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tommac
2009-Nov-09, 08:43 PM
If we did a mathmatical time reversal from the current state of our universe. What mathmatically would we show?

For example ... if our current universe is expanding ... in the time reverse we would be contracting, however, I would assume that at some point when the universe got close enough together it would become a black hole right? Or maybe a bunch of black holes that would then eventually colide into each other?

Would we know what the size of the EH of a universal mass sized BH be?

pzkpfw
2009-Nov-09, 08:48 PM
You may find this useful: http://www.bautforum.com/space-astronomy-questions-answers/87942-universe-bh-moment-bb.html

tommac
2009-Nov-09, 09:03 PM
If we just did a time reversal of what is going on now ... what would happen?

In that thread it talks about inflation and all of that ... however ... using a time reversal model how do we come to the conclusion of inflation? Wouldnt we just come to the point of the black hole?

OR would the contraction of the universe be at such a fast rate that we could only conclude inflation?

Regards,
Tom

NEOWatcher
2009-Nov-09, 09:13 PM
If we just did a time reversal of what is going on now ... what would happen?
Isn't that the whole basis of Stephen Hawking's PHD?


Wouldnt we just come to the point of the black hole?
I don't think the concept of "black hole" exists for the start of the universe.
There was a singularity but since the entire universe is the singularity, there is no gravitational effects outside of the singularity. In addition, gravity was not a seperate force in the beginning.

tommac
2009-Nov-09, 09:50 PM
Isn't that the whole basis of Stephen Hawking's PHD?


I don't think the concept of "black hole" exists for the start of the universe.
There was a singularity but since the entire universe is the singularity, there is no gravitational effects outside of the singularity. In addition, gravity was not a seperate force in the beginning.


I agree with all of this ... however ... is this all deduced from a simple time reversal? or are assumptions made?

TheMan2Astro
2009-Nov-10, 02:35 AM
I agree with all of this ... however ... is this all deduced from a simple time reversal? or are assumptions made?

Simple time reversal. I don't know about that one.

WayneFrancis
2009-Nov-10, 03:06 AM
If we did a mathmatical time reversal from the current state of our universe. What mathmatically would we show?

For example ... if our current universe is expanding ... in the time reverse we would be contracting, however, I would assume that at some point when the universe got close enough together it would become a black hole right? Or maybe a bunch of black holes that would then eventually colide into each other?

Would we know what the size of the EH of a universal mass sized BH be?

The answer is "we don't know".

2 problems.

The problem of defining the time reversal as being the same as a black hole is that they are not the same objects.

A black hole is simply an object that has enough mass within a given area that even objects travelling at c can not escape.

Now run the time backwards and not only do you have an increase in mass / vol but you have expansion, or the time reversed contraction, working to pull everything in. Now also remember that the early universe was extremely uniform so you where no more pulled in 1 direction then any other. Thus if light could travel unimpeded it would not get sucked into anything.

Second problem. At some point the forces start unifying and you come up with the problem that there is no "gravity" thus the black hole object is impossible.

It is the former answer to which I think the universe is open and infinite. Even if there was no unifying of forces there is still no problem about "black holes" as gravity is also uniform.

WayneFrancis
2009-Nov-10, 03:07 AM
If we just did a time reversal of what is going on now ... what would happen?

In that thread it talks about inflation and all of that ... however ... using a time reversal model how do we come to the conclusion of inflation? Wouldnt we just come to the point of the black hole?

OR would the contraction of the universe be at such a fast rate that we could only conclude inflation?

Regards,
Tom

Again a black hole is a non uniformity of gravity towards a single point. If you have gravity pulling you in all directions with the same force then you are not in a black hole.

WayneFrancis
2009-Nov-10, 03:09 AM
You may find this useful: http://www.bautforum.com/space-astronomy-questions-answers/87942-universe-bh-moment-bb.html

You do realise pzkpfw that the thread you linked was tommac's thread!?!?!

WayneFrancis
2009-Nov-10, 03:11 AM
I agree with all of this ... however ... is this all deduced from a simple time reversal? or are assumptions made?

It's deduced from how we understand the universe. Of course assumptions are made. I assume that if I step off the top of a tall building that I'll fall to my death. The point being is they are very well founded assumptions.

01101001
2009-Nov-10, 03:35 AM
You do realise pzkpfw that the thread you linked was tommac's thread!?!?!

And he should find the answers there useful, no?

I was about to give the same answers I had there. Nothing has changed in the interim.

WayneFrancis
2009-Nov-10, 03:37 AM
And he should find the answers there useful, no?

well...I guess I'm just assuming that if he didn't learn from it the first time he'll probably not learn from it this time or else he should have remembered his own thread without outside help :P

Starfury
2009-Nov-10, 03:39 AM
Have you ever seen the Red Dwarf episode "Backwards"? It'll give you a good idea of what it'd be like, with hilarious consequences. :lol:

Santa Claus would really suck, as he'd come down the chimney and take kids' favorite toys away. :lol:

St. Francis of Assisi would be a sicko who maimed small animals.

And don't get me started on using the bathroom in such circumstances. :lol:

bebe7
2009-Nov-10, 03:40 AM
If we did a mathmatical time reversal from the current state of our universe. What mathmatically would we show?

For example ... if our current universe is expanding ... in the time reverse we would be contracting, however, I would assume that at some point when the universe got close enough together it would become a black hole right? Or maybe a bunch of black holes that would then eventually colide into each other?

Would we know what the size of the EH of a universal mass sized BH be?

If you beliece in the theory of a cyclic universe, you would believe that the universe constantly expands and contracts to its extremes, upon the total contraction it would produce a big bang and the event would start again. Remember also that the Big Bang happen everywhere not just at one point.

WaxRubiks
2009-Nov-10, 06:29 AM
I wish people would move away from the idea of singularities.
I think the Universe has ways of avoiding them in black holes, and at the start of this universe.

I believe in a cyclic universe, where all the matter eventually becomes radiation, at which point time stops and all the matter condenses again, time starts and you have another big bang....I don't think there is a need for singularities....maybe just high density volumes of 3-sphere space....I think Rodger Penrose suggested something like this type of cyclic universe.

astromark
2009-Nov-10, 08:05 AM
If we did a mathematical time reversal from the current state of our universe. What mathematically would we show?


