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: Greg Egan's Permutation City was: The prestige
Bruno, more seriously imo. And then I tell you without further explanation that the prestige is truly more. We can come back on this later. OK I cave in, I will watch this movie :-)) 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
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: 'White Rabbit' solution summary (+ simplicity explanation)
One of my references did not 'HTMLize' properly for some reason. This one should: www.physica.freeserve.co.uk/pa01.htm - Original Message - From: Alastair Malcolm To: [EMAIL PROTECTED] Sent: Saturday, April 19, 2008 9:48 AM Subject: 'White Rabbit' solution summary (+ simplicity explanation) Since there is a distinct possibility that readers of Russell's 'Theory of Nothing' book will be left with the wrong impression that my approach to the White Rabbit problem is essentially the same as that of the author, I feel I should at least record here a brief summary of the relevant part of my own ideas, which are in essence very simple and straightforward. My starting point is a consideration of the potentially fatal 'failure of induction' (WR) challenge to the 'all logically possible universes' (alpu) solution to the question of our existence (a solution that general arbitrariness and abstract symmetry arguments appear more-or-less to ultimately require): even if the world happened to be ordered up to now, why should we happen to be in that world that continues in an ordered way, if all logically possible futures do in fact occur, as alpu requires. The solution to this challenge that is outlined here also explains why we live in a relatively simple world, and is arrived at by a general consideration of the most compressed fully accurate representation of our (past/present/future) world (which in that most compressed form may well need to include other worlds, for example those of (what would be the rest of) an Everett multiverse), conceptually in the form of Tegmark's 'bird view'; whether the form of this representation is some standard interpretation of a bit string, or an axiom list (under some common theorem-generating inference rules), the two key points are the same: first, there is nothing logically to prevent some worlds themselves (including ours) being more 'compressed' than as we would perceive them to be, and second, any difference from the world to be represented (which must also exist under alpu) has to be reflected in a difference in that representation - it then follows that in any comparison of all possible combinations of bit/axiom strings up to any equal finite (long) length (many representing not only a world but also (using 'spare' string segments inside the total length) extraneous features such as other worlds, nothing in particular, or perhaps 'invisible' intra-world entities), it is reasonable to suppose that the simplest worlds (ie those with the shortest representing string segments) will occur most often across all strings, since they will have more 'spare' irrelevant bit/axiom combinations up to that equal comparison length, than those of more complex worlds (and so similarly for all long finite comparison lengths). Thus out of all worlds inhabitable by SAS's, we are most likely to be in one of the simplest (other things being equal) - any physics-violating events like flying rabbits or dragons would require more bits/axioms to (minimally) specify their worlds, and so we should not expect to find ourselves in such a world, at any time in its history. (It also seems to me that for at least some of the scenarios where the above analysis could conceivably be considered inaccurate/incorrect (eg in comparing uncountably infinite quantities), the necessary assumptions for these scenarios render the White Rabbit problem void anyway.) These ideas are fleshed out in: www.physica.freeserve.co.uk/pa01.htm (which enlarges on the 'compressed' objective reality that corresponds to the more compressed representations), and www.physica.freeserve.co.uk/pb01.htm (a more general and informal read). (Comments welcome - particularly if any problems are spotted in the above.) Alastair Malcolm --~--~-~--~~~---~--~~ 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: 'White Rabbit' solution summary (+ simplicity explanation)
Apologies - still some technical problem (it worked when I tested it out). If anyone's interested in the ref it's best to edit the URL line or retype. - Original Message - From: Alastair Malcolm To: [EMAIL PROTECTED] Sent: Saturday, April 19, 2008 6:06 PM Subject: Re: 'White Rabbit' solution summary (+ simplicity explanation) One of my references did not 'HTMLize' properly for some reason. This one should: 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
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: 'White Rabbit' solution summary (+ simplicity explanation)
Perhaps if you added the protocol part of the URL (http://)? Without it, client programs cannot know that it is even a URL, unless it is something like the address bar of a web browser, where it is assumed to be a URL, and http:// is the default protocol if not specified. Being a bit old-fashioned, I always put the http:// on URLs, even though convention has come to leave it assumed. When I mention a bare web address, it usually is _not_ a URL. On Sat, Apr 19, 2008 at 06:24:31PM +0100, Alastair Malcolm wrote: Apologies - still some technical problem (it worked when I tested it out). If anyone's interested in the ref it's best to edit the URL line or retype. - Original Message - From: Alastair Malcolm To: [EMAIL PROTECTED] Sent: Saturday, April 19, 2008 6:06 PM Subject: Re: 'White Rabbit' solution summary (+ simplicity explanation) One of my references did not 'HTMLize' properly for some reason. This one should: www.physica.freeserve.co.uk/pa01.htm -- 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 -~--~~~~--~~--~--~---
QTI --- Expanding brains
Yes, I should have mentioned ASSA and RSSA as discussed on this list in the dark ages. I don't buy QTI for quite a few reasons. A model independent objection I have is the following. If you accept QTI, then the information you have about your history will have to grow without limit (if not, then effectively you have a finite lifetime as you can only store a finite amount of information in a finite volume). Your identity must be preserved as your brain continues to expand to make room for all that informaton that must be stored. Now, I find it hard to believe that a superlarge brain the size of the galaxy would still be me. :) - Original Message - From: Russell Standish [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Wednesday, April 16, 2008 03:24 AM Subject: 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: QTI --- Expanding brains
On 20/04/2008, Saibal Mitra [EMAIL PROTECTED] wrote: I don't buy QTI for quite a few reasons. A model independent objection I have is the following. If you accept QTI, then the information you have about your history will have to grow without limit (if not, then effectively you have a finite lifetime as you can only store a finite amount of information in a finite volume). Your identity must be preserved as your brain continues to expand to make room for all that informaton that must be stored. Now, I find it hard to believe that a superlarge brain the size of the galaxy would still be me. There's no guarantee that you will stay you in any particular way. After all, your brain is infinitely larger now than it was before your nervous system developed. -- 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: QTI --- Expanding brains
Saibal Mitra wrote: Yes, I should have mentioned ASSA and RSSA as discussed on this list in the dark ages. I don't buy QTI for quite a few reasons. A model independent objection I have is the following. If you accept QTI, then the information you have about your history will have to grow without limit (if not, then effectively you have a finite lifetime as you can only store a finite amount of information in a finite volume). Your identity must be preserved as your brain continues to expand to make room for all that informaton that must be stored. Now, I find it hard to believe that a superlarge brain the size of the galaxy would still be me. :) I had a good knockdown argument against this, but I forgot it. :-) 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 -~--~~~~--~~--~--~---
