Re: Quantum accident survivor
I have always found the RSSA rather strange. From the discussion between Mallah and Maloney: http://www.escribe.com/science/theory/m1362.html one must first define you. There are three reasonable possibilities in the ASSA: 1. One particular observer-moment. You have no past and no future. 2. A set of observer moments linked by computation. With this definition the problem is that you may be two (or more) people at the same time! The advantage with this definition is that one can predict effective probabilities of what you will see at other times similar to what you want to do with the RSSA. Thing is, if there is nonconservation of measure, the predictions start to differ from the RSSA about things like how old you should expect to be. Remember, testable prediction do NOT depend on definitions, so it is often better to use def. #1 to prevent such confusion. 3. A particular implementation of an extended computation. Similar to 2; allows death, when that implementation ends. I prefer this or #1. #1 seems the most reasonable option to me. You do away with the reference class problem. Also it is fully consistent with ''normal'' physics. Saibal - Oorspronkelijk bericht - Van: Russell Standish [EMAIL PROTECTED] Aan: Saibal Mitra [EMAIL PROTECTED] CC: [EMAIL PROTECTED] Verzonden: Sunday, November 02, 2003 05:45 AM Onderwerp: Re: Quantum accident survivor I disagree. You can only get an effect like this if the RSSA is invalid. You've been on this list long enough to remember the big debates about RSSA vs ASSA. I believe the ASSA is actually contrary to experience - but never mind - in order to get the effect you want you would need an SSA that is neither RSSA nor ASSA, but something *much* weirder. Cheers Saibal Mitra wrote: There have been many replies to this. I would say that you wouldn't expect to survive such accidents. Assume that we are sampled from a probability distribution over a set of possible states. E.g. in eternal inflation theories all possible quantum states the observable universe can be in are all realized, so all possible situations you can be in, do occur with some finite probability. In such theories you ''always'' exist. But this doesn't mean that if you are Mohammed Atta saying your prayer just before impact with the WTC, your next experience is that the plane has tunneled through the WTC without doing any harm. This is because there are many more Mohammed Attas in the universe that do not have this experience. So, you would ''survive'', but in a different branch with memory loss plus some aditional ''false'' memories. In that branch you wouldn't have been in that plane to begin with. You should think of yourself at any time as if you were chosen by a random generator sampled from a fixed probability distribution over the set of all possible states you can be in. The state that corresponds to you have experienced flying through the WTC is assigned an extremely small probability. How does this square with the normal experience of continuity through time? Well, every ''observer moment'' as chosen by the random generator has a memory of past experiences. So, if you go to bed now and wake up the next morning, you have the feeling of continuity, but this is only because the person waking up has the memory of going to bed. You could just as well say that the person going to bed survives in any one of the possible states he can be in. The state that happens to have the memory of going to bed is just one of these possible states. That particular state has the illusion of being the continuation of the first state. Oorspronkelijk bericht - Van: David Kwinter [EMAIL PROTECTED] Aan: [EMAIL PROTECTED] Verzonden: Friday, October 31, 2003 02:58 AM Onderwerp: Quantum accident survivor Another quickie: Assume I survive a car/plane crash which we assume could have many different quantum outcomes including me (dead || alive) Since I was the same person (entire life history) up until the crash/quantum 'branch' - then can't I assume that since there was at least one outcome where I survived, that TO ME I will always survive other such life/death branches? Furthermore if I witness a crash where someone dies can I assume that the victim will survive in their own world so far as at least one quantum branch of survivability seems possible? David Kwinter -- -- A/Prof Russell StandishDirector High Performance Computing Support Unit, Phone 9385 6967, 8308 3119 (mobile) UNSW SYDNEY 2052 Fax 9385 6965, 0425 253119 () Australia[EMAIL PROTECTED] Room 2075, Red Centre http://parallel.hpc.unsw.edu.au/rks International prefix +612,
Re: Quantum accident survivor
Dear Saibal and Russell, Does not this entire notion of quantum immortality assume some kind of mind/body dualism in that the mind, consciousness, is independent of the particular physical circumstances? There must be some way for the Moments, specifiec in #1, to be strung together in a first person way. This is, IMHO, strongly implied in Marchal's ideas using the UD. Even Barbour's time capsules imply this. I must confess to a bias toward dualistic models, particularly Vaughan Pratt's Chu space transform based idea, but this is something that is implied but does not seem to ever be discussed. Why? Stephen - Original Message - From: Saibal Mitra [EMAIL PROTECTED] To: Russell Standish [EMAIL PROTECTED] Cc: [EMAIL PROTECTED] Sent: Monday, November 03, 2003 7:27 AM Subject: Re: Quantum accident survivor I have always found the RSSA rather strange. From the discussion between Mallah and Maloney: http://www.escribe.com/science/theory/m1362.html one must first define you. There are three reasonable possibilities in the ASSA: 1. One particular observer-moment. You have no past and no future. 