BUT... from your OP you are making what I see as a mistake. I would answer the question with a 0. Nothing would be changed. Time can not run backward. Nothing could happen. If for example the expansion rate of the universe were to simply stop. Allowing gravity to pull all galactic matter into the Big Crunch. Is that the end of the Universe and time ? That is not reversing time. Time might however stop at that point when gravity force exceeds the existence of matter. Yes some sort of massive but small entity we call a singularity. My argument regarding the prohibitive properties of times progression are at best confusing as we know that time would appear to slow for an observer of this universal colapse...as matter accelerates into oblivion time would seem to have stopped... It has not and can not. Allowing for the fact that due to some anomaly of time flow I too will except that time does slow when the bus is late and and I am in a hurry...:)

And now if we are to just play with this idea and ask the question; The answer is not available to me. I have no idea how you would or could indicate time having been reversed. There would seem not to be a mathematical method of expression in that regard. Could this be the answer.?

NEOWatcher
2009-Nov-10, 12:54 PM
I agree with all of this ...
Then why use the wrong terms, especially after you have an entire thread devoted to telling you it is not a black hole?

JohnD
2009-Nov-10, 01:25 PM
Tommac,

At present, all the larger objects outside our galaxay are retreating from us, so if you reversed time from that point of view, then everything would contract down onto us.
But, if you moved a significant distance, like to another galaxy, and did the same the same would happen - the Universe contracts down onto your new home. But the Universe did not start in two points, or the very many possible points from which you could observe this effect.

I think that the fallacious 'balloon analogy' can help here. The two dimensional surface of the balloon expands as it inflates, and every point on that surface retreats from every other point. Reverse time, and the balloon contracts to a point (allow me a little poetic licence here!), but that point is in the centre of the balloon, not at any point on its surface.

John

WaxRubiks
2009-Nov-10, 02:21 PM
instead of that balloon shrinking to a point, I think it might be more likely just to shrink to a small balloon.


anyway, what's fallacious about the balloon analogy?
The universe might well be a 3-sphere.

Argos
2009-Nov-10, 02:41 PM
Discussion of this issue requires some info on symmetries (http://en.wikipedia.org/wiki/Symmetry_in_physics).

The second law seems to prevent the universe from showing perfect symmetry under time reversal.

tommac
2009-Nov-10, 04:36 PM
but based on a time reversal ... wouldnt the point where the forces start unifying past the point of time where we would have enough mass close enough together to have a black hole situation?


Second problem. At some point the forces start unifying and you come up with the problem that there is no "gravity" thus the black hole object is impossible.



What I would like to understand is the state of the universe very close to the EH of the universal sized black hole.

I was trying to work out the size of the black hole ( still doing the math )

2 GM / c^2 = 2 ( 6.7 x 10^ -8 dynes cm^2 / gm^2 ) (1.6 x 10^ 55 kg ) / (3 x 10^10 cm / sec ) ^2

will break this down in a few. Now would this black hole form only if the universe is uniform? Otherwise we would start having a series of black holes forming prior to them combining into a black hole.

The problem with all of this is what is the observers point of reference for all of this contraction right? At what point does the obsever get sucked into a black hole ;-) )

tommac
2009-Nov-10, 04:39 PM
Again a black hole is a non uniformity of gravity towards a single point. If you have gravity pulling you in all directions with the same force then you are not in a black hole.


Huh? Is this true? Certainly you can be at a point where gravity is pulling you equally in two or more directions and still in a black hole because of the net potential gravity.


For example at the point where two black holes come close to each other. There is a point between them with 0 gravitational pull but high enough gravitational potential for it to be part of a black hole ( from the perspective of an observer outside of the the gravitational pull of the two BHs ).

tommac
2009-Nov-10, 04:41 PM
It's deduced from how we understand the universe. Of course assumptions are made. I assume that if I step off the top of a tall building that I'll fall to my death. The point being is they are very well founded assumptions.

That is the point of this thread ... vs my thread that was previously quoted. What I am looking for is the extrapolation of the simple time reversal vs "assumed" mainstream viewpoints. I am not claiming the mainstream is wrong ... but rather trying to understanding what is wrong with the simple time reversal ... if that make sense.

tommac
2009-Nov-10, 04:44 PM
mathmatical time reversal ... not time running in reverse.



BUT... from your OP you are making what I see as a mistake. I would answer the question with a 0. Nothing would be changed. Time can not run backward. Nothing could happen. If for example the expansion rate of the universe were to simply stop. Allowing gravity to pull all galactic matter into the Big Crunch. Is that the end of the Universe and time ? That is not reversing time. Time might however stop at that point when gravity force exceeds the existence of matter. Yes some sort of massive but small entity we call a singularity. My argument regarding the prohibitive properties of times progression are at best confusing as we know that time would appear to slow for an observer of this universal colapse...as matter accelerates into oblivion time would seem to have stopped... It has not and can not. Allowing for the fact that due to some anomaly of time flow I too will except that time does slow when the bus is late and and I am in a hurry...:)

And now if we are to just play with this idea and ask the question; The answer is not available to me. I have no idea how you would or could indicate time having been reversed. There would seem not to be a mathematical method of expression in that regard. Could this be the answer.?

tommac
2009-Nov-10, 04:46 PM
Then why use the wrong terms, especially after you have an entire thread devoted to telling you it is not a black hole?

But wouldnt a time reversal extrapolate us into a black hole? That is the difference of the threads.

If the loaf of bread is exanding ... wouldnt the time reversal bring it back into flatness ( the BH )?

tommac
2009-Nov-10, 04:49 PM
Yes exactly. This is my point. As the baloon contracts past a certain density the mass at any point would be high enough for a black hole? Unless other events are taken into account. If the universe contracted to the size of the earth or the size of our solar system ... every point would have enough mass or energy to be a black hole.



Tommac,

At present, all the larger objects outside our galaxay are retreating from us, so if you reversed time from that point of view, then everything would contract down onto us.
But, if you moved a significant distance, like to another galaxy, and did the same the same would happen - the Universe contracts down onto your new home. But the Universe did not start in two points, or the very many possible points from which you could observe this effect.

I think that the fallacious 'balloon analogy' can help here. The two dimensional surface of the balloon expands as it inflates, and every point on that surface retreats from every other point. Reverse time, and the balloon contracts to a point (allow me a little poetic licence here!), but that point is in the centre of the balloon, not at any point on its surface.

John

tommac
2009-Nov-10, 04:50 PM
Discussion of this issue requires some info on symmetries (http://en.wikipedia.org/wiki/Symmetry_in_physics).

