### Re: The probability problem in Everettian quantum mechanics

On 17 Oct 2013, at 00:49, LizR wrote: By the way, my son (14) asked me the other day what's the oddest prime number? Fortunately, I got the right answer! I would say 2. LOL Was it 2 that you found? To be odd is very subjective here :) Bruno -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out. http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On 15 Oct 2013, at 19:31, meekerdb wrote: On 10/15/2013 3:54 AM, Quentin Anciaux wrote: 2013/10/15 Richard Ruquist yann...@gmail.com Bruno: On the contrary: I assume only that my brain (or generalized brain) is computable, then I show that basically all the rest is not. In everything, or just in arithmetic, the computable is rare and exceptional. Richard: Wow. This contradicts everything I have ever though Bruno was claiming. How does anything exist if it is not computed by the or a machine? And I thought the generalized brain did the computations, not that it was only computed. How does Bruno show that all the rest which presumably includes energy and matter is not computed. Bruno is constantly confusing me. Energy and matter (and the universe whatever it is), is composed by the sum What does sum mean? And how does is constitute a piece of matter? of the infinity of computations going through your state as it is defined by an infinity of computations (and not one), it is not computed. But that's not a definition. It's saying the piece of matter is *constituted* by an infinity of computations. That is a misleading phrasing. The matter is not constituted of anything. It is an appearance coming from the FPI on all computations. But what associates the computations to a piece of matter that we *define* ostensively? The FPI. Bruno http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On 15 Oct 2013, at 19:39, meekerdb wrote: On 10/15/2013 7:49 AM, Bruno Marchal wrote: On 15 Oct 2013, at 12:45, Richard Ruquist wrote: Bruno: On the contrary: I assume only that my brain (or generalized brain) is computable, then I show that basically all the rest is not. In everything, or just in arithmetic, the computable is rare and exceptional. Richard: Wow. This contradicts everything I have ever though Bruno was claiming. How does anything exist if it is not computed by the or a machine? We assume the arithmetical truth. In particular we assume that all closed formula written in the language of arithmetic (and thus using logical symbol + the symbol 0, s (+1), + and *) are all either true or false, independently of us. From this we cannot prove that matter exists, or not, but we can prove that the average universal numbers will (correctly) believe in matter (but it will not know that it is correct). That's not at all clear to me. A universal number encodes proofs - is that what you mean by it believes something? Yes. (I am thinking about the Löbian universal numbers). But how is this something identified at 'matter'? It should follow from the step seven. So, if you have no problem in believing propositions like there is no biggest prime number are true independently of me and you, and the universe, then you can understand that the proposition asserting the existence of (infinitely many) computations in which you believe reading my current post, is also true independently of us. The appearance of matter emerges from the FPI that the machines cannot avoid in the arithmetical truth. Arithmetical truth escapes largely the computable arithmetical truth (by Gödel). And I thought the generalized brain did the computations, Only the computations associated to your mind. not that it was only computed. How does Bruno show that all the rest which presumably includes energy and matter is not computed. Bruno is constantly confusing me. I guess you missed the step seven of the UDA, and are perhaps not aware that arithmetical truth is incredibly big, *much* bigger than what any computer can generate or compute. Then my, or your, mind is associated to *all* computations going through your actual state of mind, That sounds like an uncomputable totality. No, by virtue of the closure of the set of partial (includes the total functions) computable functions for diagonalization, or equivalently, by the existence of universal machines/numbers, that totality is computable/enumerable, and that is why we do have a UD. What happens is that most interesting subset will be uncomputable, so that the FPI entails a priori the non computability of *some* physical things (which can be only the apparent collapse of the wave, but it could be more than that too: open problem). Bruno Brent and below your substitution level there are infinitely many such computations. They all exist in arithmetic, and the FPI glues them, in a non computable way, in possible long and deep physical histories. Bruno -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out. http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On 15 Oct 2013, at 23:04, Russell Standish wrote: On Tue, Oct 15, 2013 at 01:02:13PM -0400, Richard Ruquist wrote: Bruno: Arithmetical truth escapes largely the computable arithmetical truth (by Gödel). Richard: I guess I am too much a physicist to believe that uncomputible arithmetical truth can produce the physical. Since you read my paper you know that I think computations in this universe if holographic are limited to 10^120 bits (the Lloyd limit) which is very far from infinity. I just do not believe in infinity. In other words, I believe the largest prime number in this universe is less than 10^120. So I will drop out of these discussions. My assumptions differ from yours. Then you might well be interested in the Movie Graph Argument, which deals directly with the case where the universe doesn't have sufficient resources to run the universal dovetailer. Good point. Bruno -- Prof Russell Standish Phone 0425 253119 (mobile) Principal, High Performance Coders Visiting Professor of Mathematics hpco...@hpcoders.com.au University of New South Wales http://www.hpcoders.com.au -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out. http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

Bruno Marchal viahttp://support.google.com/mail/bin/answer.py?hl=enanswer=1311182ctx=mail googlegroups.com 2:47 AM (8 hours ago) to everything-list On 15 Oct 2013, at 19:02, Richard Ruquist wrote: Bruno: Arithmetical truth escapes largely the computable arithmetical truth (by Gödel). Richard: I guess I am too much a physicist to believe that uncomputible arithmetical truth can produce the physical. Nobody is perfect :) (You are not alone, physicalism is believed by almost everybody those days) Since you read my paper you know that I think computations in this universe if holographic are limited to 10^120 bits (the Lloyd limit) which is very far from infinity. Of course, I do not assume such a universe. I assume only that I am Turing emulable. I just do not believe in infinity. In other words, I believe the largest prime number in this universe is less than 10^120. So I will drop out of these discussions. My assumptions differ from yours. OK. And then the reasoning (UDA), if you do assume some physicalism, is that we are not Turing emulable. You are working in a non comp theory. Not sure this solves anything, as now you can't justify matter (you assume it), and are back to the usual mind-body problem, with an non satisfying identity between mind and matter. Bruno Richard: I guess you did not read my paper afterall. The Metaverse machine is what computes matter and its energy from the get-go. I grant you that I assume such a Metaverse. But the universe with its limited computations are given by known physics. Regarding MWI vs Wave Collapse , here is some interesting data: Measurement-induced collapse of quantum wavefunction captured in slow motion. http://www.nature.com/news/physicists-snatch-a-peep-into-quantum-paradox-1.13899?WT.ec_id=NEWS-20131015 On Wed, Oct 16, 2013 at 2:59 AM, Bruno Marchal marc...@ulb.ac.be wrote: On 15 Oct 2013, at 23:04, Russell Standish wrote: On Tue, Oct 15, 2013 at 01:02:13PM -0400, Richard Ruquist wrote: Bruno: Arithmetical truth escapes largely the computable arithmetical truth (by Gödel). Richard: I guess I am too much a physicist to believe that uncomputible arithmetical truth can produce the physical. Since you read my paper you know that I think computations in this universe if holographic are limited to 10^120 bits (the Lloyd limit) which is very far from infinity. I just do not believe in infinity. In other words, I believe the largest prime number in this universe is less than 10^120. So I will drop out of these discussions. My assumptions differ from yours. Then you might well be interested in the Movie Graph Argument, which deals directly with the case where the universe doesn't have sufficient resources to run the universal dovetailer. Good point. Bruno -- --**--** Prof Russell Standish Phone 0425 253119 (mobile) Principal, High Performance Coders Visiting Professor of Mathematics hpco...@hpcoders.com.au University of New South Wales http://www.hpcoders.com.au --**--** -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscribe@**googlegroups.comeverything-list%2bunsubscr...@googlegroups.com . To post to this group, send email to everything-list@googlegroups.**comeverything-list@googlegroups.com . Visit this group at http://groups.google.com/**group/everything-listhttp://groups.google.com/group/everything-list . For more options, visit https://groups.google.com/**groups/opt_outhttps://groups.google.com/groups/opt_out . http://iridia.ulb.ac.be/~**marchal/ http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscribe@**googlegroups.comeverything-list%2bunsubscr...@googlegroups.com . To post to this group, send email to everything-list@googlegroups.**comeverything-list@googlegroups.com . Visit this group at http://groups.google.com/**group/everything-listhttp://groups.google.com/group/everything-list . For more options, visit https://groups.google.com/**groups/opt_outhttps://groups.google.com/groups/opt_out . -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On Wed, Oct 16, 2013 at 11:41:46AM -0400, Richard Ruquist wrote: Measurement-induced collapse of quantum wavefunction captured in slow motion. http://www.nature.com/news/physicists-snatch-a-peep-into-quantum-paradox-1.13899?WT.ec_id=NEWS-20131015 The headline is sensationlist and misleading. What is being done is a series of weak measurements that capturing the change from a superposition to a non superposed state. An MWIer would say this is capturing the process of decoherence. It is most certainly not demonstrating wave function collapse is occurring, interesting though the experiment is for technical reasons. Cheers -- Prof Russell Standish Phone 0425 253119 (mobile) Principal, High Performance Coders Visiting Professor of Mathematics hpco...@hpcoders.com.au University of New South Wales http://www.hpcoders.com.au -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On 16 Oct 2013, at 17:41, Richard Ruquist wrote: Bruno Marchal via googlegroups.com 2:47 AM (8 hours ago) to everything-list On 15 Oct 2013, at 19:02, Richard Ruquist wrote: Bruno: Arithmetical truth escapes largely the computable arithmetical truth (by Gödel). Richard: I guess I am too much a physicist to believe that uncomputible arithmetical truth can produce the physical. Nobody is perfect :) (You are not alone, physicalism is believed by almost everybody those days) Since you read my paper you know that I think computations in this universe if holographic are limited to 10^120 bits (the Lloyd limit) which is very far from infinity. Of course, I do not assume such a universe. I assume only that I am Turing emulable. I just do not believe in infinity. In other words, I believe the largest prime number in this universe is less than 10^120. So I will drop out of these discussions. My assumptions differ from yours. OK. And then the reasoning (UDA), if you do assume some physicalism, is that we are not Turing emulable. You are working in a non comp theory. Not sure this solves anything, as now you can't justify matter (you assume it), and are back to the usual mind-body problem, with an non satisfying identity between mind and matter. Bruno Richard: I guess you did not read my paper afterall. I read it, but as you said, we start from very different assumption, and many things you say about PA seems a bit weird for a logician. The Metaverse machine is what computes matter and its energy from the get-go. I grant you that I assume such a Metaverse. But the universe with its limited computations are given by known physics. But that universe, if it exists, must be justified by using + and * and the numbers only, if comp is assumed. Regarding MWI vs Wave Collapse , here is some interesting data: Measurement-induced collapse of quantum wavefunction captured in slow motion. http://www.nature.com/news/physicists-snatch-a-peep-into-quantum-paradox-1.13899?WT.ec_id=NEWS-20131015 A slow motion movie of the wave collapse is a slow motion movie of a differentiating multiverse. Everett theory predicts such motions. Bruno On Wed, Oct 16, 2013 at 2:59 AM, Bruno Marchal marc...@ulb.ac.be wrote: On 15 Oct 2013, at 23:04, Russell Standish wrote: On Tue, Oct 15, 2013 at 01:02:13PM -0400, Richard Ruquist wrote: Bruno: Arithmetical truth escapes largely the computable arithmetical truth (by Gödel). Richard: I guess I am too much a physicist to believe that uncomputible arithmetical truth can produce the physical. Since you read my paper you know that I think computations in this universe if holographic are limited to 10^120 bits (the Lloyd limit) which is very far from infinity. I just do not believe in infinity. In other words, I believe the largest prime number in this universe is less than 10^120. So I will drop out of these discussions. My assumptions differ from yours. Then you might well be interested in the Movie Graph Argument, which deals directly with the case where the universe doesn't have sufficient resources to run the universal dovetailer. Good point. Bruno -- Prof Russell Standish Phone 0425 253119 (mobile) Principal, High Performance Coders Visiting Professor of Mathematics hpco...@hpcoders.com.au University of New South Wales http://www.hpcoders.com.au -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out. http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On 16 October 2013 06:02, Richard Ruquist yann...@gmail.com wrote: Richard: I guess I am too much a physicist to believe that uncomputible arithmetical truth can produce the physical. Since you read my paper you know that I think computations in this universe if holographic are limited to 10^120 bits (the Lloyd limit) which is very far from infinity. I just do not believe in infinity. In other words, I believe the largest prime number in this universe is less than 10^120. So I will drop out of these discussions. My assumptions differ from yours. So what happens if someone proves that, say, 2^200 - 1 is a prime number? Personally I find a statements about prime numbers in this universe to be rather odd. Would 17 remain prime in an empty universe? -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

By the way, my son (14) asked me the other day what's the oddest prime number? Fortunately, I got the right answer! -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On 10/16/2013 3:49 PM, LizR wrote: By the way, my son (14) asked me the other day what's the oddest prime number? Fortunately, I got the right answer! 2, because it's the only one that's even. Brent There are 10 kinds of people. Those who think in binary and those who don't. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

Or the largest prime number less than 10^120, because it's the biggest prime number...?!?!? :) There are two secrets to success. The first is not to give away everything you know... -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On 14 Oct 2013, at 21:30, meekerdb wrote: On 10/14/2013 1:29 AM, Bruno Marchal wrote: On 13 Oct 2013, at 22:11, meekerdb wrote: On 10/13/2013 1:48 AM, Bruno Marchal wrote: On 12 Oct 2013, at 22:53, meekerdb wrote: On 10/12/2013 10:55 AM, Bruno Marchal wrote: On 11 Oct 2013, at 03:25, meekerdb wrote: So there are infinitely many identical universes preceding a measurement. How are these universes distinct from one another? Do they divide into two infinite subsets on a binary measurement, or do infinitely many come into existence in order that some branch-counting measure produces the right proportion? Do you not see any problems with assigning a measure to infinite countable subsets (are there more even numbers that square numbers?). And why should we prefer this model to simply saying the Born rule derives from a Bayesian epistemic view of QM as argued by, for example, Chris Fuchs? If you can explain to me how this makes the parallel experiences, (then), disappearing, please do. I don't understand the question. What parallel experiences do you refer to? And you're asking why they disappeared? The question is how does Fuchs prevent a superposition to be contagious on the observer I think he takes an instrumentalist view of the wave function - so superpositions are just something that happens in the mathematics. But then I don't see how this could fit with even just the one photon interference in the two slits experiment. ?? The math predicts probabilities of events, including where a single photon will land in a Young's slit experiment - no superposition of observer required. But it illustrates that superposition is physical/real, not purely mathematical. Then linearity expands it to us. When I read Fuchs I thought this: Comp suggest a compromise: yes the quantum wave describes only psychological states, but they concern still a *many* dreams/worlds/physical-realities, including the many self-multiplication. There is no many in Fuchs interpretation, there is only the personal subjective probabilities of contemplated futures. I notice the plural of futures. Are those not many? Sure, but they are contemplated, not reified. OK. But apparently object of contemplation can interfere with the real, which is a bit weird to me. The 'interference' is a calculational event 'between' possible futures. Or even the result of considering all possible paths. That leads to instrumentalism. That is dont ask, don't try to understand or get a bigger picture. I know Fuchs criticize Everett, but I don't see how he makes the superposition disappearing. he only makes them psychological, which is not a problem for me. there are still many. Yes, that's why I said I think his approach is consistent with yours. I think Fuchs view of QM is similar to what William S. Cooper calls for at the end of his book The Evolution of Reason - a probabilistic extension of logic. This is essentially the view he defends at length in Interview with a Quantum Bayesian, arXiv: 1207.2141v1 OK. It is still Everett wave as seen from inside. We just don't know if the dreams defined an unique (multiversal) physical reality. Neither in Everett +GR, nor in comp. Bayesian epistemic view is no problem, but you have to define what is the knower, the observer, etc. If not, it falls into a cosmic form of solipsism, and it can generate some strong don't ask imperative. You assume that if others are not explained they must be rejected. I just ask for an explanation of the terms that they introduce. I think he takes the observer as primitive and undefined (and I think you do the same). What? Not at all. the observer is defined by its set of beliefs, itself define by a relative universal numbers. Fuchs defines 'the observer' as the one who bets on the outcome of his actions. Comp has a pretty well defined notion of observer, with its octalist points of view, and an whole theology including his physics, etc. Physicists, like Fuchs, and unlike philosophers, are generally comfortable with not explaining everything. Me too. but he has still to explain the terms that he is using. What's your explanation for the existence of persons? So far what I've heard is that it's an inside view of arithmetic - which I don't find very enlightening. What do you miss in the UDA? As I understand it the UD computes everything computable and it's only your inference that observers (and the rest of the multiverse) *must be in there somewhere* because you've assumed that everything is computable. On the contrary: I assume only that my brain (or generalized brain) is computable, then I show that basically all the rest is not. In everything, or just in arithmetic, the computable is rare and exceptional. Fuchs, correctly I think, says an 'interpretation'

