Space versus energy

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  • #26
Chronos
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  • #27
turbo
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Mike2 said:
I'm getting a Browser bug report from amazon. Could you supply titles please? Thanks.
Interesting, I get that when following the link I posted! Just go to Amazon and search on information theory and you'll get lots of suggestions. You might wander over to a college bookstore near you and browse the used textbooks - probably a lot cheaper, and you'll get to see if the subject is presented in a manner that you're comfortable with.
 
  • #28
turbo
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Chronos said:
Application of information theory to cosmological modeling is fairly common. Here are some links. The last paper is a bit off subject, but, you may find it interesting.
http://arxiv.org/abs/gr-qc/0402076
http://arxiv.org/abs/astro-ph/0310522
http://arxiv.org/abs/astro-ph/0309435
http://arxiv.org/abs/hep-th/0308165
http://arxiv.org/abs/cond-mat/0207707
http://arxiv.org/abs/gr-qc/0312078
http://arxiv.org/abs/astro-ph/0408014
That last paper may be "a bit off subject" but it is apropriate. Pseudo-scientists like William Dembski love manipulating information theory to "prove" Creationism - leave it to Davies to provide a cogent retort.
 
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turbo-1 said:
This may sound goofy, but if the Loop Quantum Gravity folks are on the right track, space-time comes in discrete units quantized at the Planck level, and they will either have to distort or spontaneously arise to accomodate cosmological expansion.
I seem to remember reading this last year in an issue of Science magazine that some recent observational evidence implies that space-time is not quantized. I think the title of the piece was something like "Einstein is Right Again."
 
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Here's a summary of the article which was in the 29 August 2003 issue of Science:

"Einstein 1, Quantum Gravity 0

Adrian Cho

Physicists have hoped that a flaw in Einstein's special theory of relativity might reveal that space and time aren't smooth at the smallest scale, but fuzzy and foaming. Now, two independent measurements of cosmic gamma rays show that Einstein was right after all--and that current plans to detect the foam are doomed."
 
  • #31
Nereid
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GR rules, OK?

The inspiring (depressing?) thing about good ol' Uncle Al is that the ever-growing body of experimental results continues to be consistent with GR! Or, saying the same thing in another way, the domain in which GR and QM will clearly show their mutual inconsistency remains beyond that which we can (and are likely to be able to) probe.
 
  • #32
Chronos
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Nereid said:
The inspiring (depressing?) thing about good ol' Uncle Al is that the ever-growing body of experimental results continues to be consistent with GR! Or, saying the same thing in another way, the domain in which GR and QM will clearly show their mutual inconsistency remains beyond that which we can (and are likely to be able to) probe.
Frustrating, is it not? I often wonder how big the mountain must be before even the Sherpa's question the possibility of conquering a new peak.
 
  • #33
Chronos
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turbo-1 said:
That last paper may be "a bit off subject" but it is apropriate. Pseudo-scientists like William Dembski love manipulating information theory to "prove" Creationism - leave it to Davies to provide a cogent retort.
Appropriate to what? Mike2 asked for some information relevant to his questions. I missed the part where anyone brought up 'creationism' as an issue.
 
  • #34
turbo
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Chronos said:
Appropriate to what? Mike2 asked for some information relevant to his questions. I missed the part where anyone brought up 'creationism' as an issue.
Appropriate in the sense that information theory (which was being discussed) is used to "prove" lif is emergent. Information theory is the tool of choice for Dembski, and to make it work for him, he puts some interesting constrants on what can be construed as information. Davies used the same tool with entirely different results, to "prove" life is emergent. If you Google "conservation of information" you will see some interesting links, and you will see why I emphasized the importance of defining "information".
 
  • #35
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Mike2 said:
I assume that every physical structure can be described mathematically with equations. And it would seem that there is a procedure for extracting the information in a function. Normally, information is calculated for probability distributions with an integral functional. So I suppose that the same technique could be used on any function as long as it were possible to normalize it by dividing it by the average. This means that the functions involved would have to be well behaved, not going to infinity, or at least integrable if they do. And I think this is true for any formulas of physics. Is this right?

What is remarkable about this hypothesis is that it may predict the "existence" of quantum mechanical alternatives so that the choice of some structure would equal the inherent information of that structure. Could it be any other way? Can you say that some structure has inherent information value without also saying that this mean that there must have been alternatives somewhere to chose it from? Is this a kind of extrinsic information equals intrinsic information law? Isn't information equal to information no matter how you look at it?

Do you know if there is any book about all this?
Use of information theory in quantum physics is surprisingly sophisticated. There are, of course, some inherent difficulties, but, less so than you might imagine. I don't know of any books, offhand, but there sure are some good papers. I have a couple more links that might be closer to the heart of your questions. Here is a old one.
http://arxiv.org/abs/gr-qc/9610075
Here is a more recent submission
http://arxiv.org/abs/gr-qc/0306081
Here is one I am particularly fond of
http://arxiv.org/abs/hep-th/0405160
 
  • #36
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marcus said:
I have to say it. that is one helluva profound question. space may itself require some kind of energy in order to exist.
there may be no such thing as an absolute, inert, space which can exist in a purely static way

and if space arises dynamically---that means it involves energy

this question you asked is confusing to think about----maybe I am going about it wrong----maybe you meant to ask something very simple


However I think the question has to be addressed in the context of some theoretical framework that gives a little bit more definition to the ideas of energy and volume.

In Gen Rel, space is the gravitational field and the gravitational field is what gives meaning to things like areas and volumes.
if the field is zero in some region, then that region could not have any volume
You may find these interesting
http://arxiv.org/abs/gr-qc/0405012
http://arxiv.org/abs/gr-qc/0312040
 
  • #37
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I think you get my meaning

marcus said:
I have to say it. that is one helluva profound question. space may itself require some kind of energy in order to exist.
there may be no such thing as an absolute, inert, space which can exist in a purely static way

and if space arises dynamically---that means it involves energy

this question you asked is confusing to think about----maybe I am going about it wrong----maybe you meant to ask something very simple


However I think the question has to be addressed in the context of some theoretical framework that gives a little bit more definition to the ideas of energy and volume.

In Gen Rel, space is the gravitational field and the gravitational field is what gives meaning to things like areas and volumes.
if the field is zero in some region, then that region could not have any volume
I have noticed many contradictions in alot of material I've read over the years and I have not found a consensus that supports a particular position. It seems to me that conceptual thinking would require a definite position on this matter. Personally, I've had problems dating back to the early 60's in viewing vacuum space as a volume of "nothing" as was the mainstream thinking at that time and may still be today? Which was my reason for asking the question here.

In any case, I believe one may view everything as matter or everything as a wave function and complications only arise when you try to formulate one general description using both.

Thanks for the help guys(gals).
 

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