Re: Quantum Immortality and Information Flow
Stathis Papaioannou wrote: There are many ways to escape from this scenario. If you are Tookie, you will find yourself shunted into increasingly less likely situations: not being caught in the first place; being caught but not being found guilty; being sentenced to death but getting off on appeal; being pardoned by the Governer at the last moment; finding that you are one of the 1/billion people who have a natural resistance to the lethal agent. Only your last scenario is causally connected to having received a lethal injection. What does shunted mean in the above? Once I experience having had the injection, how would I get shunted to any of the preceding outcomes? If that all falls through, you might find that your arrest and execution was all part of a dream, or that you were actually executed but your head was preserved and you were resurrected as a computer upload in the future, or you were resurrected as a result of brute force emulation of every possible human mind in the very far future. These latter possibilities may be more likely than quantum tunneling to a tropical island, but in the final analysis, however unlikely the escape route may be, if its probability is non-zero, then it *has* to happen, doesn't it? These scenarios are all causally connected to having been lethally injected. But your final question goes to the heart of the issue I raised. What is the likeliest scenario which includes the memory of being lethally injected? Are there always non-zero probability outcomes, which, according to MWI, must be realized somewhere? -Johnathan
Re: Quantum Immortality and Information Flow
Saibal Mitra wrote: To me it seems that the notion of ''successor'' has to break down at cases where the observer can die. The Tookies that are the most similar to the Tookie who got executed are the ones who got clemency. There is no objective reason why these Tookies should be excluded as ''successors''. They miss the part of their memories about things that happened after clemency was denied. Instead of those memories they have other memories. We forget things all the time. Sometimes we remember things that didn't really happen. So, we allow for information loss anyway. My point is then that we should forget about all of the information contained in the OM and just sample from the entire set of OMs. (After being away for a couple weeks, I'd like to follow up with yours and others replies.) I find this line of argument hard to follow. I think where we differ is that I assume there must be some physical causality connecting observer moments. That is, if a person is in physical state A and is experiencing state E(A), then their next subjective moment E(B) must have some connected, causal path between physical state A and physical state B. This reasoning makes the materialist assumption that subjective experience E is entirely defined by the physical state of the observer. According to MWI, physical state A actually evolves into a superposition of discrete physical states B, each with a different density or measure. So, by the logic of the previous paragraph, subjective experience E(A) must evolve into a superposition of discrete Es, each a function of the particular discrete physical state B it arises from, and each with a particular measure. Some subset of this superposition of physical states B, however, do not support the creation of subjective experience (say, where the person has died.) So some proportion of E(B)'s are null. So my original question about what is happening to Tookie now can be rephrased as the following thought experiment: Physical state A is Tookie lying on a gurney, experiencing E(A), which is getting injected with lethal toxin by the State of California. Clearly, the vast majority of the elements of superposition of states B which follow the execution are with him being dead, and do not give rise to any subjective experience at all. What are the possibilities for causally connected physical states which don't involve his death? Which B's exist which continue to give rise to new E(B)'s? In other words, which observer moments for Tookie exist which include the memories of his having received the lethal injection, but not of dying as a result? Does there have to be any at all? QTI says yes, there must be, and no matter how unlikely--there is always escape in some form. What was Tookie's? -Johnathan
Re: Quantum Immortality and Information Flow
Le 16-déc.-05, à 16:49, Stathis Papaioannou a écrit : It may be easy to find logical flaws in the above credo, but I maintain that it is so deeply ingrained in each of us that it would be very difficult to overcome, except perhaps on the intellectual level. OK but that would not make sense. I don't think any third person (intellectual) belief can put any doubt on a first person conviction. To learn that the sun is not the one going around the earth will never change our conviction that the sun apparently turns around us. Many difficulties are easier to be approached when we keep up explicitly the 1-3 distinction. One could imagine other beliefs about personal identity that might have evolved if there were the appropriate selection pressure; for example, identifying as part of a group or swarm organism. The point is, our belief is not scientifically or philosophically right; it is just our belief. All right. I will say more because some people ask me out of line what are G, G*, and G* \ G. I am thinking to define machine science by what machine can prove correctly about themselves, and by machine theology what machine can hope correctly about themselves ; where a machine proves a proposition p correctly when the machine proves p and p is true, and a machine hopes p correctly when the machine hopes p and p is true. This is a non normative definition of science and theology because such definition does not forces us to revise any scientific or theological prejudices we could have, a priori. Now let M be a sound machine. By definition a sound machine is a machine which proves only true propositions. Let us write Bp the proposition that the machine M proves p. To say that the machine is sound is equivalent as saying that IF the machine proves p THEN p is true. This means the proposition Bp -> p is always true, whatever particular proposition p represents (assuming of course that p is written in some language the machine can understand or at least manipulates formally). So for each p the proposition Bp -> p is true for M, and this is just equivalent as saying that the machine is sound. Question: is it true that for each p B(Bp -> p) will be true? Let p b any obviously false sentence like a contradiction (like q ~q, or better the constant f). If B(Bp -> p) was always true, we would have B(Bf -> f); which means (giving that Ba means that the machine proves a) that the machine proves Bf -> f. But Bf -> f is equivalent with ~Bf. (Verify with a thruth table in case of doubt). But ~Bf means that the machine does not prove the false, but this means that the machine is consistent. So if B(Bp -> p) was true for any p, then the machine could prove its own consistency: the machine would prove Bf -> f, that is ~Bf (consistency; you can write it also Dt). And this is in contradiction with Godel's second incompleteness theorem. So soundness (Bp -> p) or more particularly consistency (Bf -> f) are typical example of true propositions about the sound machine M, that the machine M is unable to prove. So soundness and consistency, thanks to the second incompleteness theorem of Godel, are example of proposition that such a machine can hope for, and hope correctly, as WE know (giving that we talk by definition about a sound machine). A natural question is the following: does such a B follow some modal logical laws? The answer is affirmative. Basically, the theorem of SOLOVAY is just that for such sound machine, the modal logic G formalises completely the science of the machine, and the modal logic G* formalizes completely the theology of the machine. G has the following axioms and rules: K B(p -> q) -> (Bp -> Bq) L B(Bp -> p) -> Bp Rules : modus ponens (if the machine proves A and if the machine proves A -> B then the machine will prove B) and necessitation (if the machine proves A then the machine will prove BA). G* has the following axioms and rules: As axioms: all theorems of G, + Bp -> p (the machine is sound) Rules: modus ponens (ONLY!). In general G (and G*) are thought as being the set of theorems which can be derived from the axioms and rules given, and thus are infinite sets of formulas. What I note G* \ G is the set difference of the (infinite) set G* and G, that is: pure theology: the set of everything which is true for the machine but that the machine cannot prove. The machine can only hope such proposition, and WE know that such machine can correctly hope those propositions. I must go. Here are important formulas (and their standard name) that we will meet again and again. I let you think about which sort of multiverse (Kripke frame) makes each of those formula automatically true, whatever the illumination (the valuation of the sentence letters) is. K = B(p->q) -> (Bp -> Bq) t = Bp -> p, 4 = Bp -> BBp, B = p -> BDp, D = Bp -> Dp, 5 = Dp -> BDp, C = Dp -> ~ BDp, L = B(Bp->p)->Bp, Grz = B(B(p -> Bp) -> p) -> p. Bruno http://iridia.ulb.ac.be/~marchal/
Re: Quantum Immortality and Information Flow
Hi Bruno, Well, even if you can derive the laws of physics as we know them (in some approximation), you still can't do an experiment to prove that quantum suicide works. It can only be proven to the experimentor himself. This means that the absolute measure cannot be ruled out experimentally. - Original Message - From: Bruno Marchal [EMAIL PROTECTED] To: Saibal Mitra [EMAIL PROTECTED] Cc: everything-list@eskimo.com Sent: Thursday, December 15, 2005 01:25 PM Subject: Re: Quantum Immortality and Information Flow Le 15-déc.-05, à 03:04, Saibal Mitra a écrit : To me it seems that the notion of ''successor'' has to break down at cases where the observer can die. The Tookies that are the most similar to the Tookie who got executed are the ones who got clemency. There is no objective reason why these Tookies should be excluded as ''successors''. They miss the part of their memories about things that happened after clemency was denied. Instead of those memories they have other memories. We forget things all the time. Sometimes we remember things that didn't really happen. So, we allow for information loss anyway. My point is then that we should forget about all of the information contained in the OM and just sample from the entire set of OMs. The notion of a ''successor'' is not a fundamental notion at all. You can define it any way you like. ? It will not lead to any conflict with any experiments you can think of. ? Counterexamples will appear if I succeed to explain more of the conversation with the lobian machines. But just with the Kripke semantics we have a base to doubt what you are saying here. Indeed, it is the relation of accessibility between OMs which determine completely the invariant laws pertaining in all OMs. For example, if the multiverse is reflexive the Bp - p is true in all OMs (that is, Bp - p is invariant for any walk in the multiverse). If the mutliverse is terminal of papaioannou-like) then Dt - ~BDt is a law. In Kripke structure the accessibility relation determined the invariant laws. later, the modal logic is given by the machine interview, and from that, we will determine the structure of the multiverse, including the observable one. Bruno http://iridia.ulb.ac.be/~marchal/
Re: Quantum Immortality and Information Flow
Saibal Mitra writes: To me it seems that the notion of ''successor'' has to break down at cases where the observer can die. The Tookies that are the most similar to the Tookie who got executed are the ones who got clemency. There is no objective reason why these Tookies should be excluded as ''successors''. They miss the part of their memories about things that happened after clemency was denied. Instead of those memories they have other memories. We forget things all the time. Sometimes we remember things that didn't really happen. So, we allow for information loss anyway. My point is then that we should forget about all of the information contained in the OM and just sample from the entire set of OMs. The notion of a ''successor'' is not a fundamental notion at all. You can define it any way you like. It will not lead to any conflict with any experiments you can think of. You are right about death with a (not completely up to date) backup of your mind being equivalent to memory loss, and you are right about the notion of a successor not being fundamental to physics. Nevertheless, we can still ask questions *given* our innate theory of personal identity, which has evolved to be very powerful and difficult to change, and very consistent from person to person. What this means is that if I were facing imminent execution, try as I might, I would not get much consolation from the belief that other versions of me in the multiverse will not be killed. In fact, I don't really care what happens to versions of me in parallel branches. What I care about is what is happening to me now, and what will happen to me in the future. When I consider my immediate future, I consider and worry about the fate of all those versions of me who remember almost everything about me up to and including the present moment, which for them will be a moment ago. Once the future comes and I find myself to be one of the aforementioned versions, I immediately lose interest in all the other parallel versions, because they are no longer potentially me. Using the above structure, at the point where I am just about to have the lethal injection, what I hope for is that there will be at least one version of me in the multiverse who has just experienced having the injection a moment ago, but has somehow survived. In other words, if one or more such versions exist anywhere in the multiverse, then this is necessary and sufficient for me to survive my execution. It may be easy to find logical flaws in the above credo, but I maintain that it is so deeply ingrained in each of us that it would be very difficult to overcome, except perhaps on the intellectual level. One could imagine other beliefs about personal identity that might have evolved if there were the appropriate selection pressure; for example, identifying as part of a group or swarm organism. The point is, our belief is not scientifically or philosophically right; it is just our belief. Stathis Papaioannou _ Dont just search. Find. Check out the new MSN Search! http://search.msn.click-url.com/go/onm00200636ave/direct/01/
Re: Quantum Immortality and Information Flow
Hi Saibal, Well, even if you can derive the laws of physics as we know them (in some approximation), you still can't do an experiment to prove that quantum suicide works. I think you are completely right. It is even my main motivation for calling theology the modal logic G* (which contains all the propositional truth about the machine including those the machines cannot prove). It can only be proven to the experimentor himself. Actually I am not even sure of that, although the experimentor can in a 1-person view, believes he got evidences (but no proof). Actually I have no proof that I am alive. This means that the absolute measure cannot be ruled out experimentally. OK. But how would you verify the absolute measure. Do you think you can derive the physical laws from it (without any physicalist prior, and by being coherent with the 1-3 distinction)? See you tomorrow, Bruno - Original Message - From: Bruno Marchal [EMAIL PROTECTED] To: Saibal Mitra [EMAIL PROTECTED] Cc: everything-list@eskimo.com Sent: Thursday, December 15, 2005 01:25 PM Subject: Re: Quantum Immortality and Information Flow Le 15-déc.-05, à 03:04, Saibal Mitra a écrit : To me it seems that the notion of ''successor'' has to break down at cases where the observer can die. The Tookies that are the most similar to the Tookie who got executed are the ones who got clemency. There is no objective reason why these Tookies should be excluded as ''successors''. They miss the part of their memories about things that happened after clemency was denied. Instead of those memories they have other memories. We forget things all the time. Sometimes we remember things that didn't really happen. So, we allow for information loss anyway. My point is then that we should forget about all of the information contained in the OM and just sample from the entire set of OMs. The notion of a ''successor'' is not a fundamental notion at all. You can define it any way you like. ? It will not lead to any conflict with any experiments you can think of. ? Counterexamples will appear if I succeed to explain more of the conversation with the lobian machines. But just with the Kripke semantics we have a base to doubt what you are saying here. Indeed, it is the relation of accessibility between OMs which determine completely the invariant laws pertaining in all OMs. For example, if the multiverse is reflexive the Bp - p is true in all OMs (that is, Bp - p is invariant for any walk in the multiverse). If the mutliverse is terminal of papaioannou-like) then Dt - ~BDt is a law. In Kripke structure the accessibility relation determined the invariant laws. later, the modal logic is given by the machine interview, and from that, we will determine the structure of the multiverse, including the observable one. Bruno http://iridia.ulb.ac.be/~marchal/ http://iridia.ulb.ac.be/~marchal/