### Re: The probability problem in Everettian quantum mechanics

Bruno: On the contrary: I assume only that my brain (or generalized brain) is computable, then I show that basically all the rest is not. In everything, or just in arithmetic, the computable is rare and exceptional. Richard: Wow. This contradicts everything I have ever though Bruno was claiming. How does anything exist if it is not computed by the or a machine? And I thought the generalized brain did the computations, not that it was only computed. How does Bruno show that all the rest which presumably includes energy and matter is not computed. Bruno is constantly confusing me. On Tue, Oct 15, 2013 at 3:40 AM, Bruno Marchal marc...@ulb.ac.be wrote: On 14 Oct 2013, at 21:30, meekerdb wrote: On 10/14/2013 1:29 AM, Bruno Marchal wrote: On 13 Oct 2013, at 22:11, meekerdb wrote: On 10/13/2013 1:48 AM, Bruno Marchal wrote: On 12 Oct 2013, at 22:53, meekerdb wrote: On 10/12/2013 10:55 AM, Bruno Marchal wrote: On 11 Oct 2013, at 03:25, meekerdb wrote: So there are infinitely many identical universes preceding a measurement. How are these universes distinct from one another? Do they divide into two infinite subsets on a binary measurement, or do infinitely many come into existence in order that some branch-counting measure produces the right proportion? Do you not see any problems with assigning a measure to infinite countable subsets (are there more even numbers that square numbers?). And why should we prefer this model to simply saying the Born rule derives from a Bayesian epistemic view of QM as argued by, for example, Chris Fuchs? If you can explain to me how this makes the parallel experiences, (then), disappearing, please do. I don't understand the question. What parallel experiences do you refer to? And you're asking why they disappeared? The question is how does Fuchs prevent a superposition to be contagious on the observer I think he takes an instrumentalist view of the wave function - so superpositions are just something that happens in the mathematics. But then I don't see how this could fit with even just the one photon interference in the two slits experiment. ?? The math predicts probabilities of events, including where a single photon will land in a Young's slit experiment - no superposition of observer required. But it illustrates that superposition is physical/real, not purely mathematical. Then linearity expands it to us. When I read Fuchs I thought this: Comp suggest a compromise: yes the quantum wave describes only psychological states, but they concern still a *many* dreams/worlds/physical-realities, including the many self-multiplication. There is no many in Fuchs interpretation, there is only the personal subjective probabilities of contemplated futures. I notice the plural of futures. Are those not many? Sure, but they are contemplated, not reified. OK. But apparently object of contemplation can interfere with the real, which is a bit weird to me. The 'interference' is a calculational event 'between' possible futures. Or even the result of considering all possible paths. That leads to instrumentalism. That is dont ask, don't try to understand or get a bigger picture. I know Fuchs criticize Everett, but I don't see how he makes the superposition disappearing. he only makes them psychological, which is not a problem for me. there are still many. Yes, that's why I said I think his approach is consistent with yours. I think Fuchs view of QM is similar to what William S. Cooper calls for at the end of his book The Evolution of Reason - a probabilistic extension of logic. This is essentially the view he defends at length in Interview with a Quantum Bayesian, arXiv:1207.2141v1 OK. It is still Everett wave as seen from inside. We just don't know if the dreams defined an unique (multiversal) physical reality. Neither in Everett +GR, nor in comp. Bayesian epistemic view is no problem, but you have to define what is the knower, the observer, etc. If not, it falls into a cosmic form of solipsism, and it can generate some strong don't ask imperative. You assume that if others are not explained they must be rejected. I just ask for an explanation of the terms that they introduce. I think he takes the observer as primitive and undefined (and I think you do the same). What? Not at all. the observer is defined by its set of beliefs, itself define by a relative universal numbers. Fuchs defines 'the observer' as the one who bets on the outcome of his actions. Comp has a pretty well defined notion of observer, with its octalist points of view, and an whole theology including his physics, etc. Physicists, like Fuchs, and unlike philosophers, are generally comfortable with not explaining everything. Me too. but he has still to explain the terms that he is using. What's your explanation for the existence of

### Re: The probability problem in Everettian quantum mechanics

2013/10/15 Richard Ruquist yann...@gmail.com Bruno: On the contrary: I assume only that my brain (or generalized brain) is computable, then I show that basically all the rest is not. In everything, or just in arithmetic, the computable is rare and exceptional. Richard: Wow. This contradicts everything I have ever though Bruno was claiming. How does anything exist if it is not computed by the or a machine? And I thought the generalized brain did the computations, not that it was only computed. How does Bruno show that all the rest which presumably includes energy and matter is not computed. Bruno is constantly confusing me. Energy and matter (and the universe whatever it is), is composed by the sum of the infinity of computations going through your state as it is defined by an infinity of computations (and not one), it is not computed. A piece of matter (or you fwiw) below the substitution level is an infinity of computations. Quentin On Tue, Oct 15, 2013 at 3:40 AM, Bruno Marchal marc...@ulb.ac.be wrote: On 14 Oct 2013, at 21:30, meekerdb wrote: On 10/14/2013 1:29 AM, Bruno Marchal wrote: On 13 Oct 2013, at 22:11, meekerdb wrote: On 10/13/2013 1:48 AM, Bruno Marchal wrote: On 12 Oct 2013, at 22:53, meekerdb wrote: On 10/12/2013 10:55 AM, Bruno Marchal wrote: On 11 Oct 2013, at 03:25, meekerdb wrote: So there are infinitely many identical universes preceding a measurement. How are these universes distinct from one another? Do they divide into two infinite subsets on a binary measurement, or do infinitely many come into existence in order that some branch-counting measure produces the right proportion? Do you not see any problems with assigning a measure to infinite countable subsets (are there more even numbers that square numbers?). And why should we prefer this model to simply saying the Born rule derives from a Bayesian epistemic view of QM as argued by, for example, Chris Fuchs? If you can explain to me how this makes the parallel experiences, (then), disappearing, please do. I don't understand the question. What parallel experiences do you refer to? And you're asking why they disappeared? The question is how does Fuchs prevent a superposition to be contagious on the observer I think he takes an instrumentalist view of the wave function - so superpositions are just something that happens in the mathematics. But then I don't see how this could fit with even just the one photon interference in the two slits experiment. ?? The math predicts probabilities of events, including where a single photon will land in a Young's slit experiment - no superposition of observer required. But it illustrates that superposition is physical/real, not purely mathematical. Then linearity expands it to us. When I read Fuchs I thought this: Comp suggest a compromise: yes the quantum wave describes only psychological states, but they concern still a *many* dreams/worlds/physical-realities, including the many self-multiplication. There is no many in Fuchs interpretation, there is only the personal subjective probabilities of contemplated futures. I notice the plural of futures. Are those not many? Sure, but they are contemplated, not reified. OK. But apparently object of contemplation can interfere with the real, which is a bit weird to me. The 'interference' is a calculational event 'between' possible futures. Or even the result of considering all possible paths. That leads to instrumentalism. That is dont ask, don't try to understand or get a bigger picture. I know Fuchs criticize Everett, but I don't see how he makes the superposition disappearing. he only makes them psychological, which is not a problem for me. there are still many. Yes, that's why I said I think his approach is consistent with yours. I think Fuchs view of QM is similar to what William S. Cooper calls for at the end of his book The Evolution of Reason - a probabilistic extension of logic. This is essentially the view he defends at length in Interview with a Quantum Bayesian, arXiv:1207.2141v1 OK. It is still Everett wave as seen from inside. We just don't know if the dreams defined an unique (multiversal) physical reality. Neither in Everett +GR, nor in comp. Bayesian epistemic view is no problem, but you have to define what is the knower, the observer, etc. If not, it falls into a cosmic form of solipsism, and it can generate some strong don't ask imperative. You assume that if others are not explained they must be rejected. I just ask for an explanation of the terms that they introduce. I think he takes the observer as primitive and undefined (and I think you do the same). What? Not at all. the observer is defined by its set of beliefs, itself define by a relative universal numbers. Fuchs defines 'the observer' as the one who bets on the outcome of his

### Re: The probability problem in Everettian quantum mechanics

2013/10/15 Richard Ruquist yann...@gmail.com -- Forwarded message -- From: Quentin Anciaux allco...@gmail.com Date: Tue, Oct 15, 2013 at 6:54 AM Subject: Re: The probability problem in Everettian quantum mechanics To: everything-list@googlegroups.com 2013/10/15 Richard Ruquist yann...@gmail.com Bruno: On the contrary: I assume only that my brain (or generalized brain) is computable, then I show that basically all the rest is not. In everything, or just in arithmetic, the computable is rare and exceptional. Richard: Wow. This contradicts everything I have ever though Bruno was claiming. How does anything exist if it is not computed by the or a machine? And I thought the generalized brain did the computations, not that it was only computed. How does Bruno show that all the rest which presumably includes energy and matter is not computed. Bruno is constantly confusing me. Energy and matter (and the universe whatever it is), is composed by the sum of the infinity of computations going through your state as it is defined by an infinity of computations (and not one), it is not computed. A piece of matter (or you fwiw) below the substitution level is an infinity of computations. Quentin No I'm saying, that matter/you is not *a* computation, but the infinite set of computations going through your current state (at every state, an infinity of computations diverge, but there is still an infinity going through that state and it's for every state). Quentin You seem to be saying that the infinity of computations are not computed. That does not make sense. Richard On Tue, Oct 15, 2013 at 3:40 AM, Bruno Marchal marc...@ulb.ac.be wrote: On 14 Oct 2013, at 21:30, meekerdb wrote: On 10/14/2013 1:29 AM, Bruno Marchal wrote: On 13 Oct 2013, at 22:11, meekerdb wrote: On 10/13/2013 1:48 AM, Bruno Marchal wrote: On 12 Oct 2013, at 22:53, meekerdb wrote: On 10/12/2013 10:55 AM, Bruno Marchal wrote: On 11 Oct 2013, at 03:25, meekerdb wrote: So there are infinitely many identical universes preceding a measurement. How are these universes distinct from one another? Do they divide into two infinite subsets on a binary measurement, or do infinitely many come into existence in order that some branch-counting measure produces the right proportion? Do you not see any problems with assigning a measure to infinite countable subsets (are there more even numbers that square numbers?). And why should we prefer this model to simply saying the Born rule derives from a Bayesian epistemic view of QM as argued by, for example, Chris Fuchs? If you can explain to me how this makes the parallel experiences, (then), disappearing, please do. I don't understand the question. What parallel experiences do you refer to? And you're asking why they disappeared? The question is how does Fuchs prevent a superposition to be contagious on the observer I think he takes an instrumentalist view of the wave function - so superpositions are just something that happens in the mathematics. But then I don't see how this could fit with even just the one photon interference in the two slits experiment. ?? The math predicts probabilities of events, including where a single photon will land in a Young's slit experiment - no superposition of observer required. But it illustrates that superposition is physical/real, not purely mathematical. Then linearity expands it to us. When I read Fuchs I thought this: Comp suggest a compromise: yes the quantum wave describes only psychological states, but they concern still a *many* dreams/worlds/physical-realities, including the many self-multiplication. There is no many in Fuchs interpretation, there is only the personal subjective probabilities of contemplated futures. I notice the plural of futures. Are those not many? Sure, but they are contemplated, not reified. OK. But apparently object of contemplation can interfere with the real, which is a bit weird to me. The 'interference' is a calculational event 'between' possible futures. Or even the result of considering all possible paths. That leads to instrumentalism. That is dont ask, don't try to understand or get a bigger picture. I know Fuchs criticize Everett, but I don't see how he makes the superposition disappearing. he only makes them psychological, which is not a problem for me. there are still many. Yes, that's why I said I think his approach is consistent with yours. I think Fuchs view of QM is similar to what William S. Cooper calls for at the end of his book The Evolution of Reason - a probabilistic extension of logic. This is essentially the view he defends at length in Interview with a Quantum Bayesian, arXiv:1207.2141v1 OK. It is still Everett wave as seen from inside. We just don't know if the dreams defined an unique (multiversal) physical

### Re: The probability problem in Everettian quantum mechanics

On 15 Oct 2013, at 12:45, Richard Ruquist wrote: Bruno: On the contrary: I assume only that my brain (or generalized brain) is computable, then I show that basically all the rest is not. In everything, or just in arithmetic, the computable is rare and exceptional. Richard: Wow. This contradicts everything I have ever though Bruno was claiming. How does anything exist if it is not computed by the or a machine? We assume the arithmetical truth. In particular we assume that all closed formula written in the language of arithmetic (and thus using logical symbol + the symbol 0, s (+1), + and *) are all either true or false, independently of us. From this we cannot prove that matter exists, or not, but we can prove that the average universal numbers will (correctly) believe in matter (but it will not know that it is correct). So, if you have no problem in believing propositions like there is no biggest prime number are true independently of me and you, and the universe, then you can understand that the proposition asserting the existence of (infinitely many) computations in which you believe reading my current post, is also true independently of us. The appearance of matter emerges from the FPI that the machines cannot avoid in the arithmetical truth. Arithmetical truth escapes largely the computable arithmetical truth (by Gödel). And I thought the generalized brain did the computations, Only the computations associated to your mind. not that it was only computed. How does Bruno show that all the rest which presumably includes energy and matter is not computed. Bruno is constantly confusing me. I guess you missed the step seven of the UDA, and are perhaps not aware that arithmetical truth is incredibly big, *much* bigger than what any computer can generate or compute. Then my, or your, mind is associated to *all* computations going through your actual state of mind, and below your substitution level there are infinitely many such computations. They all exist in arithmetic, and the FPI glues them, in a non computable way, in possible long and deep physical histories. Bruno On Tue, Oct 15, 2013 at 3:40 AM, Bruno Marchal marc...@ulb.ac.be wrote: On 14 Oct 2013, at 21:30, meekerdb wrote: On 10/14/2013 1:29 AM, Bruno Marchal wrote: On 13 Oct 2013, at 22:11, meekerdb wrote: On 10/13/2013 1:48 AM, Bruno Marchal wrote: On 12 Oct 2013, at 22:53, meekerdb wrote: On 10/12/2013 10:55 AM, Bruno Marchal wrote: On 11 Oct 2013, at 03:25, meekerdb wrote: So there are infinitely many identical universes preceding a measurement. How are these universes distinct from one another? Do they divide into two infinite subsets on a binary measurement, or do infinitely many come into existence in order that some branch-counting measure produces the right proportion? Do you not see any problems with assigning a measure to infinite countable subsets (are there more even numbers that square numbers?). And why should we prefer this model to simply saying the Born rule derives from a Bayesian epistemic view of QM as argued by, for example, Chris Fuchs? If you can explain to me how this makes the parallel experiences, (then), disappearing, please do. I don't understand the question. What parallel experiences do you refer to? And you're asking why they disappeared? The question is how does Fuchs prevent a superposition to be contagious on the observer I think he takes an instrumentalist view of the wave function - so superpositions are just something that happens in the mathematics. But then I don't see how this could fit with even just the one photon interference in the two slits experiment. ?? The math predicts probabilities of events, including where a single photon will land in a Young's slit experiment - no superposition of observer required. But it illustrates that superposition is physical/real, not purely mathematical. Then linearity expands it to us. When I read Fuchs I thought this: Comp suggest a compromise: yes the quantum wave describes only psychological states, but they concern still a *many* dreams/worlds/physical- realities, including the many self-multiplication. There is no many in Fuchs interpretation, there is only the personal subjective probabilities of contemplated futures. I notice the plural of futures. Are those not many? Sure, but they are contemplated, not reified. OK. But apparently object of contemplation can interfere with the real, which is a bit weird to me. The 'interference' is a calculational event 'between' possible futures. Or even the result of considering all possible paths. That leads to instrumentalism. That is dont ask, don't try to understand or get a bigger picture. I know Fuchs criticize Everett, but I don't see how he makes the superposition disappearing. he only makes