2. A set of observer moments linked by computation. With this definition the problem is that you may be two (or more) people at the same time! The advantage with this definition is that one can predict effective probabilities of what you will see at other times similar to what you want to do with the RSSA. Thing is, if there is nonconservation of measure, the predictions start to differ from the RSSA about things like how old you should expect to be. Remember, testable prediction do NOT depend on definitions, so it is often better to use def. #1 to prevent such confusion. 3. A particular implementation of an extended computation. Similar to 2; allows death, when that implementation ends. I prefer this or #1. #1 seems the most reasonable option to me. You do away with the reference class problem. Also it is fully consistent with ''normal'' physics. Saibal - Oorspronkelijk bericht - Van: Russell Standish [EMAIL PROTECTED] Aan: Saibal Mitra [EMAIL PROTECTED] CC: [EMAIL PROTECTED] Verzonden: Sunday, November 02, 2003 05:45 AM Onderwerp: Re: Quantum accident survivor I disagree. You can only get an effect like this if the RSSA is invalid. You've been on this list long enough to remember the big debates about RSSA vs ASSA. I believe the ASSA is actually contrary to experience - but never mind - in order to get the effect you want you would need an SSA that is neither RSSA nor ASSA, but something *much* weirder. Cheers snip
Re: Dark Matter, dark eneggy, conservation
Wow Ron! That is a lot of answer for me! I will have to split mine in two installments if you don't mind. Ron McFarland wrote: Thank you list for the welcome. I look forward to many congenial debates! I am sorry but you seem to contradict yourself below! You state, quite correctly as far as I can tell, what the outcome of the most recent cosmic observations on our universe is. But them you state that Neither dark energy nor dark matter has been proven by experiment or measurement to exist. Both seem as pure postulates at this writing. Both dark matter and dark energy express little more than our puzzling with two sets of consistently observed effects which we aren't able to accommodate in the so-called concordance model of standard cosmology. What these terms designate are not (yet) definite entities so it is a bit early to even call them postulates. Theorists have sought to explain these effects along several distinct hypothetical lines but the word is still out on which one of those will prevail. Correct, and I did not define my terms. I am not sure I follow you here. Your terms are surely not the conventional ones, but that is not necessarily objectionable. Let us see... By postulate I mean the expression of an idea not yet represented by a defining mathematical statement. In that case I can't agree that dark matter and dark energy are postulates. They both have no lack of mathematical expression, the problem is that we don't really know which one describes them fully or integrates with what else we know. By theory I mean an idea supported by mathematical statement but not yet verified in all possible ways by apparent empirical evidence. Again there are serveral many theories (called scenarios) that try to account for either one, and they all aim to match the available empirical evidence. But, as data from better probes comes along, the small disparity between the scenarios should favor some over others. That is already the case, for example, when you compare the WMAP data with the Type Ia supernova surveys, for dark energy evidence... By law I mean an idea supported by a mathematical statement that can not be ruled out by empirical evidence. I am not sure that you can say that about any law of physics with much conviction. Conservation laws are associated with global symmetries and even these can be broken (think of Parity and CP for example), and consequentially ruled out by empirical evidence. To me, dark energy seems to be the more important postulate. It appears to me that if the universe will forever keep expanding at an ever increasing rate then within a non infinite time period no elementary particle of matter will be able to interact with another. Will get to the other part later... -Joao -- Joao Pedro Leao ::: [EMAIL PROTECTED] Harvard-Smithsonian Center for Astrophysics 1815 Massachussetts Av. , Cambridge MA 02140 Work Phone: (617)-496-7990 extension 124 Cell-Phone: (617)-817-1800 -- All generalizations are abusive (specially this one!) ---
Re: Dark Matter, dark eneggy, conservation