Re: Quantum Immortality and Information Flow
Le 14-déc.-05, à 01:34, Stathis Papaioannou a écrit : In the multiverse, only other people end up in dead ends. Although from a third person perspective every entity in the multiverse could be said to exist only transiently because at every point of an entity's history we can say that there sprouts a dead end branch of zero extent, from a first person perspective, these branches cannot by definition ever be experienced. If the laws of physics are contingent on the continuation of consciousness, it is very well possible that a very large majority of branches are very short and dead ends. In other words every nanoseconds we suffer a thousand deaths through events which are perceived to be unlikely due to the apparent stability of the physical laws, events such as proton decay, beta capture, nuclear fusion due to nucleus tunneling, etc... Bruno Marchal wrote: I know you have solved the only if part of following exercise: (W, R) is reflexive iff (W,R) respects Bp - p. I will come back on the if part later. Have you done this: showing that (W,R) is a Papaioannou multiverse iff(W,R) respects Dt - D(Bf). Note that this question is a little bit academical. I have already explain how I will choose the modal logics. Actually I will not choose them, I will extract them from a conversation with the machine (and its guardian angel). This will leave no choice. It will happen that the formula Dt - D(Bf) will appear in the discourse machine; indeed perhaps some of you know already that this is just the second incompleteness of Godel, once you interpret Bp by the machine proves p, coded in some language the machine can use. George
Re: Quantum Immortality and Information Flow
Le Vendredi 16 Décembre 2005 02:18, vous avez écrit : This is true, but you can only experience being one person at a time. In fact I'd say I can only experience being me ;) If I experienced being another person I wouldn't be I. When I contemplate what may happen to me tomorrow, I have to consider all the future versions of me in the multiverse as having equal right to consider themselves me. So if half the versions of me tomorrow are expected to suffer, I am worried, because I might be one of those who suffers. In fact you might not be, It's sure *you* will. But when tomorrow comes and I am not suffering, I am relieved - even though those who are suffering have as much right to consider themselves the continuation of yesterday's version of me as I do. Our psychology creates an asymmetry between the present and the future when it comes to personal identity. Some on this list (eg. Lee Corbin) have argued that this is irrational: copies that are me in the future should also be considered me in the present and past. I agree with this statement. However, our psychological makeup is as it is: our future encompasses many possibilities, but our present and past is fixed and single. This is true, but if you encompass a multiverse/everything view then you cannot ask why am I not one of those that or that experience... Why am I still in a rationnal/induction working world ? You're not because if you were, you wouldn't ask this in the first place. Stathis Papaioannou Regards, Quentin Anciaux
Re: Quantum Immortality and Information Flow
Le 14-déc.-05, à 01:34, Stathis Papaioannou a écrit : In the multiverse, only other people end up in dead ends. Although from a third person perspective every entity in the multiverse could be said to exist only transiently because at every point of an entity's history we can say that there sprouts a dead end branch of zero extent, from a first person perspective, these branches cannot by definition ever be experienced. All right. Could I take this as a defence of the Papaioannou multiverse for some third person description: those where each world where you have a next state leads to a dead end? I call them realist frames in Conscience Mechanism. Sometimes they are called terminal frames in the literature. I know you have solved the only if part of following exercise: (W, R) is reflexive iff (W,R) respects Bp - p. I will come back on the if part later. Have you done this: showing that (W,R) is a Papaioannou multiverse iff(W,R) respects Dt - D(Bf). Note that this question is a little bit academical. I have already explain how I will choose the modal logics. Actually I will not choose them, I will extract them from a conversation with the machine (and its guardian angel). This will leave no choice. It will happen that the formula Dt - D(Bf) will appear in the discourse machine; indeed perhaps some of you know already that this is just the second incompleteness of Godel, once you interpret Bp by the machine proves p, coded in some language the machine can use. = Exercises for those who begins the study of modal logics: Does every one see that all the following formula are equivalent? : Dt - ~B(Dt) Dt - D(Bf) BDt - Bf ~Bf - ~B(~Bf) Those are equivalent (in all the modal logics we will meet), and the only things people should know to prove those equivalences are that: 1) ~Bp is equivalent with D~p (not necessary p = possible not p) ~Dp is equivalent with B~p (not possible p = necessary not p) Bp is equivalent with ~D~p Dp is equivalent with ~B~p From this you can deduce a nice memo: a not ~ can jump over boxes by transforming them into diamonds, and reciprocally: For example: ~BBf is equivalent with Dt and 2) the contraposition law: (A - B) is equivalent with (~B - ~A). I urge people who have difficulties NOT to hesitate to ask me question OUT of line. Too bad to miss the marvel of all marvels (G and G*) for reason of math-notation-anxiety!!! Bruno http://iridia.ulb.ac.be/~marchal/
Re: Quantum Immortality and Information Flow
Quentin Anciaux writes: Hi Jesse, unless you are willing to say that white rabbit universes have a lower absolute measure than stable-laws-of-nature universes, you have no justification for expecting that you are unlikely to experience such events in your future. Jesse You have no justification, but in (everything like) multiverse, it is for sure (probability 1) that an extension of your present self *will* experience weird events. Because all possibilities are fullfiled in the multiverse... The problem arise because of what we call I... the I that will experience weird thing will remember being the present I... So when you say that you have to explain why *you* are unlikely to experience weird event, who is you ? All next you will remember being current you. This is true, but you can only experience being one person at a time. When I contemplate what may happen to me tomorrow, I have to consider all the future versions of me in the multiverse as having equal right to consider themselves me. So if half the versions of me tomorrow are expected to suffer, I am worried, because I might be one of those who suffers. But when tomorrow comes and I am not suffering, I am relieved - even though those who are suffering have as much right to consider themselves the continuation of yesterday's version of me as I do. Our psychology creates an asymmetry between the present and the future when it comes to personal identity. Some on this list (eg. Lee Corbin) have argued that this is irrational: copies that are me in the future should also be considered me in the present and past. However, our psychological makeup is as it is: our future encompasses many possibilities, but our present and past is fixed and single. Stathis Papaioannou _ Dont just search. Find. Check out the new MSN Search! http://search.msn.click-url.com/go/onm00200636ave/direct/01/
Re: Quantum Immortality and Information Flow
Le 13-déc.-05, à 18:37, [EMAIL PROTECTED] a écrit : In this context I'm talking about your comp multiverse. Yes, our common sense experience sees history as one way. But this is the problem. Your requirement for LASE is that the accessibility relation is symmetrical. I don't require LASE. (I recall for the other: LASE is the modal formula p - BDp, its characteristic multiverse have a symmetrical accessibility relation) It is just the main formula in a modal propositional quantum physics. LASE is an empirical discovery of the physicist (as re-expressed by modal logicians). (I use LASE for: Little Abstract Schroedinger Equation). This implies that it has to be just as consistent to go backwards in history as forwards. You are going too much quickly here. Nobody said that we need to interpret the accessibility relation in a temporal way. LASE axiomatizes a relation of proximity among quantum states or quantum consistent histories, which can be seen in some block-multiverse. From what you say above about the natural numbers, it seems that the comp assumption of natural numbers contradicts this. Yes. And that explains why it takes me more than 20 years to resolve that apparent contradiction. But I do think like you that apparently there is a contradiction. The contradiction will disappear when we will take seriously the incompleteness phenomenon into account. Strangely enough perhaps. I'd appreciate [your summary]. As part of it, I think I would need an explanation of what you mean by physical universe. Fair enough. Actually this depends of the context. I promise to say more asap; 'cause I got a new wave of working duties here alas :( It seems to me that your belief in the process of verification, when you talk about verifying comp physics vs. quantum physics, is equivalent to a belief in a physical universe. I gave an argument that if comp is correct then the *appearance* of *observables* must be explained from the (mathematical) structure of the natural border of our (us = the hopefully lobian machines) ignorance (a psychological or theological predicate). The argument is mainly the UDA + the movie-graph, and the machine ignorance is just the collection of its possible consistent extensions. This is coherent with the RSSA measure-philosophy of many in this list. Then I show that indeed any sound lobian machine who introspects herself deeply enough will find those laws of observability. And, so we can test comp by comparing those lobian observability laws with the observability laws infered by observation of the empirical reality. Would we get a complete confirmation: this would entail a confirmation that the empirical laws emerge from the immaterial machine ignorance, not from a physical or substantial independent reality. If you want I believe in empiry, not in a necessary primitively physical base for that empiry. Well, assuming comp, I believe in a base which is necessarily not physicalist. Like Chaitin has also observed (and also from incompleteness) even arithmetical reality can only be known, in great part, by observation, experiment with numbers. Oops, must go now. Hope this helps a bit, but it will be clearer with the summary, I hope. Bruno http://iridia.ulb.ac.be/~marchal/
Re: Quantum Immortality and Information Flow
On Wed, Dec 14, 2005 at 03:18:16PM -0800, George Levy wrote: The only way to talk meaningfully about measure is when you can compare two situations from a third person point of view: for example, if you witness someone die from a freak event you could conclude that he continued living in a world with lower measure than yours. This is a third person point of view. However, from that person's point of view (first person), the freak event never happened and therefore he will consider his measure to be just as high as yours. George One can talk about relative measure between two observer moments connected via an accessibility relation from the first person. The computation of this relative measure (which will in fact be a probability distribution) is given by the Born rule. Absolute measure (which will be complex in general) is a pure 3rd person phenomenon, and not accessible to observer. I argue that the absolute measure can be identified with the magnitude and phase angle of the quantum mechanical statevector representing the observer moment. These quantities are usually considered unphysical, as they are inaccessible to the observer. Only relative phase angles can be measured. Such an identification (complex absolute measure with statefunction magnitude) appears to be a novel interpretation of QM ... Cheers -- *PS: A number of people ask me about the attachment to my email, which is of type application/pgp-signature. Don't worry, it is not a virus. It is an electronic signature, that may be used to verify this email came from me if you have PGP or GPG installed. Otherwise, you may safely ignore this attachment. A/Prof Russell Standish Phone 8308 3119 (mobile) Mathematics0425 253119 () UNSW SYDNEY 2052 [EMAIL PROTECTED] Australiahttp://parallel.hpc.unsw.edu.au/rks International prefix +612, Interstate prefix 02 pgpAdT6Rp12JX.pgp Description: PGP signature
Re: Quantum Immortality and Information Flow
- Original Message - From: Johnathan Corgan [EMAIL PROTECTED] To: Stathis Papaioannou [EMAIL PROTECTED] Cc: everything-list@eskimo.com Sent: Wednesday, December 14, 2005 10:39 AM Subject: Re: Quantum Immortality and Information Flow Stathis Papaioannou wrote: In the multiverse, only other people end up in dead ends. Kind of makes you wonder what Tookie is doing right now. To us, he died as a result of lethal injection. What sort of successor observer-moments can follow a thing like that? Better question--what is the most likely type of 1st-person observer-moment that would follow experiencing lethal injection? Sure, there is an infinitesimal probability that all his constituent particles quantum-tunneled to a Pacific island paradise and right now somewhere in the multiverse he's enjoying a drink with an umbrella in it, thanking the fine State of California for his new life. More likely, but still infinitesimally small, is the probability that only the molecules of toxin in the injection syringe quantum-tunneled away and right now there are execution officials puzzling over whether to pardon him after this act-of-God miraculous reprieve from death. But seriously, when the overwhelmingly vast majority of successor moments to an instant in time are all 3rd-person dead-ends, what would would be an example of a high-expectation 1st-person successor observer-moment from the tiny sliver of physically possible (but extremely unlikely) ones left? Is there in fact always one left, no matter how unlikely? To me it seems that the notion of ''successor'' has to break down at cases where the observer can die. The Tookies that are the most similar to the Tookie who got executed are the ones who got clemency. There is no objective reason why these Tookies should be excluded as ''successors''. They miss the part of their memories about things that happened after clemency was denied. Instead of those memories they have other memories. We forget things all the time. Sometimes we remember things that didn't really happen. So, we allow for information loss anyway. My point is then that we should forget about all of the information contained in the OM and just sample from the entire set of OMs. The notion of a ''successor'' is not a fundamental notion at all. You can define it any way you like. It will not lead to any conflict with any experiments you can think of.