### Re: The probability problem in Everettian quantum mechanics

On 15 Oct 2013, at 13:21, Quentin Anciaux wrote: 2013/10/15 Richard Ruquist yann...@gmail.com -- Forwarded message -- From: Quentin Anciaux allco...@gmail.com Date: Tue, Oct 15, 2013 at 6:54 AM Subject: Re: The probability problem in Everettian quantum mechanics To: everything-list@googlegroups.com 2013/10/15 Richard Ruquist yann...@gmail.com Bruno: On the contrary: I assume only that my brain (or generalized brain) is computable, then I show that basically all the rest is not. In everything, or just in arithmetic, the computable is rare and exceptional. Richard: Wow. This contradicts everything I have ever though Bruno was claiming. How does anything exist if it is not computed by the or a machine? And I thought the generalized brain did the computations, not that it was only computed. How does Bruno show that all the rest which presumably includes energy and matter is not computed. Bruno is constantly confusing me. Energy and matter (and the universe whatever it is), is composed by the sum of the infinity of computations going through your state as it is defined by an infinity of computations (and not one), it is not computed. A piece of matter (or you fwiw) below the substitution level is an infinity of computations. Quentin No I'm saying, that matter/you is not *a* computation, but the infinite set of computations going through your current state (at every state, an infinity of computations diverge, but there is still an infinity going through that state and it's for every state). Yes. It generalizes what Everett did on the universal quantum wave, on the whole arithmetical truth (which contains the whole computer science theoretical truth). If QM is correct, the SWE is redundant, and a consequence of comp. Physics is one aspect of arithmetic seen by its internal creatures (the universal or not numbers). We can concretely extract physics from the interview of the chatty rich one (the Löbian numbers). Bruno Quentin You seem to be saying that the infinity of computations are not computed. That does not make sense. Richard On Tue, Oct 15, 2013 at 3:40 AM, Bruno Marchal marc...@ulb.ac.be wrote: On 14 Oct 2013, at 21:30, meekerdb wrote: On 10/14/2013 1:29 AM, Bruno Marchal wrote: On 13 Oct 2013, at 22:11, meekerdb wrote: On 10/13/2013 1:48 AM, Bruno Marchal wrote: On 12 Oct 2013, at 22:53, meekerdb wrote: On 10/12/2013 10:55 AM, Bruno Marchal wrote: On 11 Oct 2013, at 03:25, meekerdb wrote: So there are infinitely many identical universes preceding a measurement. How are these universes distinct from one another? Do they divide into two infinite subsets on a binary measurement, or do infinitely many come into existence in order that some branch-counting measure produces the right proportion? Do you not see any problems with assigning a measure to infinite countable subsets (are there more even numbers that square numbers?). And why should we prefer this model to simply saying the Born rule derives from a Bayesian epistemic view of QM as argued by, for example, Chris Fuchs? If you can explain to me how this makes the parallel experiences, (then), disappearing, please do. I don't understand the question. What parallel experiences do you refer to? And you're asking why they disappeared? The question is how does Fuchs prevent a superposition to be contagious on the observer I think he takes an instrumentalist view of the wave function - so superpositions are just something that happens in the mathematics. But then I don't see how this could fit with even just the one photon interference in the two slits experiment. ?? The math predicts probabilities of events, including where a single photon will land in a Young's slit experiment - no superposition of observer required. But it illustrates that superposition is physical/real, not purely mathematical. Then linearity expands it to us. When I read Fuchs I thought this: Comp suggest a compromise: yes the quantum wave describes only psychological states, but they concern still a *many* dreams/worlds/physical- realities, including the many self-multiplication. There is no many in Fuchs interpretation, there is only the personal subjective probabilities of contemplated futures. I notice the plural of futures. Are those not many? Sure, but they are contemplated, not reified. OK. But apparently object of contemplation can interfere with the real, which is a bit weird to me. The 'interference' is a calculational event 'between' possible futures. Or even the result of considering all possible paths. That leads to instrumentalism. That is dont ask, don't try to understand or get a bigger picture. I know Fuchs criticize Everett, but I don't see how he makes the superposition disappearing. he only makes them psychological, which

### Re: The probability problem in Everettian quantum mechanics

Bruno: Arithmetical truth escapes largely the computable arithmetical truth (by Gödel). Richard: I guess I am too much a physicist to believe that uncomputible arithmetical truth can produce the physical. Since you read my paper you know that I think computations in this universe if holographic are limited to 10^120 bits (the Lloyd limit) which is very far from infinity. I just do not believe in infinity. In other words, I believe the largest prime number in this universe is less than 10^120. So I will drop out of these discussions. My assumptions differ from yours. On Tue, Oct 15, 2013 at 10:53 AM, Bruno Marchal marc...@ulb.ac.be wrote: On 15 Oct 2013, at 13:21, Quentin Anciaux wrote: 2013/10/15 Richard Ruquist yann...@gmail.com -- Forwarded message -- From: Quentin Anciaux allco...@gmail.com Date: Tue, Oct 15, 2013 at 6:54 AM Subject: Re: The probability problem in Everettian quantum mechanics To: everything-list@googlegroups.com 2013/10/15 Richard Ruquist yann...@gmail.com Bruno: On the contrary: I assume only that my brain (or generalized brain) is computable, then I show that basically all the rest is not. In everything, or just in arithmetic, the computable is rare and exceptional. Richard: Wow. This contradicts everything I have ever though Bruno was claiming. How does anything exist if it is not computed by the or a machine? And I thought the generalized brain did the computations, not that it was only computed. How does Bruno show that all the rest which presumably includes energy and matter is not computed. Bruno is constantly confusing me. Energy and matter (and the universe whatever it is), is composed by the sum of the infinity of computations going through your state as it is defined by an infinity of computations (and not one), it is not computed. A piece of matter (or you fwiw) below the substitution level is an infinity of computations. Quentin No I'm saying, that matter/you is not *a* computation, but the infinite set of computations going through your current state (at every state, an infinity of computations diverge, but there is still an infinity going through that state and it's for every state). Yes. It generalizes what Everett did on the universal quantum wave, on the whole arithmetical truth (which contains the whole computer science theoretical truth). If QM is correct, the SWE is redundant, and a consequence of comp. Physics is one aspect of arithmetic seen by its internal creatures (the universal or not numbers). We can concretely extract physics from the interview of the chatty rich one (the Löbian numbers). Bruno Quentin You seem to be saying that the infinity of computations are not computed. That does not make sense. Richard On Tue, Oct 15, 2013 at 3:40 AM, Bruno Marchal marc...@ulb.ac.bewrote: On 14 Oct 2013, at 21:30, meekerdb wrote: On 10/14/2013 1:29 AM, Bruno Marchal wrote: On 13 Oct 2013, at 22:11, meekerdb wrote: On 10/13/2013 1:48 AM, Bruno Marchal wrote: On 12 Oct 2013, at 22:53, meekerdb wrote: On 10/12/2013 10:55 AM, Bruno Marchal wrote: On 11 Oct 2013, at 03:25, meekerdb wrote: So there are infinitely many identical universes preceding a measurement. How are these universes distinct from one another? Do they divide into two infinite subsets on a binary measurement, or do infinitely many come into existence in order that some branch-counting measure produces the right proportion? Do you not see any problems with assigning a measure to infinite countable subsets (are there more even numbers that square numbers?). And why should we prefer this model to simply saying the Born rule derives from a Bayesian epistemic view of QM as argued by, for example, Chris Fuchs? If you can explain to me how this makes the parallel experiences, (then), disappearing, please do. I don't understand the question. What parallel experiences do you refer to? And you're asking why they disappeared? The question is how does Fuchs prevent a superposition to be contagious on the observer I think he takes an instrumentalist view of the wave function - so superpositions are just something that happens in the mathematics. But then I don't see how this could fit with even just the one photon interference in the two slits experiment. ?? The math predicts probabilities of events, including where a single photon will land in a Young's slit experiment - no superposition of observer required. But it illustrates that superposition is physical/real, not purely mathematical. Then linearity expands it to us. When I read Fuchs I thought this: Comp suggest a compromise: yes the quantum wave describes only psychological states, but they concern still a *many* dreams/worlds/physical-realities, including the many self-multiplication. There is no many in Fuchs interpretation, there is only the personal subjective

### Re: The probability problem in Everettian quantum mechanics

On 10/15/2013 3:54 AM, Quentin Anciaux wrote: 2013/10/15 Richard Ruquist yann...@gmail.com mailto:yann...@gmail.com Bruno: On the contrary: I assume only that my brain (or generalized brain) is computable, then I show that basically all the rest is not. In everything, or just in arithmetic, the computable is rare and exceptional. Richard: Wow. This contradicts everything I have ever though Bruno was claiming. How does anything exist if it is not computed by the or a machine? And I thought the generalized brain did the computations, not that it was only computed. How does Bruno show that all the rest which presumably includes energy and matter is not computed. Bruno is constantly confusing me. Energy and matter (and the universe whatever it is), is composed by the sum What does sum mean? And how does is constitute a piece of matter? of the infinity of computations going through your state as it is defined by an infinity of computations (and not one), it is not computed. But that's not a definition. It's saying the piece of matter is *constituted* by an infinity of computations. But what associates the computations to a piece of matter that we *define* ostensively? Brent A piece of matter (or you fwiw) below the substitution level is an infinity of computations. Quentin -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On 10/15/2013 7:49 AM, Bruno Marchal wrote: On 15 Oct 2013, at 12:45, Richard Ruquist wrote: Bruno: On the contrary: I assume only that my brain (or generalized brain) is computable, then I show that basically all the rest is not. In everything, or just in arithmetic, the computable is rare and exceptional. Richard: Wow. This contradicts everything I have ever though Bruno was claiming. How does anything exist if it is not computed by the or a machine? We assume the arithmetical truth. In particular we assume that all closed formula written in the language of arithmetic (and thus using logical symbol + the symbol 0, s (+1), + and *) are all either true or false, independently of us. From this we cannot prove that matter exists, or not, but we can prove that the average universal numbers will (correctly) believe in matter (but it will not know that it is correct). That's not at all clear to me. A universal number encodes proofs - is that what you mean by it believes something? But how is this something identified at 'matter'? So, if you have no problem in believing propositions like there is no biggest prime number are true independently of me and you, and the universe, then you can understand that the proposition asserting the existence of (infinitely many) computations in which you believe reading my current post, is also true independently of us. The appearance of matter emerges from the FPI that the machines cannot avoid in the arithmetical truth. Arithmetical truth escapes largely the computable arithmetical truth (by Gödel). And I thought the generalized brain did the computations, Only the computations associated to your mind. not that it was only computed. How does Bruno show that all the rest which presumably includes energy and matter is not computed. Bruno is constantly confusing me. I guess you missed the step seven of the UDA, and are perhaps not aware that arithmetical truth is incredibly big, *much* bigger than what any computer can generate or compute. Then my, or your, mind is associated to *all* computations going through your actual state of mind, That sounds like an uncomputable totality. Brent and below your substitution level there are infinitely many such computations. They all exist in arithmetic, and the FPI glues them, in a non computable way, in possible long and deep physical histories. Bruno -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On Tue, Oct 15, 2013 at 01:02:13PM -0400, Richard Ruquist wrote: Bruno: Arithmetical truth escapes largely the computable arithmetical truth (by Gödel). Richard: I guess I am too much a physicist to believe that uncomputible arithmetical truth can produce the physical. Since you read my paper you know that I think computations in this universe if holographic are limited to 10^120 bits (the Lloyd limit) which is very far from infinity. I just do not believe in infinity. In other words, I believe the largest prime number in this universe is less than 10^120. So I will drop out of these discussions. My assumptions differ from yours. Then you might well be interested in the Movie Graph Argument, which deals directly with the case where the universe doesn't have sufficient resources to run the universal dovetailer. -- Prof Russell Standish Phone 0425 253119 (mobile) Principal, High Performance Coders Visiting Professor of Mathematics hpco...@hpcoders.com.au University of New South Wales http://www.hpcoders.com.au -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On 13 Oct 2013, at 22:11, meekerdb wrote: On 10/13/2013 1:48 AM, Bruno Marchal wrote: On 12 Oct 2013, at 22:53, meekerdb wrote: On 10/12/2013 10:55 AM, Bruno Marchal wrote: On 11 Oct 2013, at 03:25, meekerdb wrote: So there are infinitely many identical universes preceding a measurement. How are these universes distinct from one another? Do they divide into two infinite subsets on a binary measurement, or do infinitely many come into existence in order that some branch-counting measure produces the right proportion? Do you not see any problems with assigning a measure to infinite countable subsets (are there more even numbers that square numbers?). And why should we prefer this model to simply saying the Born rule derives from a Bayesian epistemic view of QM as argued by, for example, Chris Fuchs? If you can explain to me how this makes the parallel experiences, (then), disappearing, please do. I don't understand the question. What parallel experiences do you refer to? And you're asking why they disappeared? The question is how does Fuchs prevent a superposition to be contagious on the observer I think he takes an instrumentalist view of the wave function - so superpositions are just something that happens in the mathematics. But then I don't see how this could fit with even just the one photon interference in the two slits experiment. When I read Fuchs I thought this: Comp suggest a compromise: yes the quantum wave describes only psychological states, but they concern still a *many* dreams/worlds/physical-realities, including the many self-multiplication. There is no many in Fuchs interpretation, there is only the personal subjective probabilities of contemplated futures. I notice the plural of futures. Are those not many? Sure, but they are contemplated, not reified. OK. But apparently object of contemplation can interfere with the real, which is a bit weird to me. I know Fuchs criticize Everett, but I don't see how he makes the superposition disappearing. he only makes them psychological, which is not a problem for me. there are still many. Yes, that's why I said I think his approach is consistent with yours. I think Fuchs view of QM is similar to what William S. Cooper calls for at the end of his book The Evolution of Reason - a probabilistic extension of logic. This is essentially the view he defends at length in Interview with a Quantum Bayesian, arXiv: 1207.2141v1 OK. It is still Everett wave as seen from inside. We just don't know if the dreams defined an unique (multiversal) physical reality. Neither in Everett +GR, nor in comp. Bayesian epistemic view is no problem, but you have to define what is the knower, the observer, etc. If not, it falls into a cosmic form of solipsism, and it can generate some strong don't ask imperative. You assume that if others are not explained they must be rejected. I just ask for an explanation of the terms that they introduce. I think he takes the observer as primitive and undefined (and I think you do the same). What? Not at all. the observer is defined by its set of beliefs, itself define by a relative universal numbers. Comp has a pretty well defined notion of observer, with its octalist points of view, and an whole theology including his physics, etc. Physicists, like Fuchs, and unlike philosophers, are generally comfortable with not explaining everything. Me too. but he has still to explain the terms that he is using. What's your explanation for the existence of persons? So far what I've heard is that it's an inside view of arithmetic - which I don't find very enlightening. What do you miss in the UDA? Fuchs, correctly I think, says an 'interpretation' of a theory, the story that goes along with the mathematics, is important insofar as it gives you insight into how to apply the mathematics and to extend your theories. He is critical of Everett's MWI for not doing that, or at least not doing it well. Well, perhaps Fuchs is a bit out of topic, once you agree that it is only Everett in a psychological version. That is close to comp. But comp leads, by UDA, that the theory of everuthing is just elementary arithmetic (or Turing equivalent, like colmbinatirs, ...). Then everything is defined in a very precise way in that theory. And this explains both 100% matter and 99,999... % of consciousness. The explanation might be false, of course, but is testable. Bruno Brent Bruno Brent I mistrust all systematizers and avoid them. The will to a system is a lack of integrity. --- Fredrick Nietzsche, Twilight of the Idols -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To

### Re: The probability problem in Everettian quantum mechanics

On 10/14/2013 1:29 AM, Bruno Marchal wrote: On 13 Oct 2013, at 22:11, meekerdb wrote: On 10/13/2013 1:48 AM, Bruno Marchal wrote: On 12 Oct 2013, at 22:53, meekerdb wrote: On 10/12/2013 10:55 AM, Bruno Marchal wrote: On 11 Oct 2013, at 03:25, meekerdb wrote: So there are infinitely many identical universes preceding a measurement. How are these universes distinct from one another? Do they divide into two infinite subsets on a binary measurement, or do infinitely many come into existence in order that some branch-counting measure produces the right proportion? Do you not see any problems with assigning a measure to infinite countable subsets (are there more even numbers that square numbers?). And why should we prefer this model to simply saying the Born rule derives from a Bayesian epistemic view of QM as argued by, for example, Chris Fuchs? If you can explain to me how this makes the parallel experiences, (then), disappearing, please do. I don't understand the question. What parallel experiences do you refer to? And you're asking why they disappeared? The question is how does Fuchs prevent a superposition to be contagious on the observer I think he takes an instrumentalist view of the wave function - so superpositions are just something that happens in the mathematics. But then I don't see how this could fit with even just the one photon interference in the two slits experiment. ?? The math predicts probabilities of events, including where a single photon will land in a Young's slit experiment - no superposition of observer required. When I read Fuchs I thought this: Comp suggest a compromise: yes the quantum wave describes only psychological states, but they concern still a *many* dreams/worlds/physical-realities, including the many self-multiplication. There is no many in Fuchs interpretation, there is only the personal subjective probabilities of contemplated futures. I notice the plural of futures. Are those not many? Sure, but they are contemplated, not reified. OK. But apparently object of contemplation can interfere with the real, which is a bit weird to me. The 'interference' is a calculational event 'between' possible futures. Or even the result of considering all possible paths. I know Fuchs criticize Everett, but I don't see how he makes the superposition disappearing. he only makes them psychological, which is not a problem for me. there are still many. Yes, that's why I said I think his approach is consistent with yours. I think Fuchs view of QM is similar to what William S. Cooper calls for at the end of his book The Evolution of Reason - a probabilistic extension of logic. This is essentially the view he defends at length in Interview with a Quantum Bayesian, arXiv:1207.2141v1 OK. It is still Everett wave as seen from inside. We just don't know if the dreams defined an unique (multiversal) physical reality. Neither in Everett +GR, nor in comp. Bayesian epistemic view is no problem, but you have to define what is the knower, the observer, etc. If not, it falls into a cosmic form of solipsism, and it can generate some strong don't ask imperative. You assume that if others are not explained they must be rejected. I just ask for an explanation of the terms that they introduce. I think he takes the observer as primitive and undefined (and I think you do the same). What? Not at all. the observer is defined by its set of beliefs, itself define by a relative universal numbers. Fuchs defines 'the observer' as the one who bets on the outcome of his actions. Comp has a pretty well defined notion of observer, with its octalist points of view, and an whole theology including his physics, etc. Physicists, like Fuchs, and unlike philosophers, are generally comfortable with not explaining everything. Me too. but he has still to explain the terms that he is using. What's your explanation for the existence of persons? So far what I've heard is that it's an inside view of arithmetic - which I don't find very enlightening. What do you miss in the UDA? As I understand it the UD computes everything computable and it's only your inference that observers (and the rest of the multiverse) *must be in there somewhere* because you've assumed that everything is computable. Fuchs, correctly I think, says an 'interpretation' of a theory, the story that goes along with the mathematics, is important insofar as it gives you insight into how to apply the mathematics and to extend your theories. He is critical of Everett's MWI for not doing that, or at least not doing it well. Well, perhaps Fuchs is a bit out of topic, once you agree that it is only Everett in a psychological version. It's kinda funny to see only...psychological from a guy who wants to show that everything is a shared dream. That is close to comp. But comp leads, by UDA, that the theory of

