### Re: Quantum Immortality = no second law

The focus of my paper is on theories in principle fully describing universes (or u-reality). The term 'logically possible' is intended to contrast with 'physically possible' and refers to descriptions (theories) being internally non-contradictory (more in note 4 in my paper). OK Classical logic is usually intended in these kinds of cases, and I can't actually see from what I know of other logics how they might relevantly extend the range of possible inhabitable universes beyond those describable by formal systems operating according to classical logic. (There is also the issue of their additional Brent already mentioned paraconsistent logics, here a nice link: http://en.wikipedia.org/wiki/Impossible_world (the article links to an article by Zalta, the one who is responsible for this http://plato.stanford.edu/ wonderful resource. Cheers, Günther --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---

### Re: Quantum Immortality = no second law

On Apr 19, 3:46 pm, Günther Greindl [EMAIL PROTECTED] wrote: Dear Nichomachus, decision. If she measures the particle's spin as positive, she will elect to switch cases, and if she measures it with a negative spin she will keep the one she has. This is because she wants to be sure that, having gotten to this point in the game, there will be at least some branches of her existence where she experiences winning the grand prize. She is not convinced that, were she to decide what to do using only the processes available to her mind, she would guarantee that same result since it is just possible that all of the mutiple versions of herself confronted with the dilemma may make the same bad guess. I have also thought along these lines some time ago (to use a qubit to ensure that all outcomes are chosen, because one should not rely on one's mind decohering into all possible decisions). The essential question is this: what worlds exist? All possible worlds. But which worlds are possible? We have, on the one hand, physical possibility (this also includes other physical constants etc, but no totally unphysical scenarios). I have long adhered to this everything physically possible, but this does break down under closer scrutiny: first of all, physical relations are, when things come down to it, mathematical relations. So we could conclude with Max Tegmark: all possible mathematical structures exist; this is ill defined (but then, why should the Everything be well defined?) Alastair argues in his paper that everything logically possible exists (with his non arbitrariness principle) but, while initially appealing, it leads to the question: what is logically possible? In what logic? Classical/Intuitionist/Deviant logics etc etc...then we are back at Max's all possible structures. For all this, I am beginning very much to appreciate Bruno's position with the Sigma_1 sentences; but I still have to do more reading and catch up on some logic/recursion theory for a final verdict ;-)) One objection comes to mind immediately (already written above): why should the Everything be well defined? To go back to your original question: to consider if both variants are chosen by the player of the game by herself (without qubit) seems to depend on which kind of Everything you choose. And that, I think, is the crux of the matter. Cheers, Günther Thank you for your illuminating comments, Günther. And though Tegmark's ensemble may be less than well-defined right now, there are other ensembles that are. My understanding of the Universal Dovetailer is that it will generate the output of every possible computer program, which, assuming that our universe is computable, implies that it contains ours and every other possible version of our universe. And unless there are any mathematical entities or structures in Max Tegmark's ensemble that are not computable, then Tegmark's enseble should be a subset of Schmidhuber's. On this note I can't do any better than Russell's discussion in section 3.2 of Theory of Nothing, which says that Schmidhuber's plentitude should properly be considered a subset of Tegmark's ensemble. Are there any Mathematical Structures that are not computable? Surely any finite axiom system, if consistent, would have a finite number of non-trivial theorems. It is said that a program could be written to generate all theorems of any consistent axiom system, so that would seem to imply computability. (Although Goedel's theorem indicates that any system of sufficient complexity cannot be both consistent and complete, so it follows that consistent axiom systems of sufficient complexity will allow for the existence of undecidable propositions. But what bearing this has on the present discussion about the computability of these systems is sort of unclear to me.) What would constitute an uncomputable mathematical structure? I don't know, but I admit that my ignorance on the subject doesn't demonstrate their non-existence. And yes, Günther, I agree with your wholeheartedly that physical relations are mathematical relations at their core. However, simply because a mathematical expression may model a given physical process or relationship leaves us in the dark as to the reason why this equation models this particular phenomenon. Feynman gives as example in his book The Charater of Physical Law of an equation used in electrolysis that relates the current, the time exposed, and the concentration of the solution to the amount of a metal that is deposited. But the relationship so expressed is clearly seen to be a result of physical processes and not to be a consequence of more general principles. Saying that X is physically possible must be equivalent to saying that X necessarily stands in an allowable relationship to the fundamental physical process of the world. For example: imagine a simplified physics, say like a cellular automaton, that is able to support living things, yet

### Re: Quantum Immortality = no second law

- Original Message - From: Brent Meeker [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Monday, April 21, 2008 3:53 AM Subject: Re: Quantum Immortality = no second law Alastair Malcolm wrote: - Original Message - From: Günther Greindl [EMAIL PROTECTED] . . . Alastair argues in his paper that everything logically possible exists (with his non arbitrariness principle) but, while initially appealing, it leads to the question: what is logically possible? In what logic? Classical/Intuitionist/Deviant logics etc etc...then we are back at Max's all possible structures. The focus of my paper is on theories in principle fully describing universes (or u-reality). The term 'logically possible' is intended to contrast with 'physically possible' and refers to descriptions (theories) being internally non-contradictory (more in note 4 in my paper). Classical logic is usually intended in these kinds of cases, and I can't actually see from what I know of other logics how they might relevantly extend the range of possible inhabitable universes beyond those describable by formal systems operating according to classical logic. Have you considered para-consistent logics, c.f. Graham Priest In Contradiction. In terms of theories accurately representing worlds, I have more or less discounted 'A AND NOT-A' approaches (this is not the same as superposition, which should be able to be modelled within the local physics) - I have assumed that a fundamental fact about a world cannot be both true and not true. (For any other possible modes of application of paraconsistent logics hopefully my comments at the start of section 4 of my paper apply.) Alastair Paper at: http://www.physica.freeserve.co.uk/pa01.htm --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---

### Re: Quantum Immortality = no second law

- Original Message - From: Günther Greindl [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Saturday, April 19, 2008 9:46 PM Subject: Re: Quantum Immortality = no second law Dear Nichomachus, decision. If she measures the particle's spin as positive, she will elect to switch cases, and if she measures it with a negative spin she will keep the one she has. This is because she wants to be sure that, having gotten to this point in the game, there will be at least some branches of her existence where she experiences winning the grand prize. She is not convinced that, were she to decide what to do using only the processes available to her mind, she would guarantee that same result since it is just possible that all of the mutiple versions of herself confronted with the dilemma may make the same bad guess. I have also thought along these lines some time ago (to use a qubit to ensure that all outcomes are chosen, because one should not rely on one's mind decohering into all possible decisions). The essential question is this: what worlds exist? All possible worlds. But which worlds are possible? We have, on the one hand, physical possibility (this also includes other physical constants etc, but no totally unphysical scenarios). I have long adhered to this everything physically possible, but this does break down under closer scrutiny: first of all, physical relations are, when things come down to it, mathematical relations. So we could conclude with Max Tegmark: all possible mathematical structures exist; this is ill defined (but then, why should the Everything be well defined?) Alastair argues in his paper that everything logically possible exists (with his non arbitrariness principle) but, while initially appealing, it leads to the question: what is logically possible? In what logic? Classical/Intuitionist/Deviant logics etc etc...then we are back at Max's all possible structures. The focus of my paper is on theories in principle fully describing universes (or u-reality). The term 'logically possible' is intended to contrast with 'physically possible' and refers to descriptions (theories) being internally non-contradictory (more in note 4 in my paper). Classical logic is usually intended in these kinds of cases, and I can't actually see from what I know of other logics how they might relevantly extend the range of possible inhabitable universes beyond those describable by formal systems operating according to classical logic. (There is also the issue of their additional complexity, if some are somehow incorporatable.) I do mention in general terms possible alternatives to standard formal systems at the start of section 4. For my purposes all I need is a plausible way around the White Rabbit problem. In my view its deep philosophical basis and potential explanation of our relative simplicity and lawfulness are points in favour of the 'All Possible States' hypothesis, and the idea of not being able to fully characterize it is pretty much to be expected given its universal scope. Alastair Paper at: http://www.physica.freeserve.co.uk/pa01.htm --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---

### Re: Quantum Immortality = no second law

Alastair Malcolm wrote: - Original Message - From: Günther Greindl [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Saturday, April 19, 2008 9:46 PM Subject: Re: Quantum Immortality = no second law Dear Nichomachus, decision. If she measures the particle's spin as positive, she will elect to switch cases, and if she measures it with a negative spin she will keep the one she has. This is because she wants to be sure that, having gotten to this point in the game, there will be at least some branches of her existence where she experiences winning the grand prize. She is not convinced that, were she to decide what to do using only the processes available to her mind, she would guarantee that same result since it is just possible that all of the mutiple versions of herself confronted with the dilemma may make the same bad guess. I have also thought along these lines some time ago (to use a qubit to ensure that all outcomes are chosen, because one should not rely on one's mind decohering into all possible decisions). The essential question is this: what worlds exist? All possible worlds. But which worlds are possible? We have, on the one hand, physical possibility (this also includes other physical constants etc, but no totally unphysical scenarios). I have long adhered to this everything physically possible, but this does break down under closer scrutiny: first of all, physical relations are, when things come down to it, mathematical relations. So we could conclude with Max Tegmark: all possible mathematical structures exist; this is ill defined (but then, why should the Everything be well defined?) Alastair argues in his paper that everything logically possible exists (with his non arbitrariness principle) but, while initially appealing, it leads to the question: what is logically possible? In what logic? Classical/Intuitionist/Deviant logics etc etc...then we are back at Max's all possible structures. The focus of my paper is on theories in principle fully describing universes (or u-reality). The term 'logically possible' is intended to contrast with 'physically possible' and refers to descriptions (theories) being internally non-contradictory (more in note 4 in my paper). Classical logic is usually intended in these kinds of cases, and I can't actually see from what I know of other logics how they might relevantly extend the range of possible inhabitable universes beyond those describable by formal systems operating according to classical logic. Have you considered para-consistent logics, c.f. Graham Priest In Contradiction. Brent Meeker (There is also the issue of their additional complexity, if some are somehow incorporatable.) I do mention in general terms possible alternatives to standard formal systems at the start of section 4. For my purposes all I need is a plausible way around the White Rabbit problem. In my view its deep philosophical basis and potential explanation of our relative simplicity and lawfulness are points in favour of the 'All Possible States' hypothesis, and the idea of not being able to fully characterize it is pretty much to be expected given its universal scope. Alastair Paper at: http://www.physica.freeserve.co.uk/pa01.htm --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---

