Re: Dark Matter, dark eneggy, & conservation
If we are now observing acceleration, that means there was Inflation (huge acceleration) and then a huge reduction in acceleration. So, what bled off the extra original acceleration momentum? Or countered it? Are we do believe that this 'dark matter' which is out there 'increasing acceleration' is also responsible for the phase of 'decelerating acceleration' that had to have been in place prior to the current cosmological era??! James
Re: Dark Matter, dark eneggy, & conservation
On 3 Nov 2003 at 16:45, Joao Leao wrote: > Part II: > >It is not the distance that contributes, it is the > > relative rate of expansion that contributes to the apparent redshift > > (all other factors that can contribute to redshift being ignored for > > the purpose of concentrating only on the affect caused by inflation > > itself). The further something is away from us, relatively speaking, > > then the faster it is moving away from us. With inflation being on > > an > > > > ever increasing rate, there comes a point in finite time when the > > expansion rate reaches a level that causes the entire universe to > > appear dark and at absolute zero in temperature in reference to all > > its matter relative to itself. > > If the acceleration persists, which is may or not be the case, that is > surely a possibility, depending on some other features of the > concordance model being verified or not. But we are still not sure > that the acceleration is forever... That's both an astonishing and maybe just a little bit of a scary thought. Is there some hint of any kind that the acceleration of the universe might have a limiting factor? > > In other words, the redshift at all points within the universe will > > have shifted to a level of absolute zero observable energy at some > > future time because the universe is then expanding (at every point > > within itself) at or beyond a rate that would allow energy to find > > anything in the universe that it could be relative to. > > I don't quite understand this last sentence. Assume that at some distant time the inflation rate of space/time has exceeded the speed of light. At that moment, and forever thereafter, no particle within that inflation region could interact with another - - because the distance between particles is increasing faster than a particle can transverse any distance at the speed of light or below. That leads to the conclusion that the affected particle is then no longer relative to anything but itself. As far as that affected particle is concerned it IS the entire universe and nothing else exists. This of course is an illusion, from the larger viewpoint of the meta universe. But I argue that when the particle becomes in that way relative only to itself then it has in fact melded with the meta universe, meaning that its energy has in fact returned to the meta universe from which it was spawned during the big bang. >But it may be worth > pointing > out that dark energy is uniformely and isotropically distributed so > that It is? That would infer a homogeneous distribution of energy that does not appear to hold true with any other observation of the universe. If the big bang had resulted in an observable universe that is uniform in structure or composition throughout then one might expect the same of dark energy, but this does not appear to be the case. I would argue that when/if we are able to measure (as opposed to just infer) dark energy then we will find it to be distributed in much the same way as is energy that we can now measure. > it seems to be something akin to the largest scales of matter/energy > distribution, for example, inertial mass distibution (dark and lit) or > better still, curvature or torsion. There are several models of DE > proposed along these lines... Perhaps. As you say, it's too early to know. But our closed universe has of late been attributed to have a shape that is NOT a smooth spheroid. Amazingly, it appears to be composed of interlocking shapes that are not that of a sphere, but because the universe is closed the aggregate appearance is theat of a non smooth spheroid. Maybe this is not so amazing, since no perfect sphere seems to exist in nature. > > In that > > situation a particle would never be able to travel from any point A > > to any point B, although it might try to do so for as long as it > > existed. Eventually the particle could no longer exist, because it > > itself would loose coherency as its integral parts moved away from > > each other as a consequence of the space it occupies continuing to > > inflate, and thereby move its parts away from each other until > > nuclear forces could no longer maintain the attraction that keeps > > the > > > > particle (of any type whatsoever) from totally disintegrating. > > Well, I can't quite make out what you are saying here! I don't think > the "integrity of particles" is threteaned by universal acceleration. Perhaps not if indeed a particle, once the inflation rate has reached a rate relative to a particle so that the particle can no longer itneract with any other particle, then the particle has indeed melded with an thereby returned its energy to the meta universe from which it originated to begin with. But if it does not, then ALL points in space relative to that particle, including at all points within and exterior to the particle, keep increasing in expansion rate. In that case the distance between b
Re: Request for a glossary of acronyms
