shape of our universe theory and questions..

The non amateur stuff. Hawking, black holes, that sort of thing

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muddak
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Post by muddak »

davep wrote:
muddak wrote:Joe, concerning my theory being destroyed... not just yet.. after reading your post I did a quick search on the subject and here is an excerpt of an article found here : http://en.wikipedia.org/wiki/Black_hole
and this is what it says:
"On 21 July 2004 Stephen Hawking presented a new argument that black holes do eventually emit information about what they swallow,
You might also want to keep in mind this quote from Hawking himself:
http://physicsweb.org/articles/news/8/7/11/1 wrote:Hawking also dismisses his previous suggestion that the information might have leaked into a different "Baby" universe. "The information remains firmly in our universe," he told the conference. "I am sorry to disappoint science fiction fans, but if information is preserved, there is no possibility of using black holes to travel to other universes. If you jump into a black hole, your mass energy will be returned to our universe, but in a mangled form which contains the information about what you were like, but in an unrecognisable state."
Davep, if you re-read what I have writen to Joe, I am not talking about different universes, but different "Dimensions" in one universe, "our" universe, "the" universe... so even if Hawking dissmisses something about "baby" universes, it still does not affect my suggestion that there could be exchanges between different dimensions.
davep wrote:
muddak wrote:and does my use of the word "shape" not adequately represent what something would look like if we were to see it?
I'm not sure it does. What do you mean by "see it"?
we humans have organs that permit us to appreciate nature surrounding us. One of those organs is our eyes... would it not be fascinating to visualize the limit or limits of this dimension that surrounds us and that we cannot cross? What I mean by "see it" is satisfying my curiosity about things that we do not understand...
davep wrote:
muddak wrote:I also read that a black whole can be created from one single start or from a cluster of stars this means that what is important is the total mass of one area in space, if the accretion disk is massive enough or the mass of the area is massive enough, they would keep the black hole open until that mass has been completly absorbed and redistributed...
What do you think the significance of this is and how does it fit in with what you've said previously?
my answer was directed at a question Joe asked me on that subject read his post...
davep
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Post by davep »

muddak wrote:Davep, if you re-read what I have writen to Joe, I am not talking about different universes, but different "Dimensions" in one universe, "our" universe, "the" universe... so even if Hawking dissmisses something about "baby" universes, it still does not affect my suggestion that there could be exchanges between different dimensions.
Information would seem to be the key point here.
muddak wrote:
davep wrote:What do you mean by "see it"?
we humans have organs that permit us to appreciate nature surrounding us. One of those organs is our eyes... would it not be fascinating to visualize the limit or limits of this dimension that surrounds us and that we cannot cross? What I mean by "see it" is satisfying my curiosity about things that we do not understand...
Right, but one shouldn't conflate "see" and "visualise". You yourself say "cannot cross" -- hence the question.
muddak wrote:
davep wrote:What do you think the significance of this is and how does it fit in with what you've said previously?
my answer was directed at a question Joe asked me on that subject read his post...
It isn't clear which part of Joe's post you were responding to, hence the question.
GordonCopestake
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Post by GordonCopestake »

My thoughts on the matter:

Even if a blackhole was a door way to another universe, or a seperate "baby" universe itself, it would be impossible to travel "through" the blackhole as the vast tidal forces are sufficent to destroy any structured matter that gets close to the event horizon.

On communication from "the other side" as nothing can escape the blackhole, no particles or radiation can be passed from one "side" to the other. However there maybe workarounds for this using quantum entaglement between two particles to transmit information.

The accretion disc is gas that is attracted by the blackhole and "orbits" the hole. accretion discs form in binary star systems where one body has colapsed to form a singularity and "steals" matter from it's partner. As binary stars are quite common, lots of black holes have accretion disc. As the gas rotates the hole friction causes vast temperatures which is why we can see the disc at all. The gas orbiting the blackhole gets pulled in when it's orbit becomes unstable, maybe due to it's partner stars influence. As for the accretion disc jets we just dont know why they form. Probably some magnetic function of the hole, but they certanly DONT come from the hole itself.

On the size and shape of the universe, my own opinions give 2 answers.

1) the universe is infinite and has no end. Personally i dislike this theory, especially when we have a date for the beginning, at 13.7bn years ago, however the universe is over 13.7bn ly across as far as we can tell. So light starting out at one end still hasn't got to the other end. Which to me means that the universe IS infinite, at least for all practical purposes.

2) the universe isn't infinite. Which dictates that it has some boundry or edge. Again i dislike this theory as it smacks of sci-fi from the 40's when spaceships would come against some invisible wall and bump against it like a glass bottle. Inevitably this begs the question: what's on the other side of the wall? Most peeople wont be happy with the answer "nothing".