Re: Quantum Immortality and Information Flow
Le 13-déc.-05, à 02:07, Stathis Papaioannou a écrit : From the third person perspective, the annihilation of the 10^100 copies could be seen as 10^100 dead ends. (In fact, when I originally proposed this experiment, Hal Finney thought it represented the ultimate in mass murder.) If I were one of the 10^100, however, I wouldn't be worried in the slightest about the prospect of dying, because as long as at least one copy survives, this guarantees that I survive. This may go again intuition, but if you give up the notion of an immaterial soul, there is no reason why there should be a one to one relationship between earlier and later versions of a person. OK. But from this I deduce that we were agreeing. Eventually this means we don't take the dead ends into account when computing probabilities for future extensions of oneself. Bruno http://iridia.ulb.ac.be/~marchal/
Re: Quantum Immortality and Information Flow
Le 12-déc.-05, à 19:37, George Levy a écrit : Stathis Papaioannou wrote: In addition to the above arguments, consider the problem from the point of view of the subject. If multiple copies of a person are created and run in parallel for a period, what difference does this make to his experience? It seems to me that there is no test or experiment the person could do which would allow him to determine if he is living in a period of high measure or low measure. If an OM is the smallest discernible unit of conscious experience, it therefore seems reasonable to treat multiple instantiations of the same OM as one OM. Yes Stathis, I agree with you completely. This is delicate and I think we should really make the disctinction between the 3-OMs and the 1-OMs. Difference of measure of 3-OM does not change the quality of the 1-OMs experiences, but could change the relative probability of having some next 1-OMs. To justify this, I point you on the UDA, or to the lobian interview. (We are coming back on this). Bruno wrote: And this already comes from the fact that the indistinguishabilitty/distinguishabilitty crux is itself relative. By loosing memory something distinguishable can become indistinguishable, augmenting the class of (normal) self-consistent extensions. Bruno, I find this question extremely difficult. Is indistinguishability established at the physical level or at the psychological level? Psychological. Remember that with comp we take for granted some amount of folk or Grandmother psychology (enough for saying purposefully yes to the doctor). But then by the UDA, comp entails the complete structure of the physical laws. Now the goal is to make the derivation of the physical laws, so that we can test comp by comparing the comp-physics with the traditional empirical physics. With such kind of approach it is just forbidden to invoke anything physical as granted; we can certainly not take a physical multiverse or a physically based indistinguishability for granted. If we say it is established at the psychological level, then even mental errors ( ie.6+7=11) count in defining a whole world. 6+7=11 is not a mental error. It is just a false proposition. I guess you mean something like B(6+7=11). This is a *mental error*, where the mentality has been supposed to be captured by some modal epistemic logic B (a modal box). And then 6+7=11 is akin to a sort of white rabbit or flying pig, those which, of course we need still to justify the extreme rarity. This is the ultimate in relativism. I can find reasons to go either way. (Ultimately Undecided?) And now this makes sense indeed and the Ultimately Undecided is close to the Forever Undecided which will be tackle by the self-reference logics G and G*. Then I am open that from the 1 point of view, fusion increases measure, duplication decreases measure; although from the 3 pov it is the contrary. I do not agree with you on this point Bruno. From the one person point of view measures remains constant just like the speed of light, the mass of an electron, or the number of points in a line 1 meter long or 1 kilometer long. (the number of points in a continuum is always the same no matter what the length of the line is). The one person always observes a continuum in the number of opportunities available to him no matter what his past history is. That's true, but only for a notion of actual 1-OMs, not necessarily for the 3-prediction on some possible (future) 1-OMs. From the third person point of view, it makes sense to consider ratios in measures, just like it makes sense to take ratios of line segments of different lengths. OK. Bruno http://iridia.ulb.ac.be/~marchal/
Re: Quantum Immortality and Information Flow
Le 12-déc.-05, à 18:07, Tom ([EMAIL PROTECTED]) a écrit : In response to Stathis' thought experiment, to speak of an experiment being set up in a certain way is to base probabilities on an irrelevant subset of the whole, at least if the multiverse hypothesis is true. In the Plenitude, there are an additional 10^100 copies still existing, when you say that 10^100 copies are being shut-down. Talking about these additional 10^100 copies is just as consistent as talking about the original 10^100 copies (even more consistent if you consider Bruno's statement about cul-de-sacs. In the Plenitude, everything washes out to zero. And Bruno, I would even say that all consistent histories wash out to zero. I am not sure why you say this. Bruno, I've been following your posts about Kripke semantics and have done the exercises, including the one about showing that you need a symmetrical accessibility relation to have LASE. Nice ! However, my initial reaction still is that choosing a particular modal logic is scary to me, sending up red flags about hidden assumptions that are being made in the process. But I will continue to follow you as you present your case. Actually I do agree with you. But in the present case, that is with comp as I defined it (or much weaker assumption really) we will not to have to make a choice on the modal logics, they will be given by the interview of the lobian machine. Precisely G (and G*) will appear to be the complete and sound logic of the provable (and true) self-referential statements made by a sound or self-referentially correct machine. This is a consequence of a theorem in pure mathematics: Solovay theorem. Then, the translation of the UDA and in particular of the 1 and 3 notions will lead to the other modal logics we need, without us adding more (hidden) assumptions than the comp one (or much weaker). Earlier Stathis wrote: Bruno: OK but with comp I have argued that OMs are not primitive but are generated, in platonia, by the Universal Dovetailer. A 3- OM is just an UD-accessible state, and the 1-OMs inherit relative probabilities from the computer science theoretical structuring of the 3-OMs. Are OMs directly generated by the UD, or does the UD generate the physical (apparently) universe, which leads to the evolution of conscious beings, who then give rise to OMs? Stathis Papaioannou It's interesting that symmetry (Bruno's requirement for LASE) has come up lately, because Stathis' question seems to be what we are all wondering. That's the bottom line of multiverse theories: Where does the symmetry breaking come from? Actually comp put a big assymmetry at the start (the natural numbers: 0, 1, 2, 3, 4, ...), and my question for years was how to get the symmetry which apparently lives at the bottom of physics (already classical physics, still more with QM-without collapse). I maintain still that it can't come from the multiverse itself. But which multiverse? remember that the QM, or the existence of any physical multiverse are not among the hypothesis. Indeed the UDA forces us to justify completely the appearances of a physical multiverse. Even considering only consistent histories, there is no asymmetry to be found. This astonishes me a little bit. The very notion of history, it seems to me, is assymetrical. But then I am not sure if you are talking about the comp consistent extensions of some machine (the comp histories) or the quantum histories of Everett, Hartle, and Co. ? I maintain that it needs to come from outside the multiverse, which is something that we cannot explain. It certainly (with comp) needs to be explain from outside any notion of physical multiverse. Then the truth-provability gap (capture by the modal logic G* \ G, that is the set difference between the provable self-referential statements and the true self-referential statements) will explain why we cannot explain that something. I should perhaps make some summary. Bruno http://iridia.ulb.ac.be/~marchal/
Re: Quantum Immortality and Information Flow
Stathis wrote: Tom Caylor writes: In response to Stathis' thought experiment, to speak of an experiment being set up in a certain way is to base probabilities on an irrelevant subset of the whole, at least if the multiverse hypothesis is true. In the Plenitude, there are an additional 10^100 copies still existing, when you say that 10^100 copies are being shut-down. Talking about these additional 10^100 copies is just as consistent as talking about the original 10^100 copies (even more consistent if you consider Bruno's statement about cul-de-sacs. In the Plenitude, everything washes out to zero. And Bruno, I would even say that all consistent histories wash out to zero. Doesn't this ignore the concept of measure in the multiverse? If I buy a lottery ticket there are an infinite number of versions of me who win and an infinite number of versions who lose, but in some sense there have to be more losers than winners, which is why I don't buy lottery tickets. Stathis Papaioannou It seems to me that as soon as we talk about measure, it is equivalent to talking about one (physical!) universe. This is similar to your George Levy's taking the ratio of the lengths of two line segments. You don't need a multiverse to do that. I think that talking of measure in the multiverse is taking a common sense thing in a single universe and (erroneously) trying to make it make sense in the multiverse. I don't think it works. So yes I'm ignoring something that doesn't work, in my view. I brought up the problem of the additional 10^100 copies, but your bringing up the word measure doesn't solve it. The reason why you don't buy lottery tickets could just as easily be explained in a single universe. Tom Caylor
Re: Quantum Immortality and Information Flow
Bruno Marchal wrote: we are conscious only because we belong to a continuum of infinite never ending stories ... ...that's what the lobian machine's guardian angel G* says about that: true and strictly unbelievable. Bruno Since you agree that the number of histories is on a continuum, you must accept that no matter how large or small a segment of the continuum is considered, the number of histories is the same. Hence measure is the same for any observer. George
Re: Quantum Immortality and Information Flow
The reason why you don't buy lottery tickets could just as easily be explained in a single universe. I short-changed my argument. I should've said, The reason why you don't buy lottery tickets can only be explained in a single universe. Tom Caylor
Re: Quantum Immortality and Information Flow
Tom Caylor wrote: The reason why you don't buy lottery tickets could just as easily be explained in a single universe. I short-changed my argument. I should've said, The reason why you don't buy lottery tickets can only be explained in a single universe. Tom Caylor If you don't accept a measure on the entire multiverse, then you're not going to have any solution to what on this list is usually called the white rabbit problem, explaining why you don't expect to see weird events like talking white rabbits or Harry Potter style magic or 300 successive lottery wins. After all, there should be possible worlds within the multiverse where everything up to today is just the same as in a normal universe where the laws of nature stay stable, but after that point the probabilities of strange white-rabbit-style events radically increase. Since your experience up to the present is compatible with either type of universe, unless you are willing to say that white rabbit universes have a lower absolute measure than stable-laws-of-nature universes, you have no justification for expecting that you are unlikely to experience such events in your future. Jesse
Re: Quantum Immortality and Information Flow
Jesse wrote: Tom Caylor wrote: The reason why you don't buy lottery tickets could just as easily be explained in a single universe. I short-changed my argument. I should've said, The reason why you don't buy lottery tickets can only be explained in a single universe. Tom Caylor If you don't accept a measure on the entire multiverse, then you're not going to have any solution to what on this list is usually called the white rabbit problem, explaining why you don't expect to see weird events like talking white rabbits or Harry Potter style magic or 300 successive lottery wins. After all, there should be possible worlds within the multiverse where everything up to today is just the same as in a normal universe where the laws of nature stay stable, but after that point the probabilities of strange white-rabbit-style events radically increase. Since your experience up to the present is compatible with either type of universe, unless you are willing to say that white rabbit universes have a lower absolute measure than stable-laws-of-nature universes, you have no justification for expecting that you are unlikely to experience such events in your future. Jesse The white rabbit problem is a problem only for multiverse believers. Tom
Re: Quantum Immortality and Information Flow
The white rabbit problem is a problem only for multiverse believers. By the way, thanks for the reference to rabbits. It caused a rabbit-repellent ad to appear in the margin of the archive. It is lemon-scented (and another one is fox-scented!) and this will be more pleasant for me than the last garlic-and-rotten-egg scented one I tried in my back yard. But these aren't white rabbits. Tom
Re: Quantum Immortality and Information Flow
Tom Caylor writes: It seems to me that as soon as we talk about measure, it is equivalent to talking about one (physical!) universe. This is similar to your George Levy's taking the ratio of the lengths of two line segments. You don't need a multiverse to do that. I think that talking of measure in the multiverse is taking a common sense thing in a single universe and (erroneously) trying to make it make sense in the multiverse. I don't think it works. So yes I'm ignoring something that doesn't work, in my view. I brought up the problem of the additional 10^100 copies, but your bringing up the word measure doesn't solve it. The reason why you don't buy lottery tickets could just as easily be explained in a single universe. Are you saying that probability can only mean anything in a single physical universe? And that because apparently probability does have meaning, this is evidence that there is only a single physical universe? Would you go further and say that the universe must be finite, because many of the properties of the multiverse are mirrored in a single infinite universe? Stathis Papaioannou _ Over 100,000 new beginnings at Australia's #1 job site. http://a.ninemsn.com.au/b.aspx?URL=http%3A%2F%2Fninemsn%2Eseek%2Ecom%2Eau%2F_t=752315885_r=HM_EndText_m=EXT
Re: Quantum Immortality and Information Flow
In the multiverse, only other people end up in dead ends. Although from a third person perspective every entity in the multiverse could be said to exist only transiently because at every point of an entity's history we can say that there sprouts a dead end branch of zero extent, from a first person perspective, these branches cannot by definition ever be experienced. Stathis Papaioannou Le 13-déc.-05, à 02:07, Stathis Papaioannou a écrit : From the third person perspective, the annihilation of the 10^100 copies could be seen as 10^100 dead ends. (In fact, when I originally proposed this experiment, Hal Finney thought it represented the ultimate in mass murder.) If I were one of the 10^100, however, I wouldn't be worried in the slightest about the prospect of dying, because as long as at least one copy survives, this guarantees that I survive. This may go again intuition, but if you give up the notion of an immaterial soul, there is no reason why there should be a one to one relationship between earlier and later versions of a person. OK. But from this I deduce that we were agreeing. Eventually this means we don't take the dead ends into account when computing probabilities for future extensions of oneself. Bruno http://iridia.ulb.ac.be/~marchal/ _ ASUS M5 Ultra-slim lightweight is Now $1999 (was $2,999) http://a.ninemsn.com.au/b.aspx?URL=http%3A%2F%2Fwww%2Easus%2Ecom%2Eau%2F_t=752129232_r=Hotmail_tagline_23Nov05_m=EXT
Re: Quantum Immortality and Information Flow
George Levy: Bruno Marchal wrote: we are conscious only because we belong to a continuum of infinite never ending stories ... ...that's what the lobian machine's guardian angel G* says about that: true and strictly unbelievable. Bruno Since you agree that the number of histories is on a continuum, you must accept that no matter how large or small a segment of the continuum is considered, the number of histories is the same. Hence measure is the same for any observer. The whole concept of measure is based on assigning different probabilities to different infinite sets--the fact that two sets have the same cardinality doesn't imply they must have the same measure. For example, any continuous probability distribution used in statistics (the bell curve, for example) can be used to assign a measure to an arbitrary finite interval (which necessarily contains an infinite number of points), the measure just being the area under the curve over that interval. Jesse
Re: Quantum Immortality and Information Flow
George Levy wrote: Jesse Mazer wrote: George Levy: Bruno Marchal wrote: we are conscious only because we belong to a continuum of infinite never ending stories ... ...that's what the lobian machine's guardian angel G* says about that: true and strictly unbelievable. Bruno Since you agree that the number of histories is on a continuum, you must accept that no matter how large or small a segment of the continuum is considered, the number of histories is the same. Hence measure is the same for any observer. The whole concept of measure is based on assigning different probabilities to different infinite sets--the fact that two sets have the same cardinality doesn't imply they must have the same measure. For example, any continuous probability distribution used in statistics (the bell curve, for example) can be used to assign a measure to an arbitrary finite interval (which necessarily contains an infinite number of points), the measure just being the area under the curve over that interval. Jesse Jesse I agree with you from the third person perspective. You can only take a measure of infinite sets when you have more then one set . In other words you need at least two sets so you can compare them. However in the case of first person perspective, the observer has only his own set. All he has is the cardinality of the set and he has only one set. No other set to compare it to. The cardinality is the same for all first person observers. George But if you have one set with an infinite number of elements, you can assign different measures to different infinite subsets of that set. And weren't you talking about an infinite number of histories above? Jesse