### Re: Quantum Immortality = no second law

nichomachus wrote: On Apr 17, 1:21 pm, Brent Meeker [EMAIL PROTECTED] wrote: Telmo Menezes wrote: On Thu, Apr 17, 2008 at 2:37 PM, Bruno Marchal [EMAIL PROTECTED] wrote: Are you saying that the second law is verified in each of all branches of the (quantum) multiverse? I'm not saying that. I would say the second law is statistical, and is verified in most branches. In the MWI applied to quantum field it seems to me that there can be branches with an arbitrarily high number of photon creation without annihilation, and this for each period of time. I'm not sure what source of photon creation you have in mind, but QFT doesn't allow violation of energy conservation. Maybe it was vacuum energy Bruno was referring to, or else perhaps the creation of virtual particle pairs? Stephen Hawking (who by the way apparently regards Everett's theory as trivally true, in other words, instrumentalistic and without physical significance) used virtual particles to explain how black holes may evaporate. But I don't want to put words in anyone's mouth, and plus, I am not knowledgeable enough on these matters to discuss them. But if I may raise one possibility, it seems to me that despite the existence of fluke branches in which the second law is not inviolate, there are no possible branches that experience the outcome of a double slit experiment that does not result in an interference pattern. This is according to my understanding that the interference actually takes place across branches, as each path of the photon interferers constructively and destructively with itself. But that interference is of the wave-function with itself. It's squared modulus only determines a probability. So, thru a fluke of probability, the photons could strike the screen in a pattern that is arbitrarily close to the naive no-interference pattern. I say arbitrarily close since in principle no photon could land where the probability was zero. But the zero probability region is a line of measure zero. It's not very clear to me how MWI accounts for the pattern. Is it supposed that there is a separate world for every point each photon could land; the separate worlds having a certain probability weight. Or are there multiple worlds for each spot in order that the probability be proportional to the number of worlds? And what if the probability is an irrational number? Brent Meeker --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---

### Re: Quantum Immortality = no second law

Those branches exist even if the experiment is not set up. This follows necessarily from the MWI. Pick any date in history that you like. There must exist fluke branches that have experienced unlikely histories since that time. The example I mentioned previously was no atomic decay since January 1, 1900. Yes I agree. The second law is just a statistical property, is it not? I believe it is possible to observe cases where the second law does not hold, even for a long time. But it's extremely unlikely. That being said, I would argue that it would be nice if we could come to the conclusion that the quantum suicider experiment can work even without the need to resort to an highly unlikely stacking of quantum choices. --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---

### Re: Quantum Immortality = no second law

On Apr 19, 11:51 am, Telmo Menezes [EMAIL PROTECTED] wrote: Those branches exist even if the experiment is not set up. This follows necessarily from the MWI. Pick any date in history that you like. There must exist fluke branches that have experienced unlikely histories since that time. The example I mentioned previously was no atomic decay since January 1, 1900. Yes I agree. The second law is just a statistical property, is it not? I believe it is possible to observe cases where the second law does not hold, even for a long time. But it's extremely unlikely. That being said, I would argue that it would be nice if we could come to the conclusion that the quantum suicider experiment can work even without the need to resort to an highly unlikely stacking of quantum choices. How would it work? The point of the suicider experiement is that the suicider is able to prove to himself the reality of MWI by forcing himself to experience only an absurdly low probability set of events. Thus, he demonstrates to the few versions of himself who remain the existence of fluke branches, and by extension the truth of the MWI. Right, I agree that a universe in which entropy decreases monotonically would be unlikely since it would only happen in those exceedingly rare fluke branches. However, the point of the quantum suicide experiment is to prove to the suicider the reality of the MWI by verifying the existence of fluke branches, and by extension, all of the other, more likely worlds as well. The suicider steps in for the cat in the schrodinger experiment. The QTI suicide experiment simply asks what its like for the cat, instead of the observers who open the box. You can stay in that box for any length of time, and if MWI is true, which implies the QTI, you won't die. this only works because we are eliminating the consciousness of the observer in a great many more branches. But it isn't a healthy way to prove MWI in practice. Don't try this at home. :) --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---

### Re: Quantum Immortality = no second law

How would it work? The point of the suicider experiement is that the suicider is able to prove to himself the reality of MWI by forcing himself to experience only an absurdly low probability set of events. Thus, he demonstrates to the few versions of himself who remain the existence of fluke branches, and by extension the truth of the MWI. Right, I agree that a universe in which entropy decreases monotonically would be unlikely since it would only happen in those exceedingly rare fluke branches. However, the point of the quantum suicide experiment is to prove to the suicider the reality of the MWI by verifying the existence of fluke branches, and by extension, all of the other, more likely worlds as well. The suicider steps in for the cat in the schrodinger experiment. The QTI suicide experiment simply asks what its like for the cat, instead of the observers who open the box. You can stay in that box for any length of time, and if MWI is true, which implies the QTI, you won't die. this only works because we are eliminating the consciousness of the observer in a great many more branches. But it isn't a healthy way to prove MWI in practice. Don't try this at home. :) I believe this thread started with an attempt do disprove MWI by stating that the quantum suicider would violate the second law of thermodynamics. Although I do believe that the MWI logically leads to universes where the second law is violated and am fine with that, I'm just proposing that in the case of the quantum suicider no violation is observed at the macroscopic level. The macroscopic level is where the second law makes sense anyway, because of its statistical nature. I am prepared to agree that this is a pointless exercise because MWI leads to second law violations anyway. :) --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---

### Re: Quantum Immortality = no second law

Dear Nichomachus, decision. If she measures the particle's spin as positive, she will elect to switch cases, and if she measures it with a negative spin she will keep the one she has. This is because she wants to be sure that, having gotten to this point in the game, there will be at least some branches of her existence where she experiences winning the grand prize. She is not convinced that, were she to decide what to do using only the processes available to her mind, she would guarantee that same result since it is just possible that all of the mutiple versions of herself confronted with the dilemma may make the same bad guess. I have also thought along these lines some time ago (to use a qubit to ensure that all outcomes are chosen, because one should not rely on one's mind decohering into all possible decisions). The essential question is this: what worlds exist? All possible worlds. But which worlds are possible? We have, on the one hand, physical possibility (this also includes other physical constants etc, but no totally unphysical scenarios). I have long adhered to this everything physically possible, but this does break down under closer scrutiny: first of all, physical relations are, when things come down to it, mathematical relations. So we could conclude with Max Tegmark: all possible mathematical structures exist; this is ill defined (but then, why should the Everything be well defined?) Alastair argues in his paper that everything logically possible exists (with his non arbitrariness principle) but, while initially appealing, it leads to the question: what is logically possible? In what logic? Classical/Intuitionist/Deviant logics etc etc...then we are back at Max's all possible structures. For all this, I am beginning very much to appreciate Bruno's position with the Sigma_1 sentences; but I still have to do more reading and catch up on some logic/recursion theory for a final verdict ;-)) One objection comes to mind immediately (already written above): why should the Everything be well defined? To go back to your original question: to consider if both variants are chosen by the player of the game by herself (without qubit) seems to depend on which kind of Everything you choose. And that, I think, is the crux of the matter. Cheers, Günther --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---

### Re: Quantum Immortality = no second law

nichomachus wrote: On Apr 19, 2:17 am, Brent Meeker [EMAIL PROTECTED] wrote: nichomachus wrote: On Apr 17, 1:21 pm, Brent Meeker [EMAIL PROTECTED] wrote: Telmo Menezes wrote: On Thu, Apr 17, 2008 at 2:37 PM, Bruno Marchal [EMAIL PROTECTED] wrote: Are you saying that the second law is verified in each of all branches of the (quantum) multiverse? I'm not saying that. I would say the second law is statistical, and is verified in most branches. In the MWI applied to quantum field it seems to me that there can be branches with an arbitrarily high number of photon creation without annihilation, and this for each period of time. I'm not sure what source of photon creation you have in mind, but QFT doesn't allow violation of energy conservation. Maybe it was vacuum energy Bruno was referring to, or else perhaps the creation of virtual particle pairs? Stephen Hawking (who by the way apparently regards Everett's theory as trivally true, in other words, instrumentalistic and without physical significance) used virtual particles to explain how black holes may evaporate. But I don't want to put words in anyone's mouth, and plus, I am not knowledgeable enough on these matters to discuss them. But if I may raise one possibility, it seems to me that despite the existence of fluke branches in which the second law is not inviolate, there are no possible branches that experience the outcome of a double slit experiment that does not result in an interference pattern. This is according to my understanding that the interference actually takes place across branches, as each path of the photon interferers constructively and destructively with itself. But that interference is of the wave-function with itself. It's squared modulus only determines a probability. So, thru a fluke of probability, the photons could strike the screen in a pattern that is arbitrarily close to the naive no-interference pattern. I say arbitrarily close since in principle no photon could land where the probability was zero. But the zero probability region is a line of measure zero. It's not very clear to me how MWI accounts for the pattern. Is it supposed that there is a separate world for every point each photon could land; the separate worlds having a certain probability weight. Or are there multiple worlds for each spot in order that the probability be proportional to the number of worlds? And what if the probability is an irrational number? Mutiple worlds for each spot on the screen, according to my understanding of Feynman's explanation of the experiment. However, I think it is important to distinguish between the probability function that describes the interference pattern registering on the screen/ photodetector array, and the probability function that results from the square of the psi modulus. IIRC, Feynman said that the interference pattern from the double slit experiment (or equivalently, the emergent probability function that is the same across branches) results from the fact that for any point on the screen where a photon may fall from the slits there are multiple paths that one photon may take to get to that point. The next step is to say that there are other branches (due to MWI), each of which describes another possible path taken by that same photon, and that, depending on the relative difference in path lengths to the point in question, summing over all possible paths taken by a photon to that point results in a value somewhere between completely desctructive interference and completely constructive. I take this scenario to mean that the total interference pattern is a probability function describing how likely it is to measure a single photon at any point on the screen, and that this probability function is an emergent property of light particles interfering with parallel versions of themselves across branches. Since they are summed across the branches, so to speak, the interference pattern resulting from the double slit experiement is one example of getting a deterministic result from probabilistic interactions, and is in fact the same pattern across all branches representing outcomes of the experiment. So the psi function may be thought of as being proportional to the number of universes, but the probability function representing the distribution of photons on the screen is not. But psi*|psi is the probability function. And the some pattern does not occur across all branches. The patterns are only the same in the statistical sense of having the same limit as the number of particles goes to infinity; which is to say in theory, since in practice the number is always finite. Feynman's multiple-path formulation is mathematically identical to the Schroedinger equation for and Heisenberg matrix form - there is nothing new in it except the mental image evoked. This is what I was thinking when I first mentioned the experiment, although I