The second law seems to prevent the universe from showing perfect symmetry under time reversal.


This is interesting ... can you please explain?

Argos
2009-Nov-10, 05:01 PM
This is interesting ... can you please explain?

Maybe this link (http://en.wikipedia.org/wiki/T-symmetry) will be able to explain what Im referring to, tommac.


One can, however equally well imagine a state of the universe in which the motions of all of the particles at one instant were the reverse (strictly, the CPT reverse). Such a state would then evolve in reverse, so presumably entropy would decrease (Loschmidt's paradox). Why is 'our' state preferred over the other?

Pardon me if I havent understood the nature of your questioning.

NEOWatcher
2009-Nov-10, 06:04 PM
But wouldnt a time reversal extrapolate us into a black hole? That is the difference of the threads.
I'm not talking about extrapolation, I'm talking about your using the term "black hole". It doesn't apply since there is no outside, there is no surface, there is no outside observer. There's no there there.

bebe7
2009-Nov-10, 06:21 PM
Yes, time moves forward as in the arrow of time (forward), that is the difficulties facing a trye time machine.

Re expansion and contraction of the U, there are theories called the Big Rip, Freeze and Crunch in addition to the Big Bang.

cosmocrazy
2009-Nov-10, 07:07 PM
I'm not talking about extrapolation, I'm talking about your using the term "black hole". It doesn't apply since there is no outside, there is no surface, there is no outside observer. There's no there there.

I think you may have a point. When we consider black-holes time and space still exists as we know it outside the EH. Regarding the universe "outside" has no meaning so thinking of the whole universe as one big BH may not be the right line of thought.

Another point which Frog march raised was about singularities being non entities. It is believed that at the early beginning of the universe for a very short period of time that the four known forces where merged together as one. In a time reversal / BH maybe this happens just prior to the threshold of the formation of a singularity. Maybe gravity as we observe it becomes undefined therefore the notion of a singularity has no meaning at this point.

tommac
2009-Nov-10, 07:33 PM
Maybe this link (http://en.wikipedia.org/wiki/T-symmetry) will be able to explain what Im referring to, tommac.

While I kind of get what it is talking about ... I am not sure how that all plays into this discussion ... Like in time reversal it is clear that the entropy is not symetrical. However ... I dont get the link to how this prevents us from extrapolating back into a black hole.

PetersCreek
2009-Nov-10, 07:37 PM
Perhaps for the purpose of this discussion, you should define what you mean by a "black hole".

tommac
2009-Nov-10, 07:47 PM
I'm not talking about extrapolation, I'm talking about your using the term "black hole". It doesn't apply since there is no outside, there is no surface, there is no outside observer. There's no there there.

OK I get your point ... and I guess this is the start of the answer I was asking.

So lets set up a situation. Lets assume that the universe if 100% uniform and that we would technically predict that we would be in a black hole situation in T-10 days. We should be able to figure this out based on the trend of increasing energy density.

There is no way for an observer to escape this black hole as it is being formed from all directions ... even light cant escape because there is no where for it to go as it cant get to a point that will not be inside the black hole by the time it gets there.

Wouldnt the entire universe start feeling relativistic effects with time running relatively slower than it used to and space seemingly larger than it used to be ? in other words wouldnt our clocks run slower and our yardsticks be shorter?

Would an equalibrium be reached where our yardsticks be getting shorter at the same rate as the universe is contracting?

tommac
2009-Nov-10, 07:56 PM
Perhaps for the purpose of this discussion, you should define what you mean by a "black hole".

This one:
a black hole is a region of space in which the gravity well is so deep that gravitational time dilation halts time completely and an event horizon forms


The thing is that we would be collapsing into the EH, or rather the EH would be forming all around us. No matter what we did we would end up inside the EH.

I have 2 questions.
1) At the point where the gravity well is so deep in the entire universe that time dilation halts time completely. Wouldnt anything "before" that not make sense? OR at minimum be undefined? ( probably the latter ) ... how is that different than falling past the EH of a black hole? The only real difference is that the BH formed around the observer without the observer passing through the EH.

2) As our time slowed compared to what it will be in the future ... wouldnt the dimensions of the universe be quite different? Wouldnt all we do to measure the universe be different? I would think that at one point as we were seconds before forming a EH our time would be moving so slowly and our yardsticks so shortened that we would not realize that we were about to be part of a black hole.

loglo
2009-Nov-13, 12:58 PM
tommax.... In what frame is the entire universe's time seen to have slowed down?

tommac
2009-Nov-13, 06:38 PM
I think you may have a point. When we consider black-holes time and space still exists as we know it outside the EH. Regarding the universe "outside" has no meaning so thinking of the whole universe as one big BH may not be the right line of thought.

Another point which Frog march raised was about singularities being non entities. It is believed that at the early beginning of the universe for a very short period of time that the four known forces where merged together as one. In a time reversal / BH maybe this happens just prior to the threshold of the formation of a singularity. Maybe gravity as we observe it becomes undefined therefore the notion of a singularity has no meaning at this point.

I fully agree with all of this ... however ... are we still inside this black hole? If not how did we escape this black hole from the inside of the EH to the outside?

tommac
2009-Nov-13, 06:40 PM
tommax.... In what frame is the entire universe's time seen to have slowed down?

Our current frame. The rate of time that we experience now ... compared to the rate of time that we used to experience, if we time reversed to the point where we were just about to form ( escape from ) a black hole condition. We were definitely in a much deeper gravitational well then than we are now right?

cosmocrazy
2009-Nov-13, 07:49 PM
I fully agree with all of this ... however ... are we still inside this black hole? If not how did we escape this black hole from the inside of the EH to the outside?

The difference between what we assume to be a black hole and what the universe was like at the beginning could be quite different.
First off, based on the BB model, the EH of the universe would be the edge of the universe (space/time). Now since defining this edge may not be possible, if it at all exists, then we must assume that there is no EH or its not physically possible to cross it. Alternative to this would be to consider the early universe expanding faster than C which in turn would mean that escaping the singularity of the BB would not be an issue. It appears that space/time is indeed expanding faster than C far out at the edge of the observable universe, therefore maybe escaping the initial "singularity" (for want of a better word) is exactly what is happening.

tommac
2009-Nov-13, 09:11 PM
The difference between what we assume to be a black hole and what the universe was like at the beginning could be quite different.
First off, based on the BB model, the EH of the universe would be the edge of the universe (space/time). Now since defining this edge may not be possible, if it at all exists, then we must assume that there is no EH or its not physically possible to cross it. Alternative to this would be to consider the early universe expanding faster than C which in turn would mean that escaping the singularity of the BB would not be an issue. It appears that space/time is indeed expanding faster than C far out at the edge of the observable universe, therefore maybe escaping the initial "singularity" (for want of a better word) is exactly what is happening.