Re: Quantum Immortality and Information Flow
Le 11-déc.-05, à 11:58, Stathis Papaioannou a écrit : You find yourself alone in a room with a light that alternates red/green with a period of one minute. A letter in the room informs you that every other minute, 10^100 copies of you are created and run in parallel for one minute, then shut down. The transition between the two states (low measure/ high measure) corresponds with the change in the colour of the light, and you task is to guess which colour corresponds to which state. The problem is, whether the light is red or green, you could argue that you are vastly more likely to be sampled from the 10^100 group. You might decide to say that *both* red and green correspond to the larger group, because if you say this 10^100 copies in the multiverse will be correct and only one copy will be wrong. But clearly, this tyranny of the majority strategy brings you no closer to the truth. If you tossed a coin, at least you would have a 1/2 chance of being right. Yes but this is due to the shut down. (if I got correctly your experiment).The probabilities can be taken only on the stories without dead-ends, and I guess you consider the shut down as sort of absolute annihilation. I know this is hard to believe, but apparently we are conscious only because we belong to a continuum of infinite never ending stories ... I don't believe this, but then that's what the lobian machine's guardian angel G* says about that: true and strictly unbelievable. Do you accept that your argument won't go through if the shut down are deleted? Bruno http://iridia.ulb.ac.be/~marchal/
Re: Quantum Immortality and Information Flow
Bruno wrote: Le 11-déc.-05, à 11:58, Stathis Papaioannou a écrit : You find yourself alone in a room with a light that alternates red/green with a period of one minute. A letter in the room informs you that every other minute, 10^100 copies of you are created and run in parallel for one minute, then shut down. The transition between the two states (low measure/ high measure) corresponds with the change in the colour of the light, and you task is to guess which colour corresponds to which state. The problem is, whether the light is red or green, you could argue that you are vastly more likely to be sampled from the 10^100 group. You might decide to say that *both* red and green correspond to the larger group, because if you say this 10^100 copies in the multiverse will be correct and only one copy will be wrong. But clearly, this tyranny of the majority strategy brings you no closer to the truth. If you tossed a coin, at least you would have a 1/2 chance of being right. Yes but this is due to the shut down. (if I got correctly your experiment).The probabilities can be taken only on the stories without dead-ends, and I guess you consider the shut down as sort of absolute annihilation. I know this is hard to believe, but apparently we are conscious only because we belong to a continuum of infinite never ending stories ... I don't believe this, but then that's what the lobian machine's guardian angel G* says about that: true and strictly unbelievable. Do you accept that your argument won't go through if the shut down are deleted? Bruno http://iridia.ulb.ac.be/~marchal/ In response to Stathis' thought experiment, to speak of an experiment being set up in a certain way is to base probabilities on an irrelevant subset of the whole, at least if the multiverse hypothesis is true. In the Plenitude, there are an additional 10^100 copies still existing, when you say that 10^100 copies are being shut-down. Talking about these additional 10^100 copies is just as consistent as talking about the original 10^100 copies (even more consistent if you consider Bruno's statement about cul-de-sacs. In the Plenitude, everything washes out to zero. And Bruno, I would even say that all consistent histories wash out to zero. Bruno, I've been following your posts about Kripke semantics and have done the exercises, including the one about showing that you need a symmetrical accessibility relation to have LASE. However, my initial reaction still is that choosing a particular modal logic is scary to me, sending up red flags about hidden assumptions that are being made in the process. But I will continue to follow you as you present your case. Earlier Stathis wrote: Bruno: OK but with comp I have argued that OMs are not primitive but are generated, in platonia, by the Universal Dovetailer. A 3- OM is just an UD-accessible state, and the 1-OMs inherit relative probabilities from the computer science theoretical structuring of the 3-OMs. Are OMs directly generated by the UD, or does the UD generate the physical (apparently) universe, which leads to the evolution of conscious beings, who then give rise to OMs? Stathis Papaioannou It's interesting that symmetry (Bruno's requirement for LASE) has come up lately, because Stathis' question seems to be what we are all wondering. That's the bottom line of multiverse theories: Where does the symmetry breaking come from? I maintain still that it can't come from the multiverse itself. Even considering only consistent histories, there is no asymmetry to be found. I maintain that it needs to come from outside the multiverse, which is something that we cannot explain. Tom Caylor
Re: Quantum Immortality and Information Flow
Stathis Papaioannou wrote: In addition to the above arguments, consider the problem from the point of view of the subject. If multiple copies of a person are created and run in parallel for a period, what difference does this make to his experience? It seems to me that there is no test or experiment the person could do which would allow him to determine if he is living in a period of high measure or low measure. If an OM is the smallest discernible unit of conscious experience, it therefore seems reasonable to treat multiple instantiations of the same OM as one OM. Yes Stathis, I agree with you completely. Bruno wrote: And this already comes from the fact that the "indistinguishabilitty/distinguishabilitty" crux is itself relative. By loosing memory something distinguishable can become indistinguishable, augmenting the class of (normal) self-consistent extensions. Bruno, I find this question extremely difficult. Is indistinguishability established at the physical level or at the psychological level? If we say it is established at the psychological level, then even mental errors ( ie.6+7=11) count in defining a whole world. This is the ultimate in relativism. I can find reasons to go either way. (Ultimately Undecided?) Then I am open that from the 1 point of view, fusion increases measure, duplication decreases measure; although from the 3 pov it is the contrary. I do not agree with you on this point Bruno. >From the one person point of view measures remains constant just like the speed of light, the mass of an electron, or the number of points in a line 1 meter long or 1 kilometer long. (the number of points in a continuum is always the same no matter what the length of the line is). The one person always observes a continuum in the number of opportunities available to him no matter what his past history is. >From the third person point of view, it makes sense to consider ratios in measures, just like it makes sense to take ratios of line segments of different lengths. George
Re: Quantum Immortality and Information Flow
From the third person perspective, the annihilation of the 10^100 copies could be seen as 10^100 dead ends. (In fact, when I originally proposed this experiment, Hal Finney thought it represented the ultimate in mass murder.) If I were one of the 10^100, however, I wouldn't be worried in the slightest about the prospect of dying, because as long as at least one copy survives, this guarantees that I survive. This may go again intuition, but if you give up the notion of an immaterial soul, there is no reason why there should be a one to one relationship between earlier and later versions of a person. Stathis Papaioannou Le 11-déc.-05, à 11:58, Stathis Papaioannou a écrit : You find yourself alone in a room with a light that alternates red/green with a period of one minute. A letter in the room informs you that every other minute, 10^100 copies of you are created and run in parallel for one minute, then shut down. The transition between the two states (low measure/ high measure) corresponds with the change in the colour of the light, and you task is to guess which colour corresponds to which state. The problem is, whether the light is red or green, you could argue that you are vastly more likely to be sampled from the 10^100 group. You might decide to say that *both* red and green correspond to the larger group, because if you say this 10^100 copies in the multiverse will be correct and only one copy will be wrong. But clearly, this tyranny of the majority strategy brings you no closer to the truth. If you tossed a coin, at least you would have a 1/2 chance of being right. Yes but this is due to the shut down. (if I got correctly your experiment).The probabilities can be taken only on the stories without dead-ends, and I guess you consider the shut down as sort of absolute annihilation. I know this is hard to believe, but apparently we are conscious only because we belong to a continuum of infinite never ending stories ... I don't believe this, but then that's what the lobian machine's guardian angel G* says about that: true and strictly unbelievable. Do you accept that your argument won't go through if the shut down are deleted? Bruno http://iridia.ulb.ac.be/~marchal/ _ Is your PC infected? Get a FREE online computer virus scan from McAfee® Security. http://clinic.mcafee.com/clinic/ibuy/campaign.asp?cid=3963
Re: Quantum Immortality and Information Flow
Tom Caylor writes: In response to Stathis' thought experiment, to speak of an experiment being set up in a certain way is to base probabilities on an irrelevant subset of the whole, at least if the multiverse hypothesis is true. In the Plenitude, there are an additional 10^100 copies still existing, when you say that 10^100 copies are being shut-down. Talking about these additional 10^100 copies is just as consistent as talking about the original 10^100 copies (even more consistent if you consider Bruno's statement about cul-de-sacs. In the Plenitude, everything washes out to zero. And Bruno, I would even say that all consistent histories wash out to zero. Doesn't this ignore the concept of measure in the multiverse? If I buy a lottery ticket there are an infinite number of versions of me who win and an infinite number of versions who lose, but in some sense there have to be more losers than winners, which is why I don't buy lottery tickets. Stathis Papaioannou _ realestate.com.au: the biggest address in property http://ninemsn.realestate.com.au
Re: Quantum Immortality and Information Flow
Bruno Marchal writes: Le 10-déc.-05, à 13:24, Stathis Papaioannou a écrit : In addition to the above arguments, consider the problem from the point of view of the subject. If multiple copies of a person are created and run in parallel for a period, what difference does this make to his experience? It seems to me that there is no test or experiment the person could do which would allow him to determine if he is living in a period of high measure or low measure. To determine this with certainty? I agree with you in that case. But we can make sure bets. Take the iterated self-duplication (thought) experiment: You are read, cut and then pasted in two identical rooms except one has 1 drawn on the wall where the other has 0. Then each of you do it again and again. After 64 duplications you stop. A vast majority among the 2^64 yous will confirms they bet on their normality. Normal experience here is guarantied by the incompressible information of most bits sequences (provable by a simple combinatorial analysis). This is equivalent of betting the halving of the intensity of a beam of x polarized photons going through a y analyser, with Everett QM. What I meant above was that the presence of parallel copies per se cannot directly change the quality of the first person experience of any of the copies. It may be possible to infer the presence of other copies by indirect means; for example, in a closed system a high measure period may be characterised by faster oxygen consumption. I'm not sure what you mean by [a] vast majority among the 2^64 yous will confirms they bet on their normality, but I'm guessing that you are referring to the idea that if you bet on being sampled from high measure group rather than the low measure group, you are more likely to be right. This method has its problems. Consider this thought experiment which I proposed a few months ago: You find yourself alone in a room with a light that alternates red/green with a period of one minute. A letter in the room informs you that every other minute, 10^100 copies of you are created and run in parallel for one minute, then shut down. The transition between the two states (low measure/ high measure) corresponds with the change in the colour of the light, and you task is to guess which colour corresponds to which state. The problem is, whether the light is red or green, you could argue that you are vastly more likely to be sampled from the 10^100 group. You might decide to say that *both* red and green correspond to the larger group, because if you say this 10^100 copies in the multiverse will be correct and only one copy will be wrong. But clearly, this tyranny of the majority strategy brings you no closer to the truth. If you tossed a coin, at least you would have a 1/2 chance of being right. If an OM is the smallest discernible unit of conscious experience, it therefore seems reasonable to treat multiple instantiations of the same OM as one OM. OK but with comp I have argued that OMs are not primitive but are generated, in platonia, by the Universal Dovetailer. A 3- OM is just an UD-accessible state, and the 1-OMs inherit relative probabilities from the computer science theoretical structuring of the 3-OMs. It is the 1 3 person distinction which forces, I think, the relativity or conditionality of the measure. There is no a priori means to know if we are, just now, in a Harry Potter (abnormally informative) type of OM, but we can always bet our next OMs will belong to the set of their most normal continuators (probably the product of long (deep) computations with stability on dovetailing on the reals or noise). Are OMs directly generated by the UD, or does the UD generate the physical (apparently) universe, which leads to the evolution of conscious beings, who then give rise to OMs? Stathis Papaioannou _ Win over $10,000 in Dell prizes this Christmas http://ninemsn.com.au/share/redir/adTrack.asp?mode=clickclientID=151referral=HotmailtaglineURL=http://shoppingau.ninemsn.com.au/compintro.aspx?compid=174
Re: Quantum Immortality and Information Flow
George Levy writes: Hi Quentin, Stathis, Bruno It all depends how you see the plenitude, OMs and the branching. Is consciousness like a traveller in a network of roads traversing the plenitude, some roads branching some roads merging? If yes then you could have several independent consciousness occupying the same spot, or the same OM. Then their measure at that spot is their sum. This approach is a third person point of view and it leads to the concept of absolute measure. If you see consiousness as the road itself, then measure is not increased after a merge and does not decrease after a split. An OM is just a point on the road. If the road turns unexpectedly to avoids an obstacle (like quantum suicide or just plain death), then consiousness will just move on into a direction which has a low 3-rd person probability but unity first person probability. Viewing consciousness as a network of roads is a first person point of view and it leads to the concept of relative measure: Measure is always 1 where you are. From a given point you may reach many points - Then measure increases with respect to that point. Or reversibly, from many points you may reach only one point. Then measure decreases. Bruno writes: neither elimination of information, nor duplication of information. The crux of the matter is the concept of indistinguishability: whether you consider two identical persons (OMs) occupying two identical universes the same person (point on the road). It is clear that if you consider the problem from the information angle, then duplication of information does not increase the measure of that information. This would support the relative interpretation of measure. In addition to the above arguments, consider the problem from the point of view of the subject. If multiple copies of a person are created and run in parallel for a period, what difference does this make to his experience? It seems to me that there is no test or experiment the person could do which would allow him to determine if he is living in a period of high measure or low measure. If an OM is the smallest discernible unit of conscious experience, it therefore seems reasonable to treat multiple instantiations of the same OM as one OM. Stathis Papaioannou _ Express yourself instantly with MSN Messenger! Download today - it's FREE! http://messenger.msn.click-url.com/go/onm00200471ave/direct/01/
Re: Quantum Immortality and Information Flow