On 3 Nov 2003 at 10:18, Joao Leao wrote: Wow Ron! That is a lot of answer for me! I will have to split mine in two installments if you don't mind. My apology for the length of the answer. The answer was for the most part a restatement of something I wrote and was aired on radio over a decade ago, a Billy something Show that was out of Nevada (I had to string a long wire to receive it!) and which was very similar to the now very popular CoastToCoastAM.com related international radio show that airs nightly in most cities (and which sometimes guests very respectable scientists).. Although I claim absolutely no credit for any or the ideas expounded upon by myself then or now, I do not find much in the way of inconsistancy with the general ideas expressed by the very qualified people who came up with the ideas that I merely attempt to assemble into understandable arrangement. ... By postulate I mean the expression of an idea not yet represented by a defining mathematical statement. In that case I can't agree that dark matter and dark energy are postulates. They both have no lack of mathematical expression, the problem is that we don't really know which one describes them fully or integrates with what else we know. I certainly accept that any idea set forth within a peer review scientific community will almost certainly be accompanied by math. But math at a postulate level is not a requirement unless it purports to rise to the level of a theory (in which case it is no longer merely a postulate). Restated, a postulate by general definition is To make claim for; demand. To assume or assert the truth, reality, or necessity of, especially as a basis of an argument. To assume as a premise or axiom; take for granted. See Synonyms at presume. By theory I mean an idea supported by mathematical statement but not yet verified in all possible ways by apparent empirical evidence. Again there are serveral many theories (called scenarios) that try to account for either one, and they all aim to match the available empirical evidence. In this we seem to fully agree, in that a theory is an attempt to lay a math foundation that fully describes empiracal evidence. But it remains untested by peer review (experimentation and observation), or at least not as fully tested as be practical. Until that type of peer review has completed it is but a theory that does not rise to the level of being considered to be a law. But, as data from better probes comes along, the small disparity between the scenarios should favor some over others. That is already the case, for example, when you compare the WMAP data with the Type Ia supernova surveys, for dark energy evidence... Thank the universe for the apparent consistency of exactly how some supernova do their thing. They were at the root of a problem where some seemed to be older than the expected age of the universe! But when the universe went from a slowing down type of expansion to a speeding up type of expansion the redshift data made sense and seems to have reconciled that age problem. Basically a phase shift occurred, but only in the sense that as the universe expanded the weakening of gravity as felt by objects in the universe reached a point where it started becoming less attractive than be the what until then was the less powerful repulsive (inflationary) force that is being referred to as dark energy. By law I mean an idea supported by a mathematical statement that can not be ruled out by empirical evidence. I am not sure that you can say that about any law of physics with much conviction. Conservation laws are associated with global symmetries and even these can be broken (think of Parity and CP for example), and consequentially ruled out by empirical evidence. It was a red flag that called for re-evaluation of our basic assumptions. If a law can be broken then the breakage is not part of the law and it follows that the law is not a law nor even a valid postulate - because it has been disproven by empirical evidence. Will get to the other part later... -Joao :) Ron McFarland
Re: Quantum accident survivor
Not dualism per se - I'm sure Bruno would argue that he doesn't need the hypothesis of a concrete universe with physial bodies in it. However, I think you are correct in suggesting it does depend on an independence of substrate, which is what Bruno means by COMP - survivability of first person experience through substitution of the substrate. NB even though Bruno calls this hypothesis COMP, it is really more general than computationalism, in that computationalism = COMP but the reverse syllogism is not demonstrated anywhere to my knowledge. Cheers Stephen Paul King wrote: Dear Saibal and Russell, Does not this entire notion of quantum immortality assume some kind of mind/body dualism in that the mind, consciousness, is independent of the particular physical circumstances? There must be some way for the Moments, specifiec in #1, to be strung together in a first person way. This is, IMHO, strongly implied in Marchal's ideas using the UD. Even Barbour's time capsules imply this. I must confess to a bias toward dualistic models, particularly Vaughan Pratt's Chu space transform based idea, but this is something that is implied but does not seem to ever be discussed. Why? Stephen A/Prof Russell Standish Director High Performance Computing Support Unit, Phone 9385 6967, 8308 3119 (mobile) UNSW SYDNEY 2052 Fax 9385 6965, 0425 253119 () Australia[EMAIL PROTECTED] Room 2075, Red Centrehttp://parallel.hpc.unsw.edu.au/rks International prefix +612, Interstate prefix 02
Re: Quantum accident survivor