This is why I wanted to simplify the problem by doing a time reversal. How would this all work out ... if things were rushing towards each other creating a increasingly deeper gravitational well? Then at one point a BH would form around every point in the universe ( or again possibly having some parts forming BH's before others).

The EH would not be reachable or even detectable by any point inside in the same way that nothing can escape the EH for something that fell in. Mathmatically I believe the way this would work is that the EH would have to be large enough to encompass the entire universe ( obviously in a very condensed state ).

tommac
2009-Nov-13, 09:15 PM
It appears that space/time is indeed expanding faster than C far out at the edge of the observable universe.

Is this true? I thought the expansion of the universe is uniform it just appears to be expanding faster at places that are distant to the observer?

From an observer " far out at the edge of the observable universe" they would see their expansion as being slow ... and expansion around the milky way as being near the speed of light.

To me this seems more like a function of distance / time.

PetersCreek
2009-Nov-14, 12:13 AM
tommac,

I sure hope this isn't another chapter of your "the Universe is a black hole" ATM theory. Not only has that book has been closed, this is the Q&A forum.

loglo
2009-Nov-14, 08:15 AM
Our current frame. The rate of time that we experience now ... compared to the rate of time that we used to experience, if we time reversed to the point where we were just about to form ( escape from ) a black hole condition. We were definitely in a much deeper gravitational well then than we are now right?

No. Time always moves for us at one second per second. You seem to be imagining a global time coordinate... there isn't one. There is no meaning in saying time moved slower or faster in the past. GR certainly has nothing to say about it.

tommac
2009-Nov-15, 01:16 AM
Another peculiar thing here is that the closer you get to the moment that the universe would have had the mass density to be in a BH state, the slower object would be moving towards it. Which is strange ... you would think that as something nears a BH or potential BH the faster things would collapse on each other. Even though this is a time reversal a BH ( or white hole ) exerts gravitational pull.

I am not sure but it would seem by the time reversal that there is sort of some anti-gravity or something that slows down everything as it approaches a BH state?

tommac
2009-Nov-15, 01:18 AM
tommac,

I sure hope this isn't another chapter of your "the Universe is a black hole" ATM theory. Not only has that book has been closed, this is the Q&A forum.

No ... I dont think that the time reversal shows the behavior of a BH ... which is kind of the point. It the universe came from inside a black hole ... which it is no longer in you would think that the expansion on the universe would be slowing ( or speeding up when doing the time reversal ) ... but this is not the case.

tommac
2009-Nov-15, 01:21 AM
No. Time always moves for us at one second per second. You seem to be imagining a global time coordinate... there isn't one. There is no meaning in saying time moved slower or faster in the past. GR certainly has nothing to say about it.

Yeah I get this ... but ... lets would two observers in two different G-Relativistic states observe things differently? Like for example if two things were bound to each other at a certain distance would two observers in different G-relativistic states judge their distances differently?

loglo
2009-Nov-15, 09:16 AM
Yeah I get this ... but ... lets would two observers in two different G-Relativistic states observe things differently? Like for example if two things were bound to each other at a certain distance would two observers in different G-relativistic states judge their distances differently?

Yes.

tommac
2009-Nov-15, 08:03 PM
Yes.
So then the observer at time = 0 can measure things differently than the observer at time = time at the point where the universe would be approaching a black hole density. Right?

WayneFrancis
2009-Nov-16, 03:28 AM
Huh? Is this true? Certainly you can be at a point where gravity is pulling you equally in two or more directions and still in a black hole because of the net potential gravity.


For example at the point where two black holes come close to each other. There is a point between them with 0 gravitational pull but high enough gravitational potential for it to be part of a black hole ( from the perspective of an observer outside of the the gravitational pull of the two BHs ).

Well I guess if you can get to the very centre of a BH and a BH mass has a mass density that is not infinity that you could be in a black hole being pulled equally in all directions. This would be like if you where in the centre of the Earth. But beyond that I know of no configuration where gravity would be uniform in all directions and you are inside a black hole.

The scenario you presented is interesting but in the early universe it wouldn't just be opposing points but in every direction. Also if there is a point with 0 gravitational pull then by definition this wouldn't be inside or a point you would be able to ever get to.

WayneFrancis
2009-Nov-16, 03:41 AM
That is the point of this thread ... vs my thread that was previously quoted. What I am looking for is the extrapolation of the simple time reversal vs "assumed" mainstream viewpoints. I am not claiming the mainstream is wrong ... but rather trying to understanding what is wrong with the simple time reversal ... if that make sense.

Well say we lived 2,000 years ago and we brought up the time reversal situation. The people of those days would argue that you'd get to a point where the universe is just solid rock because that was the assumption of how matter worked back then.

Now we know that as energy density gets higher that the forces start to unify so we don't have that problem any more.

Our assumption is that if you just reversed time that the energy density kept getting higher. We assume that there is no blockage to the upper end of energy density. We believe our assumptions are correct back to less then 1 second after the big bang because we've tested matter in very high energy densities and we get consistent results.

So our assumptions are that the universe would work the same way. Then we have more assumptions on top of that that after that point, or before depending on how you look at it, the forces would continue to unify but the science here is a lot more speculation or better put "educated guesses"

WayneFrancis
2009-Nov-16, 04:18 AM
But wouldnt a time reversal extrapolate us into a black hole? That is the difference of the threads.

If the loaf of bread is exanding ... wouldnt the time reversal bring it back into flatness ( the BH )?

No it is not the same.

Lets take a look at a black hole. It has a given energy density inside of its EH directly proportional to is EH size.

This works out to about 1.75875x1017kg/m3

Now what is the difference between an object in space with an energy density of 1.75875x1017kg/m3 and the entire universe at a energy density of 1.75875x1017kg/m3?

Well its the empty space around the object in space having no net pull on another object near that first object with the energy density of 1.75875x1017kg/m3.

So the 2nd object just gets sucked in if it isn't in a stable orbit or on a trajectory that slings it out into deep space.