### Re: Quantum Immortality = no second law

Günther Greindl wrote: Dear Nichomachus, decision. If she measures the particle's spin as positive, she will elect to switch cases, and if she measures it with a negative spin she will keep the one she has. This is because she wants to be sure that, having gotten to this point in the game, there will be at least some branches of her existence where she experiences winning the grand prize. She is not convinced that, were she to decide what to do using only the processes available to her mind, she would guarantee that same result since it is just possible that all of the mutiple versions of herself confronted with the dilemma may make the same bad guess. I have also thought along these lines some time ago (to use a qubit to ensure that all outcomes are chosen, because one should not rely on one's mind decohering into all possible decisions). The essential question is this: what worlds exist? All possible worlds. But which worlds are possible? We have, on the one hand, physical possibility (this also includes other physical constants etc, but no totally unphysical scenarios). I have long adhered to this everything physically possible, but this does break down under closer scrutiny: first of all, physical relations are, when things come down to it, mathematical relations. So we could conclude with Max Tegmark: all possible mathematical structures exist; this is ill defined (but then, why should the Everything be well defined?) There's no compelling reason the everything, or The Everything, should be well defined. In fact all our theories to date have contingent aspects, usually in the form of boundary conditions, that are not defined by the theory. But mathematical structures are different, they don't have contingent parts. So if a mathematical set is not well defined then we don't know what we're talking about when we discuss it. Brent Meeker Alastair argues in his paper that everything logically possible exists (with his non arbitrariness principle) but, while initially appealing, it leads to the question: what is logically possible? In what logic? Classical/Intuitionist/Deviant logics etc etc...then we are back at Max's all possible structures. For all this, I am beginning very much to appreciate Bruno's position with the Sigma_1 sentences; but I still have to do more reading and catch up on some logic/recursion theory for a final verdict ;-)) One objection comes to mind immediately (already written above): why should the Everything be well defined? To go back to your original question: to consider if both variants are chosen by the player of the game by herself (without qubit) seems to depend on which kind of Everything you choose. And that, I think, is the crux of the matter. Cheers, Günther --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---

### Re: Quantum Immortality = no second law

On Apr 19, 4:26 pm, Brent Meeker [EMAIL PROTECTED] wrote: nichomachus wrote: On Apr 19, 11:51 am, Telmo Menezes [EMAIL PROTECTED] wrote: Those branches exist even if the experiment is not set up. This follows necessarily from the MWI. Pick any date in history that you like. There must exist fluke branches that have experienced unlikely histories since that time. The example I mentioned previously was no atomic decay since January 1, 1900. Yes I agree. The second law is just a statistical property, is it not? I believe it is possible to observe cases where the second law does not hold, even for a long time. But it's extremely unlikely. That being said, I would argue that it would be nice if we could come to the conclusion that the quantum suicider experiment can work even without the need to resort to an highly unlikely stacking of quantum choices. How would it work? The point of the suicider experiement is that the suicider is able to prove to himself the reality of MWI by forcing himself to experience only an absurdly low probability set of events. Thus, he demonstrates to the few versions of himself who remain the existence of fluke branches, and by extension the truth of the MWI. Right, I agree that a universe in which entropy decreases monotonically would be unlikely since it would only happen in those exceedingly rare fluke branches. If it were also expanding in spacetime it would be exactly like our universe. I read recently that entropy is increasing, but a measure called entropy density is decreasing due to inflation. This is how it was supposed that a universe tending toward maximum entropy could avoid heat death, as the theoretical entropy max grows along with the universe. --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---

### Re: Quantum Immortality = no second law

nichomachus wrote: On Apr 19, 4:26 pm, Brent Meeker [EMAIL PROTECTED] wrote: nichomachus wrote: On Apr 19, 11:51 am, Telmo Menezes [EMAIL PROTECTED] wrote: Those branches exist even if the experiment is not set up. This follows necessarily from the MWI. Pick any date in history that you like. There must exist fluke branches that have experienced unlikely histories since that time. The example I mentioned previously was no atomic decay since January 1, 1900. Yes I agree. The second law is just a statistical property, is it not? I believe it is possible to observe cases where the second law does not hold, even for a long time. But it's extremely unlikely. That being said, I would argue that it would be nice if we could come to the conclusion that the quantum suicider experiment can work even without the need to resort to an highly unlikely stacking of quantum choices. How would it work? The point of the suicider experiement is that the suicider is able to prove to himself the reality of MWI by forcing himself to experience only an absurdly low probability set of events. Thus, he demonstrates to the few versions of himself who remain the existence of fluke branches, and by extension the truth of the MWI. Right, I agree that a universe in which entropy decreases monotonically would be unlikely since it would only happen in those exceedingly rare fluke branches. If it were also expanding in spacetime it would be exactly like our universe. I read recently that entropy is increasing, but a measure called entropy density is decreasing due to inflation. This is how it was supposed that a universe tending toward maximum entropy could avoid heat death, as the theoretical entropy max grows along with the universe. Right. That is how the universe could have started in a state of maximum entropy (e.g. 1bit in a Planck volume) and evolved always increasing entropy and yet be in a state far from equilibrium now. It doesn't exactly avoid death though. That phrase was used to describe a universe that came to equilibrium - all the same temperature - so that there would be no free energy to support life. But it now appears that the universe will expand indefinitely and will suffer cold death. The available free energy will still go to zero, not because the universe is in equilibrium, but because its temperature approaches zero. Brent Meeker --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---

### Re: Quantum Immortality = no second law

Hi John, Le 17-avr.-08, à 16:48, John Mikes a écrit : Bruno, ashamed, because I decided many times not to barge into topics I do not understand and now I misuse your (and the list's) patience again: you use statistical. - verified in MOST branches. I think my view is not too far away: statistical in my dictionary means a choice-set of cases selected for observation and in such selection we COUNT the matching and non-matching occurrences. The conclusions are strictly group-restricted. Choose different boundaries (maybe include domains we don't even know of) and the 'statistical' result may be different. Yes. Actually this is what the comp suicide (and the quantum suicide) is all about. By preventing your continuation in some branch, you change your boundaries. Accordingly I would not say Those branches do violate the second law... I would rather say the II law is not valid (identified?) in those branches. OK. For that period of time? I consider the MWI a one-plane extract of MW As I said often, but without success (:-)), I believe (like deWitt, Everett's editor) that Everett has never proposed a new interpretation of QM, but has just given a new *formulation* of QM. Well, this is obvious (for a logician or metamathematician). Everett theory is really given by the Copenhagen axioms minus the collapse axiom. Then the interpretations are derived from the talk of the normal and correct physicists as being described (correctly by definition) by the SWE. The interpretation of the SWE are given by the average discourse of the physicists described by the SWE. and in my 'narrative' (i don't use 'theory' for unsubstantiatable ideas, even if certain math can justify it) the multitude of universes is not in any qualitative bound. ? (I am using theories only for unsubstantiable ideas (and unjustifiable). Ah ok ... I think you mean unpalatable or something like that. Diversity exceeds our human (scientific?) fantasy. I am not sure how you could know that, unless you are just saying that our theology exceeds our science. The lobian scientific theology just says that. It is the beauty of the incompleteness phenomenon: Machines can know that they know almost nothing. The wise and knowing machine know she has to be modest. For ever. Time, however, is a coordinate of THIS universe and I have no idea what kind of and what at all time may reign in other, totally different universes. Our physics is just our physics. Yes. And with comp physics can only be defined and recover correctly from that idea. And then, again with comp (or weakenings), the correct physics has to be derived by our physics with our physics = the physics of us, and us = the lobian machine/entity. Put in another way: physics has to be the science of the border of our ignorance, and our ignorance get a precise mathematical structure, once we assume our lobian mechanicalness. About time, I am not sure there is any physical third person time. I do believe in the subjective duration, and I am willing to bet that local physical time is a first person plural construct. I honor Everett as a pioneer and allow pioneers to be overstepped. (Another of my heresy: * probability * I consider as starting similarly to the above statistical formulation of mine, with an added superstition that the next (not necessarily the following one) will be adjusted to the 'statistically found' and chosen variant.). No problem. I like your phrasing: ...**IF** comp is true. This is of the upmost importance. That is why I insist so much on that if, and of the fact that a comp practice (like saying yes to the doctor) is a religious (if not funeral-like) act. It is a belief in a form of reincarnation, and it transforms computer science, as applied to us, into an authentic theology. I know it seems paradoxical, but no machine can ever know she is a machine: she can only hope (or fear) that she is a machine. I could even say (but don't always dare to say) that the first person I of the machine is 100% correct when she says I am not a machine. It is here that the gap between first person and third person is maximal. It is also here that we are on the verge of a contradiction, but our topic lives there. If your doctor pretends (scientifically) that you are a machine, you have to run away ... You can say yes to the doctor (yes for an artificial digital brain substitution) only when your doctor says something like let us bet you are a machine at this or that third person level of description. And then you can... pray. Have a good day, Bruno On Thu, Apr 17, 2008 at 9:37 AM, Bruno Marchal [EMAIL PROTECTED] wrote: Are you saying that the second law is verified in each of all branches of the (quantum) multiverse? I would say the second law is statistical, and is verified in most branches. In the MWI applied to quantum field it seems to me that there can be

### Re: Quantum Immortality = no second law

Le 17-avr.-08, à 19:45, Telmo Menezes a écrit : On Thu, Apr 17, 2008 at 2:37 PM, Bruno Marchal [EMAIL PROTECTED] wrote: Are you saying that the second law is verified in each of all branches of the (quantum) multiverse? I'm not saying that. OK. Sorry. I would say the second law is statistical, and is verified in most branches. In the MWI applied to quantum field it seems to me that there can be branches with an arbitrarily high number of photon creation without annihilation, and this for each period of time. Yes, I would tend to agree with that, although I can't say I'm 100% convinced. Anyway I'm a relative newcomer to this list so I don't feel I have an informed opinion yet. Need to catch up with all the arguments. Also have a thesis to finish, which tends to get in the way :) I can understand. Academy is like Democracy, as described by Churchill. The worst except for the rest. I wish you good luck (or shit, as in the french tradition). I'm just arguing that the experiment with the rifle and the geiger counter does not imply any second law anomaly. Yes, you are forcing your consciousness to move to states where the atom never decays, but if you consider the larger system, which one? the quantum one. entropy is increasing as normal because of the preparation and maintenance of the apparatus needed for the experiment. Do you think this makes sense? I am not sure I understand. I do agree with Brent Meker's comment though. If you agree with him, take his answer as mine (hope Brent does not mind). Best, bruno http://iridia.ulb.ac.be/~marchal/ --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---

### Re: Quantum Immortality = no second law

Le 17-avr.-08, à 18:21, Günther Greindl a écrit : David Deutsch argues in Fabric of Reality that only the Multiverse conserves quantity (not single branches). The rest is probabilistic stuff (see Bruno's post) Yes. And I think Deutsch has the most correct interpretation of Everett's theory (and Wallace, by the way, in a paper in the british journal of philosophy that I have just discover recently has the most correct interpretation of Deutsch). But they seems not be aware that by making their move, they have to take the 1-person indeterminacy a bit more seriously, something which Wallace *explicitly* does not. This motivates me a bit to submit a paper btw. Because, such indeterminacy forces us to consider that the SWE has to be also probabilistic. A bit like if comp makes us live in a multi-multiverse. But this is an analogy which can be misleading in some way... bruno http://iridia.ulb.ac.be/~marchal/ --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---