Le 10-déc.-05, à 13:24, Stathis Papaioannou a écrit : In addition to the above arguments, consider the problem from the point of view of the subject. If multiple copies of a person are created and run in parallel for a period, what difference does this make to his experience? It seems to me that there is no test or experiment the person could do which would allow him to determine if he is living in a period of high measure or low measure. To determine this with certainty? I agree with you in that case. But we can make sure bets. Take the iterated self-duplication (thought) experiment: You are read, cut and then pasted in two identical rooms except one has 1 drawn on the wall where the other has 0. Then each of you do it again and again. After 64 duplications you stop. A vast majority among the 2^64 yous will confirms they bet on their normality. Normal experience here is guarantied by the incompressible information of most bits sequences (provable by a simple combinatorial analysis). This is equivalent of betting the halving of the intensity of a beam of x polarized photons going through a y analyser, with Everett QM. If an OM is the smallest discernible unit of conscious experience, it therefore seems reasonable to treat multiple instantiations of the same OM as one OM. OK but with comp I have argued that OMs are not primitive but are generated, in platonia, by the Universal Dovetailer. A 3- OM is just an UD-accessible state, and the 1-OMs inherit relative probabilities from the computer science theoretical structuring of the 3-OMs. It is the 1 3 person distinction which forces, I think, the relativity or conditionality of the measure. There is no a priori means to know if we are, just now, in a Harry Potter (abnormally informative) type of OM, but we can always bet our next OMs will belong to the set of their most normal continuators (probably the product of long (deep) computations with stability on dovetailing on the reals or noise). Bruno http://iridia.ulb.ac.be/~marchal/
Re: Quantum Immortality and Information Flow
Le 09-déc.-05, à 22:44, George Levy a écrit : The crux of the matter is the concept of indistinguishability: whether you consider two identical persons (OMs) occupying two identical universes the same person (point on the road). It is clear that if you consider the problem from the information angle, then duplication of information does not increase the measure of that information. This would support the relative interpretation of measure. Yes. And this already comes from the fact that the indistinguishabilitty/distinguishabilitty crux is itself relative. By loosing memory something distinguishable can become indistinguishable, augmenting the class of (normal) self-consistent extensions. Then I am open that from the 1 point of view, fusion increases measure, duplication decreases measure; although from the 3 pov it is the contrary. Bruno http://iridia.ulb.ac.be/~marchal/
Re: Quantum Immortality and Information Flow
Le 08-déc.-05, à 22:21, George Levy a écrit : Bruno Marchal wrote: Le 05-déc.-05, à 02:46, Saibal Mitra a écrit : I still think that if you double everything and then annihilate only the doubled person, the probability will be 1. Actually I agree with this. So far we have been talking about splitting universes and people. Let's consider the case where two branches of the universe merge. Of course this is the an hard and interesting question ... I would say that Everett, Deutsch, Hartle somehow answer it in the quantum realm. I would say that empirically or apparently, at the bottom there is neither elimination of information, nor duplication of information. Irreversibility and non cloning. I believe comp entails this too. Got evidence from the interview with the Lobian Machine, but also from some intuitive way to put (first person) measure on the computational histories generated by the UD. In other words, two different paths eventually happen to become identical - At the bottom I don't think this can happens. Like Deutch I think that both bifurcation and fusion are really differentiation and dedifferentiation by *apparent* lack of memory. Remember Y = II If you bifurcate I think you just grow the measure on your past. If you fuse consistently you don't change the measure. To be sure I have also different arguments in favor of an increase of measure when you fuse (loosing memory makes greater your possible histories, like substracting equations in a system of equations augments the possible number of solutions (the Galois connection). All this is very difficult, that I think we should take benefit of Godel, Lob, Solovay and the discovery of the (modal) logic of self-reference G and G* to ask the opinion of a universal machine ... Of course when this happens all their branching futures also become identical. This is not so obvious. You should define a notion of identity for the branches, path, etc. Would you say that such a double branch has double the measure of a single branch even though the two branches are totally indistinguishable? How can you possibly assert that any branch is single, double, or a bundle composed of any number of identical individual branches? Indeed, how? And from which point of view? Bruno http://iridia.ulb.ac.be/~marchal/
Re: Quantum Immortality and Information Flow
Hi Quentin, Stathis, Bruno Quentin Anciaux wrote: Hi Georges, if you start from OMs as basic, then a branch is a set of OMs (only "consistent"/ordered set ?). Then it means a branch is unique. Some part of different branches could overlap, but as I don't understand what could be an absolute measure (meaning it never change and is fixed forever) between all branches, I don't see how to assert the measure of a branch... Also viewing from this point each 1st pov "lives" in its own branch (as a branch is an ordered set of OMs which in turn is associated to a 1st person). Hi Quentin, Stathis, Bruno It all depends how you see the plenitude, OMs and the branching. Is consciousness like a traveller in a network of roads traversing the plenitude, some roads branching some roads merging? If yes then you could have several independent consciousness occupying the same spot, or the same OM. Then their measure at that spot is their sum. This approach is a third person point of view and it leads to the concept of absolute measure. If you see consiousness as the road itself, then measure is not increased after a merge and does not decrease after a split. An OM is just a point on the road. If the road turns unexpectedly to avoids an obstacle (like quantum suicide or just plain death), then consiousness will just move on into a direction which has a low 3-rd person probability but unity first person probability. Viewing consciousness as a network of roads is a first person point of view and it leads to the concept of relative measure: Measure is always 1 where you are. >From a given point you may reach many points - Then measure increases with respect to that point. Or reversibly, from many points you may reach only one point. Then measure decreases. Bruno writes: neither elimination of information, nor duplication of information. The crux of the matter is the concept of indistinguishability: whether you consider two identical persons (OMs) occupying two identical universes the same person (point on the road). It is clear that if you consider the problem from the information angle, then duplication of information does not increase the measure of that information. This would support the relative interpretation of measure. George Quentin Le Jeudi 8 Décembre 2005 22:21, George Levy a écrit : Bruno Marchal wrote: Le 05-déc.-05, à 02:46, Saibal Mitra a écrit : I still think that if you double everything and then annihilate only the doubled person, the probability will be 1. Actually I agree with this. So far we have been talking about splitting universes and people. Let's consider the case where two branches of the universe merge. In other words, two different paths eventually happen to become identical - Of course when this happens all their branching futures also become identical. Would you say that such a double branch has double the measure of a single branch even though the two branches are totally indistinguishable? How can you possibly assert that any branch is single, double, or a bundle composed of any number of identical individual branches? George
Re: Quantum Immortality and Information Flow
Bruno Marchal wrote: Le 05-dc.-05, 02:46, Saibal Mitra a crit : I still think that if you double everything and then annihilate only the doubled person, the probability will be 1. Actually I agree with this. So far we have been talking about splitting universes and people. Let's consider the case where two branches of the universe merge. In other words, two different paths eventually happen to become identical - Of course when this happens all their branching futures also become identical. Would you say that such a double branch has double the measure of a single branch even though the two branches are totally indistinguishable? How can you possibly assert that any branch is single, double, or a bundle composed of any number of identical individual branches? George
Re: Quantum Immortality and Information Flow
Le 05-déc.-05, à 02:46, Saibal Mitra a écrit : I still think that if you double everything and then annihilate only the doubled person, the probability will be 1. Actually I agree with this. This is simply a consequence of using the absolute measure. Ah ? I am not sure this makes sense. If this makes sense, then the Absolute Measurer and the Relative one are closer than I was used to think. The idea is that the future is ''already out there''. Again I agree, but I would say the 2^aleph_0 futures are already out there. That's why we need a measure. I could say that the mathematical shape of that measure should be absolute (the same in all the worlds of the multiverse). The value of the measure with respect to the choice of some experiment is relative. Would you agree? So, the correct picture is not that suddenly the plenitude is made larger because a copy of the person plus (part of) his universe is appended to the plenitude. The plenitude itself is a timeless entity, containing all possible states. If someone wants to carry out a duplication experiment then the results of that are ''already'' present in the plenitude. I agree if you are talking about the 3-plenitude. For the 1-plenitude, the question is more delicate. (G* can show that the 1 and 3 notions of plenitude are the same, but from the machine point of view (either 1 or 3 view) this in not the case at all: the 1-plenitude will look much vaster than the 3-plenitude. This is akin to the Skolem paradox in axiomatic set theory, but also to some carrolian or monthy-python like fantasies where some place look tiny as seen from outside and very big from inside :) When death can be ignored then the apparent time evolution can be described by a relative measure which is given as the ratio of absolute measures taken before and after an experiment (as pointed out by George Levy in a previous reply). Yes but as far as I remember older posts by George Levy, we need also to take into account some fusion of histories, by amnesy or quantum erasure, and this prohibits trust in the use of intuitive probabilities. Then the interview of the Universal machine explains somehow why things are counter-intuitive there (self-reference limitations). Note that the locality of the laws of physics imply that you can never directly experience the past. Yes but then you should make clear if you assume the laws of physics just for illustration or as a fundamental hypothesis. From you other recent post I guess you don't assume the physical laws, just the algorithm (and I add the mathematical execution of those algorithm in platonia. OK? So, if you measure the z-component of a spin polarized in the x-direction, you will find yourself in a state where you have measured, say, spin up, while you have a memory of how you prepaired the spin of the particle, some time before you made the measurement. One thus has to distinguish between the three states: S1: the experimenter prepaires the spin of the particle S2: the experimenter finds spin up while having the memory of being in S1 S3: the experimenter finds spin down while having the memory of being in S1 These three states are ''timeless'' elements of the plenitude. They have their own intrinsic measures. I challenge people on this list to explain why this is not the case. If you have a plenitude you have everything. So, S1, S2 and S3 are just ''out there''. OK. The measure of S2 and S3 are half that of S1. The probability of being in either S2 or S3 is thus the same as being in S1. OK (relatively). 3-point-of- view talk. But if measuring spin down leads to instant death, then the probability of being alive after the experiment is half that of being alive before the experiment. Except that death has no 1-meaning, and should not be taken into account for evaluating a probability question. Here too George Levy argued some time ago that, strictly speaking the probability to find oneself 1-alive is always 1. But here too it is a little delicate because it is a typical pure theological truth, it belongs to G* \ G. I recall G formalizes correctly and completely what sound machines can prove about themselves, and that G* formalizes correctly and completely what is true about the sound machine, but not necessarily provable (that's mainly Solovay theorem). G* \ G literally axiomatizes what sound machines can correctly hope about themselves. Your post makes me doubt the difference between Absolutist and Relativist, about measure, is less big than I was used to think. Bruno http://iridia.ulb.ac.be/~marchal/
Re: Quantum Immortality and Information Flow
Le 03-déc.-05, à 11:12, Stathis Papaioannou a écrit : Bruno Marchal writes: Le 01-déc.-05, à 07:17, Stathis Papaioannou a écrit : Why does an OM need to contain so much information to link it to other OMs making up a person? [the complete message is below]. I am not sure I understand. Are you saying, like Saibal Mitra, that OMs (Observer-Moments) are not related? How, in this case, would you interpret your own talk about next observer moment (those which could be dead end)? Is there not a confusion between the idea of physicalist (causal) view of the relation between OMs (which, as Brent meeker said should be explained from a more primitive (mathematical, immaterial, not causal, ...) notion of OM, with those very (more primitive) OMs. Are you assuming some notion of multiverse richer than (or just different from) a notion of multi-OMs? In our ordinary experience, the OMs making up an individual's stream of consciousness are causally related by virtue of the fact that that they occur inside the same brain. If we consider thought experiments involving teleportation or mind uploading, again the sequential OMs are causally related due to transfer of the relevant brain pattern (or whatever) information. However, this information tranfer is not actually *necessary* for the OMs to be experienced as moments in the same stream of consciousness. Say an observer experiencing OM a1 enters a teleporter which then causes another observer experiencing OM a2 to be created at the receiving station. Then a1 and a2 are sequential OMs, constituting a stream of consciousness a1a2 sampled from the life of an individual. If this is so, then if a1 occurs anywhere in the multiverse, and a2 occurs anywhere else, the same stream of consciousness a1a2 should be experienced - even if a1 and a2 occur completely at random, with no causal link between them. No causal link. OK. But there is an arithmetical or computer-science-theoretical link. This includes memories, consistency conditions, etc. I am agnostic regarding the question of whether OMs are primitive or derivative. The world could be as it appears: the physical universe (whatever that means) gives rise to certain special physical processes which result in moments of conscious experience, and those moments which are related through being the product of circumscribed subsets of physical processes constitute a stream of consciousness in an individual life. On the other hand, in a world where exactly the same OMs as postulated in the previous sentence exist, but all mixed up and not connected to any (or any particular) physical process, exactly the same individual streams of consciousness would result. OK. So why ever postulate a physical world, given that the OMs you describe already exist independently of us (in arithmetical platonia), and that nobody has ever succeed in explaining what a primitive physical world could be, and that nobody has ever succeed in relating OMs as lived by people and some putative concrete substantial reality? I think that with OCCAM, any notion of computationalist OMs, makes the idea of a ontologically primitive physical multiverse useless. (and the Olympia/movie-graph makes it senseless, but here I would say that remark is off-topic). Bruno http://iridia.ulb.ac.be/~marchal/
Re: Quantum Immortality and Information Flow (was off-list)
Hi Stathis,
Hi Bruno,
I replied to the first part of your post earlier, but it took a bit
more time to digest the rest. For what it is worth, I have included my
thinking out loud below.
Thanks for replying, and thanks for authorizing me to comment online.
Mhh I know this could look like jargon. Let me give
easy exercises for anybody following this list.
Let me define a Multiverse (called also frame by Kripke) as any
non-empty set W together with an accessibility relation R defined on
the set. Elements of that set are called world, by definition, and
I follow the convention to denote worlds by greek letters (or their
english transcription: alpha, beta, gamma, delta, eta, epsilon, iota,
kappa, omega, nu, theta, etc.). R is called the accessibility
relation.
Is W the entire multiverse, containing everything past, present and
future, or is it a snapshot of the multiverse at a particular time
point? If it contains everything, are the elements then snapshots of
particular worlds at particular times?
Does R operate on W mapping its elements to another set, or does it
indicate that a particular element of W is related to another element?
What exactly does accessibility mean in reality? Does it mean a
world is accessible from my present situation if it is possible that I
will experience that world in my subjective future? What is and isn't
accessible in this sense is subject to debate, rather than being
self-evident.
I totally agree with you. The point of modal logic and their multiverse
semantics does not consist in closing that debate, but just in giving
us a tool to manage the subtleties inherent with the subject. As you
correct yourself below, W is any (non-empty) set, and R is any relation
mapping some element of W to element(s) of W. One element goes to zero,
one, or more elements. W cannot be empty, by definition, but R can be.
I am really acting like mathematicians are used to act. I provide a
very general notion of multiverse: any set with any binary relation
will do. Only later we will reason to find out which multiverses are
more interesting than others, for example with respect to the measure
problem, or the 1-3 distinction problem, or the comp hyp, etc.
At this point anybody should be able to begin a list of all
multiverses, or at least the finite one ...