In the early universe we can have an energy density of 1.75875x1017kg/m3 without a singularity because any object in the universe is being pulled equally in all directions compared to the single object with energy density of 1.75875x1017kg/m3 being in a single direction.

WayneFrancis
2009-Nov-16, 04:22 AM
I'm not talking about extrapolation, I'm talking about your using the term "black hole". It doesn't apply since there is no outside, there is no surface, there is no outside observer. There's no there there.

Wow, that explanation is so much easier to understand then my last post. Thanks NEO, I wish I read ahead before posting.

Take the short easy to understand answer or my answer with needless detail. End product is the same RussT.

WayneFrancis
2009-Nov-16, 04:23 AM
I'll also point out this, at least for me, is the prime reason I believe our universe is unbounded.

WayneFrancis
2009-Nov-16, 04:27 AM
This one:
a black hole is a region of space in which the gravity well is so deep that gravitational time dilation halts time completely and an event horizon forms
...


But the time dilation is relative to something outside the EH. In the early universe, errrr heck in the universe now, there is no "outside" for us to compare to.

WayneFrancis
2009-Nov-16, 04:35 AM
Our current frame. The rate of time that we experience now ... compared to the rate of time that we used to experience, if we time reversed to the point where we were just about to form ( escape from ) a black hole condition. We were definitely in a much deeper gravitational well then than we are now right?

Yes but it doesn't have the effect you think it does.

Take the sheet analogy. The universe projected onto 2D would have many dimples in it some deeper then others. But if you roll time backwards those dimples would smooth out and merge. Eventually you would just have a flat sheet.

There is no gravitational potential here. Because it is the expanding of space that is moving galaxies apart then there is no gain in gravitational potential. So you can't look at the universe back then having a deeper well. The well was flat. IE if you are being pulled in all directions by a force of n you would have no difference in sensation then if you where being pulled in all directions by a force of nx101000

The early universe is like the universe now. There is no where you can escape from it....barring falling into a black hole but lets not get into that philosophical debate.

WayneFrancis
2009-Nov-16, 04:42 AM
Another peculiar thing here is that the closer you get to the moment that the universe would have had the mass density to be in a BH state, the slower object would be moving towards it. Which is strange ... you would think that as something nears a BH or potential BH the faster things would collapse on each other. Even though this is a time reversal a BH ( or white hole ) exerts gravitational pull.

I am not sure but it would seem by the time reversal that there is sort of some anti-gravity or something that slows down everything as it approaches a BH state?

Now you are confusing coordinate systems.

Again to see this effect you would have to be "outside" the universe.

Think of it this way. Falling into a black hole someone that is 10m in front of you is deeper in the gravity well. In the early universe someone 10m from you, in any direction, is point of the gravity well as you. There are no problems like you have with a BH. No tidal forces to rip you apart. If you could survive the high temperatures then you'd be just fine as the "gravity" doesn't mean anything. It would be like you where "floating" in deep space. The reasons you would die is because it is so hot that your atoms would rip apart.

DrRocket
2009-Nov-16, 04:44 AM
If we just did a time reversal of what is going on now ... what would happen?

Regards,
Tom

That is basically what Hawking and Penrose did to show that general relativity implies the big bang.

For details you can read The large scale structure of space-time by Hawking and Ellis.

WayneFrancis
2009-Nov-16, 04:59 AM
So then the observer at time = 0 can measure things differently than the observer at time = time at the point where the universe would be approaching a black hole density. Right?

If I understand you then no as I've answered you before.

The energy density of a BH is ~1.75875x1017kg/m3

what happens if we increase this energy density, uniformly, across the entire universe to 1.75875x1017,000,000kg/m3

As far as "time" goes all we've done is ensure that we've smoothed out the differences in time dilation even more. IE the further back in time we go the less difference there will be for any 2 points in space when you compare their frames.

I believe Hawking, I could well be wrong, has brought up the fact that as you run time backwards that because the energy density was higher that time was slower and thus there may never have been a "beginning" to the universe. But I always viewed that as a popular science type explanation.

What does it mean if the universe at T1 has a time dilation of x and at T2 the time dilation is <x?

Again we have no point to compare this to that really gives us useful information. If you want to think of the entire universe's clocks as running faster and faster as the energy densities go down then fine. What use is that to you since the whole universe is experiencing this?

tommac
2009-Nov-18, 11:25 PM
Well I guess if you can get to the very centre of a BH and a BH mass has a mass density that is not infinity that you could be in a black hole being pulled equally in all directions. This would be like if you where in the centre of the Earth. But beyond that I know of no configuration where gravity would be uniform in all directions and you are inside a black hole.

The scenario you presented is interesting but in the early universe it wouldn't just be opposing points but in every direction. Also if there is a point with 0 gravitational pull then by definition this wouldn't be inside or a point you would be able to ever get to.

Obviously the time reversal situation is different than the simple scenerio I proposed. In the time reversal where everything was close to everything else in all directions you could in theory have 0 pull in any particular direction but be in a very deep gravitational well with a very high gravitational potential.

The dual point scenerio is just a simple scenerio that shows that a point with 0 gravitational pull can still be in a very deep gravitational well with very high potential gravity. I believe this happens when two black holes travel within 1.5x the diameter of their EH ( assuming they are of the same mass ). That point would have 0 directional pull but light would not be able to escape to an external observer.

tommac
2009-Nov-18, 11:28 PM
In the early universe we can have an energy density of 1.75875x1017kg/m3 without a singularity because any object in the universe is being pulled equally in all directions compared to the single object with energy density of 1.75875x1017kg/m3 being in a single direction.

I dont think direction has anything to do with it. You are still in a deep gravitational well. At this point you may be inside the EH ... but there is an event horizon.

tommac
2009-Nov-18, 11:39 PM
Now you are confusing coordinate systems.

Again to see this effect you would have to be "outside" the universe.

Think of it this way. Falling into a black hole someone that is 10m in front of you is deeper in the gravity well. In the early universe someone 10m from you, in any direction, is point of the gravity well as you. There are no problems like you have with a BH. No tidal forces to rip you apart. If you could survive the high temperatures then you'd be just fine as the "gravity" doesn't mean anything. It would be like you where "floating" in deep space. The reasons you would die is because it is so hot that your atoms would rip apart.

No I dont think I am ... this is very simple and straight forward. If the universe is currently expanding and speeding up, then if you do a time reversal the universe would be contracting and slowing down.