### Re: Quantum Immortality = no second law

entropy is increasing as normal because of the preparation and maintenance of the apparatus needed for the experiment. Do you think this makes sense? I am not sure I understand. I do agree with Brent Meker's comment though. If you agree with him, take his answer as mine (hope Brent does not mind). I don't think I was clear enough, but Russell's rephrasing a few mails ago was excellent. Have a great weekend, Telmo Menezes. --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---

### Re: Quantum Immortality = no second law

On Apr 16, 11:16 am, Quentin Anciaux [EMAIL PROTECTED] wrote: HI, 2008/4/16, nichomachus [EMAIL PROTECTED]: On Apr 16, 4:54 am, Bruno Marchal [EMAIL PROTECTED] wrote: Le 16-avr.-08, à 03:24, Russell Standish a écrit : On Wed, Apr 16, 2008 at 02:22:23AM +0200, Saibal Mitra wrote: First off, how is it that the MWI does not imply quantum immortality? MWI is just quantum mechanics without the wavefunction collapse postulate. This then implies that after a measurement your wavefuntion will be in a superposition of the states corresponding to definite outcomes. But we cannot just consider suicide experiments and then say that just because branches of the wavefuntion exist in which I survive, I'll find myself there with 100% probability. The fact that probabilities are conserved follows from unitary time evolution. If a state evolves into a linear combination of states in which I'm dead and alive then the probabilities of all these states add up to 1. The probability of finding myself to be alive at all after the experiment is then less than the probability of me finding myself about to perform the suicide experiment. The probability of me finding myself to be alive after n suicide experiments decays exponentially with n. Therefore I should not expect to find myself having survived many suicide experiments. Note that contrary to what you often read in the popular accounts of the multiverse, the multiverse does not split when we make observations. The most natural state for the entire multiverse is just an eigenstate of the Hamiltonian. The energy can be taken to be zero, therefore the wavefunction of the multiverse satisfies the equation: One should also note that this is the ASSA position. The ASSA was introduced by Jacques Mallah in his argument against quantum immortality, and a number of participants in this list adhere to the ASSA position. Its counterpart if the RSSA, which does imply quantum immortality (provided that the no cul-de-sac conjecture holds), and other list participants adhere to the RSSA. To date, no argument has convincingly demonstrated which of the ASSA or RSSA should be preferred, so it has become somewhat a matter of taste. There is some discussion of this in my book Theory of Nothing. Actually, I am not sure the ASSA makes sense once we take into account the distinction between first and third person point of view. Comp immortality is an almost trivial consequence that personal death cannot be a first person experience at all. Quantum immortality is most plausibly equivalent with comp immortality if the quantum level describes our correct comp substitution level. But this does not mean that we can know what shape the comp immortality can have, given that comp forbids us to know which machine we are or which computations bear us. Why is this the case? Whether Comp is true or not, it would seem that the direction of physical research and investigation is in the direction of discovering the presumed foundational TOE that accounts for everything we observe. Say, for example, that it were possible to create in a computer simulation an artificial universe that would evolve intelligent life forms by virtue of the physics of the artificial universe alone. Why, in principle, is it not possible for those intelligent beings to discover the fundamental rules that underlie their existence? They will not be able to discover any details of the architecture of the particular turing machine that is simulating their universe (even whether or not they are in fact being computed), but I don't see any a priori reason why they would not be able to discover their own basic physical laws. Because from the 1st person pov you cannot tell which computation (there are an infinities) support you hence the RSSA because the probability of your next states are relative to the current state you are. With the no cul de sac (means there exists no universe state which does not have a next state) comp predict comp immortality... Hi, Quentin, I am not sure what exactly is meant by cul-de-sac since it seems that, unless we are speaking about observer-moments, there can be no cul-de- sac. (A series of observer moments would seem to me to end with the death of the observer, or else the moment before death, but I am new and so am not familiar with the history of the debates here. I am not sure if that is agreed upon by those reading this list.) How can any state of the universe fail to have a successor? The MWI states that there must be many successors (branches), or, equivalently, merely one -- a continuously evolving universal wave equation. Further, I have heard it claimed that it could be that

### Re: Quantum Immortality = no second law

On first blush, it would seem to be irrelevant to the fact that there are possible histories in which the second law is not found to hold. All the atom and rifle apparatus does is eliminate the living subject in those branches where the decay occurs, leaving the subject alive in only the unlikely fluke branches where no decay is detected. It must be the case that the the question of whether or not the decay takes place is independent of the scientist making his quietus. On Apr 18, 11:10 am, Telmo Menezes [EMAIL PROTECTED] wrote: entropy is increasing as normal because of the preparation and maintenance of the apparatus needed for the experiment. Do you think this makes sense? I am not sure I understand. I do agree with Brent Meker's comment though. If you agree with him, take his answer as mine (hope Brent does not mind). I don't think I was clear enough, but Russell's rephrasing a few mails ago was excellent. Have a great weekend, Telmo Menezes. --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---

### Re: Quantum Immortality = no second law

On Apr 17, 1:21 pm, Brent Meeker [EMAIL PROTECTED] wrote: Telmo Menezes wrote: On Thu, Apr 17, 2008 at 2:37 PM, Bruno Marchal [EMAIL PROTECTED] wrote: Are you saying that the second law is verified in each of all branches of the (quantum) multiverse? I'm not saying that. I would say the second law is statistical, and is verified in most branches. In the MWI applied to quantum field it seems to me that there can be branches with an arbitrarily high number of photon creation without annihilation, and this for each period of time. I'm not sure what source of photon creation you have in mind, but QFT doesn't allow violation of energy conservation. Maybe it was vacuum energy Bruno was referring to, or else perhaps the creation of virtual particle pairs? Stephen Hawking (who by the way apparently regards Everett's theory as trivally true, in other words, instrumentalistic and without physical significance) used virtual particles to explain how black holes may evaporate. But I don't want to put words in anyone's mouth, and plus, I am not knowledgeable enough on these matters to discuss them. But if I may raise one possibility, it seems to me that despite the existence of fluke branches in which the second law is not inviolate, there are no possible branches that experience the outcome of a double slit experiment that does not result in an interference pattern. This is according to my understanding that the interference actually takes place across branches, as each path of the photon interferers constructively and destructively with itself. The upshot of this is simply a recognition that not every outcome is possible, and there remain situations that are not realized in any extant universe. Yes, I would tend to agree with that, although I can't say I'm 100% convinced. Anyway I'm a relative newcomer to this list so I don't feel I have an informed opinion yet. Need to catch up with all the arguments. Also have a thesis to finish, which tends to get in the way :) I'm just arguing that the experiment with the rifle and the geiger counter does not imply any second law anomaly. Yes, you are forcing your consciousness to move to states where the atom never decays, but if you consider the larger system, entropy is increasing as normal because of the preparation and maintenance of the apparatus needed for the experiment. Do you think this makes sense? Telmo Menezes. The idea of the multiverse derives from quantum mechanics, e.g. the Everett no-collapse interpretation. But in that model the (microscopic) entropy never increases (or decreases), because QM evolution is unitary. It is only the coarse-grained entropy, i.e. restricted to this branch, that increases. Certainly within this branch you are correct that the entropy increase due to firing a gun is very much greater than the decrease due to an atom not decaying. But the gun would only fire if the atom did in fact decay. It would not fire in the branches where no decay was detected. Brent Meeker- Hide quoted text - - Show quoted text -- Hide quoted text - - Show quoted text - --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---

### Re: Quantum Immortality = no second law

On 17/04/2008, Quentin Anciaux [EMAIL PROTECTED] wrote: You cannot experience death if you define death by the absolute end of your conscious experience. Since you can't be conscious if you're dead nor knowing it (which would require consciousness) by definition, death is not a first person experience (either if comp is true or not, this holds true for this definition of death). Another way to look at it is that you are dead almost everywhere in the multiverse: dead at the centre of the Earth, dead in the Andromeda Galaxy, dead in 5000 BC, etc. etc. However, you don't experience this being dead. You only experience those extremely rare parts of the multiverse where you are alive. -- Stathis Papaioannou --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---

### Re: Quantum Immortality = no second law

I would like to argue that in setting this experiment, energy is being expended to prevent the increase in entropy, albeit not in an obvious way. It is a trivial observation that systems may be devised that prevent increases in entropy by paying energy costs. One example is an ice cube in the freezer. In the case of this experiment, and assuming MWI, we are creating a scenario where the atomic decay is not possible from the experimenter's perspective. However, the experimenter is setting a system that includes the rifle and the geiger counter. Both these devices need energy to operate. Maybe it's just a convoluted version of the ice cube in the freezer? Best regards, Telmo Menezes. On Tue, Apr 15, 2008 at 12:18 AM, nichomachus [EMAIL PROTECTED] wrote: In the description of the quantum immortality gedanken experiment, a physicist rigs an automatic rifle to a geiger counter to fire into him upon the detection of an atomic decay event from a bit of radioactive material. If the many worlds hypothesis is true, the self-awareness of the physicist will continue to find himself alive after any length of time in front of his gun, since there exist parallel worlds where the decay does not occur. On a microscopic scale this is analogous to the observing a reality in which the second law of thermodynamics does not hold. for example, since there is a non-zero probability that molecular interactions will result in a decrease in entropy in a particular sealed volume under observation, there exist histories in which this must be observed. This is never observed. Therefore the MWI is shown to be false. --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---

### Re: Quantum Immortality = no second law

It's not so much the input of energy, it's the production of more entropy where the energy is taken from. On 17/04/2008, Telmo Menezes [EMAIL PROTECTED] wrote: I would like to argue that in setting this experiment, energy is being expended to prevent the increase in entropy, albeit not in an obvious way. It is a trivial observation that systems may be devised that prevent increases in entropy by paying energy costs. One example is an ice cube in the freezer. In the case of this experiment, and assuming MWI, we are creating a scenario where the atomic decay is not possible from the experimenter's perspective. However, the experimenter is setting a system that includes the rifle and the geiger counter. Both these devices need energy to operate. Maybe it's just a convoluted version of the ice cube in the freezer? Best regards, Telmo Menezes. On Tue, Apr 15, 2008 at 12:18 AM, nichomachus [EMAIL PROTECTED] wrote: In the description of the quantum immortality gedanken experiment, a physicist rigs an automatic rifle to a geiger counter to fire into him upon the detection of an atomic decay event from a bit of radioactive material. If the many worlds hypothesis is true, the self-awareness of the physicist will continue to find himself alive after any length of time in front of his gun, since there exist parallel worlds where the decay does not occur. On a microscopic scale this is analogous to the observing a reality in which the second law of thermodynamics does not hold. for example, since there is a non-zero probability that molecular interactions will result in a decrease in entropy in a particular sealed volume under observation, there exist histories in which this must be observed. This is never observed. Therefore the MWI is shown to be false. -- They couldn't hit an elephant at this dist- Last words of Gen. John Sedgwick, spoken as he looked out over the parapet at enemy lines during the Battle of Spotsylvania in 1864. --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---

