon lies in the past and the singularity of the black hole lies, unseen, in the future. All timelike and lightlike world lines in our universe lead from the event horizon to the singularity of the black hole. To travel to the event horizon would be to travel backward in time. Therefore, there is no path we can take that will bring us closer to the event horizon.
In this imaginary model, the only point of the spacetime of our universe that is connected to the event horizon of the giant black hole is the point in space and time at which the Big Bang occurred. With a powerful enough telescope, one can, in theory, look in any direction and see the Big Bang (or at least 380,000 years after the Big Bang, when the universe became transparent). One can look around in any direction and see the Big Bang, yet one cannot travel toward it, because it lies in the past. This is the way of things inside any black hole. Even a super-powerful rocket cannot prevail against the gentle timelike acceleration toward the singularity at the center of a black hole.
Could we detect the presence of this gigantic black hole? If we had sensitive enough instruments, it should be possible to detect the tidal acceleration gradient, at least over astronomical distances. This might be mistaken for a slight variation in the strength of gravity over very large distances. Also, the expansion of the universe should eventually slow down and reverse, as the universe moves closer to the central singularity of the black hole. In this model, our universe would eventually shrink down to a single point (the Big Crunch).
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"Are We Living Inside of a Black Hole ?"
Not anylonger... [;D] [;D] [;D]
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I took a look on that first paper you linked. It's using the Schwarzschild metric for non spinning Black Holes. Although it says that the solutions it presents should fit the Kerr metric for spinning black holes I'm not sure on that. The impression I've gotten is that you can't apply the Schwarzschild metric on spinning Black Holes, I could be wrong though?
Otherwise it's impressive. As for the idea of a black hole creating our universe I don't know, what we do seem to have is super massive Black Holes in the middle of all galaxies. As far as I understand they are all of them spinning though. The idea of three dimensions + time is a description of what we have now. It doesn't, to me that is, imply that there was anything of that before the so called 'inflation'. If matter and space goes together as I think and so defining a 'times arrow', then those 'remnants inside our galaxies all could be the beginning of that.
It goes well with the idea that matter won't disappear inside those EV:s (Event horizons) until the 'heat death' of spacetime where everything is a equalized soup. I think. Then those BH will be the only thing 'working' on what is left of spacetime sucking it in until it dismantles our universe. As they are in all galaxies (probably:), it seems to me that they should have something to do with the BB (Big Bang) if so. The question one might ask is if they then were the first causes of spacetime or just a result of a Big Bang. If nothing ever can pass the EV as some see it then that seems a strong clue for them being more than remnants of a BB to me. Then they are to my eyes more like 'unfinished parts' of what we see as spacetime, and that would imply some sort of 'center for a BB.
If they, on the other hand, allows matter to finally pass through then they might be seen as 'cosmic lungs', once before our 3D + time breathing out, now 'breathing in'. That as distance as well times arrow according to the gospel of... me:) shouldn't come into 'play' before a spacetime was created/defined by matter and space, finding its times arrow in the process. And if so, then 'spacetime' truly has no 'center' as it was those super massive black holes that started 'spacetime' creating both matter and space, as well as that arrow of time pointing in only one direction.
That leaves us the question of what makes photons so special? We are 'fermions', photons are 'bosons', and space is.. nothing? To find a explanation for that I will blame it on 'transitional states' that I know nothing about, nuuthing I say. It just seems like there must be such a thing as we in spacetime have both dead and living matter. Spacetime to me seems very much a question of 'density' with 'photons' being on one outer 'side' of spacetime being massless and timeless according to mainstream physics, able to be superimposed on each other into eternity without taking any physical space.
On the other hand we have what we call 'mass', with 'matter' as yet another 'state transition', and living 'matter' one step further away. I'm sure I've forgotten a lot of important things, but I'm taking a 'mind trip' of my own here, indulging us both ::)) Remember that this is just me playing with 'possibilities', still, it's fun to speculate. Also this to me should imply some sort of fractal principle steering it. And that would explain why it is so hard to backtrack what we see, to being some sort of primary constituents, as when a fractal bifurcates (splits) into new 'possibilities' or 'tracks', there is no way of 'backing it up', to see what it was that lead to that 'possibility', not after you are standing there, desperatedly trying to seek your way 'back' to a 'beginning', ah. at least as I understands it. So this is one (mine) saga of our universe, well, at least it is tonight. Hope it made some sense:)
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I forgot, if so they shouldn't really be seen as 'Black Holes', but rather as 'White Holes' as those ones also, from our perspective that is, will be seen as to be 'breathing in', observed from our 'frame of reference' in spacetime, that is.