The list will be like (with set notation):
{a} with R = empty
{a} with R = {(a,a)}
{a,b} with R = empty
{a,b} with R = {(a,a)}
{a, b} with R = {(b,b)}
{a, b} with R = {(a,a),(b,b)}
{a, b} with R = {(a,a), (a,b), (b,b)}
{a, b} with R = {(a,a) (a, b)}
{a, b} with R = {(a,b)(b,b}}
etc.
I use set notations because I cannot make drawings here, but please
translate all those description into little drawings, it is much more
readable. To say R = {(a,a) (a,b)} is the same as saying that aRa and
aRb, that is (in multiverse terms): the world a can reach the world a,
and the world a can reach the world b. In a drawing the world are
points and the relation are arrows from a to b when aRb, etc. OK?
The very nature of the worlds a, b, c is left unspecified, and the
relation of accessibility R is entirely defined by its graph (its set
of inputs/outputs).
The multiverse {a} and the multiverse {b} really denote the same
multiverse if nothing special is said about a and b. Snobbish
algebraists would say they are isomorphic, and that could be wise at
some point, but that would be too much at this stage.
So the simplest example of multiverse is given by the set {alpha} +
the empty relation (so just one dead end!). Another example is the
set of natural numbers with the divisibility relation ( n R m iff n
divide m iff there is a k such that n * k = m).
OK, I think this means R indicates one element in W is related to
another element in W.
Yes indeed.
Let me define a notion of illuminated multiverse (called model by
the modal logicians). It is just a Kripke multiverse where we
associate to each world a value 1 or 0 to each sentence letter. The
Kripke multiverse is illuminated when a truth value (1 or 0) is
assigned to each proposition, in each world.
Remember that in (propositional) logic we have sentence letter p, q,
r, etc.
We also say that p is true in alpha for p has value 1 in alpha (in
some illuminated multiverse).
To clarify: each world alpha, beta etc. in W contains many
propositions p, q, r etc., and W is called illuminated when we know
for each proposition whether it is true (1) or false (0).
Yes, except I prefer to say that a proposition is true at or in a
world, instead of saying the proposition is in the world.
This confuses me a bit, because I think of physical worlds as
containing things, not propositions.
Just what I was saying! Except that I am not limiting myself to
physical worlds.
I suppose you could redefine a world as containing only propositions.
There is a sense to do that, once the multiverse is
Re: Quantum Immortality and Information Flow (was off-list)
Bruno Marchal wrote: ... What could this mean in a real world example? Take W as the set of places in Brussels. Take R to be accessible by walking in a finite number of foot steps. Then each places at Brussels is accessible from itself, giving that you can access it with zero steps, or two steps (forward, backward, ...). Take W as the set of humans, say that aRb if a can see directly, without mirror, the back of b. Then a can access all humans except themselves. R is said to be irreflexive. Another important concrete example, which will help us latter to study the modal logic of quantum logic. Take the worlds to be the vector of an Hilbert Space (or of the simpler 3-dimensional euclidian space). Say that a is accessible to b, i.e. aRb, if the scalar product of a and b is non null (i.e. a and b are not orthogonal). These are good illustrative examples, but how do they apply to worlds that just consist of propositions? What is the relation of accessibility in the p,q,r world(s)? Is it negation? Brent Meeker
Re: Quantum Immortality and Information Flow
Le 05-déc.-05, à 22:49, Russell Standish a écrit : On Mon, Dec 05, 2005 at 03:58:20PM +0100, Bruno Marchal wrote: Well at least this isn't a problem of translation. But I still have difficulty in understanding why Pp=Bp -B-p should be translated into English as to bet on p (or for that matter pourquoi on devrait le traduire par a parier a p) For me Bp -B-p is simply a statement of consistency - perhaps what we mean by mathematical truth. ... So probability of p (in world alpha) is equal to one is well captured by BpDp (in world alpha). This means (Kripke-semantically) p is true in all accessible world there is at least one possible world where true is false. ... Tell me if this is clear enough. Euh I hope you agree that To bet on p can be used for the probability one, of course. If that is the problem, remember I limit myself to the study of the probability one and its modal dual probability different from zero. I must go now and I have not really the time to reread myself, hope I manage the s correctly. Apology if not. Please ask any question if I have been unclear. Bruno http://iridia.ulb.ac.be/~marchal/ Yes - this does make sense. Kripke frames are a good way of explaining why BpDp captures prob=1 type statements. I'm still not sure bet on is the correct verb though, as in normal life one bets on things with prob 1 (eg on a horse winning a race). Prob=1 is a sure bet, but I can't quite think of an appropriate verb. Well thanks, and sure bet is probably better than my phrasing. It is really the particular case of probability one. I will surely explain asap why Quantum Logic can be interpreted as the logic of probability one in quantum mechanics. This has been single out by Maria Louisa Dalla Chiara, the quantum logician of Florence (Firenze) Italy, but it was the main basic motivation of von Neumann when he opened the field of quantum logic. Let me give you the main result (by Goldblatt) connecting quantum logic and modal logic. It is a theorem of representation of quantum logic into modal logic. There exist a function R translating quantum logic in modal logic. R can be described recursively in the following way: The atomic statement p are interpreted by the quantization(*) BDp. i.e R(p) = BDp the negative statement ~A is interpreted by B~R(A), i.e, R(~A) = B~R(A) conjonction: R(A B) = R(A) R(B). Goldblatt proved that MQL proves A iff the modal logic B proves R(A) MQL is for Minimal Quantum Logic (the result can be extended to the standard orthomodular quantum logic). And B is the logic having as 1) axioms: K, T, and LASE (p - BDp), the little abstract Schroedinger equation); 2) inferences rules: Modus ponens and Necessitation rule. (Those who have forget should search LASE in the archive). Exercise: could someone guess which multiverses (W,R) makes LASE valid (true in all worlds for all illumination on the worlds)? Answer: R need just to be symmetrical. See why? More explanation soon. I intend to answer an off-line mail by Stathis who asks good questions, asap (not today, probably tomorrow). Later I will explain how the translation of the UDA (Universal Dovetailer Argument) in the language of a lobian machine gives rise to LASE for the probability 1, the sure bets. Cheers, Bruno (*) The term quantization in this setting has been introduced by Rawling and Selesnick in a paper where they modelize a quantum NOT with the modal logic B. Reference and abstract here: http://portal.acm.org/citation.cfm?id=347481. http://iridia.ulb.ac.be/~marchal/
Rép : Quantum Immortality and Information Flow
Le 03-déc.-05, à 15:14, Saibal Mitra a écrit : Yes, but it's a fact that there exists laws of physics. I am of the opinion that what really exists is an ensemble of algorithms and that the laws of physics is a consequence of this. OK. (Except I am not sure that the existence of physical laws are a fact, just an inference from facts). Whatever your starting point, you'll end up with an absolute measure over the set of all OMs. That is an open question for me (absolute measure still does not make sense for me and for ... the lobian machine). But even if that is true it is not clear for me if such a measure could be relevant. But this is again the Relative/Absolute sampling debate. Once I got a little bit more time I will explain why an absolute measure would need an S5 modal logic, the one which cannot really appear in the lobian talk ... Sorry to invoke the lobian beast so often, but I'm only his humble messenger ... ;) Bruno http://iridia.ulb.ac.be/~marchal/
Re: Quantum Immortality and Information Flow
On Mon, Dec 05, 2005 at 03:58:20PM +0100, Bruno Marchal wrote: Well at least this isn't a problem of translation. But I still have difficulty in understanding why Pp=Bp -B-p should be translated into English as to bet on p (or for that matter pourquoi on devrait le traduire par a parier a p) For me Bp -B-p is simply a statement of consistency - perhaps what we mean by mathematical truth. ... So probability of p (in world alpha) is equal to one is well captured by BpDp (in world alpha). This means (Kripke-semantically) p is true in all accessible world there is at least one possible world where true is false. ... Tell me if this is clear enough. Euh I hope you agree that To bet on p can be used for the probability one, of course. If that is the problem, remember I limit myself to the study of the probability one and its modal dual probability different from zero. I must go now and I have not really the time to reread myself, hope I manage the s correctly. Apology if not. Please ask any question if I have been unclear. Bruno http://iridia.ulb.ac.be/~marchal/ Yes - this does make sense. Kripke frames are a good way of explaining why BpDp captures prob=1 type statements. I'm still not sure bet on is the correct verb though, as in normal life one bets on things with prob 1 (eg on a horse winning a race). Prob=1 is a sure bet, but I can't quite think of an appropriate verb. Cheers -- *PS: A number of people ask me about the attachment to my email, which is of type application/pgp-signature. Don't worry, it is not a virus. It is an electronic signature, that may be used to verify this email came from me if you have PGP or GPG installed. Otherwise, you may safely ignore this attachment. A/Prof Russell Standish Phone 8308 3119 (mobile) Mathematics0425 253119 () UNSW SYDNEY 2052 [EMAIL PROTECTED] Australiahttp://parallel.hpc.unsw.edu.au/rks International prefix +612, Interstate prefix 02 pgp5FSJa3RF9L.pgp Description: PGP signature
Re: Quantum Immortality and Information Flow
I'm perhaps missing something here. In a no-collapse interpretation of QM, doesn't everything double every moment? So, if only one of the doubled versions of a person is annihilated, doesn't this mean the probability of survival is 1? Although the plenitude is timeless, containing all possible states, we self-aware substructures certainly experience the illusion (if you prefer, the emergent phenomenon) of time. When I consider which parts of the plenitude are of selfish interest to me, I need only consider those parts which I perceive to be in my unique present or in my pluripotent future. More narrowly, I need only consider those parts which I perceive to be in my immediate future - my next conscious moment - since it is only through this process, a moment at a time, that potential future experiences become actual present experiences, rather than irrelevant side-branches, such as the version of me who migrated to New Zealand when I was 5 years old. What this means is that when I consider the subjective probability of what will happen to me in the next moment, I don't have to think about those versions of me which are in the past, in the far future, have turned into George Bush or are dead. I could put this differently: as a matter of fact, it is not incorrect to say that I will suddenly become 5 years old again, or turn into Geoge Bush, since all these states exist timelessly in the plenitude and there is no absolute sense in which it can be said that one state becomes another state. However, from my selfish point of view, when I consider the next moment, all those other states are irrelevant. The only relevant states are those which count as my next moment, as normally understood by humans. Where there are multiple candidate next moments, the probability that I will experience one of them depends on the relative measure of each in the plenitude. If there is no candidate next moments at all, then I will die. Stathis Papaioannou Saibal Mitra writes: I still think that if you double everything and then annihilate only the doubled person, the probability will be 1. This is simply a consequence of using the absolute measure. The idea is that the future is ''already out there''. So, the correct picture is not that suddenly the plenitude is made larger because a copy of the person plus (part of) his universe is appended to the plenitude. The plenitude itself is a timeless entity, containing all possible states. If someone wants to carry out a duplication experiment then the results of that are ''already'' present in the plenitude. When death can be ignored then the apparent time evolution can be described by a relative measure which is given as the ratio of absolute measures taken before and after an experiment (as pointed out by George Levy in a previous reply). Note that the locality of the laws of physics imply that you can never directly experience the past. So, if you measure the z-component of a spin polarized in the x-direction, you will find yourself in a state where you have measured, say, spin up, while you have a memory of how you prepaired the spin of the particle, some time before you made the measurement. One thus has to distinguish between the three states: S1: the experimenter prepaires the spin of the particle S2: the experimenter finds spin up while having the memory of being in S1 S3: the experimenter finds spin down while having the memory of being in S1 These three states are ''timeless'' elements of the plenitude. They have their own intrinsic measures. I challenge people on this list to explain why this is not the case. If you have a plenitude you have everything. So, S1, S2 and S3 are just ''out there''. The measure of S2 and S3 are half that of S1. The probability of being in either S2 or S3 is thus the same as being in S1. But if measuring spin down leads to instant death, then the probability of being alive after the experiment is half that of being alive before the experiment. _ Buy now @ Tradingpost.com.au http://a.ninemsn.com.au/b.aspx?URL=http%3A%2F%2Fad%2Eau%2Edoubleclick%2Enet%2Fclk%3B23850242%3B12217581%3Bw%3Fhttp%3A%2F%2Fwww%2Etradingpost%2Ecom%2Eau%2F%3Freferrer%3DnmsnHMetag_t=11482_r=emaildec05_m=EXT
Re: Quantum Immortality and Information Flow
Hi Saibal, Le Samedi 3 Décembre 2005 02:15, Saibal Mitra a écrit : Correction, I seem to have misunderstood Statis' set up. If you really create a new world and then create and kill the person there then the probability of survival is 1. This is different from quantum mechanical branch splitting. To see this, consider first what would have happened had the person not been killed. Then his measure would have doubled. But because he is killed in one of the two copies of Earth, his measure stays the same. In a quantum suicide experiment his measure would be reduced by a factor two. His measure would be reduced by a factor two relative to what ? Do you mean there exists an absolute measure ? Quentin
Re: Quantum Immortality and Information Flow
On Mon, Nov 21, 2005 at 03:39:58PM +0100, Bruno Marchal wrote: Observation is implicitly defined here by measurement capable of selecting alternatives on which we are able to bet (or to gamble ?). The french word is parier. Well at least this isn't a problem of translation. But I still have difficulty in understanding why Pp=Bp -B-p should be translated into English as to bet on p (or for that matter pourquoi on devrait le traduire par a parier a p) For me Bp -B-p is simply a statement of consistency - perhaps what we mean by mathematical truth. Cheers -- *PS: A number of people ask me about the attachment to my email, which is of type application/pgp-signature. Don't worry, it is not a virus. It is an electronic signature, that may be used to verify this email came from me if you have PGP or GPG installed. Otherwise, you may safely ignore this attachment. A/Prof Russell Standish Phone 8308 3119 (mobile) Mathematics0425 253119 () UNSW SYDNEY 2052 [EMAIL PROTECTED] Australiahttp://parallel.hpc.unsw.edu.au/rks International prefix +612, Interstate prefix 02 pgpkcUOk05h9X.pgp Description: PGP signature
Re: Quantum Immortality and Information Flow