### Re: Quantum Immortality = no second law

Yes, you're right. Still I think my argument holds. The production of the rifle, bullet and geiger counter system plus the geiger counter operation should produce more than enough entropy to compensate for the atom not decaying. On Thu, Apr 17, 2008 at 1:45 PM, Michael Rosefield [EMAIL PROTECTED] wrote: It's not so much the input of energy, it's the production of more entropy where the energy is taken from. On 17/04/2008, Telmo Menezes [EMAIL PROTECTED] wrote: I would like to argue that in setting this experiment, energy is being expended to prevent the increase in entropy, albeit not in an obvious way. It is a trivial observation that systems may be devised that prevent increases in entropy by paying energy costs. One example is an ice cube in the freezer. In the case of this experiment, and assuming MWI, we are creating a scenario where the atomic decay is not possible from the experimenter's perspective. However, the experimenter is setting a system that includes the rifle and the geiger counter. Both these devices need energy to operate. Maybe it's just a convoluted version of the ice cube in the freezer? Best regards, Telmo Menezes. On Tue, Apr 15, 2008 at 12:18 AM, nichomachus [EMAIL PROTECTED] wrote: In the description of the quantum immortality gedanken experiment, a physicist rigs an automatic rifle to a geiger counter to fire into him upon the detection of an atomic decay event from a bit of radioactive material. If the many worlds hypothesis is true, the self-awareness of the physicist will continue to find himself alive after any length of time in front of his gun, since there exist parallel worlds where the decay does not occur. On a microscopic scale this is analogous to the observing a reality in which the second law of thermodynamics does not hold. for example, since there is a non-zero probability that molecular interactions will result in a decrease in entropy in a particular sealed volume under observation, there exist histories in which this must be observed. This is never observed. Therefore the MWI is shown to be false. --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---

### Re: Quantum Immortality = no second law

Are you saying that the second law is verified in each of all branches of the (quantum) multiverse? I would say the second law is statistical, and is verified in most branches. In the MWI applied to quantum field it seems to me that there can be branches with an arbitrarily high number of photon creation without annihilation, and this for each period of time. Those branches do violate the second law for that period of time, although in most of branches, such violation are quite ephemera. The probability to find ourself in such branch, a priori, is very little, but the probability to *remain* in such a branch is exponentially more negligible, if I can say. And that is what counts, if you accept the RSSA. (Then if comp is true, my point is that even schroedinger equation itself has to come from a statistical phenomenon, albeit pertaining on number (or abstract machines) relations: Everett is correct but don't push his methodology sufficiently far). Isn't it? Bruno Le 17-avr.-08, à 15:02, Telmo Menezes a écrit : Yes, you're right. Still I think my argument holds. The production of the rifle, bullet and geiger counter system plus the geiger counter operation should produce more than enough entropy to compensate for the atom not decaying. On Thu, Apr 17, 2008 at 1:45 PM, Michael Rosefield [EMAIL PROTECTED] wrote: It's not so much the input of energy, it's the production of more entropy where the energy is taken from. On 17/04/2008, Telmo Menezes [EMAIL PROTECTED] wrote: I would like to argue that in setting this experiment, energy is being expended to prevent the increase in entropy, albeit not in an obvious way. It is a trivial observation that systems may be devised that prevent increases in entropy by paying energy costs. One example is an ice cube in the freezer. In the case of this experiment, and assuming MWI, we are creating a scenario where the atomic decay is not possible from the experimenter's perspective. However, the experimenter is setting a system that includes the rifle and the geiger counter. Both these devices need energy to operate. Maybe it's just a convoluted version of the ice cube in the freezer? Best regards, Telmo Menezes. On Tue, Apr 15, 2008 at 12:18 AM, nichomachus [EMAIL PROTECTED] wrote: In the description of the quantum immortality gedanken experiment, a physicist rigs an automatic rifle to a geiger counter to fire into him upon the detection of an atomic decay event from a bit of radioactive material. If the many worlds hypothesis is true, the self-awareness of the physicist will continue to find himself alive after any length of time in front of his gun, since there exist parallel worlds where the decay does not occur. On a microscopic scale this is analogous to the observing a reality in which the second law of thermodynamics does not hold. for example, since there is a non-zero probability that molecular interactions will result in a decrease in entropy in a particular sealed volume under observation, there exist histories in which this must be observed. This is never observed. Therefore the MWI is shown to be false. http://iridia.ulb.ac.be/~marchal/ --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---

### Re: Quantum Immortality = no second law

Bruno, ashamed, because I decided many times not to barge into topics I do not understand and now I misuse your (and the list's) patience again: you use statistical. - verified in MOST branches. I think my view is not too far away: statistical in my dictionary means a choice-set of cases selected for observation and in such selection we COUNT the matching and non-matching occurrences. The conclusions are strictly group-restricted. Choose different boundaries (maybe include domains we don't even know of) and the 'statistical' result may be different. Accordingly I would not say Those branches do violate the second law... I would rather say the II law is not valid (identified?) in those branches. For that period of time? I consider the MWI a one-plane extract of MW and in my 'narrative' (i don't use 'theory' for unsubstantiatable ideas, even if certain math can justify it) the multitude of universes is not in any qualitative bound. Diversity exceeds our human (scientific?) fantasy. Time, however, is a coordinate of THIS universe and I have no idea what kind of and what at all time may reign in other, totally different universes. Our physics is just our physics. I honor Everett as a pioneer and allow pioneers to be overstepped. (Another of my heresy: * probability * I consider as starting similarly to the above statistical formulation of mine, with an added superstition that the next (not necessarily the following one) will be adjusted to the 'statistically found' and chosen variant.). I like your phrasing: ...**IF** comp is true. Best regards John Mikes On Thu, Apr 17, 2008 at 9:37 AM, Bruno Marchal [EMAIL PROTECTED] wrote: Are you saying that the second law is verified in each of all branches of the (quantum) multiverse? I would say the second law is statistical, and is verified in most branches. In the MWI applied to quantum field it seems to me that there can be branches with an arbitrarily high number of photon creation without annihilation, and this for each period of time. Those branches do violate the second law for that period of time, although in most of branches, such violation are quite ephemera. The probability to find ourself in such branch, a priori, is very little, but the probability to *remain* in such a branch is exponentially more negligible, if I can say. And that is what counts, if you accept the RSSA. (Then if comp is true, my point is that even schroedinger equation itself has to come from a statistical phenomenon, albeit pertaining on number (or abstract machines) relations: Everett is correct but don't push his methodology sufficiently far). Isn't it? Bruno Le 17-avr.-08, à 15:02, Telmo Menezes a écrit : Yes, you're right. Still I think my argument holds. The production of the rifle, bullet and geiger counter system plus the geiger counter operation should produce more than enough entropy to compensate for the atom not decaying. On Thu, Apr 17, 2008 at 1:45 PM, Michael Rosefield [EMAIL PROTECTED] wrote: It's not so much the input of energy, it's the production of more entropy where the energy is taken from. On 17/04/2008, Telmo Menezes [EMAIL PROTECTED] wrote: I would like to argue that in setting this experiment, energy is being expended to prevent the increase in entropy, albeit not in an obvious way. It is a trivial observation that systems may be devised that prevent increases in entropy by paying energy costs. One example is an ice cube in the freezer. In the case of this experiment, and assuming MWI, we are creating a scenario where the atomic decay is not possible from the experimenter's perspective. However, the experimenter is setting a system that includes the rifle and the geiger counter. Both these devices need energy to operate. Maybe it's just a convoluted version of the ice cube in the freezer? Best regards, Telmo Menezes. On Tue, Apr 15, 2008 at 12:18 AM, nichomachus [EMAIL PROTECTED] wrote: In the description of the quantum immortality gedanken experiment, a physicist rigs an automatic rifle to a geiger counter to fire into him upon the detection of an atomic decay event from a bit of radioactive material. If the many worlds hypothesis is true, the self-awareness of the physicist will continue to find himself alive after any length of time in front of his gun, since there exist parallel worlds where the decay does not occur. On a microscopic scale this is analogous to the observing a reality in which the second law of thermodynamics does not hold. for example, since there is a non-zero probability that molecular interactions will result in a decrease in entropy in a particular sealed volume under observation, there exist histories in which this must be observed. This is never observed. Therefore the MWI is shown to be false. http://iridia.ulb.ac.be/~marchal/

### Re: Quantum Immortality = no second law

Hi, David Deutsch argues in Fabric of Reality that only the Multiverse conserves quantity (not single branches). The rest is probabilistic stuff (see Bruno's post) Cheers, Günther Telmo Menezes wrote: Yes, you're right. Still I think my argument holds. The production of the rifle, bullet and geiger counter system plus the geiger counter operation should produce more than enough entropy to compensate for the atom not decaying. On Thu, Apr 17, 2008 at 1:45 PM, Michael Rosefield [EMAIL PROTECTED] wrote: It's not so much the input of energy, it's the production of more entropy where the energy is taken from. On 17/04/2008, Telmo Menezes [EMAIL PROTECTED] wrote: I would like to argue that in setting this experiment, energy is being expended to prevent the increase in entropy, albeit not in an obvious way. It is a trivial observation that systems may be devised that prevent increases in entropy by paying energy costs. One example is an ice cube in the freezer. In the case of this experiment, and assuming MWI, we are creating a scenario where the atomic decay is not possible from the experimenter's perspective. However, the experimenter is setting a system that includes the rifle and the geiger counter. Both these devices need energy to operate. Maybe it's just a convoluted version of the ice cube in the freezer? Best regards, Telmo Menezes. On Tue, Apr 15, 2008 at 12:18 AM, nichomachus [EMAIL PROTECTED] wrote: In the description of the quantum immortality gedanken experiment, a physicist rigs an automatic rifle to a geiger counter to fire into him upon the detection of an atomic decay event from a bit of radioactive material. If the many worlds hypothesis is true, the self-awareness of the physicist will continue to find himself alive after any length of time in front of his gun, since there exist parallel worlds where the decay does not occur. On a microscopic scale this is analogous to the observing a reality in which the second law of thermodynamics does not hold. for example, since there is a non-zero probability that molecular interactions will result in a decrease in entropy in a particular sealed volume under observation, there exist histories in which this must be observed. This is never observed. Therefore the MWI is shown to be false. -- Günther Greindl Department of Philosophy of Science University of Vienna [EMAIL PROTECTED] http://www.univie.ac.at/Wissenschaftstheorie/ Blog: http://dao.complexitystudies.org/ Site: http://www.complexitystudies.org --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---