### Re: The probability problem in Everettian quantum mechanics

On Mon, Oct 14, 2013 at 2:30 PM, meekerdb meeke...@verizon.net wrote: On 10/14/2013 1:29 AM, Bruno Marchal wrote: On 13 Oct 2013, at 22:11, meekerdb wrote: On 10/13/2013 1:48 AM, Bruno Marchal wrote: On 12 Oct 2013, at 22:53, meekerdb wrote: On 10/12/2013 10:55 AM, Bruno Marchal wrote: On 11 Oct 2013, at 03:25, meekerdb wrote: So there are infinitely many identical universes preceding a measurement. How are these universes distinct from one another? Do they divide into two infinite subsets on a binary measurement, or do infinitely many come into existence in order that some branch-counting measure produces the right proportion? Do you not see any problems with assigning a measure to infinite countable subsets (are there more even numbers that square numbers?). And why should we prefer this model to simply saying the Born rule derives from a Bayesian epistemic view of QM as argued by, for example, Chris Fuchs? If you can explain to me how this makes the parallel experiences, (then), disappearing, please do. I don't understand the question. What parallel experiences do you refer to? And you're asking why they disappeared? The question is how does Fuchs prevent a superposition to be contagious on the observer I think he takes an instrumentalist view of the wave function - so superpositions are just something that happens in the mathematics. But then I don't see how this could fit with even just the one photon interference in the two slits experiment. ?? The math predicts probabilities of events, including where a single photon will land in a Young's slit experiment - no superposition of observer required. When I read Fuchs I thought this: Comp suggest a compromise: yes the quantum wave describes only psychological states, but they concern still a *many* dreams/worlds/physical-realities, including the many self-multiplication. There is no many in Fuchs interpretation, there is only the personal subjective probabilities of contemplated futures. I notice the plural of futures. Are those not many? Sure, but they are contemplated, not reified. OK. But apparently object of contemplation can interfere with the real, which is a bit weird to me. The 'interference' is a calculational event 'between' possible futures. Or even the result of considering all possible paths. According to Fuchs, who does the consideration have to be made by? Obviously no person (nor any practical classical computer) could contemplate all possible paths of a large quantum computation. So whose contemplation reifies or interferes with the product of that computation? Jason I know Fuchs criticize Everett, but I don't see how he makes the superposition disappearing. he only makes them psychological, which is not a problem for me. there are still many. Yes, that's why I said I think his approach is consistent with yours. I think Fuchs view of QM is similar to what William S. Cooper calls for at the end of his book The Evolution of Reason - a probabilistic extension of logic. This is essentially the view he defends at length in Interview with a Quantum Bayesian, arXiv:1207.2141v1 OK. It is still Everett wave as seen from inside. We just don't know if the dreams defined an unique (multiversal) physical reality. Neither in Everett +GR, nor in comp. Bayesian epistemic view is no problem, but you have to define what is the knower, the observer, etc. If not, it falls into a cosmic form of solipsism, and it can generate some strong don't ask imperative. You assume that if others are not explained they must be rejected. I just ask for an explanation of the terms that they introduce. I think he takes the observer as primitive and undefined (and I think you do the same). What? Not at all. the observer is defined by its set of beliefs, itself define by a relative universal numbers. Fuchs defines 'the observer' as the one who bets on the outcome of his actions. Comp has a pretty well defined notion of observer, with its octalist points of view, and an whole theology including his physics, etc. Physicists, like Fuchs, and unlike philosophers, are generally comfortable with not explaining everything. Me too. but he has still to explain the terms that he is using. What's your explanation for the existence of persons? So far what I've heard is that it's an inside view of arithmetic - which I don't find very enlightening. What do you miss in the UDA? As I understand it the UD computes everything computable and it's only your inference that observers (and the rest of the multiverse) *must be in there somewhere* because you've assumed that everything is computable. Fuchs, correctly I think, says an 'interpretation' of a theory, the story that goes along with the mathematics, is important insofar as it gives you insight into how to apply the mathematics

### Re: The probability problem in Everettian quantum mechanics

On 12 Oct 2013, at 22:53, meekerdb wrote: On 10/12/2013 10:55 AM, Bruno Marchal wrote: On 11 Oct 2013, at 03:25, meekerdb wrote: So there are infinitely many identical universes preceding a measurement. How are these universes distinct from one another? Do they divide into two infinite subsets on a binary measurement, or do infinitely many come into existence in order that some branch-counting measure produces the right proportion? Do you not see any problems with assigning a measure to infinite countable subsets (are there more even numbers that square numbers?). And why should we prefer this model to simply saying the Born rule derives from a Bayesian epistemic view of QM as argued by, for example, Chris Fuchs? If you can explain to me how this makes the parallel experiences, (then), disappearing, please do. I don't understand the question. What parallel experiences do you refer to? And you're asking why they disappeared? The question is how does Fuchs prevent a superposition to be contagious on the observer When I read Fuchs I thought this: Comp suggest a compromise: yes the quantum wave describes only psychological states, but they concern still a *many* dreams/worlds/physical-realities, including the many self-multiplication. There is no many in Fuchs interpretation, there is only the personal subjective probabilities of contemplated futures. I notice the plural of futures. Are those not many? I know Fuchs criticize Everett, but I don't see how he makes the superposition disappearing. he only makes them psychological, which is not a problem for me. there are still many. It is still Everett wave as seen from inside. We just don't know if the dreams defined an unique (multiversal) physical reality. Neither in Everett +GR, nor in comp. Bayesian epistemic view is no problem, but you have to define what is the knower, the observer, etc. If not, it falls into a cosmic form of solipsism, and it can generate some strong don't ask imperative. You assume that if others are not explained they must be rejected. I just ask for an explanation of the terms that they introduce. Physicists, like Fuchs, and unlike philosophers, are generally comfortable with not explaining everything. Me too. but he has still to explain the terms that he is using. Bruno Brent I mistrust all systematizers and avoid them. The will to a system is a lack of integrity. --- Fredrick Nietzsche, Twilight of the Idols -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out. http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On 10/13/2013 1:48 AM, Bruno Marchal wrote: On 12 Oct 2013, at 22:53, meekerdb wrote: On 10/12/2013 10:55 AM, Bruno Marchal wrote: On 11 Oct 2013, at 03:25, meekerdb wrote: So there are infinitely many identical universes preceding a measurement. How are these universes distinct from one another? Do they divide into two infinite subsets on a binary measurement, or do infinitely many come into existence in order that some branch-counting measure produces the right proportion? Do you not see any problems with assigning a measure to infinite countable subsets (are there more even numbers that square numbers?). And why should we prefer this model to simply saying the Born rule derives from a Bayesian epistemic view of QM as argued by, for example, Chris Fuchs? If you can explain to me how this makes the parallel experiences, (then), disappearing, please do. I don't understand the question. What parallel experiences do you refer to? And you're asking why they disappeared? The question is how does Fuchs prevent a superposition to be contagious on the observer I think he takes an instrumentalist view of the wave function - so superpositions are just something that happens in the mathematics. When I read Fuchs I thought this: Comp suggest a compromise: yes the quantum wave describes only psychological states, but they concern still a *many* dreams/worlds/physical-realities, including the many self-multiplication. There is no many in Fuchs interpretation, there is only the personal subjective probabilities of contemplated futures. I notice the plural of futures. Are those not many? Sure, but they are contemplated, not reified. I know Fuchs criticize Everett, but I don't see how he makes the superposition disappearing. he only makes them psychological, which is not a problem for me. there are still many. Yes, that's why I said I think his approach is consistent with yours. I think Fuchs view of QM is similar to what William S. Cooper calls for at the end of his book The Evolution of Reason - a probabilistic extension of logic. This is essentially the view he defends at length in Interview with a Quantum Bayesian, arXiv:1207.2141v1 It is still Everett wave as seen from inside. We just don't know if the dreams defined an unique (multiversal) physical reality. Neither in Everett +GR, nor in comp. Bayesian epistemic view is no problem, but you have to define what is the knower, the observer, etc. If not, it falls into a cosmic form of solipsism, and it can generate some strong don't ask imperative. You assume that if others are not explained they must be rejected. I just ask for an explanation of the terms that they introduce. I think he takes the observer as primitive and undefined (and I think you do the same). Physicists, like Fuchs, and unlike philosophers, are generally comfortable with not explaining everything. Me too. but he has still to explain the terms that he is using. What's your explanation for the existence of persons? So far what I've heard is that it's an inside view of arithmetic - which I don't find very enlightening. Fuchs, correctly I think, says an 'interpretation' of a theory, the story that goes along with the mathematics, is important insofar as it gives you insight into how to apply the mathematics and to extend your theories. He is critical of Everett's MWI for not doing that, or at least not doing it well. Brent Bruno Brent I mistrust all systematizers and avoid them. The will to a system is a lack of integrity. --- Fredrick Nietzsche, Twilight of the Idols -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com mailto:everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com mailto:everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out. http://iridia.ulb.ac.be/~marchal/ http://iridia.ulb.ac.be/%7Emarchal/ No virus found in this message. Checked by AVG - www.avg.com http://www.avg.com Version: 2014.0.4158 / Virus Database: 3614/6742 - Release Date: 10/11/13 -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop

### Re: The probability problem in Everettian quantum mechanics

On 11 Oct 2013, at 17:00, Jason Resch wrote: On Oct 11, 2013, at 9:06 AM, Bruno Marchal marc...@ulb.ac.be wrote: On 11 Oct 2013, at 13:16, Pierz wrote: And just to follow up on that, there are still an infinite number of irrational numbers between 0 and 0.1. But not as large an infinity as those between 0.1 and 1. It is the same cardinal (2^aleph_zero). But cardinality is not what count when searching a measure. So extrapolating to universes, the very low probability, white rabbit universes also occur an infinite number of times, but that does not make them equally as likely as the universes which behave as we would classically expect. That is what remain to be seen. But if comp is true, we know the measure has to exist, and the math gives some clues that it is indeed the case, from machines' (consistent and/or true) points of view. Bruno, Could the matter of the countably infinite number of programs be irrelevant from the first person perspective because any given mind contains/is aware of only a finite amount of information? Say some mind contains a million bits of information. Then there is a finite number (2^100) of distinct combinations of content for that mind. These differations are all that matter from the first person view, and some may be more probable than others. (But deciding the measures for each of those finite number of possibilities depends on infinite computations, and so would they be real numbers?) Even if the 3-mind (my current 3-state) is finite, the FPI will bear on non enumerable continuations. I will be able to distinguish only finite numbers of cluster of histories in that infinity of continuations, but the measure will bear (like in QM) on the distinguishable in-principle continuation, so the relative indeterminacy might depends on them all, and so it is consistent that real numbers will be at play. Now, the real measure takes the fusion- amnesia-backtracking into account, and the real picture is beyond our intuition, and has to be extracted from the semantics of the (q)Hm. (q for quantification in the logician sense, and Hm is for the relevant material hypostases (Bp Dt, Bp Dt p, but also on Bp p, as it gives a quantization (in the physicist sense) when p is in the UD (p is sigma_1). Bruno http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On 11 Oct 2013, at 19:07, meekerdb wrote: On 10/11/2013 2:28 AM, Russell Standish wrote: On Thu, Oct 10, 2013 at 06:25:45PM -0700, meekerdb wrote: So there are infinitely many identical universes preceding a measurement. How are these universes distinct from one another? Do they divide into two infinite subsets on a binary measurement, or do infinitely many come into existence in order that some branch-counting measure produces the right proportion? Do you not see any problems with assigning a measure to infinite countable subsets (are there more even numbers that square numbers?). But infinite subsets in question will contain an uncountable number of elements. I don't think being uncountable makes it any easier unless they form a continuum, which I don't think they do. I QM an underlying continuum (spacetime) is assumed, but not in Bruno's theory. There is necessarily a continuum in comp, because the UD is so dumb as making interacting all programs (rich enough) with a dovetailing on the real, complex, quanternions, octonions, etc. Very plausibly, the winning universal numbers exploit this, with the algbraic measure structure (imposed by self-reference constraints) to multiply enough the first person views. I would not have believe myself in this without the QM empirical evidences. Without QM, I would probably not find comp plausible at all. Bruno Brent That is why I'm not sure that problems with assigning measures to countably infinite sets (such as your example above re even and square numbers) are really such a problem. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out. http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On 11 Oct 2013, at 23:46, Russell Standish wrote: On Fri, Oct 11, 2013 at 10:07:58AM -0700, meekerdb wrote: On 10/11/2013 2:28 AM, Russell Standish wrote: On Thu, Oct 10, 2013 at 06:25:45PM -0700, meekerdb wrote: So there are infinitely many identical universes preceding a measurement. How are these universes distinct from one another? Do they divide into two infinite subsets on a binary measurement, or do infinitely many come into existence in order that some branch-counting measure produces the right proportion? Do you not see any problems with assigning a measure to infinite countable subsets (are there more even numbers that square numbers?). But infinite subsets in question will contain an uncountable number of elements. I don't think being uncountable makes it any easier unless they form a continuum, which I don't think they do. I QM an underlying continuum (spacetime) is assumed, but not in Bruno's theory. UD* (trace of the universal dovetailer) is a continuum, AFAICT. From the first person views statistics. It has the cardinality of the reals, and a natural metric (d(x,y) = 2^{-n}, where n is the number of leading bits in common between x and y). That would be a sort of measure on infinite programs, not so much on the computations, which will need a sort of measure on experiences, which needs the definition of experiences and thus of the knower logic and semantics, and for this I use the (counter-intuitive) arithmetic of self-reference. Bruno ISTM, this metric induces a natural measure over sets of program executions that is rather continuum like - but maybe I'm missing something? Cheers -- Prof Russell Standish Phone 0425 253119 (mobile) Principal, High Performance Coders Visiting Professor of Mathematics hpco...@hpcoders.com.au University of New South Wales http://www.hpcoders.com.au -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out. http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On 12 Oct 2013, at 00:12, LizR wrote: On 12 October 2013 10:46, Russell Standish li...@hpcoders.com.au wrote: On Fri, Oct 11, 2013 at 10:07:58AM -0700, meekerdb wrote: I don't think being uncountable makes it any easier unless they form a continuum, which I don't think they do. I QM an underlying continuum (spacetime) is assumed, but not in Bruno's theory. UD* (trace of the universal dovetailer) is a continuum, AFAICT. It has the cardinality of the reals, and a natural metric (d(x,y) = 2^{-n}, where n is the number of leading bits in common between x and y). ISTM, this metric induces a natural measure over sets of program executions that is rather continuum like - but maybe I'm missing something? I always assumed the UD output bits - i.e. not a continuum, but a countable infinity of symbols - but maybe I'm missing something? The first/third person distinction. I might add explanation later. It looks like even those who grasp the FPI forget to apply it. The invariance of UD-steps-delay plays a crucial role here. It entails that the consciousness differentiation on the UD* takes zero second, and that is why we are confronted with continua. Bruno -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out. http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On 12 Oct 2013, at 00:14, LizR wrote: On 12 October 2013 11:12, LizR lizj...@gmail.com wrote: On 12 October 2013 10:46, Russell Standish li...@hpcoders.com.au wrote: On Fri, Oct 11, 2013 at 10:07:58AM -0700, meekerdb wrote: I don't think being uncountable makes it any easier unless they form a continuum, which I don't think they do. I QM an underlying continuum (spacetime) is assumed, but not in Bruno's theory. UD* (trace of the universal dovetailer) is a continuum, AFAICT. It has the cardinality of the reals, and a natural metric (d(x,y) = 2^{-n}, where n is the number of leading bits in common between x and y). ISTM, this metric induces a natural measure over sets of program executions that is rather continuum like - but maybe I'm missing something? I always assumed the UD output bits - i.e. not a continuum, but a countable infinity of symbols - but maybe I'm missing something? Am I missing diagonalisation? i.e. Can the UD output be diagonalised? It cannot. For the same reason that the partial computabe functions is immune to diagonlaization. That is why it is universal. But as I said, you forget to take into account the 1p/3p distinction. You are forgetting step 7. Bruno http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On 12 Oct 2013, at 01:04, LizR wrote: On 12 October 2013 11:35, Russell Standish li...@hpcoders.com.au wrote: The UD doesn't output anything. If it did, then certainly, the output could not be an uncountable set due to the diagonalisation argument. Yes, I wasn't speaking very precisely. Obviously there is no output, because where would it go? I meant the trace, which I assume is a record of its operation, which itself exists in arithmetic (I think?) Yes. In different ways, but that would be technical to describe. Shortly: arithmetic contains only finite pieces of computations, but the first person indeterminacy (and thus the consciousness differentiation) will glue them all. Bruno Rather UD* is like the internal view of the operation of the dovetailer, like the sum of all possible experiences of the Helsinki man being duplicated to Washington and Moscow that is being discussed rather a lot lately. Ah! Should read to the end :) Thanks. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out. http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On 12 Oct 2013, at 01:05, Pierz wrote: On Saturday, October 12, 2013 5:42:06 AM UTC+11, Brent wrote: On 10/11/2013 4:16 AM, Pierz wrote: And just to follow up on that, there are still an infinite number of irrational numbers between 0 and 0.1. But not as large an infinity as those between 0.1 and 1. No, the two are exactly the same uncountable infinity, because there is a 1-to-1 mapping between them. My mathematical terminology may not be up to scratch. The measure is different. So extrapolating to universes, the very low probability, white rabbit universes also occur an infinite number of times, but that does not make them equally as likely as the universes which behave as we would classically expect. But computationalism only produces rational numbers. We were talking MWI, where a measure is permitted because of the underlying physical continuum. It does seem that the measure problem is an open one for comp, as far as I can tell from Bruno's responses, but he seems confident it's not insurmountable. I'm not competent to judge. The comp measure problem *is* the same problem as deriving physics from comp. It is *the* problem. The apparition of a quantum-like quantization in the material hypostases gives much hopes indeed. Bruno Brent On Friday, October 11, 2013 10:04:40 PM UTC+11, Liz R wrote: If you subdivide a continuum, I assume you can do so in a way that gives the required probabilities. For example if the part of the multiverse that is involved in performing a quantum measurement with a 50-50 chance of either outcome is represented by the numbers 0 to 1, you can divide those into 0-0.5 and 0.5 to 1. Doesn't David do something like this in FOR? (Or is this too plistic?) -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-li...@googlegroups.com. To post to this group, send email to everyth...@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out. No virus found in this message. Checked by AVG - www.avg.com Version: 2014.0.4158 / Virus Database: 3609/6739 - Release Date: 10/10/13 -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out. http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On 12 Oct 2013, at 01:08, meekerdb wrote: On 10/11/2013 3:44 PM, Russell Standish wrote: On Fri, Oct 11, 2013 at 03:08:30PM -0700, meekerdb wrote: UD* (trace of the universal dovetailer) is a continuum, AFAICT. It has the cardinality of the reals, and a natural metric (d(x,y) = 2^{- n}, where n is the number of leading bits in common between x and y). Hmm? So 1000 is the same distance from 10 and 111? What's the measure on this space? 1000... and 101... are 0.25 apart. 1000.. and 111... are 0.5 apart. (the ... refers to an infinite number of bits that are not relevant to the computation). So the answer to your question is that these these three strings are not the same distance from each other. The measure over a set of these things would be something like the supremum over the distance between any two pairs drawn from the set. Of course, that assumes that only sets defined by finite length prefixes, and countable unions and intersections thereof are considered. My maths chops aren't quite up to generalising this for arbitrary sets of binary strings. Maybe I'm not clear on what UD* means. I took it to be, at a given state of the UD, the last bit output by the 1st prog, the last bit output by the 2nd program,...up to the last prog that the UD has started. Right? Imagine a universal (and thus finite) game of life pattern. Then you can look at UD* as the infinite cone obtained by adding all the planes describing its evolution. That gives a static view of UD* as a discrete infinite 3D conic object. It is, as Russell and Liz said, the trace of the programs which runs all computations in that parallel -dovetailing manner. But physics and theology are emerging from the internal relative machines points of views, and that gives a richer structure, relying on the continuum. The 1/3 distinction has a key role here. Bruno Brent -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out. http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On 12 Oct 2013, at 01:16, meekerdb wrote: On 10/11/2013 4:05 PM, Pierz wrote: It does seem that the measure problem is an open one for comp, as far as I can tell from Bruno's responses, but he seems confident it's not insurmountable. Bruno's so confident that he argues that there must be a measure (because he's assumed comp is true and his argument from comp is valid). :-) Haha! Yes, that's a good point. IF COMP is true that measure must exist, even if it took a billions years for humans to extract it. But the apparently universal machine get quickly a quantized structure (thanks to the p - []p appearing at the right places). So hope can exist that such problem is not that insurmountable. Bruno Brent -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out. http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On 12 Oct 2013, at 01:36, Russell Standish wrote: On Fri, Oct 11, 2013 at 04:08:05PM -0700, meekerdb wrote: Maybe I'm not clear on what UD* means. I took it to be, at a given state of the UD, the last bit output by the 1st prog, the last bit output by the 2nd program,...up to the last prog that the UD has started. Right? Its not the output, because the UD doesn't actually output anything. Rather its an internal view of the states the machines emulated by the UD pass through, rather like what the Helsinki man experiences when being duplicated to Moscow and Washington. Its a subtle point, and I fell into the same trap you did (and Liz did also, this morning) a few years ago. I'm not sure anyone has a clear, crisp mathematical explanation of what UD* is - I certainly don't. To do that needs the phi_i, or the W_i. It is the sequence phi_0(0)^0, phi_0(0)^1, etc. With the three numbers (i, j, k) going through all element of NxNxN, and phi_i(j)^k = the kth state /step of the computation of machine/number i, on input j. Bruno http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On 12 Oct 2013, at 04:52, Russell Standish wrote: On Fri, Oct 11, 2013 at 05:46:57PM -0700, meekerdb wrote: On 10/11/2013 4:36 PM, Russell Standish wrote: On Fri, Oct 11, 2013 at 04:08:05PM -0700, meekerdb wrote: Maybe I'm not clear on what UD* means. I took it to be, at a given state of the UD, the last bit output by the 1st prog, the last bit output by the 2nd program,...up to the last prog that the UD has started. Right? Its not the output, because the UD doesn't actually output anything. Rather its an internal view of the states the machines emulated by the UD pass through, rather like what the Helsinki man experiences when being duplicated to Moscow and Washington. Its a subtle point, and I fell into the same trap you did (and Liz did also, this morning) a few years ago. I'm not sure anyone has a clear, crisp mathematical explanation of what UD* is - I certainly don't. Even if we have the complete record of everything the UD has done up to some point I don't see how we can define the kind of measure we need over that, because the measure has to be over all threads of computation corresponding to a particular classical state. And these correspond to a countable union of sets of strings sharing the same prefix, which is just the Solomonoff-Levin measure. I think this might play some role in the thermodynamic, but the quantum and the very existence of physics needs the measure on the points of view (which I handle with the self-reference logics). Bruno -- Prof Russell Standish Phone 0425 253119 (mobile) Principal, High Performance Coders Visiting Professor of Mathematics hpco...@hpcoders.com.au University of New South Wales http://www.hpcoders.com.au -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out. http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On 12 Oct 2013, at 05:15, meekerdb wrote: On 10/11/2013 7:52 PM, Russell Standish wrote: On Fri, Oct 11, 2013 at 05:46:57PM -0700, meekerdb wrote: On 10/11/2013 4:36 PM, Russell Standish wrote: On Fri, Oct 11, 2013 at 04:08:05PM -0700, meekerdb wrote: Maybe I'm not clear on what UD* means. I took it to be, at a given state of the UD, the last bit output by the 1st prog, the last bit output by the 2nd program,...up to the last prog that the UD has started. Right? Its not the output, because the UD doesn't actually output anything. Rather its an internal view of the states the machines emulated by the UD pass through, rather like what the Helsinki man experiences when being duplicated to Moscow and Washington. Its a subtle point, and I fell into the same trap you did (and Liz did also, this morning) a few years ago. I'm not sure anyone has a clear, crisp mathematical explanation of what UD* is - I certainly don't. Even if we have the complete record of everything the UD has done up to some point I don't see how we can define the kind of measure we need over that, because the measure has to be over all threads of computation corresponding to a particular classical state. And these correspond to a countable union of sets of strings sharing the same prefix, which is just the Solomonoff-Levin measure. But there are infinitely more threads going thru (near) this state which have not yet been computed. So the threads counted up to some point are of zero measure. ? But the arithmetical truth is time independent, and all computations are computed, like in a block universe. The FPI do the rest. Then you are right, all finite portion of UD* have no role, and the thread counted up to some point have zero measure. The 1-p exploits the neighborhood of omega, not zero. Bruno Brent -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out. http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On 11 Oct 2013, at 03:25, meekerdb wrote: So there are infinitely many identical universes preceding a measurement. How are these universes distinct from one another? Do they divide into two infinite subsets on a binary measurement, or do infinitely many come into existence in order that some branch- counting measure produces the right proportion? Do you not see any problems with assigning a measure to infinite countable subsets (are there more even numbers that square numbers?). And why should we prefer this model to simply saying the Born rule derives from a Bayesian epistemic view of QM as argued by, for example, Chris Fuchs? If you can explain to me how this makes the parallel experiences, (then), disappearing, please do. When I read Fuchs I thought this: Comp suggest a compromise: yes the quantum wave describes only psychological states, but they concern still a *many* dreams/worlds/physical-realities, including the many self-multiplication. It is still Everett wave as seen from inside. We just don't know if the dreams defined an unique (multiversal) physical reality. Neither in Everett +GR, nor in comp. Bayesian epistemic view is no problem, but you have to define what is the knower, the observer, etc. If not, it falls into a cosmic form of solipsism, and it can generate some strong don't ask imperative. Bruno Brent On 10/10/2013 6:11 PM, Pierz wrote: I'm puzzled by the controversy over this issue - although given that I'm not a physicist and my understanding comes from popular renditions of MWI by Deutsch and others, it may be me who's missing the point. But in my understanding of Deutsch's version of MWI, the reason for Born probabilities lies in the fact that there is no such thing as a single branch. Every branch of the multiverse contains an infinity of identical, fungible universes. When a quantum event occurs, that set of infinite universes divides proportionally according to Schroedinger's equation. The appearance of probability arises, as in Bruno's comp, from multiplication of the observer in those infinite branches. Why is this problematic? On Saturday, October 5, 2013 2:27:18 AM UTC+10, yanniru wrote: Foad Dizadji-Bahmani, 2013. The probability problem in Everettian quantum mechanics persists. British Jour. Philosophy of Science IN PRESS. ABSTRACT. Everettian quantum mechanics (EQM) results in ‘multiple, emergent, branching quasi-classical realities’ (Wallace [2012]). The possible outcomes of measurement as per ‘orthodox’ quantum mechanics are, in EQM, all instantiated. Given this metaphysics, Everettians face the ‘probability problem’—how to make sense of probabilities, and recover the Born Rule. To solve the probability problem, Wallace, following Deutsch ([1999]), has derived a quantum representation theorem. I argue that Wallace’s solution to the probability problem is unsuccessful, as follows. First, I examine one of the axioms of rationality used to derive the theorem, Branching Indifference (BI). I argue that Wallace is not successful in showing that BI is rational. While I think it is correct to put the burden of proof on Wallace to motivate BI as an axiom of rationality, it does not follow from his failing to do so that BI is not rational. Thus, second, I show that there is an alternative strategy for setting one’s credences in the face of branching which is rational, and which violates BI. This is Branch Counting (BC). Wallace is aware of BC, and has proffered various arguments against it. However, third, I argue that Wallace’s arguments against BC are unpersuasive. I conclude that the probability problem in EQM persists. http://www.foaddb.com/FDBCV.pdf Publications (a Ph.D. in Philosophy, London School of Economics, May 2012) ‘The Probability Problem in Everettian Quantum Mechanics Persists’, British Journal for Philosophy of Science, forthcoming ‘The Aharanov Approach to Equilibrium’, Philosophy of Science, 2011 78(5): 976-988 ‘Who is Afraid of Nagelian Reduction?’, Erkenntnis, 2010 73: 393-412, (with R. Frigg and S. Hartmann) ‘Conﬁrmation and Reduction: A Bayesian Account’, Synthese, 2011 179(2): 321-338, (with R. Frigg and S. Hartmann) His paper may be an interesting read once it comes out. Also available in: ‘Why I am not an Everettian’, in D. Dieks and V. Karakostas (eds): Recent Progress in Philosophy of Science: Perspectives and Foundational Problems, 2013, (The Third European Philosophy of Science Association Proceedings), Dordrecht: Springer I think this list needs another discussion of the possible MWI probability problem although it has been covered here and elsewhere by members of this list. Previous discussions have not been personally convincing. Richard -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving

### Re: The probability problem in Everettian quantum mechanics

On 10/12/2013 10:55 AM, Bruno Marchal wrote: On 11 Oct 2013, at 03:25, meekerdb wrote: So there are infinitely many identical universes preceding a measurement. How are these universes distinct from one another? Do they divide into two infinite subsets on a binary measurement, or do infinitely many come into existence in order that some branch-counting measure produces the right proportion? Do you not see any problems with assigning a measure to infinite countable subsets (are there more even numbers that square numbers?). And why should we prefer this model to simply saying the Born rule derives from a Bayesian epistemic view of QM as argued by, for example, Chris Fuchs? If you can explain to me how this makes the parallel experiences, (then), disappearing, please do. I don't understand the question. What parallel experiences do you refer to? And you're asking why they disappeared? When I read Fuchs I thought this: Comp suggest a compromise: yes the quantum wave describes only psychological states, but they concern still a *many* dreams/worlds/physical-realities, including the many self-multiplication. There is no many in Fuchs interpretation, there is only the personal subjective probabilities of contemplated futures. It is still Everett wave as seen from inside. We just don't know if the dreams defined an unique (multiversal) physical reality. Neither in Everett +GR, nor in comp. Bayesian epistemic view is no problem, but you have to define what is the knower, the observer, etc. If not, it falls into a cosmic form of solipsism, and it can generate some strong don't ask imperative. You assume that if others are not explained they must be rejected. Physicists, like Fuchs, and unlike philosophers, are generally comfortable with not explaining everything. Brent I mistrust all systematizers and avoid them. The will to a system is a lack of integrity. --- Fredrick Nietzsche, Twilight of the Idols -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On Thu, Oct 10, 2013 at 06:25:45PM -0700, meekerdb wrote: So there are infinitely many identical universes preceding a measurement. How are these universes distinct from one another? Do they divide into two infinite subsets on a binary measurement, or do infinitely many come into existence in order that some branch-counting measure produces the right proportion? Do you not see any problems with assigning a measure to infinite countable subsets (are there more even numbers that square numbers?). But infinite subsets in question will contain an uncountable number of elements. That is why I'm not sure that problems with assigning measures to countably infinite sets (such as your example above re even and square numbers) are really such a problem. -- Prof Russell Standish Phone 0425 253119 (mobile) Principal, High Performance Coders Visiting Professor of Mathematics hpco...@hpcoders.com.au University of New South Wales http://www.hpcoders.com.au -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

If you subdivide a continuum, I assume you can do so in a way that gives the required probabilities. For example if the part of the multiverse that is involved in performing a quantum measurement with a 50-50 chance of either outcome is represented by the numbers 0 to 1, you can divide those into 0-0.5 and 0.5 to 1. Doesn't David do something like this in FOR? (Or is this too simplistic?) -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On Friday, October 11, 2013 12:25:45 PM UTC+11, Brent wrote: So there are infinitely many identical universes preceding a measurement. How are these universes distinct from one another? They aren't 'distinct'. The hypothesis is that every universe branch contains an *uncountable* infinity of fungible (identical and interchangeable) universes. While this seems extravagant, it actually kind of makes more sense than the idea of a universe splitting into two (where did the second universe come from?). Instead, uncountable infinities of universes are differentiated from one another. Quantum interference patterns arise because of the possibility of universes merging back into one another again. Do they divide into two infinite subsets on a binary measurement, or do infinitely many come into existence in order that some branch-counting measure produces the right proportion? Do you not see any problems with assigning a measure to infinite countable subsets (are there more even numbers that square numbers?). The former. Deutsch goes into the problem of infinite countable sets in great detail and shows how this is *not* a problem for these uncountable infinities (as Russell points out)), whereas it may be a problem for Bruno's computations - a point I've tried to argue with Bruno, but he bamboozles my sophomoric maths with his replies. To me it seems you can't count computations that go through a state, because for every function f that computes a certain function, there is also some function f1 that also computes f such that f1 = f + 1 - 1. But maybe that can be solved by counting only the functions with the least number of steps (?). And why should we prefer this model to simply saying the Born rule derives from a Bayesian epistemic view of QM as argued by, for example, Chris Fuchs? I don't know about Chris Fuchs, although isn't that just Copenhagen? It's clear that one would need strong reasons to favour MWI with its crazy proliferation of entities, which at first blush seems to run against Occam's razor. However Deutsch makes a damn good fist of explaining why we in fact have those reasons. For instance, when a quantum computer calculates a function based on a superposition of states, MWI can explain where these calculations are occurring - in other universes. The computer is exploiting the possibility of massive parallelism inherent in that infinity of universes. It is entirely unclear how these calculations occur in the standard interpretation. MWI also solves the problem of what happens to non-realized measurement states once a system decoheres. And of course it gets around the intractable difficulties of non-computable wave collapse. So it's a case of choose your poison: infinite universes or conceptual incoherence. I'll take the former, even though in some ways I'd like the universe (or the multiverse) better if it wasn't that way. Max Born was my great grandfather. I wonder what he would have made of Everett if he'd been a bit younger. When he died in 1970, it was still probably too out there for him to have seriously considered. Brent On 10/10/2013 6:11 PM, Pierz wrote: I'm puzzled by the controversy over this issue - although given that I'm not a physicist and my understanding comes from popular renditions of MWI by Deutsch and others, it may be me who's missing the point. But in my understanding of Deutsch's version of MWI, the reason for Born probabilities lies in the fact that there is no such thing as a single branch. Every branch of the multiverse contains an infinity of identical, fungible universes. When a quantum event occurs, that set of infinite universes divides proportionally according to Schroedinger's equation. The appearance of probability arises, as in Bruno's comp, from multiplication of the observer in those infinite branches. Why is this problematic? On Saturday, October 5, 2013 2:27:18 AM UTC+10, yanniru wrote: Foad Dizadji-Bahmani, 2013. The probability problem in Everettian quantum mechanics persists. British Jour. Philosophy of Science IN PRESS. ABSTRACT. Everettian quantum mechanics (EQM) results in ‘multiple, emergent, branching quasi-classical realities’ (Wallace [2012]). The possible outcomes of measurement as per ‘orthodox’ quantum mechanics are, in EQM, all instantiated. Given this metaphysics, Everettians face the ‘probability problem’—how to make sense of probabilities, and recover the Born Rule. To solve the probability problem, Wallace, following Deutsch ([1999]), has derived a quantum representation theorem. I argue that Wallace’s solution to the probability problem is unsuccessful, as follows. First, I examine one of the axioms of rationality used to derive the theorem, Branching Indifference (BI). I argue that Wallace is not successful in showing that BI is rational. While I think it is correct to put the burden of proof on Wallace to