Stephen Paul King, [EMAIL PROTECTED], writes: My problem is that COMP requires the existence of an infinite computational system that is immune from the laws of thermodynamics. That makes it HIGHLY suspect in my book. First, I'm not sure that Bruno's COMP hypothesis (which is basically that minds can't tell what is computing them) does require this, but arguably the hypothesis that our entire universe is a computer program, and that all such programs and all such universes exist, requires some such assumption. But is this any more problematic than the conventional view that there exists an infinitely reliable set of mathematical equations that specify the laws of nature? Even if we make the leap of faith and assume that all that exists is numbers and the relations among them, how do we explain the reason that the illusion of a flow of time occurs? That's a good question, and I would suggest two answers. The first is that when we apply the anthropic principle and look for universes that contain observers, we are implicitly assuming that observers require a flow of time. It is almost impossible to conceive of an observer that would be timeless, and if such a thing existed, we would not recognize it as an observer. But if we do accept that in some sense timeless observers could exist, then no doubt they do exist, in universes that may not have anything like a flow of time. The second answer is that it may be that the simplest set of laws that allows for observers like ourselves to exist inherently requires something like time to exist as well. We are complex, and we know that in our universe, we were the result of the process of evolution starting with simple chemistry and building up complex biology. To get our level of complexity you either need a complex universe, which implies a large and improbable program, or you need a simple universe with a flow of time sufficient to let something like evolution operate. Therefore it is more likely that systems complex enough to be called observers will exist in universes where there is causality, consistency and evolution. Hal
Re: Quantum accident survivor
Dear Hal, Interleaving. - Original Message - From: Hal Finney [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Monday, November 03, 2003 9:10 PM Subject: Re: Quantum accident survivor Stephen Paul King, [EMAIL PROTECTED], writes: My problem is that COMP requires the existence of an infinite computational system that is immune from the laws of thermodynamics. That makes it HIGHLY suspect in my book. [HF] First, I'm not sure that Bruno's COMP hypothesis (which is basically that minds can't tell what is computing them) does require this, but arguably the hypothesis that our entire universe is a computer program, and that all such programs and all such universes exist, requires some such assumption. But is this any more problematic than the conventional view that there exists an infinitely reliable set of mathematical equations that specify the laws of nature? [SPK] Is it that there is a requirement of an infinitely reliable set of mathematics or, as I would put it, an infallible representation, or is it like I have asked previously: What if we consider that the best possible simulation of some object is indistinguishable from a actual object? It has often been stated that there is more that one curve that connects together the same set of points in the same order. We also have reasons to appeal to Occam's razor to help us find the best theory. But are we sure that our specifications of the laws of physics are something that is unproblematic? I often wonder if we are just communicating within the commonalities of our individual existences and not some pre-specifiable laws of physics! Have you read J. Wheeler's essay Law without law? Wheeler, J. A. (1983), Law Without Law. In Quantum Theory and Measurement, ed. J. Wheeler and W. Zurek. Princeton, N. J.: Princeton Univ. Press. [SPK] Even if we make the leap of faith and assume that all that exists is numbers and the relations among them, how do we explain the reason that the illusion of a flow of time occurs? [HF] That's a good question, and I would suggest two answers. The first is that when we apply the anthropic principle and look for universes that contain observers, we are implicitly assuming that observers require a flow of time. It is almost impossible to conceive of an observer that would be timeless, and if such a thing existed, we would not recognize it as an observer. But if we do accept that in some sense timeless observers could exist, then no doubt they do exist, in universes that may not have anything like a flow of time. [SPK] Sure, but you are explicitly only considering entities like you and I as prototypical. This reminds me of the way that people tend to define life and involves things like DNA and carbon. But it is that this line of thought seems to allow a kind of teleological thinking that has no place in philosophy of science. While it is a probability of 1 that an observer will find itself in a universe that is consistent with the existence of that observer, this tells us nothing at all whether or not such an observer is a priori possible. The latter requires us to postulate such things as Plenitudes, Platonias and Kripkean and Leibnizian analogs of possible worlds. The problem that I see is that these collections of all possible do not include some necessity of the experience of time and its included distingtions between past and future. We can recall the debate that Boltzman had with his critics regarding the H-theorem as an illustration. It is one thing to see the necessity of all possibilities, it is something else entirely to necesitate my own experience of a flow of time. Something is happening and it isn't just a static set of relations. [HF] The second answer is that it may be that the simplest set of laws that allows for observers like ourselves to exist inherently requires something like time to exist as well. We are complex, and we know that in our universe, we were the result of the process of evolution starting with simple chemistry and building up complex biology. To get our level of complexity you either need a complex universe, which implies a large and improbable program, or you need a simple universe with a flow of time sufficient to let something like evolution operate. Therefore it is more likely that systems complex enough to be called observers will exist in universes where there is causality, consistency and evolution. [SPK] That I can go along with. I only ask for some reasoning as to how it is that we have an arrow of time. My suggestion is that we consider that there is process both implicit in and necessary for computation. ;-) Kindest regards, Stephen