### Re: Quantum Immortality = no second law

On Thu, Apr 17, 2008 at 2:37 PM, Bruno Marchal [EMAIL PROTECTED] wrote: Are you saying that the second law is verified in each of all branches of the (quantum) multiverse? I'm not saying that. I would say the second law is statistical, and is verified in most branches. In the MWI applied to quantum field it seems to me that there can be branches with an arbitrarily high number of photon creation without annihilation, and this for each period of time. Yes, I would tend to agree with that, although I can't say I'm 100% convinced. Anyway I'm a relative newcomer to this list so I don't feel I have an informed opinion yet. Need to catch up with all the arguments. Also have a thesis to finish, which tends to get in the way :) I'm just arguing that the experiment with the rifle and the geiger counter does not imply any second law anomaly. Yes, you are forcing your consciousness to move to states where the atom never decays, but if you consider the larger system, entropy is increasing as normal because of the preparation and maintenance of the apparatus needed for the experiment. Do you think this makes sense? Telmo Menezes. --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---

### Re: Quantum Immortality = no second law

Telmo Menezes wrote: On Thu, Apr 17, 2008 at 2:37 PM, Bruno Marchal [EMAIL PROTECTED] wrote: Are you saying that the second law is verified in each of all branches of the (quantum) multiverse? I'm not saying that. I would say the second law is statistical, and is verified in most branches. In the MWI applied to quantum field it seems to me that there can be branches with an arbitrarily high number of photon creation without annihilation, and this for each period of time. I'm not sure what source of photon creation you have in mind, but QFT doesn't allow violation of energy conservation. Yes, I would tend to agree with that, although I can't say I'm 100% convinced. Anyway I'm a relative newcomer to this list so I don't feel I have an informed opinion yet. Need to catch up with all the arguments. Also have a thesis to finish, which tends to get in the way :) I'm just arguing that the experiment with the rifle and the geiger counter does not imply any second law anomaly. Yes, you are forcing your consciousness to move to states where the atom never decays, but if you consider the larger system, entropy is increasing as normal because of the preparation and maintenance of the apparatus needed for the experiment. Do you think this makes sense? Telmo Menezes. The idea of the multiverse derives from quantum mechanics, e.g. the Everett no-collapse interpretation. But in that model the (microscopic) entropy never increases (or decreases), because QM evolution is unitary. It is only the coarse-grained entropy, i.e. restricted to this branch, that increases. Certainly within this branch you are correct that the entropy increase due to firing a gun is very much greater than the decrease due to an atom not decaying. Brent Meeker --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---

### Re: Quantum Immortality = no second law

To pull a fatuous idea from where the sun doth not shine, what if energy is merely moving 'between universes'; it is conserved just because of statistical balance. On 17/04/2008, Brent Meeker [EMAIL PROTECTED] wrote: I'm not sure what source of photon creation you have in mind, but QFT doesn't allow violation of energy conservation. -- They couldn't hit an elephant at this dist- Last words of Gen. John Sedgwick, spoken as he looked out over the parapet at enemy lines during the Battle of Spotsylvania in 1864. --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---

### Re: Quantum Immortality = no second law

It's conserved because we require that the Hamiltonian not be explicitly time dependent (we want our laws to apply equally at all times); that and Noether's theorem imply conservation of 4-momentum. Brent Meeker Michael Rosefield wrote: To pull a fatuous idea from where the sun doth not shine, what if energy is merely moving 'between universes'; it is conserved just because of statistical balance. On 17/04/2008, *Brent Meeker* [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] wrote: I'm not sure what source of photon creation you have in mind, but QFT doesn't allow violation of energy conservation. -- They couldn't hit an elephant at this dist- Last words of Gen. John Sedgwick, spoken as he looked out over the parapet at enemy lines during the Battle of Spotsylvania in 1864. --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---

### Re: Quantum Immortality = no second law

On Thu, Apr 17, 2008 at 06:45:59PM +0100, Telmo Menezes wrote: I'm just arguing that the experiment with the rifle and the geiger counter does not imply any second law anomaly. Yes, you are forcing your consciousness to move to states where the atom never decays, but if you consider the larger system, entropy is increasing as normal because of the preparation and maintenance of the apparatus needed for the experiment. Do you think this makes sense? Telmo Menezes. I think this is an intriguing idea, but I can't say yet whether it is right. Let me paraphrase, as some of the discussion on this thread has been barking up the wrong trees. Whilst the second law holds in a first person statistical sense (as pointed out by a number of people), entropy is in fact conserved in a third person sense (conservation of probability, unitarity of evolution etc.) What Telmo is suggesting is a little different. He is saying that the quantum suicider will still see entropy increasing in er universe, as the atom and rifle is not an isolated system, and the thermodynamic costs of maintaining the experimental aparatus cause entropy to be raised elsewhere in the suicider's universe. This strikes me as similar to Slizard's analysis of the Maxwell daemon, and could probably be handled the same way. Unfortunately I don't have the time now to refresh my memory of how these arguments work - but perhaps Brent can do the analysis? Cheers -- A/Prof Russell Standish Phone 0425 253119 (mobile) Mathematics UNSW SYDNEY 2052 [EMAIL PROTECTED] Australiahttp://www.hpcoders.com.au --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---

### Re: Quantum Immortality = no second law

Le 16-avr.-08, à 03:24, Russell Standish a écrit : On Wed, Apr 16, 2008 at 02:22:23AM +0200, Saibal Mitra wrote: First off, how is it that the MWI does not imply quantum immortality? MWI is just quantum mechanics without the wavefunction collapse postulate. This then implies that after a measurement your wavefuntion will be in a superposition of the states corresponding to definite outcomes. But we cannot just consider suicide experiments and then say that just because branches of the wavefuntion exist in which I survive, I'll find myself there with 100% probability. The fact that probabilities are conserved follows from unitary time evolution. If a state evolves into a linear combination of states in which I'm dead and alive then the probabilities of all these states add up to 1. The probability of finding myself to be alive at all after the experiment is then less than the probability of me finding myself about to perform the suicide experiment. The probability of me finding myself to be alive after n suicide experiments decays exponentially with n. Therefore I should not expect to find myself having survived many suicide experiments. Note that contrary to what you often read in the popular accounts of the multiverse, the multiverse does not split when we make observations. The most natural state for the entire multiverse is just an eigenstate of the Hamiltonian. The energy can be taken to be zero, therefore the wavefunction of the multiverse satisfies the equation: One should also note that this is the ASSA position. The ASSA was introduced by Jacques Mallah in his argument against quantum immortality, and a number of participants in this list adhere to the ASSA position. Its counterpart if the RSSA, which does imply quantum immortality (provided that the no cul-de-sac conjecture holds), and other list participants adhere to the RSSA. To date, no argument has convincingly demonstrated which of the ASSA or RSSA should be preferred, so it has become somewhat a matter of taste. There is some discussion of this in my book Theory of Nothing. Actually, I am not sure the ASSA makes sense once we take into account the distinction between first and third person point of view. Comp immortality is an almost trivial consequence that personal death cannot be a first person experience at all. Quantum immortality is most plausibly equivalent with comp immortality if the quantum level describes our correct comp substitution level. But this does not mean that we can know what shape the comp immortality can have, given that comp forbids us to know which machine we are or which computations bear us. We have not yet answered the question of how many first persons are. If it is one, amoeba duplication already entails immortality, although not necessarily a reassuring (or frightening) one like some of those suggested by some religion or popular beliefs. We are mainly ignorant of those matters, and necessarily so, in case comp (or its transfinitely many weakenings) is (are) correct. But we can make inferences, i.e. theories, and *define* matter by the explicit addition of the no-cul-de-sac principle, by adding Dt to Bp, going from the primary hypostases to the secondary one: this gives a quantum propositional theory of matter but this (lobian) theory is still in lack of a good tensor product capable of extracting a non trivial first person *plural* notion. Strictly speaking, it remains amazing we can interact ... Bruno http://iridia.ulb.ac.be/~marchal/ --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---

### Re: Quantum Immortality = no second law

On Apr 16, 4:54 am, Bruno Marchal [EMAIL PROTECTED] wrote: Le 16-avr.-08, à 03:24, Russell Standish a écrit : On Wed, Apr 16, 2008 at 02:22:23AM +0200, Saibal Mitra wrote: First off, how is it that the MWI does not imply quantum immortality? MWI is just quantum mechanics without the wavefunction collapse postulate. This then implies that after a measurement your wavefuntion will be in a superposition of the states corresponding to definite outcomes. But we cannot just consider suicide experiments and then say that just because branches of the wavefuntion exist in which I survive, I'll find myself there with 100% probability. The fact that probabilities are conserved follows from unitary time evolution. If a state evolves into a linear combination of states in which I'm dead and alive then the probabilities of all these states add up to 1. The probability of finding myself to be alive at all after the experiment is then less than the probability of me finding myself about to perform the suicide experiment. The probability of me finding myself to be alive after n suicide experiments decays exponentially with n. Therefore I should not expect to find myself having survived many suicide experiments. Note that contrary to what you often read in the popular accounts of the multiverse, the multiverse does not split when we make observations. The most natural state for the entire multiverse is just an eigenstate of the Hamiltonian. The energy can be taken to be zero, therefore the wavefunction of the multiverse satisfies the equation: One should also note that this is the ASSA position. The ASSA was introduced by Jacques Mallah in his argument against quantum immortality, and a number of participants in this list adhere to the ASSA position. Its counterpart if the RSSA, which does imply quantum immortality (provided that the no cul-de-sac conjecture holds), and other list participants adhere to the RSSA. To date, no argument has convincingly demonstrated which of the ASSA or RSSA should be preferred, so it has become somewhat a matter of taste. There is some discussion of this in my book Theory of Nothing. Actually, I am not sure the ASSA makes sense once we take into account the distinction between first and third person point of view. Comp immortality is an almost trivial consequence that personal death cannot be a first person experience at all. Quantum immortality is most plausibly equivalent with comp immortality if the quantum level describes our correct comp substitution level. But this does not mean that we can know what shape the comp immortality can have, given that comp forbids us to know which machine we are or which computations bear us. Why is this the case? Whether Comp is true or not, it would seem that the direction of physical research and investigation is in the direction of discovering the presumed foundational TOE that accounts for everything we observe. Say, for example, that it were possible to create in a computer simulation an artificial universe that would evolve intelligent life forms by virtue of the physics of the artificial universe alone. Why, in principle, is it not possible for those intelligent beings to discover the fundamental rules that underlie their existence? They will not be able to discover any details of the architecture of the particular turing machine that is simulating their universe (even whether or not they are in fact being computed), but I don't see any a priori reason why they would not be able to discover their own basic physical laws. Max Tegmark has indicated that it may be possible to get some idea of which mathematical structure bears our own existence by approaching from the opposite direction. Though we may never know which one contains ourselves, it may be possible to derive a probability distribution describing the likelihood of our location in the ensemble. To go back to the comments you were making about the Prestige: If the subject of a quantum immortality experiment finds himself improbably alive, is he in some sense guilty of the murder of the other versions of himself? Or not, since those are merely third person experiences. What constitutes a first person experience? It seems that you are defining it as an uninterrupted consciousness since comp implies the almost trivial consequence that personal death cannot be a first person experience at all. I am confused by exactly what is meant by first and third person experiences. --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---