This doubling of the absolute measure is important. In another posting you wrote about being teleported to many places and then being annihilated everywhere except at the original place. This won't affect the probability of being alive at the original place. But in a QC experiment where you have many outcomes, all leading to death except one, the probability of experiencing that branch is very small. - Original Message - From: Stathis Papaioannou [EMAIL PROTECTED] To: [EMAIL PROTECTED]; everything-list@eskimo.com Sent: Saturday, December 03, 2005 11:38 AM Subject: Re: Quantum Immortality and Information Flow Well, I did actually intend my example to be analogous to the Tegmark QS experiment. Are you saying that if there is only one world and magically an identical, separate world comes into being this is fundamentally different to what happens in quantum branch splitting? It seems to me that in both cases the relative measure of everything in the world stays the same, even though in absolute terms there is double of everything. Stathis Papaioannou Saibal Mitra writes: Correction, I seem to have misunderstood Statis' set up. If you really create a new world and then create and kill the person there then the probability of survival is 1. This is different from quantum mechanical branch splitting. To see this, consider first what would have happened had the person not been killed. Then his measure would have doubled. But because he is killed in one of the two copies of Earth, his measure stays the same. In a quantum suicide experiment his measure would be reduced by a factor two. If on the basis of a coin toss the world splits, and in one branch I am instantaneously killed while in the other I continue living, there are several possible ways this might be interpreted from the 1st person viewpoint: (a) Pr(I live) = Pr(I die) = 0.5 (b) Pr(I live) = 1, Pr(I die) = 0 (c) Pr(I live) = 0, Pr(I die) = 1 _ Buy now @ Tradingpost.com.au http://a.ninemsn.com.au/b.aspx?URL=http%3A%2F%2Fad%2Eau%2Edoubleclick%2Enet%2Fclk%3B23850242%3B12217581%3Bw%3Fhttp%3A%2F%2Fwww%2Etradingpost%2Ecom%2Eau%2F%3Freferrer%3DnmsnHMetag_t=11482_r=emaildec05_m=EXT
Re: Quantum Immortality and Information Flow
There is, of course, a difference between being duplicated so that there are multiple copies of you in the one Universe, as in teleportation, and being duplicated along with the rest of the Universe as a result of MWI branching. In the former case your relative measure increases and problems will arise when it comes to deciding who will get the spouse, house, bank account etc. In the latter case your relative measure stays the same because everything else is duplicated along with you and nothing will seem to have changed. You agree that in the teleportation example if your duplicate is instantaneously annihilated the moment he comes into being, you will continue living with probability 1, as if the duplication had not taken place. On the other hand, in the MWI branching example, you would argue that if your duplicate in one of the branches is annihilated, then your subjective probability of survival is 1/2. Now, suppose that instead of just you the entire Earth, or Galaxy, or Universe is duplicated along with you, while as before your duplicate (and only he) is annihilated the moment he comes into being on the new Earth (or Galaxy, or Universe). It could be argued that your measure relative to the rest of the Universe (or that part of it which is duplicated) has now decreased. Is your expectation of survival in this case more like the original teleportation example, or more like the MWI branching example? Stathis Papaioannou Saibal Mitra writes: This doubling of the absolute measure is important. In another posting you wrote about being teleported to many places and then being annihilated everywhere except at the original place. This won't affect the probability of being alive at the original place. But in a QC experiment where you have many outcomes, all leading to death except one, the probability of experiencing that branch is very small. - Original Message - From: Stathis Papaioannou [EMAIL PROTECTED] To: [EMAIL PROTECTED]; everything-list@eskimo.com Sent: Saturday, December 03, 2005 11:38 AM Subject: Re: Quantum Immortality and Information Flow Well, I did actually intend my example to be analogous to the Tegmark QS experiment. Are you saying that if there is only one world and magically an identical, separate world comes into being this is fundamentally different to what happens in quantum branch splitting? It seems to me that in both cases the relative measure of everything in the world stays the same, even though in absolute terms there is double of everything. Stathis Papaioannou Saibal Mitra writes: Correction, I seem to have misunderstood Statis' set up. If you really create a new world and then create and kill the person there then the probability of survival is 1. This is different from quantum mechanical branch splitting. To see this, consider first what would have happened had the person not been killed. Then his measure would have doubled. But because he is killed in one of the two copies of Earth, his measure stays the same. In a quantum suicide experiment his measure would be reduced by a factor two. If on the basis of a coin toss the world splits, and in one branch I am instantaneously killed while in the other I continue living, there are several possible ways this might be interpreted from the 1st person viewpoint: (a) Pr(I live) = Pr(I die) = 0.5 (b) Pr(I live) = 1, Pr(I die) = 0 (c) Pr(I live) = 0, Pr(I die) = 1 _ Buy now @ Tradingpost.com.au http://a.ninemsn.com.au/b.aspx?URL=http%3A%2F%2Fad%2Eau%2Edoubleclick%2Enet%2Fclk%3B23850242%3B12217581%3Bw%3Fhttp%3A%2F%2Fwww%2Etradingpost%2Ecom%2Eau%2F%3Freferrer%3DnmsnHMetag_t=11482_r=emaildec05_m=EXT _ Express yourself instantly with MSN Messenger! Download today - it's FREE! http://messenger.msn.click-url.com/go/onm00200471ave/direct/01/
Re: Quantum Immortality and Information Flow
Correction, I seem to have misunderstood Statis' set up. If you really create a new world and then create and kill the person there then the probability of survival is 1. This is different from quantum mechanical branch splitting. To see this, consider first what would have happened had the person not been killed. Then his measure would have doubled. But because he is killed in one of the two copies of Earth, his measure stays the same. In a quantum suicide experiment his measure would be reduced by a factor two. - Original Message - From: Saibal Mitra [EMAIL PROTECTED] To: Stathis Papaioannou [EMAIL PROTECTED]; [EMAIL PROTECTED]; Jesse Mazer [EMAIL PROTECTED] Cc: everything-list@eskimo.com Sent: Sunday, November 27, 2005 02:25 AM Subject: Re: Quantum Immortality and Information Flow The answer must be a) because (and here I disagree with Jesse), all that exists is an ensemble of isolated observer moments. The future, the past, alternative histories, etc. they all exist in a symmetrical way. It don't see how some states can be more ''real'' than other states. Of course, the universe we experience seems to be real to us while alternative universes, or past or future states of this universe are not being experienced by us. So, you must think of yourself at any time as being randomly sampled from the set of all possible observer moments. To get to answer b) you have to redefine your identity so that experiencing having done the experiment becomes a necessary part of your identity. But this is cheating because you wouldn't say that if ''death'' were replaced by a partial memory erasure such that the experience of having done the experiment were wiped out form your memory. - Original Message - From: Stathis Papaioannou [EMAIL PROTECTED] To: [EMAIL PROTECTED] Cc: everything-list@eskimo.com Sent: Saturday, November 26, 2005 11:51 AM Subject: Re: Quantum Immortality and Information Flow Stathis Papaioannou writes: If on the basis of a coin toss the world splits, and in one branch I am instantaneously killed while in the other I continue living, there are several possible ways this might be interpreted from the 1st person viewpoint: (a) Pr(I live) = Pr(I die) = 0.5 (b) Pr(I live) = 1, Pr(I die) = 0 (c) Pr(I live) = 0, Pr(I die) = 1 Even on this list, there are people who might say (a) above is the case rather than (b) or (c). Bruno Marchal replies: Are you sure? I was thinking of people who accept some ensemble theory such as MWI, but don't believe in QTI. I must admit, I find it difficult to understand how even a dualist might justify (a) as being correct. Would anyone care to help? Stathis _ Start something musical - 15 free ninemsn Music downloads! http://ninemsn.com.au/share/redir/adTrack.asp?mode=clickclientID=667referral=HotmailTaglineNovURL=http://www.ninemsn.com.au/startsomething
Re: Quantum Immortality and Information Flow
Saibal Mitra wrote: Correction, I seem to have misunderstood Statis' set up. If you really create a new world and then create and kill the person there then the probability of survival is 1. This is different from quantum mechanical branch splitting. To see this, consider first what would have happened had the person not been killed. Then his measure would have doubled. But because he is killed in one of the two copies of Earth, his measure stays the same. In a quantum suicide experiment his measure would be reduced by a factor two. To say that measure is doubled or halved it is not sufficient to take the measure at the final point. You really must compare measure at two points, in effect take a ratio. So depending where the initial point is you could come to different conclusions. If your initial point is before the new world is created (and the clone in that world is killed), then, you are right. There is no change in the measure of the original person. However, if the initial point is taken after the world is created but before the clone is killed, then the measure of the clone goes to zero "in that world." One could always argue that the world branches and the clone continues living in other worlds. George
Re: Quantum Immortality and Information Flow
Why does an OM need to contain so much information to link it to other OMs making up a person? I certainly don't spend every waking moment reminding myself of who I am, let alone going over my entire past history, and I still think all my thoughts are my thoughts. I don't think that the fact these thoughts are contained in my head makes the difference, because as you seemed to agree, continuity of consciousness can in theory extend over discontinuities in time and/or space, as in teleportation. On the other hand, I could suddenly become psychotic and as a result believe I am a completely different person, with a different past; or perhaps my mind could be taken over by an alien intelligence with a similar effect. As for one OM potentially representing a thought from thousands of different people, that is exactly what happens in the multiverse and is one of the key advantages of the concept. Suppose you and I happened to have *exactly* the same subjective experience at a particular time, say seeing a red shape on a white wall at the age of two. This would mean that, for that moment, your mind and my mind could have been interchanged, or one of our two minds could have been temporarily suspended, without making any subjective difference to either of us. An external observer monitoring my body might have noticed a momentary blankness if my mental processes were suspended at the moment of coincidence, but as far as I was concerned, it would have been exactly the same as if I were teleported away to have the red shape experience (which I would have had anyway) and teleported back. Stathis Papaioannou Stathis Papaioannou wrote: Brent Meeker writes: I agree with all you have written below as an explication of what we mean by a person in the multiverse. But it assumes an objective spacetime in order to define persons by causal continuity. I thought the point of OMs was to provide a fundamental ontology from which spacetime would be constructed. While it always seems in real life, as in my example, that there is a causal connection between related OMs, this need not necessarily be the case. For a2 to think, I stepped into the teleporter a moment ago and to consider himself the person a1a2, it is sufficient simply that a2 exist. That is, given that a2 exists, it makes no difference whether there is information transfer from a1 to a2, whether a1 precedes a2, or whether a1 exists at all. In general, if the only thing that exists is the set of all possible OMs, not ordered in any particular way and each OM completely independent and isolated, then the apparent multiverse with its complex physical laws results as an emergent phenomenon, or if you prefer, an illusion. That's taking an OM to be like Barbour's time capsule. They are ordered according to their contents. a1a2's OM with the thought that he was in a teleporter and was a1, connects to a1's OM with the thought that now I am stepping into a teleporter. But that brings me back to my objection to OMs. Barbour's time capsules contain whole states of the world. OMs don't have enough information to provide the specificity required for connections. a1a2's OM thought could be the thought of thousands of other people. To be sure, if we take a sequence of a1a2's thoughts and lump them into one OM then that OM will have enough information to place in a unique sequence indentifying a person. But then we've really assumed the thing to be explained. Brent Meeker _ Start something musical - 15 free ninemsn Music downloads! http://ninemsn.com.au/share/redir/adTrack.asp?mode=clickclientID=667referral=HotmailTaglineNovURL=http://www.ninemsn.com.au/startsomething
Re: Quantum Immortality and Information Flow
- Original Message - From: Jonathan Colvin [EMAIL PROTECTED] To: everything-list@eskimo.com Sent: Sunday, November 27, 2005 05:49 AM Subject: RE: Quantum Immortality and Information Flow Saibal wrote: The answer must be a) because (and here I disagree with Jesse), all that exists is an ensemble of isolated observer moments. The future, the past, alternative histories, etc. they all exist in a symmetrical way. It don't see how some states can be more ''real'' than other states. Of course, the universe we experience seems to be real to us while alternative universes, or past or future states of this universe are not being experienced by us. So, you must think of yourself at any time as being randomly sampled from the set of all possible observer moments. delurk I'm not sure how this works. Suppose I consider my state now at time N as a random sample of all observer moments. Now, after having typed this sentence, I consider my state at time N + 4 seconds. Is this also a random sample on all observer moments? I can do the same at now N+10, and so-on. It seems very unlikely that 3 random samples would coincide so closely. So in what sense are these states randomly sampled? It's a bit like symmetry breaking. You have an ensemble of all possible observer moment, but each observer moment can only experience its own state. So, the OM samples itself. There exists an observer moment representing you at N seconds, at N + 4 seconds and at all possible other states. They all ''just exist'' in the plenitude, as Stathis wrote. The OM representing you at N + 4 has the memory of being the OM at N. Subjectively the OMs experience time evolution, even though the plenitude itself doesn't have a time evolution at the fundamental level. Although it is a bit strange to think about time evolution in this way, it is necessary to resolve paradoxes you get when contemplating doubling and suicide experiments. It is precisely in these cases that our naive notion of time evolution breaks down. Saibal
Re: Quantum Immortality and Information Flow
Stathis Papaioannou wrote: Brent Meeker writes: [quoting Saibal Mitra] There exists an observer moment representing you at N seconds, at N + 4 seconds and at all possible other states. They all ''just exist'' in the plenitude, as Stathis wrote. The OM representing you at N + 4 has the memory of being the OM at N. This I find confusing. How is there memory associated with an obserever moment? Is it equivocation on memory? As an experience, remembering something takes much longer than what I would call a moment. It may involve a sequence images, words, and emotions. Of course in a materialist model of the world the memories are coded in the physical configuration of your brain, even when not being experienced; but an analysis that takes OM's as fundamental can't refer to that kind of memories. It is true that human cognition, memories etc. are not instantaneous. There are two ways to keep the OM concept useful despite this. One is to extend each moment so that it encompasses, for example, the minimum period of awareness (probably a substantial fraction of a second), or any interval of arbitrary length, such as the waking hours of a day. This still allows one to think about questions involving continuity of personal identity where multiple copies or near-copies of a given mind are running simultaneously, the interval of the OMs under consideration being tailored to the particular situation. But giving OMs duration seems to invite other incoherence. It means that time cannot be understood as a sequence of timeless OMs. On the other hand it solves more than just the memory problem; if OMs have duration, then the durations could overlap and thus define worlds and personal identity - i.e. provide the accessiblity relation. The other way is to bite the bullet and allow instantaneous part-cognitions. A memory is then only associated with an OM during the act of remembering, and each instantaneous OM covers only an instant of that act, in the same way a frame in a film covers only an instant of the action depicted by the series of frames. I have difficultly with an instant of cognition. A film records an instant of spatial relations, but how is one to understand a non-extensive, instant of cognition - certainly not by simple introspection. But it seems that getting an explanation of the world via introspection is why OMs were appealing in the first place. Brent Meeker