Re: Is the universe computable?
Dear David, This is a very good post! I would like to point you to a proposal that Vaughan Pratt discusses in several of his papers found here: http://chu.stanford.edu/guide.html http://chu.stanford.edu/guide.html#ratmech The basic idea goes like this: A causes B if and only if the information of B implies the information of A. or A = B iff A*- B* This goes into a commutation diagram that can be chained: ...A B - C ... | | | ...A* == B* == C* ... The idea is that physical events chain together only if their representations imply each other and the "arrows" of "causation" and "logical implication" go in opposite directions. In this way we can make sense of how the past is "so well behaved" while the future is wide open to possibilities that include pathologies. BTW, this idea is very much in line with Wheeler's "Surprise 20 Questions". Kindest regards, Stephen - Original Message - From: David Barrett-Lennard To: [EMAIL PROTECTED] Sent: Monday, November 03, 2003 10:45 PM Subject: Is the universe computable? In the words of Tegmark, lets assume that the physical world is completely mathematical; and everything that exists mathematically exists physically. I have been thinking along these lines since my days at university - where it occurred to me that any alternative is mystical. However, the problem remains to explain induction - ie the predictability of the universe. Why is it that the laws of physics can be depended on when looking into the future, if we are merely a mathematical construction - like a simulation running on a computer. It seems to me that in the ensemble of all possible computer simulations (with no limits on the complexity of the laws) the ones that remain well behaved after any given time step in the simulation have measure zero. Given the source code for the simulation of our universe, it would seem to be possible to add some extra instructions that test for a certain condition to be met in order to tamper with the simulation. It would seem likely that there will exist simulations that match our own up to a certain point in time, but then diverge. Eg it is possible for a simulation to have a rule that an object will suddenly manifest itself at a particular time and place. The simulated conscious beings in such a universe would be surprised to find that induction fails at the moment the simulation diverges. In other words, at each time step in a simulation the state vector can take different paths according to slightly different software programs with special cases that only trigger at that moment in time. It seems that a universe will continually split into vast numbers of child universes, in a manner reminiscent of the MWI. However there is a crucial difference most of these spin off universes will have bizarre things happen. It is difficult to see how a computable system can be tamper proof. How can a past which has been well behaved prevent strange things from happening in the future? In the thread a possible paradox, there was talk about a vanishingly small number of magical universes where strange things happen. However, it seems to me that the bigger risk is that a normal universe like ours will be the atypical in the ensemble! A possible argument is to invoke the anthropic principle and suggest that our universe is predictable in order for SASs to evolve and perceive that predictability. However, that predictability only needs to be a trick played on the inhabitants for long enough to develop intelligence. There is no reason why the trick needs to continue to be played. I suggest that the requirement of a tamper-proof physics is an extremely powerful principle. For example, we deduce that SASs only exist in mathematical systems that arent computable. In particular our Universe is not computable. - which is what Penrose has been saying. I have assumed that non-computability coincides with being tamper-proof but this is far from clear. For example, it is conceivable that the Universe is a Turing machine running an infinite computation (cf Tiplers Omega point), and awareness only emerges in the totality of this infinite computation. Perhaps our awareness is a manifestation of advanced waves sent backwards in time from the Omega Point! I think its important to distinguish between an underlying mathematical system, and the formal system that tries to describe it. I think this is a crucial distinction. For example, the real number system can be defined uniquely by a finite set of axioms. Uniqueness is (formally) provable - in the sense that it can be shown that an isomorphism exists between all systems that satisfy the axioms. However the real numbers
Re: Is the universe computable?