3) there is a 3rd answer which is a mixture of the other 2, where the universe is finite, but has no boundry or edge. Consider a sphere to a flatlander, there is no edge or boundry but you can walk forever, and if you walk far enough you can start back where you began. This seems the most likely explaination to my feeble mind. The universe is a sphere only in higher dimentions. A 4-sphere perhaps. or a 6-sphere. or a 27-sphere...

I recently read an article in the New Scientest on Burkhard Heim. Very interesting and reccomended reading for popular science fans like myself. Online article here

It's questions like these that keep you up at night hehe
Cliff
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Post by Cliff »

Dear al
With regards to the shape of the universe. A very very rough approximate calculation suggests that changing the scale of the universe such that Messier 31 is at the same distance from Manchester as London. (Needless to say I picked Manchester because I live thereabouts), then at that sort of scale the Earth would be in the rough order of a thousandth of an inch away from the Sun. So deciding about the shape of the universe, assuming the universe does have a shape (?) in the accepted sense, might be akin to an electron discussing with the nucleus to which it is associated, as to whether the woman that they are in the middle of is ugly or beautiful.
Best wishes from Cliff
joe
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Post by joe »

Cliff,

We are not worthy.
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davep
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Post by davep »

GordonCopestake wrote:I recently read an article in the New Scientest on Burkhard Heim. Very interesting and reccomended reading for popular science fans like myself. Online article here
You should probably see this post and onwards.
Cliff
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Post by Cliff »

Dear Joe
I just finished reading Warped Passages.
Best wishes from cliff
joe
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Post by joe »

Congratulations Cliff. I am looking forward to getting stuck in myself but I have to finish "The Extended Phenotype" by Richard Dawkins first. Perhaps at the end of it all I will have all the answers. What were the questions again? :?
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Moonstruck
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Post by Moonstruck »

The button I just pressed said "post reply",I would not dare.
If there is a something (black hole) in universe, which takes up an amount of space,such as a star does.And for simplicities sake lets say that we can only see one side, as with the moon, is this not the same with black holes.In other words some time or other we will be able to get information from round the back of a black hole?
Think I better creep back under my rock and go back to sleep. :oops:
Management has just read this and sumed up ," So much gobble-de-gog", said she.
Still going to post though.
davep
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Post by davep »

Moonstruck wrote:In other words some time or other we will be able to get information from round the back of a black hole?
What sort of "information"?
Moonstruck
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Post by Moonstruck »

Gosh Davep,that was a quick response.Only just had time to nip round to the offlicence.
Space probes gave us a view of back of the moon, so, is there not a back door to black holes? Asumming black holes take up some sort of space within the universe?
Cliff
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Post by Cliff »

Dear Joe
Thanks for sending me the congratulations.
I think I thoroughly deserve it. I hope you enjoy the Dawkins book. I quite like to see him on the telly occasionally but that is as far as it goes.
Best wishes from Cliff
davep
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Post by davep »

Moonstruck wrote:Space probes gave us a view of back of the moon,
That only seems significant because the Moon has synchronous rotation. If it didn't then you wouldn't need probes to look at the far side. You might as well have said "if I turn around I can see the horizon I couldn't see a moment ago".
Moonstruck wrote:so, is there not a back door to black holes? Asumming black holes take up some sort of space within the universe?
What do you mean by "back door"? Given your analogy, do you think that the Moon has a "back door" that is somehow special?
spodzone
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Post by spodzone »

Moonstruck wrote: Asumming black holes take up some sort of space within the universe?
What are you considering to be a black hole? The gravitationally-collapsed mass that's become a point singularity, the Schwartzschield radius within which we will never know anything (since the escape-velocity >= c there), edge-effects of virtual anti-/particle pairs where one half falls into the hole, or well-cooked matter orbitting past close-by?

I would have thought it clear that only the latter stands any chance of you ever seeing radiation emitted from the other "side" of the hole, for obvious reasons.
Last edited by spodzone on Fri Jan 20, 2006 7:03 pm, edited 1 time in total.
~Tim
joe
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Post by joe »

Moonstruck wrote:Space probes gave us a view of back of the moon, so, is there not a back door to black holes? Asumming black holes take up some sort of space within the universe?
Space probes would be able to do all that they do when they orbit the Moon, that is, they would be able to travel around and about the black hole. They would be able to "see" it from any angle or side. What they wouldn't be able to do though is to see whatever is beyond the event horizon. This is the point where nothing can escape, it is black for this reason. That is why we cannot find out what is happening inside. The black hole that everyone is familiar with is a black sphere, but that blackness is a lack of something, there is nothing there. Theory has it that at the centre is a singularity where known physical laws break down therefore we don't even know what is happening there either.
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