### Re: The probability problem in Everettian quantum mechanics

That is pretty much exactly my understanding. It does puzzle me that this argument about the supposed probability problem with MWI is still live, when that explanation seems perfectly coherent. On Friday, October 11, 2013 10:04:40 PM UTC+11, Liz R wrote: If you subdivide a continuum, I assume you can do so in a way that gives the required probabilities. For example if the part of the multiverse that is involved in performing a quantum measurement with a 50-50 chance of either outcome is represented by the numbers 0 to 1, you can divide those into 0-0.5 and 0.5 to 1. Doesn't David do something like this in FOR? (Or is this too simplistic?) -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

And just to follow up on that, there are still an infinite number of irrational numbers between 0 and 0.1. But not as large an infinity as those between 0.1 and 1. So extrapolating to universes, the very low probability, white rabbit universes also occur an infinite number of times, but that does not make them equally as likely as the universes which behave as we would classically expect. On Friday, October 11, 2013 10:04:40 PM UTC+11, Liz R wrote: If you subdivide a continuum, I assume you can do so in a way that gives the required probabilities. For example if the part of the multiverse that is involved in performing a quantum measurement with a 50-50 chance of either outcome is represented by the numbers 0 to 1, you can divide those into 0-0.5 and 0.5 to 1. Doesn't David do something like this in FOR? (Or is this too simplistic?) -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On 11 Oct 2013, at 13:09, Pierz wrote: On Friday, October 11, 2013 12:25:45 PM UTC+11, Brent wrote: So there are infinitely many identical universes preceding a measurement. How are these universes distinct from one another? They aren't 'distinct'. The hypothesis is that every universe branch contains an *uncountable* infinity of fungible (identical and interchangeable) universes. While this seems extravagant, it actually kind of makes more sense than the idea of a universe splitting into two (where did the second universe come from?). Instead, uncountable infinities of universes are differentiated from one another. Quantum interference patterns arise because of the possibility of universes merging back into one another again. With comp too, it is best to see one consciousness differentiating than actual splitting of universes. Do they divide into two infinite subsets on a binary measurement, or do infinitely many come into existence in order that some branch- counting measure produces the right proportion? Do you not see any problems with assigning a measure to infinite countable subsets (are there more even numbers that square numbers?). The former. Deutsch goes into the problem of infinite countable sets in great detail and shows how this is *not* a problem for these uncountable infinities (as Russell points out)), whereas it may be a problem for Bruno's computations - a point I've tried to argue with Bruno, but he bamboozles my sophomoric maths with his replies. To me it seems you can't count computations that go through a state, because for every function f that computes a certain function, there is also some function f1 that also computes f such that f1 = f + 1 - 1. But maybe that can be solved by counting only the functions with the least number of steps (?). You have to take all the programs, and all computations. Your relative 1-indeterminacy bears on all computations going through your state. Using little programs would beg the 1-p/3-p problem. There is an uncountable set of such computations, as they dovetail on the reals. Just keep in mind that the UD is enough dumb to implement the infinite iterated self-duplication, which leads to uncountably many histories. (Having said that, there are many ways to put probability and measure on any set, finite, enumerable, non enumerable, etc. Sometimes people just relinquish the sigma-additivity condition, and still get something very close to a measure). And why should we prefer this model to simply saying the Born rule derives from a Bayesian epistemic view of QM as argued by, for example, Chris Fuchs? I don't know about Chris Fuchs, although isn't that just Copenhagen? It's clear that one would need strong reasons to favour MWI with its crazy proliferation of entities, which at first blush seems to run against Occam's razor. However Deutsch makes a damn good fist of explaining why we in fact have those reasons. For instance, when a quantum computer calculates a function based on a superposition of states, MWI can explain where these calculations are occurring - in other universes. The computer is exploiting the possibility of massive parallelism inherent in that infinity of universes. It is entirely unclear how these calculations occur in the standard interpretation. MWI also solves the problem of what happens to non- realized measurement states once a system decoheres. And of course it gets around the intractable difficulties of non-computable wave collapse. So it's a case of choose your poison: infinite universes or conceptual incoherence. I'll take the former, even though in some ways I'd like the universe (or the multiverse) better if it wasn't that way. Max Born was my great grandfather. I wonder what he would have made of Everett if he'd been a bit younger. When he died in 1970, it was still probably too out there for him to have seriously considered. That would have been nice to know. I really love the correspondence between Max Born and Albert Einstein. I think both would have accepted Everett, even if with some grimaces, like François Englert and many quantum cosmologists. I disagree with the idea that Everett propose a new interpretation of QM. Everett proposes a new theory, which is just Copenhagen without the collapse. Everett himself talk about a new formulation of QM, not a new interpretation. that is not so important, except when we begin to use logic, which forces to be precise on what is a theory, and what is an interpretation of a theory. And Everett QM obeys Occam in the sense that he used less hypotheses. Bruno Brent On 10/10/2013 6:11 PM, Pierz wrote: I'm puzzled by the controversy over this issue - although given that I'm not a physicist and my understanding comes from popular renditions of MWI by Deutsch and others, it may be me who's missing the point. But in my

### Re: The probability problem in Everettian quantum mechanics

Pierz: Every branch of the multiverse contains an infinity of identical, fungible universes. Richard: How do you know this? Who said so? Besides the branches must contain a finite number of identical universes for probabilities to be realized. Dividing infinity by any number results in an infinity. On Thu, Oct 10, 2013 at 9:11 PM, Pierz pier...@gmail.com wrote: I'm puzzled by the controversy over this issue - although given that I'm not a physicist and my understanding comes from popular renditions of MWI by Deutsch and others, it may be me who's missing the point. But in my understanding of Deutsch's version of MWI, the reason for Born probabilities lies in the fact that there is no such thing as a single branch. Every branch of the multiverse contains an infinity of identical, fungible universes. When a quantum event occurs, that set of infinite universes divides proportionally according to Schroedinger's equation. The appearance of probability arises, as in Bruno's comp, from multiplication of the observer in those infinite branches. Why is this problematic? On Saturday, October 5, 2013 2:27:18 AM UTC+10, yanniru wrote: Foad Dizadji-Bahmani, 2013. The probability problem in Everettian quantum mechanics persists. British Jour. Philosophy of Science IN PRESS. ABSTRACT. Everettian quantum mechanics (EQM) results in ‘multiple, emergent, branching quasi-classical realities’ (Wallace [2012]). The possible outcomes of measurement as per ‘orthodox’ quantum mechanics are, in EQM, all instantiated. Given this metaphysics, Everettians face the ‘probability problem’—how to make sense of probabilities, and recover the Born Rule. To solve the probability problem, Wallace, following Deutsch ([1999]), has derived a quantum representation theorem. I argue that Wallace’s solution to the probability problem is unsuccessful, as follows. First, I examine one of the axioms of rationality used to derive the theorem, Branching Indifference (BI). I argue that Wallace is not successful in showing that BI is rational. While I think it is correct to put the burden of proof on Wallace to motivate BI as an axiom of rationality, it does not follow from his failing to do so that BI is not rational. Thus, second, I show that there is an alternative strategy for setting one’s credences in the face of branching which is rational, and which violates BI. This is Branch Counting (BC). Wallace is aware of BC, and has proffered various arguments against it. However, third, I argue that Wallace’s arguments against BC are unpersuasive. I conclude that the probability problem in EQM persists. http://www.foaddb.com/FDBCV.**pdf http://www.foaddb.com/FDBCV.pdf Publications (a Ph.D. in Philosophy, London School of Economics, May 2012) ‘The Probability Problem in Everettian Quantum Mechanics Persists’, British Journal for Philosophy of Science, forthcoming ‘The Aharanov Approach to Equilibrium’, Philosophy of Science, 2011 78(5): 976-988 ‘Who is Afraid of Nagelian Reduction?’, Erkenntnis, 2010 73: 393-412, (with R. Frigg and S. Hartmann) ‘Conﬁrmation and Reduction: A Bayesian Account’, Synthese, 2011 179(2): 321-338, (with R. Frigg and S. Hartmann) His paper may be an interesting read once it comes out. Also available in: ‘Why I am not an Everettian’, in D. Dieks and V. Karakostas (eds): Recent Progress in Philosophy of Science: Perspectives and Foundational Problems, 2013, (The Third European Philosophy of Science Association Proceedings), Dordrecht: Springer I think this list needs another discussion of the possible MWI probability problem although it has been covered here and elsewhere by members of this list. Previous discussions have not been personally convincing. Richard -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

Opps. I replied before reading the entire discussion On Fri, Oct 11, 2013 at 9:08 AM, Richard Ruquist yann...@gmail.com wrote: Pierz: Every branch of the multiverse contains an infinity of identical, fungible universes. Richard: How do you know this? Who said so? Besides the branches must contain a finite number of identical universes for probabilities to be realized. Dividing infinity by any number results in an infinity. On Thu, Oct 10, 2013 at 9:11 PM, Pierz pier...@gmail.com wrote: I'm puzzled by the controversy over this issue - although given that I'm not a physicist and my understanding comes from popular renditions of MWI by Deutsch and others, it may be me who's missing the point. But in my understanding of Deutsch's version of MWI, the reason for Born probabilities lies in the fact that there is no such thing as a single branch. Every branch of the multiverse contains an infinity of identical, fungible universes. When a quantum event occurs, that set of infinite universes divides proportionally according to Schroedinger's equation. The appearance of probability arises, as in Bruno's comp, from multiplication of the observer in those infinite branches. Why is this problematic? On Saturday, October 5, 2013 2:27:18 AM UTC+10, yanniru wrote: Foad Dizadji-Bahmani, 2013. The probability problem in Everettian quantum mechanics persists. British Jour. Philosophy of Science IN PRESS. ABSTRACT. Everettian quantum mechanics (EQM) results in ‘multiple, emergent, branching quasi-classical realities’ (Wallace [2012]). The possible outcomes of measurement as per ‘orthodox’ quantum mechanics are, in EQM, all instantiated. Given this metaphysics, Everettians face the ‘probability problem’—how to make sense of probabilities, and recover the Born Rule. To solve the probability problem, Wallace, following Deutsch ([1999]), has derived a quantum representation theorem. I argue that Wallace’s solution to the probability problem is unsuccessful, as follows. First, I examine one of the axioms of rationality used to derive the theorem, Branching Indifference (BI). I argue that Wallace is not successful in showing that BI is rational. While I think it is correct to put the burden of proof on Wallace to motivate BI as an axiom of rationality, it does not follow from his failing to do so that BI is not rational. Thus, second, I show that there is an alternative strategy for setting one’s credences in the face of branching which is rational, and which violates BI. This is Branch Counting (BC). Wallace is aware of BC, and has proffered various arguments against it. However, third, I argue that Wallace’s arguments against BC are unpersuasive. I conclude that the probability problem in EQM persists. http://www.foaddb.com/FDBCV.**pdf http://www.foaddb.com/FDBCV.pdf Publications (a Ph.D. in Philosophy, London School of Economics, May 2012) ‘The Probability Problem in Everettian Quantum Mechanics Persists’, British Journal for Philosophy of Science, forthcoming ‘The Aharanov Approach to Equilibrium’, Philosophy of Science, 2011 78(5): 976-988 ‘Who is Afraid of Nagelian Reduction?’, Erkenntnis, 2010 73: 393-412, (with R. Frigg and S. Hartmann) ‘Conﬁrmation and Reduction: A Bayesian Account’, Synthese, 2011 179(2): 321-338, (with R. Frigg and S. Hartmann) His paper may be an interesting read once it comes out. Also available in: ‘Why I am not an Everettian’, in D. Dieks and V. Karakostas (eds): Recent Progress in Philosophy of Science: Perspectives and Foundational Problems, 2013, (The Third European Philosophy of Science Association Proceedings), Dordrecht: Springer I think this list needs another discussion of the possible MWI probability problem although it has been covered here and elsewhere by members of this list. Previous discussions have not been personally convincing. Richard -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On Oct 11, 2013, at 9:06 AM, Bruno Marchal marc...@ulb.ac.be wrote: On 11 Oct 2013, at 13:16, Pierz wrote: And just to follow up on that, there are still an infinite number of irrational numbers between 0 and 0.1. But not as large an infinity as those between 0.1 and 1. It is the same cardinal (2^aleph_zero). But cardinality is not what count when searching a measure. So extrapolating to universes, the very low probability, white rabbit universes also occur an infinite number of times, but that does not make them equally as likely as the universes which behave as we would classically expect. That is what remain to be seen. But if comp is true, we know the measure has to exist, and the math gives some clues that it is indeed the case, from machines' (consistent and/or true) points of view. Bruno, Could the matter of the countably infinite number of programs be irrelevant from the first person perspective because any given mind contains/is aware of only a finite amount of information? Say some mind contains a million bits of information. Then there is a finite number (2^100) of distinct combinations of content for that mind. These differations are all that matter from the first person view, and some may be more probable than others. (But deciding the measures for each of those finite number of possibilities depends on infinite computations, and so would they be real numbers?) Jason Bruno On Friday, October 11, 2013 10:04:40 PM UTC+11, Liz R wrote: If you subdivide a continuum, I assume you can do so in a way that gives the required probabilities. For example if the part of the multiverse that is involved in performing a quantum measurement with a 50-50 chance of either outcome is represented by the numbers 0 to 1, you can divide those into 0-0.5 and 0.5 to 1. Doesn't David do something like this in FOR? (Or is this too simplistic?) -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything- l...@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out. http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On 10/11/2013 2:28 AM, Russell Standish wrote: On Thu, Oct 10, 2013 at 06:25:45PM -0700, meekerdb wrote: So there are infinitely many identical universes preceding a measurement. How are these universes distinct from one another? Do they divide into two infinite subsets on a binary measurement, or do infinitely many come into existence in order that some branch-counting measure produces the right proportion? Do you not see any problems with assigning a measure to infinite countable subsets (are there more even numbers that square numbers?). But infinite subsets in question will contain an uncountable number of elements. I don't think being uncountable makes it any easier unless they form a continuum, which I don't think they do. I QM an underlying continuum (spacetime) is assumed, but not in Bruno's theory. Brent That is why I'm not sure that problems with assigning measures to countably infinite sets (such as your example above re even and square numbers) are really such a problem. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On 10/11/2013 4:09 AM, Pierz wrote: On Friday, October 11, 2013 12:25:45 PM UTC+11, Brent wrote: So there are infinitely many identical universes preceding a measurement. How are these universes distinct from one another? They aren't 'distinct'. The hypothesis is that every universe branch contains an *uncountable* infinity of fungible (identical and interchangeable) universes. While this seems extravagant, it actually kind of makes more sense than the idea of a universe splitting into two (where did the second universe come from?). Instead, uncountable infinities of universes are differentiated from one another. Quantum interference patterns arise because of the possibility of universes merging back into one another again. Do they divide into two infinite subsets on a binary measurement, or do infinitely many come into existence in order that some branch-counting measure produces the right proportion? Do you not see any problems with assigning a measure to infinite countable subsets (are there more even numbers that square numbers?). The former. Deutsch goes into the problem of infinite countable sets in great detail and shows how this is *not* a problem for these uncountable infinities (as Russell points out)), whereas it may be a problem for Bruno's computations - a point I've tried to argue with Bruno, but he bamboozles my sophomoric maths with his replies. To me it seems you can't count computations that go through a state, because for every function f that computes a certain function, there is also some function f1 that also computes f such that f1 = f + 1 - 1. But maybe that can be solved by counting only the functions with the least number of steps (?). And why should we prefer this model to simply saying the Born rule derives from a Bayesian epistemic view of QM as argued by, for example, Chris Fuchs? I don't know about Chris Fuchs, although isn't that just Copenhagen? No, it's an interpretation of QM as personal probabilities, i.e. quantum Bayesianism. It reifies information, not quantum states, c.f. http://arxiv.org/pdf/1207.2141.pdf or http://arxiv.org/pdf/1301.3274.pdf It's might be compatible with Bruno's ideas where Copenhagen certainly isn't. It's clear that one would need strong reasons to favour MWI with its crazy proliferation of entities, which at first blush seems to run against Occam's razor. However Deutsch makes a damn good fist of explaining why we in fact have those reasons. For instance, when a quantum computer calculates a function based on a superposition of states, MWI can explain where these calculations are occurring - in other universes. The computer is exploiting the possibility of massive parallelism inherent in that infinity of universes. It is entirely unclear how these calculations occur in the standard interpretation. MWI also solves the problem of what happens to non-realized measurement states once a system decoheres. And of course it gets around the intractable difficulties of non-computable wave collapse. So it's a case of choose your poison: infinite universes or conceptual incoherence. I'll take the former, even though in some ways I'd like the universe (or the multiverse) better if it wasn't that way. If you just read this list you have the impression that MWI is the consensus true interpretation of QM; but it's still controversial (as are all other intepretations). I highly recommend reading Scott Aaronson's arXiv:1108.1791v3 Why Philosophers Should Care About Computational Complexity. Section 8 is his discussion of Deutsch's argument based on computation. He gives several reasons why Deutsch's argument, if not actually wrong, may not mean what people think it means. Here's the concluding part: = One can sharpen the point as follows: if one took the parallel-universes explanation of how a quantum computer works too seriously (as many popular writers do!), then it would be natural to make further inferences about quantum computing that are flat-out wrong. For example: “Using only a thousand quantum bits (or qubits), a quantum computer could store 21000 classical bits.” This is true only for a bizarre definition of the word “store”! The fundamental problem is that, when you measure a quantum computer’s state, you see only one of the possible outcomes; the rest disappear. Indeed, a celebrated result called Holevo’s Theorem [74] says that, using n qubits, there is no way to store more than n classical bits so that the bits can be reliably retrieved later. In other words: for at least one natural definition of “information-carrying capacity,” qubits have exactly the same capacity as bits. To take another example: “Unlike a classical computer, which can only factor numbers by trying the divisors one by one, a quantum computer could try all possible divisors in parallel.” If quantum computers can harness vast numbers of