At 16:54 05/11/03 -0500, Jesse Mazer wrote: Hal Finney wrote: One correction, in the descriptions below I should have said multiverse for all of them instead of universe. The distinction between the SSA and the SSSA is not multiverse vs universe, it is observers vs observer- moments. I'll send out an updated copy when I get some more links and/or corrections and new definitions. Hal > SSA - The Self-Sampling Assumption, which says that you should consider > yourself as a randomly sampled observer from among all observers in the > multiverse. > > SSSA - The Strong Self-Sampling Assumption, which says that you should > consider this particular observer-moment you are experiencing as being > randomly sampled from among all observer-moments in the universe. > > ASSA - The Absolute Self-Sampling Assumption, which says that you should > consider your next observer-moment to be randomly sampled from among all > observer-moments in the universe. > > RSSA - The Relative Self-Sampling Assumption, which says that you should > consider your next observer-moment to be randomly sampled from among all > observer-moments which come immediately after your current observer-moment > and belong to the same observer. In your definition of the ASSA, why do you define it in terms of your next observer moment? Wouldn't it be possible to have a version of the SSA where you consider your *current* observer moment to be randomly sampled from the set of all observer-moments, but you use something like the RSSA to guess what your next observer moment is likely to be like? Also, what about a weighted version of the ASSA? I believe other animals are conscious and thus would qualify as observers/observer-moments, which would suggest I am extraordinarily lucky to find myself as an observer-moment of what seems like the most intelligent species on the planet...but could there be an element of the anthropic principle here? Perhaps some kind of theory of consciousness would assign something like a "mental complexity" to different observer-moments, and the self-sampling assumption could be biased in favor of more complex minds. Likewise, one might use a graded version of the RSSA to deal with "degrees of similarity", instead of having it be a simple either-or whether a future observer-moment "belongs to the same observer" or not as you suggest in your definition. There could be some small probability that my next observer-moment will be of a completely different person, but in most cases it would be more likely that my next observer-moment would be basically similar to my current one. But one might also have to take into account the absolute measure on all-observer moments that I suggest above, so that if there is a very low absolute probability of a brain that can suggest a future observer-moment which is very similar to my current one (because, say, I am standing at ground zero of a nuclear explosion) then the relative probability of my next observer-moment being completely different would be higher. Again, one would need something like a theory of consciousness to quantify stuff like "degrees of similarity" and the details of how the tradeoff between relative probability and absolute probability would work. In my opinion, and if I understand Jesse Mazer properly, he is right. Now, with the comp. hyp. you have (obviously) constraints coming from computer science (itself related to number theory including universal one not depending of any particular implementation). A theory of consciousness which suits well both the traditional thought experiment (self-duplicability) and self-referential discourse can be extracted from what a machine can, in general, correctly bet on its possible consistent computational extensions. That moves corresponds to comp-immortality, we just don't take into account the cul-de-sac worlds, (which corresponds to the world with no more accessible worlds in the Kripke semantics of the logic of self-reference). It is the move going from the logic of machine-provability to the logic of machine "provability & consistency", or the move from []p to a *new* box defined by []p&-[]-p. From this (when p is restricted on the DU accessible proposition), (the $\Sigma_1 proposition for the logicians), you get A quantum logic, from which you get, I think, the similarity relations you are searching. (This because from the yes/no quantum logic you can derive an angle of PI/2 radians, and from that angle you can derive all the angles, well if THAT quantum logic behaves sufficiently well, and that's not yet clear at this point. Of course at this point things are rather technical. Just to make a link with what Hal Finney said, I have provide indeed an argument showing that if we (I) are machine then physics comes from computer science, but I have also provide the more technically involved arithmetical translation of that argument in the language of a "mean" self-referentially consistent universal Tu
Re: Request for a glossary of acronyms
At 09:24 06/11/03 +0100, Alberto Gómez wrote: For me there is no bigger step between to wonder about how conscience arises from a universe made by atoms in a Newtonian universe, particles in a quantum universe, quarks in a quantum relativistic universe and finally, superstring/n-branes in a 11 dimensional universe for one side and, on the other side, to wonder about how SAS in a complex enough mathematical structure can have a sense of conscience. I agree. It is a genuine point. [SNIP] That must be true either in our "physical" world or the world of a geometrical figure in a n-dimensional spacetime, or in a computer simulation defined by a complex enough algorithm (These three alternative ways of describing universes may be isomorphic, being the first a particular case or not. The computability of our universe doesn't matter for this question). I disagree, because if you take the comp. hyp. seriously enough the physical should emerge as some precise modality from an inside view of Arithmetical Truth. See UDA ref in Hal Finney's post. So the mathematical existence, when SAS are possible inside the mathematical formulation, implies existence (the expression "physical existence" may be a redundancy) Same remark. What you say is not only true, but with comp it is quasi-constructively true so that you can extract the logic and probability "physical rules" in computer science (even in computer's computer science). making the comp. hyp. popper-falsifiable. But, for these mathematical descriptions to exist, it is necessary the existence of being with a higher