Both time directions, show anti-gravitational tendencies.

To see the opposite of this take a black hole. In normal time ... you can see something fall into the black hole ... as it approaches the black hole things speed up. In time reversal ( white hole ) you will see something coming out of the hole very fast and slowing down the farther it gets away from the hole. The gravitational pull has the same effect regardless of the direction of time.

WayneFrancis
2009-Nov-19, 03:39 AM
Obviously the time reversal situation is different than the simple scenerio I proposed. In the time reversal where everything was close to everything else in all directions you could in theory have 0 pull in any particular direction but be in a very deep gravitational well with a very high gravitational potential.

No there is no great gravitational potential unless you could some how remove the source of inflation all together. Its like stripping off the top 200 feet of the surface of, lets say the moon. You haven't made a well.

A well implies that it is a hole of some sort. If you there is no where higher then where you are at then you are not at the bottom of a well. So there the "gravitational potential" can't be looked at as greater back then because there is no where to climb out of. If you had a region that was 2x as dense among its surrounding then you would have a gravity well but then the gravitation potential is even less. You gain gravitation potential by lifting yourself out of a gravitational well not by sitting in the bottom of it.



The dual point scenerio is just a simple scenerio that shows that a point with 0 gravitational pull can still be in a very deep gravitational well with very high potential gravity. I believe this happens when two black holes travel within 1.5x the diameter of their EH ( assuming they are of the same mass ). That point would have 0 directional pull but light would not be able to escape to an external observer.

If 2 black holes are close enough where their photons spheres intersect then then while technically there is a point where their would be a point of 0 directional pull it is useless to think of it in terms of a photon because the photon can not stay at that point. They photon will fall into one of the 2 black holes gravity wells.

But what we are talking about here is that the hole universe is flat as far as gravity goes. There just is not anywhere to "fall into".

WayneFrancis
2009-Nov-19, 03:44 AM
I dont think direction has anything to do with it. You are still in a deep gravitational well. At this point you may be inside the EH ... but there is an event horizon.

No there isn't any EH. You can't have an EH without an actual gradient of gravity. Once again you are taking an analogy to far.

There is no "deep" here because everything is at the same level. It is just FLAT. That is it. No gradient of gravity. Think of it this way. If a the EH of a black hole is a tear in the fabric of space time it is the slope of the gravity gradient that causes the tear. Since the early universe had no slope to the gravity gradient then there was no EH....anywhere.

WayneFrancis
2009-Nov-19, 04:21 AM
No I dont think I am ... this is very simple and straight forward. If the universe is currently expanding and speeding up, then if you do a time reversal the universe would be contracting and slowing down.

Both time directions, show anti-gravitational tendencies.

To see the opposite of this take a black hole. In normal time ... you can see something fall into the black hole ... as it approaches the black hole things speed up. In time reversal ( white hole ) you will see something coming out of the hole very fast and slowing down the farther it gets away from the hole. The gravitational pull has the same effect regardless of the direction of time.

I'm not sure how many ways I can put this. I don't have the time to draw pretty pictures right now.

Take the word well literally. It means a hole in the ground. A black hole is a gravity well compared to the space around it. The early universe has no well. It is FLAT.

Another way of thinking of it is this. With a black hole you can calculate its escape velocity. For a point on the EH its escape velocity = c. This can be derived from the equation
http://www.codecogs.com/eq.latex?Ug=\frac{-Gm_{1}m_{2}}{r}

The problem with this is m1 and m2 have to be treated as "body with a spherically-symmetric distribution of mass" The early universe has no region that could be defined like this. The problem is how do you define m1 and m2? m1 is the mass/energy of the universe of which m2 is included. Then you have the problem of defining r. Where is the centre of mass of the entire universe?

If you wanted to move from any point in the early universe to any other point in the universe there is no amount of energy needed to overcome gravity. Any energy you put into the system is purely for acceleration.

Another way to look at it. Take a bowl and put a ball bearing in it. Then give the ball bearing a tap. You can see that as it climbs the wall of the bowl it is gaining gravitational potential as it escapes the well. It looses that potential as it rolls back towards the bottom.

Now take that same ball bearing and roll it across the a flat floor. It never gains gravitational potential.

Now take that ball bearing to intergalactic space and give it a flick. It will travel forever with that little bit of energy.
Take that same ball bearing to the moon and give it the same flick straight up ... it will travel a finite distance.

You can treat the early universe as flat intergalactic space as far as gravity goes.

tusenfem
2009-Nov-19, 08:28 AM
No I dont think I am ... this is very simple and straight forward. If the universe is currently expanding and speeding up, then if you do a time reversal the universe would be contracting and slowing down.

Both time directions, show anti-gravitational tendencies.

To see the opposite of this take a black hole. In normal time ... you can see something fall into the black hole ... as it approaches the black hole things speed up. In time reversal ( white hole ) you will see something coming out of the hole very fast and slowing down the farther it gets away from the hole. The gravitational pull has the same effect regardless of the direction of time.


tommac, this is the Q&A section. If you want to pursue your (ever the same) ATM ideas about BHs and the universe being one, please do so in the ATM section of this board.

If you have a question, ask it. Otherwise, go to the appropriate section.

tommac
2009-Nov-19, 02:44 PM
But what we are talking about here is that the hole universe is flat as far as gravity goes. There just is not anywhere to "fall into".

I get that ... but the potential is there ... the fact that it doesnt fall into one or the other doesnt mean that the relativistic effects are not there.

tommac
2009-Nov-19, 03:06 PM
tommac, this is the Q&A section. If you want to pursue your (ever the same) ATM ideas about BHs and the universe being one, please do so in the ATM section of this board.

If you have a question, ask it. Otherwise, go to the appropriate section.

Why is this ATM? This is very straight forward?

Black Hole has Gravity
White Hole is defined as a time reversal of a Black Hole.
A White Hole also has Gravity

The Expansion of the universe show Expansion ( maybe my use of anti-gravity is bad ... but things are moving away from each other )
A time reversal of the Expansion also has the same "anti-gravity" ( of force in the oposite direction of gravity ) properties.

Please let me know what part of this even borders ATM?

tommac
2009-Nov-19, 03:11 PM
No there isn't any EH. You can't have an EH without an actual gradient of gravity. Once again you are taking an analogy to far.