But if they are 'white holes' there will be no final 'sucking in' of mass/matter, if I remember right they will just eat themselves up? On the other hand it means that all quarks gluons electrons atoms have stopped 'jiggling' at this entropic soup comes to finalization at that famous 'restaurant at the end of time', doesn't it? Or does it?? What will they become at that entropic 'death', can one still se them as 'bosons' and 'fermions' ???
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If they are seen as white holes we should have an effect where everything containing 'mass' should be placed around them in the end, if I understand it right? But if all 'energy' is seen as unable to do any work, what does that mean? that the atoms stopped jiggling or that they just have a 'ground state' where they still will 'interact'? If they don't 'interact in themselves, could matter still exist? if that final 'soup' is made of non-interacting 'stuff' what will it become then?
( Should have steered away from this one I think :)
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And Edit edit edit :)
and edit some more, it never ends..
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And yes, if they are White Holes then they very probably created our three dimensions + time, but not from any speccific center. There needs to be a 'spacetime' before there can be a distance or a direction, And as times arrow wouldn't be there as I see it then the inflation would be a 'simultaneous' effect from all of those 'White Hoses' inflating our 'spacetime'. Yep.. Which possibly would imply a center anyhow as distances would grow as rings on the water from them, meaning that in the very 'beginning' they most probably should have a common, i really really hate to write this but, 'center'.
(Now I just need my Nobel Prize, or the money, ah, forget about the prize, just hand over the money:)
Be quick, my landlord is screaming...
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Allthough I've read we know little about what goes on inside of black holes, is it possible that the Universe exists inside one? If we were, how might we know?
Yes sir, it can be under this sense, as i once wrote in a short passage for an essay:
When you hypothetically enter a black hole, the gravitational distortions are so powerful, they twist time and space together so violantly, space and time switch roles. For an observer, this would potentially be dreadful, as it would i assume rip your particles into a stream. However, you can pass into an inner horizon (if you are lucky enough to escape the singularity), and in the inner horizon, space and time switch yet again, back to normal. If our universe is a black hole, and we are inside the black hole, then our universe would be located inside the inner horizon...
Now, let us consider the facts which the scientists hold to this theory. First, let us assume the following > M is for mass, R is for radius, D is for density and V is for volume.
The radius of a balck hole is found to be directly proportional to its mass.
(R- M)
The density of a black hole is given by its mass divided by its volume,
(D=M/V)
... and since the volume is proportional to the radius of the black hole to the power of three,
(V- R^3)
... then the density of the black hole is inversely proportional to its mass raised by the second power.
(D- M^2)
But what does all of this mean? Well, it means that if our universe is a black hole, the mass content would not appear to be very dense... And if we where to squeeze every bit of matter the earth contained down to infinite density, it would fit into the size of a matchbox! Thus our universe does not seem very dense at all, and according to the theorists, could very well be a black hole. For the record, i'm not convinced.
There is the superfluous paradox of the unievrsal acceleration to consider, and as far as i can tell, a black hole should not give off these characteristics, unless of course it is expanding very fast, but for that to happen i presume, it would need to be absorbing energy from outside... a great deal of it for that matter.
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"But what does all of this mean? Well, it means that if our universe is a black hole, the mass content would not appear to be very dense... And if we where to squeeze every bit of matter the earth contained down to infinite density, it would fit into the size of a matchbox! Thus our universe does not seem very dense at all, and according to the theorists, could very well be a black hole. For the record, i'm not convinced. "
This is a misuse of the term infinite, if all the matter of the Earth was squeezed to an infinite density it would have zero dimensions not that of a matchbox
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"But what does all of this mean? Well, it means that if our universe is a black hole, the mass content would not appear to be very dense... And if we where to squeeze every bit of matter the earth contained down to infinite density, it would fit into the size of a matchbox! Thus our universe does not seem very dense at all, and according to the theorists, could very well be a black hole. For the record, i'm not convinced. "
This is a misuse of the term infinite, if all the matter of the Earth was squeezed to an infinite density it would have zero dimensions not that of a matchbox
If it could be squezzed to infinite density, then itsurely can fit into a matchbox can't it?
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To say that it can fit into a matchbox is a way of defining its dimensions, it cannot be defined it is zero.
You might just as well say it could be fitted into the Solar system or a Hydrogen atom.
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To return to the original question I would say probably yes. The Schwarzschild model is a pure mathematical concept and any real black hole must contain some angular momentum so the Kerr metric applies.
Next people talk about a "singularity" implying that in some way it has formed already this is obviously untrue. What you need to consider is the process of continued collapse inside the event horizon of a rotating black hole.
Firstly let us make things simple by saying that the material is very hot has a reasonably uniform density and is rotating at a reasonable rate. there are at the moment no singularities of any sort there is a great deal of space time curvature close to the event horizon but in the middle of the body space is flat because the net gravitational field is zero This is one of the important things that people forget they rush off to assume final singular states and think that they have solved it but that hasn't happened yet.