dimensionality and intelligence that formulate these mathematical descriptions? That is: every mathematical object does exist outside of any conscience? The issue is not to question that "mathematical existence (with SAS) implies physical existence", (according with the above arguments it is equivalent). The question is the mathematical existence itself. Now, it is fact, the failure of logicism, that you cannot define integers without implicitely postulating them. So Arithmetical existence is a quasi necessary departure reality. It is big and not unifiable by any axiomatisable theory (by Godel). (axiomatizable theory = theory such that you can verify algorithmically the proofs of the theorems) I refer often to Arithmetical Realism AR; and it constitutes 1/3 of the computationalist hypothesis, alias the comp. hyp., alias COMP: COMP = AR + CT + YD(Yes, more acronyms, sorry!) AR = Arithmetical Realism (cf also the "Hardy post") CT = Church Thesis YD = (I propose) the "Yes Doctor", It is the belief that you can be decomposed into part such that you don't experience anything when those parts are substituted by functionnaly equivalent digital parts. It makes possible to give sense saying yes to a surgeon who propose you some artificial substitution of your body. With COMP you can justify why this needs an irreductible act of faith (the consistency of COMP entails the consistency of the negation of COMP, this is akin to Godel's second incompleteness theorem. It has nothing to do with the hypothesis that there is a physical universe which would be either the running or the output of a computer program. Hal, with COMP the "identity problem" is tackled by the venerable old computer science/logic approach to self-reference (with the result by Godel, Lob, Solovay, build on Kleene, Turing, Post etc...). I will comment Jesse's post later, because I must go now. Bruno
Re: SAS and mathematical existence
On Thursday, November 6, 2003, at 01:24 AM, Alberto Gómez wrote: But, for these mathematical descriptions to exist, it is necessary the existence of being with a higher dimensionality and intelligence that formulate these mathematical descriptions? That is: every mathematical object does exist outside of any conscience? The issue is not to question that "mathematical existence (with SAS) implies physical existence", (according with the above arguments it is equivalent). The question is the mathematical existence itself. I think Tegmark's level 4 explains-away any fine tuning of our understanding of math/physics by allowing infinite sets (MWI).. every conscience observer may wonder why their maths are setup just right. In the universes which have magical math that lacks whatever consistency evolution needs - there are presumably no observers.
SAS and mathematical existence
For me there is no bigger step between to wonder about how conscience arises from a universe made by atoms in a Newtonian universe, particles in a quantum universe, quarks in a quantum relativistic universe and finally, superstring/n-branes in a 11 dimensional universe for one side and, on the other side, to wonder about how SAS in a complex enough mathematical structure can have a sense of conscience. Conscience has evolutionary advantages in biological terms, and probably the conscience will emerge, with time, in any description in which the rules permit a replication-with-variations/selection and where one objects feeds from others. It doesn't matter if the description is made of n-branes in 11 dimensional spaces or in any other mathematical/algorithmical construct. These self aware structures in their particular space-time will describe trajectories in which a superintelligent and supradimensional observer could see, inside the SAS, some components: neurons, or alike, that shows signs of troughs about themselves and the rest of their world in a way that interactions between SAS will depend on the changes of their brains -or something like brains-. This is the most that an external observer can experience about the conscience of other beings. These beings will think, so they will exist -and they will think that they exist, that is crucial - . That must be true either in our "physical" world or the world of a geometrical figure in a n-dimensional spacetime, or in a computer simulation defined by a complex enough algorithm (These three alternative ways of describing universes may be isomorphic, being the first a particular case or not. The computability of our universe doesn't matter for this question). So the mathematical existence, when SAS are possible inside the mathematical formulation, implies existence (the expression "physical existence" may be a redundancy) But, for these mathematical descriptions to exist, it is necessary the existence of being with a higher dimensionality and intelligence that formulate these mathematical descriptions? That is: every mathematical object does exist outside of any conscience? The issue is not to question that "mathematical existence (with SAS) implies physical existence", (according with the above arguments it is equivalent). The question is the mathematical existence itself.
Re: Quantum accident survivor
On Tuesday, November 4, 2003, at 10:47 AM, Eric Cavalcanti wrote: Let me stress this point: *I am, for all practical purposes, one and only one specific configuration of atoms in a specific universe. I could never say that ' I ' is ALL the copies, since I NEVER experience what the other copies experience. The other copies are just similar configurations of atoms in other universes, which shared the same history, prior to a given point in time.* I would consider these other copies entirely equal to myself IF AND ONLY IF they are succeeding RSSA observer-moments. Glossary references : ) RSSA - The Relative Self-Sampling Assumption, which says that you should consider your next observer-moment to be randomly sampled from among all observer-moments which come immediately after your current observer-moment and belong to the same observer.