There is no "deep" here because everything is at the same level. It is just FLAT. That is it. No gradient of gravity. Think of it this way. If a the EH of a black hole is a tear in the fabric of space time it is the slope of the gravity gradient that causes the tear. Since the early universe had no slope to the gravity gradient then there was no EH....anywhere.


Anywhere within the universe. Assuming that there is nothing outside of the universe you would be right. However ... wouldnt the relativistic effects still exist regardless of is the whole universe is inside a situaltion where the gravitational density would warrent a black hole or not?

tommac
2009-Nov-19, 03:15 PM
Why is this ATM? This is very straight forward?

Black Hole has Gravity
White Hole is defined as a time reversal of a Black Hole.
A White Hole also has Gravity

The Expansion of the universe show Expansion ( maybe my use of anti-gravity is bad ... but things are moving away from each other )
A time reversal of the Expansion also has the same "anti-gravity" ( of force in the oposite direction of gravity ) properties.

Please let me know what part of this even borders ATM?

The point here is that if you do a time reversal of the expansion of the universe ... it doesnt show what I would expect. Thus my confusion.

I would think that if you time reversed you would get to the point where the universe was a state of a black hole ( I get that everything is in the same state ... no slope ) A short time after ... everything is expanding and accelerating, rather than starting fast and slowing. I think this is actually Main Stream ... and accredited to Dark Energy ...

tommac
2009-Nov-19, 03:43 PM
I'm not sure how many ways I can put this. I don't have the time to draw pretty pictures right now.

Take the word well literally. It means a hole in the ground. A black hole is a gravity well compared to the space around it. The early universe has no well. It is FLAT.

Another way of thinking of it is this. With a black hole you can calculate its escape velocity. For a point on the EH its escape velocity = c. This can be derived from the equation
http://www.codecogs.com/eq.latex?Ug=\frac{-Gm_{1}m_{2}}{r}

The problem with this is m1 and m2 have to be treated as "body with a spherically-symmetric distribution of mass" The early universe has no region that could be defined like this. The problem is how do you define m1 and m2? m1 is the mass/energy of the universe of which m2 is included. Then you have the problem of defining r. Where is the centre of mass of the entire universe?

If you wanted to move from any point in the early universe to any other point in the universe there is no amount of energy needed to overcome gravity. Any energy you put into the system is purely for acceleration.

Another way to look at it. Take a bowl and put a ball bearing in it. Then give the ball bearing a tap. You can see that as it climbs the wall of the bowl it is gaining gravitational potential as it escapes the well. It looses that potential as it rolls back towards the bottom.

Now take that same ball bearing and roll it across the a flat floor. It never gains gravitational potential.

Now take that ball bearing to intergalactic space and give it a flick. It will travel forever with that little bit of energy.
Take that same ball bearing to the moon and give it the same flick straight up ... it will travel a finite distance.

You can treat the early universe as flat intergalactic space as far as gravity goes.

I dont know why you are talking about the early universe ... I am not. All I am talking about is taking our current observation and logically following through with a simple time reversal.

What we see now is that everything is expanding away from everything else and speeding up, in the time reversal everything would be getting closer together and slowing down. Are we agreed here?

At some point any observer in the universe would start feeling the gravitational effects of the other stuff in the universe as it gets closer and closer to the observer ... Do we still agree?

Now you are saying that the pull is in every direction. I agree with that. However what I claim is that even though the pull is in every direction ( leaving us with 0 directional pull ) but surrounded by potential gravity.
This is where I think we disagree.

Are you saying that potential gravity is relative to the potential gravity surrounding you?

Also note that the entire universe is inside of the same potential gravitational situation at a certain time ... however allong a timeline it is not. The further back in T one goes ( based on the reversal concept ) the greater the potential gravity should be.

tommac
2009-Nov-19, 04:04 PM
Another way of thinking of it is this. With a black hole you can calculate its escape velocity. For a point on the EH its escape velocity = c.

Again ... yes a black hole has an escape velocity. However the escape velocity is the escape velocity of the system. To escape from the black hole.

Forget about black holes for a second. Lets take binary stars. Assume they are exactly the same mass. Directly between the two stars there is no gravitational pull in any direction. However there is potential gravity.

Is there an escape velocity? Locally there is no gravitational pull but once I try to escape the system I start feeling the sum of the gravitational pulls from all of the objects in the system. So the answer is yes ... the escape velocity is to escape from the system.

Lets go back to the time reversal. In all directions there is energy. Lets say we go back far enough where we extrapolate to the entire universe fitting in the size of solar system. We could calculate the escape velocity to escape to a place outside of this system. It can be easily calculated. However this velocity will be well beyond the speed of light. So although we can calculate the escape velocity GR says that it is not possible.

tommac
2009-Nov-19, 05:23 PM
Another way of thinking of it is this. With a black hole you can calculate its escape velocity. For a point on the EH its escape velocity = c. This can be derived from the equation
http://www.codecogs.com/eq.latex?Ug=\frac{-Gm_{1}m_{2}}{r}

The problem with this is m1 and m2 have to be treated as "body with a spherically-symmetric distribution of mass" The early universe has no region that could be defined like this. The problem is how do you define m1 and m2? m1 is the mass/energy of the universe of which m2 is included. Then you have the problem of defining r. Where is the centre of mass of the entire universe?.

Dont you have all of the same limitations when trying to calculate the escape velocity of a rocketship trying to escape from a black hole? I am confused? As far as I see it ... the only difference would be that m is signifigantly greater when using the universe. m1 would be the mass of the black hole including the rocketship and m2 would be the mass of the rocketship r is undefined ( i believe ).

NOTE: I am not saying the universe is in a black hole ... I am actually saying it is not ... however the reason you are giving above seems to jive regardless.

phunk
2009-Nov-19, 07:38 PM
However ... wouldnt the relativistic effects still exist regardless of is the whole universe is inside a situaltion where the gravitational density would warrent a black hole or not?

Regarding the bolded part... relative to what?

WayneFrancis
2009-Nov-20, 12:00 AM
Anywhere within the universe. Assuming that there is nothing outside of the universe you would be right. However ... wouldnt the relativistic effects still exist regardless of is the whole universe is inside a situaltion where the gravitational density would warrent a black hole or not?

I've tried to explain this in many ways and it still eludes you so here it is, simple answer.

NO! The fact is the effects inside the EN of a BH is NOT the same as the effects of being in a universe that is uniformly dense > 1.75875x1017kg/m3. It the black hole the there is a gravitational gradient in the early universe there is NO gradient.