### Re: The probability problem in Everettian quantum mechanics

On 10/11/2013 4:16 AM, Pierz wrote: And just to follow up on that, there are still an infinite number of irrational numbers between 0 and 0.1. But not as large an infinity as those between 0.1 and 1. No, the two are exactly the same uncountable infinity, because there is a 1-to-1 mapping between them. So extrapolating to universes, the very low probability, white rabbit universes also occur an infinite number of times, but that does not make them equally as likely as the universes which behave as we would classically expect. But computationalism only produces rational numbers. Brent On Friday, October 11, 2013 10:04:40 PM UTC+11, Liz R wrote: If you subdivide a continuum, I assume you can do so in a way that gives the required probabilities. For example if the part of the multiverse that is involved in performing a quantum measurement with a 50-50 chance of either outcome is represented by the numbers 0 to 1, you can divide those into 0-0.5 and 0.5 to 1. Doesn't David do something like this in FOR? (Or is this too plistic?) -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out. No virus found in this message. Checked by AVG - www.avg.com http://www.avg.com Version: 2014.0.4158 / Virus Database: 3609/6739 - Release Date: 10/10/13 -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

I know I shouldn't be flattered to hear that Max Born's great grandson endorses my view of quantum probability, but. :D :D :D On 12 October 2013 00:11, Pierz pier...@gmail.com wrote: That is pretty much exactly my understanding. It does puzzle me that this argument about the supposed probability problem with MWI is still live, when that explanation seems perfectly coherent. On Friday, October 11, 2013 10:04:40 PM UTC+11, Liz R wrote: If you subdivide a continuum, I assume you can do so in a way that gives the required probabilities. For example if the part of the multiverse that is involved in performing a quantum measurement with a 50-50 chance of either outcome is represented by the numbers 0 to 1, you can divide those into 0-0.5 and 0.5 to 1. Doesn't David do something like this in FOR? (Or is this too simplistic?) -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On Fri, Oct 11, 2013 at 10:07:58AM -0700, meekerdb wrote: On 10/11/2013 2:28 AM, Russell Standish wrote: On Thu, Oct 10, 2013 at 06:25:45PM -0700, meekerdb wrote: So there are infinitely many identical universes preceding a measurement. How are these universes distinct from one another? Do they divide into two infinite subsets on a binary measurement, or do infinitely many come into existence in order that some branch-counting measure produces the right proportion? Do you not see any problems with assigning a measure to infinite countable subsets (are there more even numbers that square numbers?). But infinite subsets in question will contain an uncountable number of elements. I don't think being uncountable makes it any easier unless they form a continuum, which I don't think they do. I QM an underlying continuum (spacetime) is assumed, but not in Bruno's theory. UD* (trace of the universal dovetailer) is a continuum, AFAICT. It has the cardinality of the reals, and a natural metric (d(x,y) = 2^{-n}, where n is the number of leading bits in common between x and y). ISTM, this metric induces a natural measure over sets of program executions that is rather continuum like - but maybe I'm missing something? Cheers -- Prof Russell Standish Phone 0425 253119 (mobile) Principal, High Performance Coders Visiting Professor of Mathematics hpco...@hpcoders.com.au University of New South Wales http://www.hpcoders.com.au -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On Fri, Oct 11, 2013 at 04:09:20AM -0700, Pierz wrote: The former. Deutsch goes into the problem of infinite countable sets in great detail and shows how this is *not* a problem for these uncountable infinities (as Russell points out)), whereas it may be a problem for Interesting. I wasn't aware that Deutsch had done that. I was aware of his critiques of measuring countable sets (such as in the infinity hotel chapter of BoI), but not that he showed there was no such problems with uncountable sets. Do you have a reference? Of course, I take the position that it will be alright on the night, and give a plausible account of it in my solution of the White Rabbit problem in my paper Why Occams razor, but that has been criticised, particularly by Bruno, that the measure issue is not so simple. I don't feel confident enough in the maths of measure theory to say that it isn't a problem, just that I can't see a problem in using Solomonoff's measure. Hence my interest in Deutsch's take. Cheers -- Prof Russell Standish Phone 0425 253119 (mobile) Principal, High Performance Coders Visiting Professor of Mathematics hpco...@hpcoders.com.au University of New South Wales http://www.hpcoders.com.au -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On 10/11/2013 2:46 PM, Russell Standish wrote: On Fri, Oct 11, 2013 at 10:07:58AM -0700, meekerdb wrote: On 10/11/2013 2:28 AM, Russell Standish wrote: On Thu, Oct 10, 2013 at 06:25:45PM -0700, meekerdb wrote: So there are infinitely many identical universes preceding a measurement. How are these universes distinct from one another? Do they divide into two infinite subsets on a binary measurement, or do infinitely many come into existence in order that some branch-counting measure produces the right proportion? Do you not see any problems with assigning a measure to infinite countable subsets (are there more even numbers that square numbers?). But infinite subsets in question will contain an uncountable number of elements. I don't think being uncountable makes it any easier unless they form a continuum, which I don't think they do. I QM an underlying continuum (spacetime) is assumed, but not in Bruno's theory. UD* (trace of the universal dovetailer) is a continuum, AFAICT. It has the cardinality of the reals, and a natural metric (d(x,y) = 2^{-n}, where n is the number of leading bits in common between x and y). Hmm? So 1000 is the same distance from 10 and 111? What's the measure on this space? Brent ISTM, this metric induces a natural measure over sets of program executions that is rather continuum like - but maybe I'm missing something? Cheers -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On 12 October 2013 11:12, LizR lizj...@gmail.com wrote: On 12 October 2013 10:46, Russell Standish li...@hpcoders.com.au wrote: On Fri, Oct 11, 2013 at 10:07:58AM -0700, meekerdb wrote: I don't think being uncountable makes it any easier unless they form a continuum, which I don't think they do. I QM an underlying continuum (spacetime) is assumed, but not in Bruno's theory. UD* (trace of the universal dovetailer) is a continuum, AFAICT. It has the cardinality of the reals, and a natural metric (d(x,y) = 2^{-n}, where n is the number of leading bits in common between x and y). ISTM, this metric induces a natural measure over sets of program executions that is rather continuum like - but maybe I'm missing something? I always assumed the UD output bits - i.e. not a continuum, but a countable infinity of symbols - but maybe I'm missing something? Am I missing diagonalisation? i.e. Can the UD output be diagonalised? -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On Sat, Oct 12, 2013 at 11:14:32AM +1300, LizR wrote: On 12 October 2013 11:12, LizR lizj...@gmail.com wrote: On 12 October 2013 10:46, Russell Standish li...@hpcoders.com.au wrote: On Fri, Oct 11, 2013 at 10:07:58AM -0700, meekerdb wrote: I don't think being uncountable makes it any easier unless they form a continuum, which I don't think they do. I QM an underlying continuum (spacetime) is assumed, but not in Bruno's theory. UD* (trace of the universal dovetailer) is a continuum, AFAICT. It has the cardinality of the reals, and a natural metric (d(x,y) = 2^{-n}, where n is the number of leading bits in common between x and y). ISTM, this metric induces a natural measure over sets of program executions that is rather continuum like - but maybe I'm missing something? I always assumed the UD output bits - i.e. not a continuum, but a countable infinity of symbols - but maybe I'm missing something? Am I missing diagonalisation? i.e. Can the UD output be diagonalised? The UD doesn't output anything. If it did, then certainly, the output could not be an uncountable set due to the diagonalisation argument. Rather UD* is like the internal view of the operation of the dovetailer, like the sum of all possible experiences of the Helsinki man being duplicated to Washington and Moscow that is being discussed rather a lot lately. -- Prof Russell Standish Phone 0425 253119 (mobile) Principal, High Performance Coders Visiting Professor of Mathematics hpco...@hpcoders.com.au University of New South Wales http://www.hpcoders.com.au -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On Fri, Oct 11, 2013 at 03:08:30PM -0700, meekerdb wrote: UD* (trace of the universal dovetailer) is a continuum, AFAICT. It has the cardinality of the reals, and a natural metric (d(x,y) = 2^{-n}, where n is the number of leading bits in common between x and y). Hmm? So 1000 is the same distance from 10 and 111? What's the measure on this space? 1000... and 101... are 0.25 apart. 1000.. and 111... are 0.5 apart. (the ... refers to an infinite number of bits that are not relevant to the computation). So the answer to your question is that these these three strings are not the same distance from each other. The measure over a set of these things would be something like the supremum over the distance between any two pairs drawn from the set. Of course, that assumes that only sets defined by finite length prefixes, and countable unions and intersections thereof are considered. My maths chops aren't quite up to generalising this for arbitrary sets of binary strings. -- Prof Russell Standish Phone 0425 253119 (mobile) Principal, High Performance Coders Visiting Professor of Mathematics hpco...@hpcoders.com.au University of New South Wales http://www.hpcoders.com.au -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On 12 October 2013 11:35, Russell Standish li...@hpcoders.com.au wrote: The UD doesn't output anything. If it did, then certainly, the output could not be an uncountable set due to the diagonalisation argument. Yes, I wasn't speaking very precisely. Obviously there is no output, because where would it go? I meant the trace, which I assume is a record of its operation, which itself exists in arithmetic (I think?) Rather UD* is like the internal view of the operation of the dovetailer, like the sum of all possible experiences of the Helsinki man being duplicated to Washington and Moscow that is being discussed rather a lot lately. Ah! Should read to the end :) Thanks. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On Saturday, October 12, 2013 5:42:06 AM UTC+11, Brent wrote: On 10/11/2013 4:16 AM, Pierz wrote: And just to follow up on that, there are still an infinite number of irrational numbers between 0 and 0.1. But not as large an infinity as those between 0.1 and 1. No, the two are exactly the same uncountable infinity, because there is a 1-to-1 mapping between them. My mathematical terminology may not be up to scratch. The measure is different. So extrapolating to universes, the very low probability, white rabbit universes also occur an infinite number of times, but that does not make them equally as likely as the universes which behave as we would classically expect. But computationalism only produces rational numbers. We were talking MWI, where a measure is permitted because of the underlying physical continuum. It does seem that the measure problem is an open one for comp, as far as I can tell from Bruno's responses, but he seems confident it's not insurmountable. I'm not competent to judge. Brent On Friday, October 11, 2013 10:04:40 PM UTC+11, Liz R wrote: If you subdivide a continuum, I assume you can do so in a way that gives the required probabilities. For example if the part of the multiverse that is involved in performing a quantum measurement with a 50-50 chance of either outcome is represented by the numbers 0 to 1, you can divide those into 0-0.5 and 0.5 to 1. Doesn't David do something like this in FOR? (Or is this too plistic?) -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-li...@googlegroups.com javascript:. To post to this group, send email to everyth...@googlegroups.comjavascript: . Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out. No virus found in this message. Checked by AVG - www.avg.com Version: 2014.0.4158 / Virus Database: 3609/6739 - Release Date: 10/10/13 -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