### Re: Quantum Immortality = no second law

HI, 2008/4/16, nichomachus [EMAIL PROTECTED]: On Apr 16, 4:54 am, Bruno Marchal [EMAIL PROTECTED] wrote: Le 16-avr.-08, à 03:24, Russell Standish a écrit : On Wed, Apr 16, 2008 at 02:22:23AM +0200, Saibal Mitra wrote: First off, how is it that the MWI does not imply quantum immortality? MWI is just quantum mechanics without the wavefunction collapse postulate. This then implies that after a measurement your wavefuntion will be in a superposition of the states corresponding to definite outcomes. But we cannot just consider suicide experiments and then say that just because branches of the wavefuntion exist in which I survive, I'll find myself there with 100% probability. The fact that probabilities are conserved follows from unitary time evolution. If a state evolves into a linear combination of states in which I'm dead and alive then the probabilities of all these states add up to 1. The probability of finding myself to be alive at all after the experiment is then less than the probability of me finding myself about to perform the suicide experiment. The probability of me finding myself to be alive after n suicide experiments decays exponentially with n. Therefore I should not expect to find myself having survived many suicide experiments. Note that contrary to what you often read in the popular accounts of the multiverse, the multiverse does not split when we make observations. The most natural state for the entire multiverse is just an eigenstate of the Hamiltonian. The energy can be taken to be zero, therefore the wavefunction of the multiverse satisfies the equation: One should also note that this is the ASSA position. The ASSA was introduced by Jacques Mallah in his argument against quantum immortality, and a number of participants in this list adhere to the ASSA position. Its counterpart if the RSSA, which does imply quantum immortality (provided that the no cul-de-sac conjecture holds), and other list participants adhere to the RSSA. To date, no argument has convincingly demonstrated which of the ASSA or RSSA should be preferred, so it has become somewhat a matter of taste. There is some discussion of this in my book Theory of Nothing. Actually, I am not sure the ASSA makes sense once we take into account the distinction between first and third person point of view. Comp immortality is an almost trivial consequence that personal death cannot be a first person experience at all. Quantum immortality is most plausibly equivalent with comp immortality if the quantum level describes our correct comp substitution level. But this does not mean that we can know what shape the comp immortality can have, given that comp forbids us to know which machine we are or which computations bear us. Why is this the case? Whether Comp is true or not, it would seem that the direction of physical research and investigation is in the direction of discovering the presumed foundational TOE that accounts for everything we observe. Say, for example, that it were possible to create in a computer simulation an artificial universe that would evolve intelligent life forms by virtue of the physics of the artificial universe alone. Why, in principle, is it not possible for those intelligent beings to discover the fundamental rules that underlie their existence? They will not be able to discover any details of the architecture of the particular turing machine that is simulating their universe (even whether or not they are in fact being computed), but I don't see any a priori reason why they would not be able to discover their own basic physical laws. Because from the 1st person pov you cannot tell which computation (there are an infinities) support you hence the RSSA because the probability of your next states are relative to the current state you are. With the no cul de sac (means there exists no universe state which does not have a next state) comp predict comp immortality... Max Tegmark has indicated that it may be possible to get some idea of which mathematical structure bears our own existence by approaching from the opposite direction. Though we may never know which one contains ourselves, it may be possible to derive a probability distribution describing the likelihood of our location in the ensemble. That means the universe is not one mathematical structure nor the multiverse is, but the infinite set of functionnaly equivalent computation... well from a certain point of view these universes aren't differentiated... So it is difficult to say that at any moment we are in such or such computation, we're in all of them (that support us). To go back to the comments you were making about the Prestige: If the subject of a quantum immortality experiment finds

### Re: Quantum Immortality = no second law

Even though I believe in QI, I try not to be too blase with my life due to the guilt I'd feel for all sorrow I'd cause my friends family in the worlds I died in. I also think the mathematical laws underlying the universes we are in are also subject to anthropic multiplicity; we don't just filter universes, but metaphysics too. Ultimately, all possible laws are admissable, and I expect the really interesting part is how much everything is 'equivalentisable' (to make a word up). At root, I suspect we have two kinds of metaphysics; generative (those that create law and structure ab initio), and holistic (those that describe the shape of the entirity) -- and that they are both correct and equivalent. You'd think with a master's in mathematical logic I'd be able to do better than that, but... :) Michael On 16/04/2008, nichomachus [EMAIL PROTECTED] wrote: On Apr 16, 4:54 am, Bruno Marchal [EMAIL PROTECTED] wrote: Le 16-avr.-08, à 03:24, Russell Standish a écrit : On Wed, Apr 16, 2008 at 02:22:23AM +0200, Saibal Mitra wrote: First off, how is it that the MWI does not imply quantum immortality? MWI is just quantum mechanics without the wavefunction collapse postulate. This then implies that after a measurement your wavefuntion will be in a superposition of the states corresponding to definite outcomes. But we cannot just consider suicide experiments and then say that just because branches of the wavefuntion exist in which I survive, I'll find myself there with 100% probability. The fact that probabilities are conserved follows from unitary time evolution. If a state evolves into a linear combination of states in which I'm dead and alive then the probabilities of all these states add up to 1. The probability of finding myself to be alive at all after the experiment is then less than the probability of me finding myself about to perform the suicide experiment. The probability of me finding myself to be alive after n suicide experiments decays exponentially with n. Therefore I should not expect to find myself having survived many suicide experiments. Note that contrary to what you often read in the popular accounts of the multiverse, the multiverse does not split when we make observations. The most natural state for the entire multiverse is just an eigenstate of the Hamiltonian. The energy can be taken to be zero, therefore the wavefunction of the multiverse satisfies the equation: One should also note that this is the ASSA position. The ASSA was introduced by Jacques Mallah in his argument against quantum immortality, and a number of participants in this list adhere to the ASSA position. Its counterpart if the RSSA, which does imply quantum immortality (provided that the no cul-de-sac conjecture holds), and other list participants adhere to the RSSA. To date, no argument has convincingly demonstrated which of the ASSA or RSSA should be preferred, so it has become somewhat a matter of taste. There is some discussion of this in my book Theory of Nothing. Actually, I am not sure the ASSA makes sense once we take into account the distinction between first and third person point of view. Comp immortality is an almost trivial consequence that personal death cannot be a first person experience at all. Quantum immortality is most plausibly equivalent with comp immortality if the quantum level describes our correct comp substitution level. But this does not mean that we can know what shape the comp immortality can have, given that comp forbids us to know which machine we are or which computations bear us. Why is this the case? Whether Comp is true or not, it would seem that the direction of physical research and investigation is in the direction of discovering the presumed foundational TOE that accounts for everything we observe. Say, for example, that it were possible to create in a computer simulation an artificial universe that would evolve intelligent life forms by virtue of the physics of the artificial universe alone. Why, in principle, is it not possible for those intelligent beings to discover the fundamental rules that underlie their existence? They will not be able to discover any details of the architecture of the particular turing machine that is simulating their universe (even whether or not they are in fact being computed), but I don't see any a priori reason why they would not be able to discover their own basic physical laws. Max Tegmark has indicated that it may be possible to get some idea of which mathematical structure bears our own existence by approaching from the opposite direction. Though we may never know which one contains ourselves, it may be possible to derive a probability distribution describing the likelihood of our location in the ensemble. To go back to the comments you were making about the

### Re: Quantum Immortality = no second law

On Mon, Apr 14, 2008 at 10:24:12PM -0700, nichomachus wrote: Hi, Russell, Surely the framework of the Many Worlds interpretation would say that the likelyhood of measuring a quantum observable in state A rather than B reflects the number of histories in which the observable is measured as being in state A divided by number of histories in which either is seen. Molecules in a gas chamber may not be the best example, as I am personally unclear as to whether the macroscopic behavior of the aggregate is reduceable to probabilistic quantum events. But the point remains that it is impossible to adhere to the MWI without also affirming not only the existence of histories in which unlikely events happen, but also ones in which *only* unlikely events happen. Absolutely - there are histories in which entropy decreases continuously. This doesn't contradict the second law, because the second law is probabilistic. Many, many more histories exist with increasing entropy than decreasing entropy. The chance of an observer observing continuous decrease in entropy is negligible, but small exceptions to the second law can be observed in our world. IIRC, some guys at ANU showed this a few years back, which got a bit of press, although its not surprising when you understand what the second law really is - I think it was Ken Baldwin's group, but you can try Google for details. This includes universes where the cat never dies, uranium never decays, and (perhaps) the second law does not hold. Is it right to think that this is unproblematic? Yes. Or perhaps we should regard the Many Worlds formalism as merely an instrumentalistic interpretation, similar to how Bohr and Heisenberg regarded their Copenhagen interpretation, rather than granting full ontological significance to alternate possible histories. I take the Many Worlds as ontologically significant, unlike Bohr or Heisenberg. In any case, QTI does not change the observed outcome of likely versus unlikely events, it just changes the set of possible outcome on which to apply the second law. What does QTI stand for? Quantum Theory of Immortality. What you are talking about with Tegmark's suicide experiment. So our suicidal physicist would have enabled himself to observe the extremely scenario of seeing radioactive elements never decay, by killing himself in all histories where decay ocurred and thereby selecting only the ones where it did not take place to continue his awareness in.Of course, those branches of his identity would still have observed the same outcomes even if the gun was unloaded, so he doesn't really have to kill himself in nearly all universes in order to get to see it. But if I accept the above as true, then I must also accept that there are histories that have been experienced in which no atom of an unstable element has decayed since Jan. 1, 1900. (or any date you prefer) Yes. When Thomas Young performed his double slit experiment, were there any versions of himself that did not observe an interference pattern? Probably. There were others where his apparatus blew up, or a cat peed on a vital component and so on. Why not? I appreciate the replies as I am more questions than answers at this point on these topics. -- A/Prof Russell Standish Phone 0425 253119 (mobile) Mathematics UNSW SYDNEY 2052 [EMAIL PROTECTED] Australiahttp://www.hpcoders.com.au --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---