Comprenez-vous?

let me say this a bit more
BH = gravitational gradient
Early Universe = NO gravitational gradient

BH != Early Universe

Early Universe != Early Universe

PERIOD. The early universe was NOT a BH. It didn't behave like a black hole because it wasn't a BH.

WayneFrancis
2009-Nov-20, 12:05 AM
The point here is that if you do a time reversal of the expansion of the universe ... it doesnt show what I would expect. Thus my confusion.

I would think that if you time reversed you would get to the point where the universe was a state of a black hole ( I get that everything is in the same state ... no slope ) A short time after ... everything is expanding and accelerating, rather than starting fast and slowing. I think this is actually Main Stream ... and accredited to Dark Energy ...

Point here is the universe doesn't have to work like you expect. It has been explained to you over and over that the universe was not in the state of a black hole. Only where you cherry pick pieces of information and disregard the rest of the picture can you say that the early universe is like a black hole.

Its kind of like me saying that I'm a world class athlete because I have muscles but disregard the fact that I'm not out training and strengthening those muscles to world class levels then throwing up my hands and saying "I don't understand why I'm not a world class athlete" mean while everyone is yelling at me "Exercise more!" and I keep ignoring them or just going "Yah, but I don't understand why I'm not a world class athlete, I've got muscles!"

WayneFrancis
2009-Nov-20, 12:28 AM
I dont know why you are talking about the early universe ... I am not. All I am talking about is taking our current observation and logically following through with a simple time reversal.

I'm coming close to getting infraction points here I can feel it.

If you reverse time then by definition you will be in a point earlier in the universe

Unless you want to explain how you can do time reversal and not get a condition like the universe was earlier on in its existence.



What we see now is that everything is expanding away from everything else and speeding up, in the time reversal everything would be getting closer together and slowing down. Are we agreed here?


Someone correct me if I'm wrong but I don't believe Ω has always been < 0

The inflation rate has changed a lot in the last 14.5 billion years both slowing down and speeding up.



At some point any observer in the universe would start feeling the gravitational effects of the other stuff in the universe as it gets closer and closer to the observer ... Do we still agree?


So? You are complaining about the the propagation of gravity might be =c in which case there will be items that are now causally disconnected that in the past where not? How does this help your case. Please show your maths because if you spent 15 minutes and actually did the maths you would see that it doesn't change the outcome if you raise the mass/energy of the entire system uniformly.



Now you are saying that the pull is in every direction. I agree with that. However what I claim is that even though the pull is in every direction ( leaving us with 0 directional pull ) but surrounded by potential gravity.
This is where I think we disagree.



Yes because you don't care to educate yourself in basic physics and instead prefer to go with your gut feel.

Being at the bottom of a gravity well means you have ZERO gravitational potential energy.



from http://hyperphysics.phy-astr.gsu.edu/HBASE/gpot.html
is energy an object possesses because of its position in a gravitational field.


Everything in the universe is at the same position in the gravitational field. Thus there is ZERO Gravitational Potential Energy



Are you saying that potential gravity is relative to the potential gravity surrounding you?


Ummm YES. If you can't fall deeper and release that energy then you are in a sense in the ground state for your gravitational potential.



Also note that the entire universe is inside of the same potential gravitational situation at a certain time ... however allong a timeline it is not. The further back in T one goes ( based on the reversal concept ) the greater the potential gravity should be.

You can't harness that power. It is the same everywhere.

Take a base ball and drop it. The energy release at impact ...where does that come from? It came from lifting that baseball out of the well in the first place.

You really have to learn basic physics Tommac. This is physics concepts that they teach in elementary school these days and my son had learn the maths for this at the start of this year (8th grade)

WayneFrancis
2009-Nov-20, 12:37 AM
Dont you have all of the same limitations when trying to calculate the escape velocity of a rocketship trying to escape from a black hole? I am confused? As far as I see it ... the only difference would be that m is signifigantly greater when using the universe. m1 would be the mass of the black hole including the rocketship and m2 would be the mass of the rocketship r is undefined ( i believe ).

NOTE: I am not saying the universe is in a black hole ... I am actually saying it is not ... however the reason you are giving above seems to jive regardless.

You are missing the point. The formula can't apply to the early universe.
The formula is the formula for gravitational potential energy.

By your own statement .


r is undefined ( i believe ).

r is undefined....thus you can't get an answer for some objects gravitational potential with regard to the rest of the universe. It is a nonsensical question.
You know the saying "There are no stupid questions just stupid people"? Well I say this is a stupid question. Your asking for a answer to a question that by your own admission on the components of the question will have NO ANSWER.

Again if you just spent a few minutes and did the maths you would quickly say


Gravitational Potential = http://www.codecogs.com/eq.latex?Ug=\frac{-Gm_{1}m_{2}}{r}
r is undefined...
Oh look that means there is no answer to "what is the gravitational potential of something inside of the universe in relation to the rest of the universe."

I'm not sure....ooops almost said something I'd get infraction points for.

You think that an energy density of 1.75875x1017kg/m3 = BH. It does NOT. It need not have any attributes of a BH other then its energy density.

You make this big leap that the early universe is some time reversed black hole and the logic does not actually follow.

tommac
2009-Nov-20, 08:24 PM
Regarding the bolded part... relative to what?
Relative to a different part of space with less gravity in a different time.

tommac
2009-Nov-20, 08:26 PM
The early universe was NOT a BH. It didn't behave like a black hole because it wasn't a BH.

Good then we finally agree. the early universe was definitely not a black hole.

tommac
2009-Nov-20, 08:31 PM
Point here is the universe doesn't have to work like you expect.
Please re-read my post. What I said was I was that when I started doing the math I expected the universe to have come from a BH state .... but what I found was that if you do a time reversal of the expansion of the universe that it actually shows some "anit-gravitational" effects ... a total opposite of a black hole.

I agree the universe didnt work like I expected.


It has been explained to you over and over that the universe was not in the state of a black hole. Only where you cherry pick pieces of information and disregard the rest of the picture can you say that the early universe is like a black hole.


You can explain it over and over and I will continue to agree with you over and over ... I 100% agree with you that the universe was not in the state of a black hole. I am not cherry picking ... I am 100% in agreement with you here ... not sure what the rest of the picture you are talking about.

captain swoop
2009-Nov-20, 08:39 PM
If we all agree then the question is answered, the early universe wasn't a black hole and reversing time won't make it one. Thread closed