This topic has been discussed on this list a number of times, under the heading White Rabbit paradox. My personally preferred solution to this problem is described in my paper Why Occam's Razor. Alternative approaches exist - for example that of Schmidhuber's second paper (it's referenced in Occam), whereby any ensemble generated by a resource bounded machine will automatically have a prior that solves the white rabbit problem - the so called speed prior. I don't quite follow why noncomputability of the universe would help. If anything, I would have thought it would make the problem worse (random strings are noncomputable). Cheers David Barrett-Lennard wrote: But what would, exactly, constitute strange behavior on the part of the universe? One could argue that the universe can't go completely wacko because we would cease to exist, and that would violate, the anthropic principle. It is true that in the ensemble of all possible programs (that are all equally valid by Tegmarks premise), the ones that go completely wacho (and we cease to exist) exist but no one is there to observe it. However it would seem there will be an enormous number in which we indeed witness bizarre events like popping up pink elephants.The options seem to be either 1. Programs with a special rule that is waiting to fire at a given time/place in order to cause a bizarre event are mathematically impossible 2. Programs with such special rules hardly ever occur (in terms of the ensemble); or 3. Programs with such special rules are common but we have been extraordinarily lucky None of these options appear reasonable. It seems that the simplistic notion of a simulation on a computer is not tamper proof. In the ensemble of all possible programs we must accept arbitrarily complex programs - we have no right to limit ourselves to programs that maintain consistent physical law over time. The invariants in physics all point to a program for our universe that is tamper proof. One potential solution is that awareness only emerges in the totality of an infinite computation. This could be tamper proof because of a holistic relationship between virtual time and simulation time. Another solution is that our universe is not computable in any sense. - David -Original Message- From: Frank [mailto:[EMAIL PROTECTED] Sent: Tuesday, 4 November 2003 5:54 PM To: [EMAIL PROTECTED] Subject: Re: Is the universe computable? Hi, this is my second post. My name is Frank Cizmic and I'm a computer Engineer from Uruguay. David Barrett, I'd like to comment on one aspect of your reasoning with which I have some doubts. If I understand correctly, you are saying that *if* the universe is the result of a program, then it is very strange that at any one point in time this program doesn't go nuts, making strange things occur, like popping pink elephants out of nowhere, or resisting prediction by us sentient beings by violating its previous good behavior. But what would, exactly, constitute strange behavior on the part of the universe? One could argue that the universe can't go completely wacko because we would cease to exist, and that would violate, the anthropic principle. So what would constitute strange behavior? Isn't life strange enough? Aren't we facing new facts every day? If by strange you mean twilight zone kind of events, wouldn't we eventually adjust to this and end by considering it normal behavior. Isn't this, in a sense, what we experience since birth? A wacky universe, that is always surprising us , but never to the point where we lose sanity. One could posit that we, in a sense, would cease to be, if we lost our mental health. This might be formulated like a variant of the anthropic principle. We always live in a Universe that makes a minimum of sense, otherwise, our psyque would eventually break down, and we would, essentially, cease to be. cheers - Original Message - From: David Barrett-Lennard To: [EMAIL PROTECTED] Sent: Monday, November 03, 2003 7:45 PM Subject: Is the universe computable? How can a past which has been well behaved prevent strange things from happening in the future? A/Prof Russell Standish Director High Performance Computing Support Unit, Phone 9385 6967, 8308 3119 (mobile) UNSW SYDNEY 2052 Fax 9385 6965, 0425 253119 () Australia[EMAIL PROTECTED] Room 2075, Red Centrehttp://parallel.hpc.unsw.edu.au/rks International prefix +612, Interstate prefix 02