Re: Quantum Immortality and Information Flow
Stathis Papaioannou wrote: I was thinking of people who accept some ensemble theory such as MWI, but don't believe in QTI. I must admit, I find it difficult to understand how even a dualist might justify (a) as being correct. Would anyone care to help? What do you think of my argument here? http://www.mail-archive.com/everything-list@eskimo.com/msg04692.html
Re: Quantum Immortality and Information Flow
Le Samedi 26 Novembre 2005 18:47, Jesse Mazer a écrit : Stathis Papaioannou wrote: I was thinking of people who accept some ensemble theory such as MWI, but don't believe in QTI. I must admit, I find it difficult to understand how even a dualist might justify (a) as being correct. Would anyone care to help? What would be the meaning to accept solution a ? Are we only sentient entities for a small(art) moment ? It sounds stupid to only be sentient for a moment... just because a moment has no meaning for entities like us. Like I like to repeat, what could it means to not be self aware... ? Could we as first person perspective be aware of not being aware ? It sounds non sense. While I agree it is quite of topic.. this is something that I got lot of interest into. Why are we looking for a consistent meaning of our own life ? Quentin
RE: Quantum Immortality and Information Flow
Saibal wrote: The answer must be a) because (and here I disagree with Jesse), all that exists is an ensemble of isolated observer moments. The future, the past, alternative histories, etc. they all exist in a symmetrical way. It don't see how some states can be more ''real'' than other states. Of course, the universe we experience seems to be real to us while alternative universes, or past or future states of this universe are not being experienced by us. So, you must think of yourself at any time as being randomly sampled from the set of all possible observer moments. delurk I'm not sure how this works. Suppose I consider my state now at time N as a random sample of all observer moments. Now, after having typed this sentence, I consider my state at time N + 4 seconds. Is this also a random sample on all observer moments? I can do the same at now N+10, and so-on. It seems very unlikely that 3 random samples would coincide so closely. So in what sense are these states randomly sampled? Jonathan Colvin
Re: Quantum Immortality and Information Flow
Stathis Papaioannou wrote: Stathis Papaioannou writes: If on the basis of a coin toss the world splits, and in one branch I am instantaneously killed while in the other I continue living, there are several possible ways this might be interpreted from the 1st person viewpoint: (a) Pr(I live) = Pr(I die) = 0.5 (b) Pr(I live) = 1, Pr(I die) = 0 (c) Pr(I live) = 0, Pr(I die) = 1 Your example underscores the need for interpreting Pr as a relative concept ( this is my favorite point of view): c) is A observing A. It is seen through the first person A who is killed in one branch and live in another branch. This is called the first person on this list. a) is B observing A: It is seen through a first person B who witnesses the event hapenning to A but lives in both branches. His point of view is called the third person on this list: b) is C observing A. It is seen through a first person C who experiences the complement events of A. He lives when A dies and vice versa. The probability that he will see A live is 0. We do not have a name for this point of view on this list but I could suggest the complement first person. Thus all answers are correct depending on your relative point of view. George
Re: Quantum Immortality and Information Flow
Please disregard previous post. The b and c cases were inverted. Stathis Papaioannou wrote: Stathis Papaioannou writes: If on the basis of a coin toss the world splits, and in one branch I am instantaneously killed while in the other I continue living, there are several possible ways this might be interpreted from the 1st person viewpoint: (a) Pr(I live) = Pr(I die) = 0.5 (b) Pr(I live) = 1, Pr(I die) = 0 (c) Pr(I live) = 0, Pr(I die) = 1 Your example underscores the need for interpreting Pr as a relative concept ( this is my favorite point of view): b) is A observing A. It is seen through the first person A who is killed in one branch and live in another branch. This is called the first person on this list. a) is B observing A: It is seen through a first person B who witnesses the event hapenning to A but lives in both branches. His point of view is called the third person on this list: c) is C observing A. It is seen through a first person C who experiences the complement events of A. He lives when A dies and vice versa. The probability that he will see A live is 0. We do not have a name for this point of view on this list but I could suggest the complement first person. Thus all answers are correct depending on your relative point of view. George
Re: Quantum Immortality and Information Flow
Bruno Marchal writes: If on the basis of a coin toss the world splits, and in one branch I am instantaneously killed while in the other I continue living, there are several possible ways this might be interpreted from the 1st person viewpoint: (a) Pr(I live) = Pr(I die) = 0.5 I hope everyone sees that this (a) is not defensible once we *assume* comp. Good, we agree here. I don't think everyone on this list would agree. (b) Pr(I live) = 1, Pr(I die) = 0 And this one (b) is a consequence of comp. (c) Pr(I live) = 0, Pr(I die) = 1 Option (c) may look a bit strange but is the one that I favour: all first person experiences are transient, all branches are dead ends, no world is accessible from any other world. I think I figure out why you say that and why you take it probably as a consequence of comp. Let us see. However, the various independent, transient observer moments are ordered in such a way in what we experience as ordinary life that the illusion of (b) occurs. Yes right. But that illusion is all what the first person notion is all about. Your c is too strong. What would you say if your comp doctor proposes you an artificial brain and adds that the Pr(I die), for you, is 1. I think you would say no doctor. Then the doctor (not you!, I know you are doctor!) adds that in all case Pr(I die) = 1. Then you will tell him that he has not given any clue about the probability your first person illusion (I hate this word) lasts. The real question we ask to the doctor is what is the probability my illusion will lasts *as* it lasts for any other medical operation when it is said the operation has been successful. What I have called Papaioannou's multiverse are just your transient observer moments *together* with the order you are indeed adding on them for giving sense to ordinary experience. That order *is* an accessibility relation. OK, you've put that quite well. Even if continuity of identity is an illusion, it is an important illusion. An analogy would be going to the cinema to see a movie: the reality might be that we are watching a series of still images, but the important thing for the audience is that the illusion of motion is maintained by having a certain minimum frame rate. So yes, this does give rise to an accessibility relationship, but it presupposes a theory of personal identity. Even on this list, there are people who might say (a) above is the case rather than (b) or (c). This covers such (theoretical, at present) cases as the apparent continuity of identity between two observer moments that just happen to seem to be consecutive frames in a person's life even though there is no physical or informational connection between them. But you cannot deny that with comp, there *is* some informational connection between them. The connection will appear to be exclusively mathematical and immaterial. And will appear to be the logical root of another illusion: a physical world. We know this by UDA (the Universal Dovetailer Argument), but we need to isolate completely the structure of the multiverse extractible from comp if we want to derive the precise physics from comp (and then to compare with the empirical physics to evaluate empirically the plausibility of comp (or of its many variants). What I meant by informational connection was actual information transfer from one frame to the next, by some physical process. This is what happens normally by virtue of the fact that consecutive frames are implemented by the same physical brain. It is also what would happen, in a different way, with teleportation. This is sufficient for the experience of continuity of consciousness, but it is not necessary: the appropriate frames or observer moments might occur completely randomly in different parts of the multiverse, and the first person experience would be the same. (Such is not the case for observation of third persons: the frames or observer moments must be explicitly ordered, or they will be lost in the noise). Is this what you mean by the connection will appear to be exclusively mathematical and immaterial? Stathis Papaioannou _ Start something musical - 15 free ninemsn Music downloads! http://ninemsn.com.au/share/redir/adTrack.asp?mode=clickclientID=667referral=HotmailTaglineNovURL=http://www.ninemsn.com.au/startsomething
Re: Quantum Immortality and Information Flow
On Sat, Nov 19, 2005 at 04:22:58PM +0100, Bruno Marchal wrote: Now observation and knowledge are defined in the logics of self-reference, i.e. by transformation of G and G*, and so are each multiplied by two. Actually and amazingly for the knower (the first person) G and G* give the same logic, like if the first person conflates truth and provability. But for the notion of observation, G and G* give again different logics, so that the observer can distinguish communicable observations (physical facts) and non communicable observations (sensations, I would argue). Are you now saying that your operators Pp = Bp -B-p and Op = Bp p -B-p correspond to to observe (Op being to validly observe I suppose)?. Previously, you would say that Pp is to bet on p, and Op to correctly bet on p, which never really made sense to me. What's the French word you would use for this - I may know it, or perhaps I can figure the relevant English term from a dictionary. Cheers -- *PS: A number of people ask me about the attachment to my email, which is of type application/pgp-signature. Don't worry, it is not a virus. It is an electronic signature, that may be used to verify this email came from me if you have PGP or GPG installed. Otherwise, you may safely ignore this attachment. A/Prof Russell Standish Phone 8308 3119 (mobile) Mathematics0425 253119 () UNSW SYDNEY 2052 [EMAIL PROTECTED] Australiahttp://parallel.hpc.unsw.edu.au/rks International prefix +612, Interstate prefix 02 pgpJYedQAs9lc.pgp Description: PGP signature
Re: Quantum Immortality and Information Flow
Dear Bruno, Are you claiming that the communicable part is to the non-communicable part as the classical is to the quantum? The Non-cloning aspect of QM and the copyability of the classical seems to be implied. Is this intentional? Onward! Stephen - Original Message - From: Bruno Marchal [EMAIL PROTECTED] To: [EMAIL PROTECTED] Cc: Everything-List List everything-list@eskimo.com Sent: Friday, November 18, 2005 10:03 AM Subject: Re: Quantum Immortality and Information Flow snip Well, actually I hope it will gives the qubits. I am not contesting the Everett-Hartle-... Deutsch-Zurek explanation of how bits come from qubits. Just saying comp gives a path from bits to qubits too. A double path. It is the incompleteness phenomenon(*) which makes that path double, i.e. separated into a communicable part and a non communicable part explaining simultaneously quanta and qualia (I would argue).
Re: Quantum Immortality and Information Flow
Le 15-nov.-05, à 10:56, Brian Scurfield a écrit : --- In [EMAIL PROTECTED], Bruno Marchal [EMAIL PROTECTED] wrote: It has often been pointed out on this list that universes are those parts of the multiverse down which information flows. So Harry Potter universes are not in fact universes. What do you mean by parts of the multiverse down which information flows? OK, let's start with information. I have in mind David's qualitative definition here: http://xxx.lanl.gov/abs/quant-ph/0104033 To quote: 1. A physical system S *contains information* about a parameter b if … the probability of some outcome of some measurement on S depends on b. 2. A physical system S *contains no information* about b if … there exists a complete description of S that is independent on b. What is meant by information flow is explained here: http://groups.yahoo.com/group/Fabric-of-Reality/message/9247 Basically, information flows when the output depends in some way on the input. As David has shown, the structure of the multiverse is determined by information flow. A universe is a part of the multiverse where information flows freely. OK. I guess you know that this is not a standard use of the term information, like the one of Shannon, where the bits measure some degree of surprise and unpredictibility (and this can been make precise with notion of Kolmogorov/Chaitin/Solovay notion of information). David Deutsch's notion of information can be related to some logician's attempt to define a sort of qualitative information, and as such it is quite interesting, but also natural, to find it in an attempt to retrieve classical computational histories from the quantum theory. Now you should keep in mind that David does postulate the existence of some continuum causal structure, and, as you know, I am doubtful this can make sense once we accept the computationalist hypothesis (cf Maudlin's Olympia, my work, etc.). Actually I think David Hume makes already important steps in that direction. Just to illustrate: imagine the case of iterated self-duplication with reconstitutions in Sidney and Beijing: S and B. From the point of view of the average candidate normal histories, in the form of sequences of P and S, will be highly unpredictable, but in all case there will be no causal relations between the events I feel myself to be in S or I feel myself to be in P. Exceptional histories, like the one in which the sequence gives the binary digits of the number PI, play the role, curiously enough, of the Harry Potter histories, in that case. So the two notion of information are quite complementary. It is almost like one grows up when the other diminishes. Harry Potter universes are just improbable, and information grows to much there. Things spontaneously organise themselves in an HPU, but the output does not depend on the input; there is no information flow in the sense described above. So I agree. And of course I was considering a Shannon form of information. When Harry Potter does a trick, in almost all universes the trick does not work. But one cannot say the trick succeeded in those universes that do become HPU's because one can't single out beforehand those exceptionally rare universes that will become HPU's. I agree. It is almost like they got singularities in the amount of information. But death, well, really it is an open problem, because you must take into account the normal (statistical, based on the measure on the observer/moment/states/worlds...) possible histories just going locally through exceptional states, Meaningful histories must have a flow of information right? I don't think so. I would say that meaningful histories are the relatively consistent (non contradictory) one---which will get some right measure assuming comp, and the correctness of my derivation, to be sure. Those meaningful histories will appear, from the observer first person point of view be related to some local flux of information in David's sense. But I don't know how to take for granted those meaningful histories at the start (unless, like David, you already postulate some prior programs as an explanation of the appearance of the universe. But then again you will be confronted with the comp version of the Mind/Body, or 1-person/3-person relations again. In some histories, the Universal Dovetailer has outputted a series of random numbers that just happen to be indistinguishable from your life history up to today. In these histories, your past state does not determine your present state (although they are in every way indistinguishable from histories where your past state really does determine your present state). I would say you belong to all histories. But with comp you are so constituted that only the consistent one will make sense and will be stable enough. Almost all of these histories will turn to junk at the very next moment.