### Re: Quantum Immortality = no second law

On Wed, Apr 16, 2008 at 02:22:23AM +0200, Saibal Mitra wrote: First off, how is it that the MWI does not imply quantum immortality? MWI is just quantum mechanics without the wavefunction collapse postulate. This then implies that after a measurement your wavefuntion will be in a superposition of the states corresponding to definite outcomes. But we cannot just consider suicide experiments and then say that just because branches of the wavefuntion exist in which I survive, I'll find myself there with 100% probability. The fact that probabilities are conserved follows from unitary time evolution. If a state evolves into a linear combination of states in which I'm dead and alive then the probabilities of all these states add up to 1. The probability of finding myself to be alive at all after the experiment is then less than the probability of me finding myself about to perform the suicide experiment. The probability of me finding myself to be alive after n suicide experiments decays exponentially with n. Therefore I should not expect to find myself having survived many suicide experiments. Note that contrary to what you often read in the popular accounts of the multiverse, the multiverse does not split when we make observations. The most natural state for the entire multiverse is just an eigenstate of the Hamiltonian. The energy can be taken to be zero, therefore the wavefunction of the multiverse satisfies the equation: One should also note that this is the ASSA position. The ASSA was introduced by Jacques Mallah in his argument against quantum immortality, and a number of participants in this list adhere to the ASSA position. Its counterpart if the RSSA, which does imply quantum immortality (provided that the no cul-de-sac conjecture holds), and other list participants adhere to the RSSA. To date, no argument has convincingly demonstrated which of the ASSA or RSSA should be preferred, so it has become somewhat a matter of taste. There is some discussion of this in my book Theory of Nothing. Cheers -- A/Prof Russell Standish Phone 0425 253119 (mobile) Mathematics UNSW SYDNEY 2052 [EMAIL PROTECTED] Australiahttp://www.hpcoders.com.au --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---

### Re: Quantum Immortality = no second law

Citeren nichomachus [EMAIL PROTECTED]: In the description of the quantum immortality gedanken experiment, a physicist rigs an automatic rifle to a geiger counter to fire into him upon the detection of an atomic decay event from a bit of radioactive material. If the many worlds hypothesis is true, the self-awareness of the physicist will continue to find himself alive after any length of time in front of his gun, since there exist parallel worlds where the decay does not occur. This has never been rigorously proven. I can give you some argumetns why the MWI does not imply Quantum Immortality. On a microscopic scale this is analogous to the observing a reality in which the second law of thermodynamics does not hold. for example, since there is a non-zero probability that molecular interactions will result in a decrease in entropy in a particular sealed volume under observation, there exist histories in which this must be observed. This is never observed. Therefore the MWI is shown to be false. This is also not a correct conclusion (if you replace MWI by quantum immortality). --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---

### Re: Quantum Immortality = no second law

Citeren nichomachus [EMAIL PROTECTED]: In the description of the quantum immortality gedanken experiment, a physicist rigs an automatic rifle to a geiger counter to fire into him upon the detection of an atomic decay event from a bit of radioactive material. If the many worlds hypothesis is true, the self-awareness of the physicist will continue to find himself alive after any length of time in front of his gun, since there exist parallel worlds where the decay does not occur. This has never been rigorously proven. I can give you some argumetns why the MWI does not imply Quantum Immortality. On a microscopic scale this is analogous to the observing a reality in which the second law of thermodynamics does not hold. for example, since there is a non-zero probability that molecular interactions will result in a decrease in entropy in a particular sealed volume under observation, there exist histories in which this must be observed. This is never observed. Therefore the MWI is shown to be false. This is also not a correct conclusion (if you replace MWI by quantum immortality). --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---

### Re: Quantum Immortality = no second law

No, it just means no-one's put enough stress on the 2nd Law yet :) Besides, it's not so much a law as a guideline. Well, a strong statistical tendency On 15/04/2008, nichomachus [EMAIL PROTECTED] wrote: In the description of the quantum immortality gedanken experiment, a physicist rigs an automatic rifle to a geiger counter to fire into him upon the detection of an atomic decay event from a bit of radioactive material. If the many worlds hypothesis is true, the self-awareness of the physicist will continue to find himself alive after any length of time in front of his gun, since there exist parallel worlds where the decay does not occur. On a microscopic scale this is analogous to the observing a reality in which the second law of thermodynamics does not hold. for example, since there is a non-zero probability that molecular interactions will result in a decrease in entropy in a particular sealed volume under observation, there exist histories in which this must be observed. This is never observed. Therefore the MWI is shown to be false. -- They couldn't hit an elephant at this dist- Last words of Gen. John Sedgwick, spoken as he looked out over the parapet at enemy lines during the Battle of Spotsylvania in 1864. --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---

### Re: Quantum Immortality = no second law

On 15/04/2008, Michael Rosefield [EMAIL PROTECTED] wrote: No, it just means no-one's put enough stress on the 2nd Law yet :) Besides, it's not so much a law as a guideline. Well, a strong statistical tendency As Michael pointed out, the 2nd law is a statistical law, which says that a decrease in entropy is unlikely, not impossible.. QTI predicts that you will survive the most probable way possible. This means it is unlikely that you will find yourself in a world where you choose to attempt quantum suicide experiments in the first place, but if you do the least improbable way of surviving is very improbable in absolute terms, but not impossible. -- Stathis Papaioannou --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---

### Re: Quantum Immortality = no second law

Further to this, to say that the 2nd law is falsified, we'd have to have circumstances where the less likely outcome ocurred more frequently than the more often. (ie entropy decreases more often than it increases). But this begs the question of what we mean by likelihood of outcome, if not related to frequency of occurrence. In any case, QTI does not change the observed outcome of likely versus unlikely events, it just changes the set of possible outcome on which to apply the second law. On Tue, Apr 15, 2008 at 11:30:05AM +1000, Stathis Papaioannou wrote: On 15/04/2008, Michael Rosefield [EMAIL PROTECTED] wrote: No, it just means no-one's put enough stress on the 2nd Law yet :) Besides, it's not so much a law as a guideline. Well, a strong statistical tendency As Michael pointed out, the 2nd law is a statistical law, which says that a decrease in entropy is unlikely, not impossible.. QTI predicts that you will survive the most probable way possible. This means it is unlikely that you will find yourself in a world where you choose to attempt quantum suicide experiments in the first place, but if you do the least improbable way of surviving is very improbable in absolute terms, but not impossible. -- Stathis Papaioannou -- A/Prof Russell Standish Phone 0425 253119 (mobile) Mathematics UNSW SYDNEY 2052 [EMAIL PROTECTED] Australiahttp://www.hpcoders.com.au --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---

### Re: Quantum Immortality = no second law

On Apr 14, 9:21 pm, Russell Standish [EMAIL PROTECTED] wrote: Further to this, to say that the 2nd law is falsified, we'd have to have circumstances where the less likely outcome ocurred more frequently than the more often. (ie entropy decreases more often than it increases). But this begs the question of what we mean by likelihood of outcome, if not related to frequency of occurrence. Hi, Russell, Surely the framework of the Many Worlds interpretation would say that the likelyhood of measuring a quantum observable in state A rather than B reflects the number of histories in which the observable is measured as being in state A divided by number of histories in which either is seen. Molecules in a gas chamber may not be the best example, as I am personally unclear as to whether the macroscopic behavior of the aggregate is reduceable to probabilistic quantum events. But the point remains that it is impossible to adhere to the MWI without also affirming not only the existence of histories in which unlikely events happen, but also ones in which *only* unlikely events happen. This includes universes where the cat never dies, uranium never decays, and (perhaps) the second law does not hold. Is it right to think that this is unproblematic? Or perhaps we should regard the Many Worlds formalism as merely an instrumentalistic interpretation, similar to how Bohr and Heisenberg regarded their Copenhagen interpretation, rather than granting full ontological significance to alternate possible histories. In any case, QTI does not change the observed outcome of likely versus unlikely events, it just changes the set of possible outcome on which to apply the second law. What does QTI stand for? So our suicidal physicist would have enabled himself to observe the extremely scenario of seeing radioactive elements never decay, by killing himself in all histories where decay ocurred and thereby selecting only the ones where it did not take place to continue his awareness in.Of course, those branches of his identity would still have observed the same outcomes even if the gun was unloaded, so he doesn't really have to kill himself in nearly all universes in order to get to see it. But if I accept the above as true, then I must also accept that there are histories that have been experienced in which no atom of an unstable element has decayed since Jan. 1, 1900. (or any date you prefer) When Thomas Young performed his double slit experiment, were there any versions of himself that did not observe an interference pattern? Why not? I appreciate the replies as I am more questions than answers at this point on these topics. On Tue, Apr 15, 2008 at 11:30:05AM +1000, Stathis Papaioannou wrote: On 15/04/2008, Michael Rosefield [EMAIL PROTECTED] wrote: No, it just means no-one's put enough stress on the 2nd Law yet :) Besides, it's not so much a law as a guideline. Well, a strong statistical tendency As Michael pointed out, the 2nd law is a statistical law, which says that a decrease in entropy is unlikely, not impossible.. QTI predicts that you will survive the most probable way possible. This means it is unlikely that you will find yourself in a world where you choose to attempt quantum suicide experiments in the first place, but if you do the least improbable way of surviving is very improbable in absolute terms, but not impossible. -- Stathis Papaioannou -- ---- A/Prof Russell Standish Phone 0425 253119 (mobile) Mathematics UNSW SYDNEY 2052 [EMAIL PROTECTED] Australia http://www.hpcoders.com.au ----- Hide quoted text - - Show quoted text - --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---

### Re: Quantum Immortality = no second law

On Apr 14, 6:26 pm, Saibal Mitra [EMAIL PROTECTED] wrote: Citeren nichomachus [EMAIL PROTECTED]: In the description of the quantum immortality gedanken experiment, a physicist rigs an automatic rifle to a geiger counter to fire into him upon the detection of an atomic decay event from a bit of radioactive material. If the many worlds hypothesis is true, the self-awareness of the physicist will continue to find himself alive after any length of time in front of his gun, since there exist parallel worlds where the decay does not occur. This has never been rigorously proven. I can give you some argumetns why the MWI does not imply Quantum Immortality. Ok. I would like to hear them. On a microscopic scale this is analogous to the observing a reality in which the second law of thermodynamics does not hold. for example, since there is a non-zero probability that molecular interactions will result in a decrease in entropy in a particular sealed volume under observation, there exist histories in which this must be observed. This is never observed. Therefore the MWI is shown to be false. This is also not a correct conclusion (if you replace MWI by quantum immortality). I agree. I don't believe the argument truly works whether we are talking about WMI or quantum immortality. But what I am interested in is why not. That is why I posed the argument. If it is flawed, it will help me understand everything better if you could tell me how you think it is flawed. First off, how is it that the MWI does not imply quamtum immortality? --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Everything List group. To post to this group, send email to [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~--~~~~--~~--~--~---