Haha. The flattery may be undone by learning that your view of quantum probability is also endorsed by Olivia Newton-John's nephew! :) On Saturday, October 12, 2013 8:26:23 AM UTC+11, Liz R wrote: I know I shouldn't be flattered to hear that Max Born's great grandson endorses my view of quantum probability, but. :D :D :D On 12 October 2013 00:11, Pierz pie...@gmail.com javascript: wrote: That is pretty much exactly my understanding. It does puzzle me that this argument about the supposed probability problem with MWI is still live, when that explanation seems perfectly coherent. On Friday, October 11, 2013 10:04:40 PM UTC+11, Liz R wrote: If you subdivide a continuum, I assume you can do so in a way that gives the required probabilities. For example if the part of the multiverse that is involved in performing a quantum measurement with a 50-50 chance of either outcome is represented by the numbers 0 to 1, you can divide those into 0-0.5 and 0.5 to 1. Doesn't David do something like this in FOR? (Or is this too simplistic?) -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On 10/11/2013 3:44 PM, Russell Standish wrote: On Fri, Oct 11, 2013 at 03:08:30PM -0700, meekerdb wrote: UD* (trace of the universal dovetailer) is a continuum, AFAICT. It has the cardinality of the reals, and a natural metric (d(x,y) = 2^{-n}, where n is the number of leading bits in common between x and y). Hmm? So 1000 is the same distance from 10 and 111? What's the measure on this space? 1000... and 101... are 0.25 apart. 1000.. and 111... are 0.5 apart. (the ... refers to an infinite number of bits that are not relevant to the computation). So the answer to your question is that these these three strings are not the same distance from each other. The measure over a set of these things would be something like the supremum over the distance between any two pairs drawn from the set. Of course, that assumes that only sets defined by finite length prefixes, and countable unions and intersections thereof are considered. My maths chops aren't quite up to generalising this for arbitrary sets of binary strings. Maybe I'm not clear on what UD* means. I took it to be, at a given state of the UD, the last bit output by the 1st prog, the last bit output by the 2nd program,...up to the last prog that the UD has started. Right? Brent -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On 10/11/2013 4:05 PM, Pierz wrote: It does seem that the measure problem is an open one for comp, as far as I can tell from Bruno's responses, but he seems confident it's not insurmountable. Bruno's so confident that he argues that there must be a measure (because he's assumed comp is true and his argument from comp is valid). :-) Brent -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On Fri, Oct 11, 2013 at 04:08:05PM -0700, meekerdb wrote: Maybe I'm not clear on what UD* means. I took it to be, at a given state of the UD, the last bit output by the 1st prog, the last bit output by the 2nd program,...up to the last prog that the UD has started. Right? Its not the output, because the UD doesn't actually output anything. Rather its an internal view of the states the machines emulated by the UD pass through, rather like what the Helsinki man experiences when being duplicated to Moscow and Washington. Its a subtle point, and I fell into the same trap you did (and Liz did also, this morning) a few years ago. I'm not sure anyone has a clear, crisp mathematical explanation of what UD* is - I certainly don't. Cheers -- Prof Russell Standish Phone 0425 253119 (mobile) Principal, High Performance Coders Visiting Professor of Mathematics hpco...@hpcoders.com.au University of New South Wales http://www.hpcoders.com.au -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On Saturday, October 12, 2013 9:07:57 AM UTC+11, Russell Standish wrote: On Fri, Oct 11, 2013 at 04:09:20AM -0700, Pierz wrote: The former. Deutsch goes into the problem of infinite countable sets in great detail and shows how this is *not* a problem for these uncountable infinities (as Russell points out)), whereas it may be a problem for Interesting. I wasn't aware that Deutsch had done that. I was aware of his critiques of measuring countable sets (such as in the infinity hotel chapter of BoI), but not that he showed there was no such problems with uncountable sets. Do you have a reference? Of course, I take the position that it will be alright on the night, and give a plausible account of it in my solution of the White Rabbit problem in my paper Why Occams razor, but that has been criticised, particularly by Bruno, that the measure issue is not so simple. I don't feel confident enough in the maths of measure theory to say that it isn't a problem, just that I can't see a problem in using Solomonoff's measure. Hence my interest in Deutsch's take. Cheers Sorry to disappoint you. I was referring rather to his arguments in BoI that the measure problem is not an issue for MWI because of the underlying relationships between the universes (on page 179-180 for instance). It wasn't actually about uncountable infinities versus countable ones :( -- Prof Russell Standish Phone 0425 253119 (mobile) Principal, High Performance Coders Visiting Professor of Mathematics hpc...@hpcoders.com.aujavascript: University of New South Wales http://www.hpcoders.com.au -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On Saturday, October 12, 2013 10:08:05 AM UTC+11, Brent wrote: On 10/11/2013 3:44 PM, Russell Standish wrote: On Fri, Oct 11, 2013 at 03:08:30PM -0700, meekerdb wrote: UD* (trace of the universal dovetailer) is a continuum, AFAICT. It has the cardinality of the reals, and a natural metric (d(x,y) = 2^{-n}, where n is the number of leading bits in common between x and y). Hmm? So 1000 is the same distance from 10 and 111? What's the measure on this space? 1000... and 101... are 0.25 apart. 1000.. and 111... are 0.5 apart. (the ... refers to an infinite number of bits that are not relevant to the computation). So the answer to your question is that these these three strings are not the same distance from each other. The measure over a set of these things would be something like the supremum over the distance between any two pairs drawn from the set. Of course, that assumes that only sets defined by finite length prefixes, and countable unions and intersections thereof are considered. My maths chops aren't quite up to generalising this for arbitrary sets of binary strings. Maybe I'm not clear on what UD* means. I took it to be, at a given state of the UD, the last bit output by the 1st prog, the last bit output by the 2nd program,...up to the last prog that the UD has started. Right? Brent But Russell just said there *is* no output. There are only machine states (computation X is at step Y and so on). I thought the UD* was the entire history of computational states the the UD passes through from the moment it starts up to ... well, forever. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On 12 October 2013 12:06, Pierz pier...@gmail.com wrote: Haha. The flattery may be undone by learning that your view of quantum probability is also endorsed by Olivia Newton-John's nephew! :) OMG!!! :D :D :D It's electrifying! -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On 10/11/2013 4:45 PM, Pierz wrote: On Saturday, October 12, 2013 10:08:05 AM UTC+11, Brent wrote: On 10/11/2013 3:44 PM, Russell Standish wrote: On Fri, Oct 11, 2013 at 03:08:30PM -0700, meekerdb wrote: UD* (trace of the universal dovetailer) is a continuum, AFAICT. It has the cardinality of the reals, and a natural metric (d(x,y) = 2^{-n}, where n is the number of leading bits in common between x and y). Hmm? So 1000 is the same distance from 10 and 111? What's the measure on this space? 1000... and 101... are 0.25 apart. 1000.. and 111... are 0.5 apart. (the ... refers to an infinite number of bits that are not relevant to the computation). So the answer to your question is that these these three strings are not the same distance from each other. The measure over a set of these things would be something like the supremum over the distance between any two pairs drawn from the set. Of course, that assumes that only sets defined by finite length prefixes, and countable unions and intersections thereof are considered. My maths chops aren't quite up to generalising this for arbitrary sets of binary strings. Maybe I'm not clear on what UD* means. I took it to be, at a given state of the UD, the last bit output by the 1st prog, the last bit output by the 2nd program,...up to the last prog that the UD has started. Right? Brent But Russell just said there *is* no output. I just meant last printed onto the tape. Brent There are only machine states (computation X is at step Y and so on). I thought the UD* was the entire history of computational states the the UD passes through from the moment it starts up to ... well, forever. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out. No virus found in this message. Checked by AVG - www.avg.com http://www.avg.com Version: 2014.0.4158 / Virus Database: 3614/6742 - Release Date: 10/11/13 -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On 10/11/2013 4:36 PM, Russell Standish wrote: On Fri, Oct 11, 2013 at 04:08:05PM -0700, meekerdb wrote: Maybe I'm not clear on what UD* means. I took it to be, at a given state of the UD, the last bit output by the 1st prog, the last bit output by the 2nd program,...up to the last prog that the UD has started. Right? Its not the output, because the UD doesn't actually output anything. Rather its an internal view of the states the machines emulated by the UD pass through, rather like what the Helsinki man experiences when being duplicated to Moscow and Washington. Its a subtle point, and I fell into the same trap you did (and Liz did also, this morning) a few years ago. I'm not sure anyone has a clear, crisp mathematical explanation of what UD* is - I certainly don't. Even if we have the complete record of everything the UD has done up to some point I don't see how we can define the kind of measure we need over that, because the measure has to be over all threads of computation corresponding to a particular classical state. Brent -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On Fri, Oct 11, 2013 at 05:46:57PM -0700, meekerdb wrote: On 10/11/2013 4:36 PM, Russell Standish wrote: On Fri, Oct 11, 2013 at 04:08:05PM -0700, meekerdb wrote: Maybe I'm not clear on what UD* means. I took it to be, at a given state of the UD, the last bit output by the 1st prog, the last bit output by the 2nd program,...up to the last prog that the UD has started. Right? Its not the output, because the UD doesn't actually output anything. Rather its an internal view of the states the machines emulated by the UD pass through, rather like what the Helsinki man experiences when being duplicated to Moscow and Washington. Its a subtle point, and I fell into the same trap you did (and Liz did also, this morning) a few years ago. I'm not sure anyone has a clear, crisp mathematical explanation of what UD* is - I certainly don't. Even if we have the complete record of everything the UD has done up to some point I don't see how we can define the kind of measure we need over that, because the measure has to be over all threads of computation corresponding to a particular classical state. And these correspond to a countable union of sets of strings sharing the same prefix, which is just the Solomonoff-Levin measure. -- Prof Russell Standish Phone 0425 253119 (mobile) Principal, High Performance Coders Visiting Professor of Mathematics hpco...@hpcoders.com.au University of New South Wales http://www.hpcoders.com.au -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

On 10/11/2013 7:52 PM, Russell Standish wrote: On Fri, Oct 11, 2013 at 05:46:57PM -0700, meekerdb wrote: On 10/11/2013 4:36 PM, Russell Standish wrote: On Fri, Oct 11, 2013 at 04:08:05PM -0700, meekerdb wrote: Maybe I'm not clear on what UD* means. I took it to be, at a given state of the UD, the last bit output by the 1st prog, the last bit output by the 2nd program,...up to the last prog that the UD has started. Right? Its not the output, because the UD doesn't actually output anything. Rather its an internal view of the states the machines emulated by the UD pass through, rather like what the Helsinki man experiences when being duplicated to Moscow and Washington. Its a subtle point, and I fell into the same trap you did (and Liz did also, this morning) a few years ago. I'm not sure anyone has a clear, crisp mathematical explanation of what UD* is - I certainly don't. Even if we have the complete record of everything the UD has done up to some point I don't see how we can define the kind of measure we need over that, because the measure has to be over all threads of computation corresponding to a particular classical state. And these correspond to a countable union of sets of strings sharing the same prefix, which is just the Solomonoff-Levin measure. But there are infinitely more threads going thru (near) this state which have not yet been computed. So the threads counted up to some point are of zero measure. ? Brent -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

I'm puzzled by the controversy over this issue - although given that I'm not a physicist and my understanding comes from popular renditions of MWI by Deutsch and others, it may be me who's missing the point. But in my understanding of Deutsch's version of MWI, the reason for Born probabilities lies in the fact that there is no such thing as a single branch. Every branch of the multiverse contains an infinity of identical, fungible universes. When a quantum event occurs, that set of infinite universes divides proportionally according to Schroedinger's equation. The appearance of probability arises, as in Bruno's comp, from multiplication of the observer in those infinite branches. Why is this problematic? On Saturday, October 5, 2013 2:27:18 AM UTC+10, yanniru wrote: Foad Dizadji-Bahmani, 2013. The probability problem in Everettian quantum mechanics persists. British Jour. Philosophy of Science IN PRESS. ABSTRACT. Everettian quantum mechanics (EQM) results in ‘multiple, emergent, branching quasi-classical realities’ (Wallace [2012]). The possible outcomes of measurement as per ‘orthodox’ quantum mechanics are, in EQM, all instantiated. Given this metaphysics, Everettians face the ‘probability problem’—how to make sense of probabilities, and recover the Born Rule. To solve the probability problem, Wallace, following Deutsch ([1999]), has derived a quantum representation theorem. I argue that Wallace’s solution to the probability problem is unsuccessful, as follows. First, I examine one of the axioms of rationality used to derive the theorem, Branching Indifference (BI). I argue that Wallace is not successful in showing that BI is rational. While I think it is correct to put the burden of proof on Wallace to motivate BI as an axiom of rationality, it does not follow from his failing to do so that BI is not rational. Thus, second, I show that there is an alternative strategy for setting one’s credences in the face of branching which is rational, and which violates BI. This is Branch Counting (BC). Wallace is aware of BC, and has proffered various arguments against it. However, third, I argue that Wallace’s arguments against BC are unpersuasive. I conclude that the probability problem in EQM persists. http://www.foaddb.com/FDBCV.pdf Publications (a Ph.D. in Philosophy, London School of Economics, May 2012) ‘The Probability Problem in Everettian Quantum Mechanics Persists’, British Journal for Philosophy of Science, forthcoming ‘The Aharanov Approach to Equilibrium’, Philosophy of Science, 2011 78(5): 976-988 ‘Who is Afraid of Nagelian Reduction?’, Erkenntnis, 2010 73: 393-412, (with R. Frigg and S. Hartmann) ‘Conﬁrmation and Reduction: A Bayesian Account’, Synthese, 2011 179(2): 321-338, (with R. Frigg and S. Hartmann) His paper may be an interesting read once it comes out. Also available in: ‘Why I am not an Everettian’, in D. Dieks and V. Karakostas (eds): Recent Progress in Philosophy of Science: Perspectives and Foundational Problems, 2013, (The Third European Philosophy of Science Association Proceedings), Dordrecht: Springer I think this list needs another discussion of the possible MWI probability problem although it has been covered here and elsewhere by members of this list. Previous discussions have not been personally convincing. Richard -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

### Re: The probability problem in Everettian quantum mechanics

So there are infinitely many identical universes preceding a measurement. How are these universes distinct from one another? Do they divide into two infinite subsets on a binary measurement, or do infinitely many come into existence in order that some branch-counting measure produces the right proportion? Do you not see any problems with assigning a measure to infinite countable subsets (are there more even numbers that square numbers?). And why should we prefer this model to simply saying the Born rule derives from a Bayesian epistemic view of QM as argued by, for example, Chris Fuchs? Brent On 10/10/2013 6:11 PM, Pierz wrote: I'm puzzled by the controversy over this issue - although given that I'm not a physicist and my understanding comes from popular renditions of MWI by Deutsch and others, it may be me who's missing the point. But in my understanding of Deutsch's version of MWI, the reason for Born probabilities lies in the fact that there is no such thing as a single branch. Every branch of the multiverse contains an infinity of identical, fungible universes. When a quantum event occurs, that set of infinite universes divides proportionally according to Schroedinger's equation. The appearance of probability arises, as in Bruno's comp, from multiplication of the observer in those infinite branches. Why is this problematic? On Saturday, October 5, 2013 2:27:18 AM UTC+10, yanniru wrote: Foad Dizadji-Bahmani, 2013. The probability problem in Everettian quantum mechanics persists. British Jour. Philosophy of Science IN PRESS. ABSTRACT. Everettian quantum mechanics (EQM) results in ‘multiple, emergent, branching quasi-classical realities’ (Wallace [2012]). The possible outcomes of measurement as per ‘orthodox’ quantum mechanics are, in EQM, all instantiated. Given this metaphysics, Everettians face the ‘probability problem’—how to make sense of probabilities, and recover the Born Rule. To solve the probability problem, Wallace, following Deutsch ([1999]), has derived a quantum representation theorem. I argue that Wallace’s solution to the probability problem is unsuccessful, as follows. First, I examine one of the axioms of rationality used to derive the theorem, Branching Indifference (BI). I argue that Wallace is not successful in showing that BI is rational. While I think it is correct to put the burden of proof on Wallace to motivate BI as an axiom of rationality, it does not follow from his failing to do so that BI is not rational. Thus, second, I show that there is an alternative strategy for setting one’s credences in the face of branching which is rational, and which violates BI. This is Branch Counting (BC). Wallace is aware of BC, and has proffered various arguments against it. However, third, I argue that Wallace’s arguments against BC are unpersuasive. I conclude that the probability problem in EQM persists. http://www.foaddb.com/FDBCV.pdf http://www.foaddb.com/FDBCV.pdf Publications (a Ph.D. in Philosophy, London School of Economics, May 2012) ‘The Probability Problem in Everettian Quantum Mechanics Persists’, British Journal for Philosophy of Science, forthcoming ‘The Aharanov Approach to Equilibrium’, Philosophy of Science, 2011 78(5): 976-988 ‘Who is Afraid of Nagelian Reduction?’, Erkenntnis, 2010 73: 393-412, (with R. Frigg and S. Hartmann) ‘Conﬁrmation and Reduction: A Bayesian Account’, Synthese, 2011 179(2): 321-338, (with R. Frigg and S. Hartmann) His paper may be an interesting read once it comes out. Also available in: ‘Why I am not an Everettian’, in D. Dieks and V. Karakostas (eds): Recent Progress in Philosophy of Science: Perspectives and Foundational Problems, 2013, (The Third European Philosophy of Science Association Proceedings), Dordrecht: Springer I think this list needs another discussion of the possible MWI probability problem although it has been covered here and elsewhere by members of this list. Previous discussions have not been personally convincing. Richard -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out. No virus found in this message. Checked by AVG - www.avg.com http://www.avg.com Version: 2014.0.4158 / Virus Database: 3609/6739 - Release Date: 10/10/13 -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com.

### Re: The probability problem in Everettian quantum mechanics

On 04 Oct 2013, at 23:30, John Mikes wrote: Richard: I grew into denying probability in cases where not - ALL - circumstances are known. I agree with this. That is why there are many other attempt to study ignorance and beliefs (like believability theories, which is like probability, except they can sum and go above 1). Now I am not sure Dizadji-Bahmani is successful on his critics on branching indifference, which of ourse can be seen as part of the first person indeterminacy in the (more general) comp or arithmetical duplication situations. Bruno Since we know only part of the infinite complexity of the WORLD, we buy in for a mistake if fixing anything like 'probability'. The same goes for statistical: push the borderlines abit further away and the COUNT of the studied item (= statistical value) will change. Also the above argument for probability is valid for results as 'statistical' values. JM On Fri, Oct 4, 2013 at 12:27 PM, Richard Ruquist yann...@gmail.com wrote: Foad Dizadji-Bahmani, 2013. The probability problem in Everettian quantum mechanics persists. British Jour. Philosophy of Science IN PRESS. ABSTRACT. Everettian quantum mechanics (EQM) results in ‘multiple, emergent, branching quasi-classical realities’ (Wallace [2012]). The possible outcomes of measurement as per ‘orthodox’ quantum mechanics are, in EQM, all instantiated. Given this metaphysics, Everettians face the ‘probability problem’—how to make sense of probabilities, and recover the Born Rule. To solve the probability problem, Wallace, following Deutsch ([1999]), has derived a quantum representation theorem. I argue that Wallace’s solution to the probability problem is unsuccessful, as follows. First, I examine one of the axioms of rationality used to derive the theorem, Branching Indifference (BI). I argue that Wallace is not successful in showing that BI is rational. While I think it is correct to put the burden of proof on Wallace to motivate BI as an axiom of rationality, it does not follow from his failing to do so that BI is not rational. Thus, second, I show that there is an alternative strategy for setting one’s credences in the face of branching which is rational, and which violates BI. This is Branch Counting (BC). Wallace is aware of BC, and has proffered various arguments against it. However, third, I argue that Wallace’s arguments against BC are unpersuasive. I conclude that the probability problem in EQM persists. http://www.foaddb.com/FDBCV.pdf Publications (a Ph.D. in Philosophy, London School of Economics, May 2012) ‘The Probability Problem in Everettian Quantum Mechanics Persists’, British Journal for Philosophy of Science, forthcoming ‘The Aharanov Approach to Equilibrium’, Philosophy of Science, 2011 78(5): 976-988 ‘Who is Afraid of Nagelian Reduction?’, Erkenntnis, 2010 73: 393-412, (with R. Frigg and S. Hartmann) ‘Conﬁrmation and Reduction: A Bayesian Account’, Synthese, 2011 179(2): 321-338, (with R. Frigg and S. Hartmann) His paper may be an interesting read once it comes out. Also available in: ‘Why I am not an Everettian’, in D. Dieks and V. Karakostas (eds): Recent Progress in Philosophy of Science: Perspectives and Foundational Problems, 2013, (The Third European Philosophy of Science Association Proceedings), Dordrecht: Springer I think this list needs another discussion of the possible MWI probability problem although it has been covered here and elsewhere by members of this list. Previous discussions have not been personally convincing. Richard -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out. -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out. http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups Everything List group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.