The material will continue to collapse heat up and rotate faster TOWARDS the Kerr limit of a ring singularity (but it has not got there yet) eventually components of residual angular momentum in the other two dimensions will come into play and the collapse will be towards a toroidal surface.
Because if the high velocities of the particles involved time will become stretched
My proposal is that this collapse could be considered as a collapse of the real dimensions of space towards a singular surface that is time like is paralleled with the expansion of the imaginary dimensions of time into something that is space like and the true mathematical singularities will never form.
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That leaves us the question of what makes photons so special? We are 'fermions', photons are 'bosons', and space is.. nothing?
I also like to consider that empty space is nothing. However, the theories we are expected to accept give space at least some properties. It can stretch? What stretches. How can I examine an isolated piece of space and determine its state of stretch.[:)]
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I think we are living in a black hole. The scientists say that the further away a galaxy is from us the faster it moves away. This continues until they get faster than the speed of light. Beyond a certain point (the event horizon), we cannot see the light as is limited in its speed. Similarly, we cannot ever reach those faraway galaxies as the space between us and them is growing faster than any speed we could gather. So, we are living in an area out of which we cannot escape and this situation seems awfully similar to what goes on in a black hole, don't you think?
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okhouri, you are right about recent observations that seem to suggest that the universe's expansion is accelerating but I think your conclusion is wrong. The analogy regarding an apparent event horizon is the wrong way round - not being able to see distant galaxies would imply that you were looking into a black hole not that we were inside one looking out. In any case, this particular observation does not necessarily point to the known universe being in a black hole or not, but possibly means that there is stuff called dark energy out there. This theory also precludes finding out, in the near future, whether the universe is closed, flat or open - this is to do with the shape of the four-dimensional geometry.
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We do not live in a black hole. First, our solar system is completely intact. Under no circumstances would this be the case in a black hole. The entire solar system would be dissasembled into an acretion disk of increasingly disparate parts even before it got inside.
Further, a small black hole would rip all matter appart because its gravity increases very fast over short distances as you enter. Specifically, your feet might be subject to 500 gs while your head might only be subjected to 450 gs. Larger black holes may be more gentle. However, the accelerations involved for any mass entering the event horizon would simply splay the entire enterage like a flat screen projection onto an imobile sphere. This is because these matterial objects would be under such gravitational attraction they would approach the speed of light.
That means two things. First, their time comes to a near stop, and two, they become increasingly two dimensional and pretty much stop accelerating. This is because they approach the impossible speed of light, and approach infinite mass. Because time distance and speed are all relativistic, this globual of mass will become paper thin simply to accomodate the time dialation inside.
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We do not live in a black hole. First, our solar system is completely intact. Under no circumstances would this be the case in a black hole. The entire solar system would be dissasembled into an acretion disk of increasingly disparate parts even before it got inside.
Further, a small black hole would rip all matter appart because its gravity increases very fast over short distances as you enter. Specifically, your feet might be subject to 500 gs while your head might only be subjected to 450 gs. Larger black holes may be more gentle. However, the accelerations involved for any mass entering the event horizon would simply splay the entire enterage like a flat screen projection onto an imobile sphere. This is because these matterial objects would be under such gravitational attraction they would approach the speed of light.
That means two things. First, their time comes to a near stop, and two, they become increasingly two dimensional and pretty much stop accelerating. This is because they approach the impossible speed of light, and approach infinite mass. Because time distance and speed are all relativistic, this globual of mass will become paper thin simply to accomodate the time dialation inside.
Not exactly - matter can exist in what are called free boundary's of the internal structure of black holes. In black holes, you will find around four boundaries where spacetime switch roles and do some pretty weird things. But there is one boundary where spacetime moves in the correct way, and if there are any planets floating around in this boundary, it will be indestinguishable from normal experience of spacetime; thus giving the universe the slight possibility we are fact inside a massive black hole.
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MR s:
You may have some comments on this question. Can a Neutron star colapse to a black hole through simple mass accretion? I have not had a good answer to this question but my speculation is this: A black hole can not be created without mass acceleration into the relm of relativistic speeds.
In other words, the mass that creates a black hole needs two things. First, enough mass to do the thing; and 2) Adequate velocity to become relativistic and create an event horizon. To this date no one has explaned that a simple neutron star would become a black hole from simple, slow, and accumlated mass acreation. [PS this excludes to neutrongstars merging and all the other weird stuff that COULD happen.]
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Can a Neutron star colapse to a black hole through simple mass accretion?
Not as far as i am aware. The density of the neutron star is far more denser than the material found in accretion disks. Remember, density contriubutes to the density, and density is what determines a black holes creation.
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I could easily be wrong though. I am not an astrophysics student.