Re: Cryonics punched cards and the brain
On Fri, Apr 29, 2016 a John Mikes wrote: > > Bruno: do you have a good definition you could use for "physical"? > If it's physical then if it is of a large enough magnitude it can impact one of the senses without any intermediary. That's why a number like a billion is not physical, it has a large magnitude but a billion of something is needed to effect the senses, a billion alone can't do anything. A number is a idea, and a idea needs a physical brain to think it. Given that Bruno talks about "3p" so much a better question to ask is " Exactly what does the personal pronoun "you" mean?". I didn't just provide a list of synonyms, I explained what "physical" means; but when Bruno is asked about "3p" it's all circular definitions. John K Clark -- 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 https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Non-locality and MWI
On 29/04/2016 9:09 pm, Bruno Marchal wrote: On 28 Apr 2016, at 03:33, Bruce Kellett wrote: On 27/04/2016 4:57 pm, Bruno Marchal wrote: On 27 Apr 2016, at 06:49, Bruce Kellett wrote: On 27/04/2016 1:51 pm, Brent Meeker wrote: That's pretty much the many-universes model that Bruno proposes. But it's non-local in the sense that the "matching scheme" must take account of which measurements are compatible, i.e. it "knows" the results even while they are spacelike separated. Exactly, the model assumes the results it is trying to get. It is not a local physical model because the statistics do not originate locally. The statistic did originate locally. Alice and Bob did prepare the singlet state locally, and then travel away. That is not strictly correct. The singlet state is conventionally prepared centrally between A and B so that the measurements can be made at spacelike separation. That would not be possible if A and B jointly prepare the state then move away. The measurement? OK. Not the preparation. They are in infinitely many worlds, and in each with opposite spin. There are only two possible spin states for each -- so there are really only two distinct possible worlds. Multiplying copies of these two does not seem to accomplish much. There is an infinity of possible states for each. There is an infinity of possible distinct possible worlds. In each one A's and B's particle spin are opposite/correlated, but neither Alice nor Bob can know which one. I think you are getting confused by the basis problem again. The cos^2(theta) is given by the math of the 1/sqrt(2)AB(I+>I-> - I->I+>)) = 1/sqrt(2)ABI+>I-> - 1/sqrt(2)ABI->I+>. With your explanation to Jesse, I keep the feeling that you talk like if Alice or Bob reduce the wave after their measurement, but they just localize themselves in the relative branches. Certainly, the cos^2(theta/2) comes from applying the standard quantum rules to the singlet state |psi> = (|+>|-> - |->|+>)/sqrt(2) (adding AB to this state adds nothing). We need them to get all the statistics correct. I think it would be instructive to actually go through the usual quantum derivation of the correlations because what you call "reducing the wave after the measurement" is actually the result of applying the standard quantum rules. It has nothing to do with so-called 'collapse' interpretations: it is simply in the theory. Well, either the meaurement give specific outcome, or, if there is no physical collapse it is only an entanglement between A (or B) with the singlet state. That is why A and B are needed in the derivation. A measurement results in an entanglement between the state and the observer. But in order for the observer to see only one result (and not a superposition) you need the projection postulate. That is decoherence, not a rejection of many worlds. Quantum rules for measurement say that the initial state can be expanded in the basis corresponding to the particular measurement in question (contextuality). That is what the state |psi> above is -- the quantum expansion of the singlet state in the basis in which say Alice is doing her measurement. OK, but that state does not represent two possible worlds. It looks like that for Alice because she has decided to make the measurement "in that base", but, as we know, the correlation does not depend on the choice of Alice's measurement. She will just entangled herself with the singlet state, whatever the base or measuring apparatus is. Quantum rules then say that the result of the measurement (after decoherence has fully operated) Decoherence is only the contagion of the superposition to the observer and/or his/her environment. It does not lead to a classical universe. That is only what the infinitely many Alice will phenomenologivally realize. Decoherence is the basis for the (apparent) emergence of the classical from the quantum. Decoherence allows coarse-graining, partial tracing over environmental variables, and the other things that enable us to get definite experimental results. is one of the eigenstates in the expansion, and the measurement result is the corresponding eigenvalue. In our case, there are two possibilities for Alice after her measurement is complete: result '+', with corresponding eigenstate |+>|->, or '-', with corresponding eigenstate |->|+>. There are no other possibilities, and Alice has a 50% chance of obtaining either result, or of being in the corresponding branch of the evolved wave function. That is correct phenomenologically. But QM-without collapse just say that we get a new Ipsi> equal to A(|+>|-> - |->|+>)/sqrt(2) = (A|+>|-> - A|->|+>)/sqrt(2). At no moment is Alice in front of only |+>|-> or |->|+>. The singlet state never disappear. That is the basis of your confusion. What you are saying, in effect, is that the state is not reduced to the eigenvector corresponding to the obtained eigenvalue after meas
Re: Cryonics punched cards and the brain
Bruno: do you have a good definition you could use for "physical"? (I mean: beyond what science calls physics in physical sciences). * In my agnostic mind whatever might be included into - even - some thinking of potentially imaginable domains/factors/items/complexifiers etc. - "IS" - existing in the Entirety of which we have had access only in a tiny-tiny little fraction so far. Even that: adjusted to our (simple?) capabilities of the 'contemporary'' human mind. (The perfect agnosticism). I feel free to 'think' beyond whatever we can think of today. Of course, without substance. I.O.W.: to allow more to 'exist' than our knowables. JOhn Mikes On Wed, Apr 20, 2016 at 1:47 AM, Bruno Marchal wrote: > > On 20 Apr 2016, at 00:12, John Clark wrote: > > On Tue, Apr 19, 2016 at 12:30 PM, Bruno Marchal wrote: > > >> > >> "is" in which sense? >> > > "sense" in which sense? > > You must be a fan of Bill Clinton who notoriously said in answer to a > question in a legal deposition: > > "It depends on what the meaning of the word 'is' i > s." > > > >> > >> Some multi or multimulti verses could be everything physical that there >> is, but not everything needs to be physical >> > > But physicists deal in the physical that why they're bored to tears when > people start talking about what things would look like from places that are > impossible to exist even in theory. > > >> > >> exemple: the natural numbers, the complex numbers, >> > > First of all we don't even know for certain that the Real Numbers exist > much less the > > Complex Numbers, and even it they do they don't have a location. but a > viewpoint does, it's a > position of observation > ; and if that location is not inside the multiverse it does not exist. > > >> > >> but logically, it is conceivable to have structure containing themselves, >> > > Fine, but it is not logical to have something that is not part of itself > be part of itself; like a place that is not part of the multiverse you can > stand on to look at it from the outside. The multiverse has no outside. > > > That is why Nagel called it the point of view of nowhere, and sometimes I > call something slightly similar the 0th person point of view. What you say > does not refute what I said, given that here, the 0th point of view is > given by the mathematics of the Everett Universal Wave. It just means that > we look at the wave function of the universe assuming QM without collapse. > And I have not use this, only any superposition coming from Alice and Bob > entangling themselves with a singlet state (sometehing you have eliminate > from the successive quotes, so we were leading astray from the topic). > > Bruno > > > > >> >>> If the works of >>> >>> Galilee, Einstein >>> >>> or >>> >>> Maxwell >>> >>> were built on unphysical foundation >>> s >>> then today nobody would remember their names, instead they are among the >>> most >>> famous >>> physicists of all time. In fact Einstein came up with relativity by >>> trying to imagine what the viewpoint would be of somebody moving at the >>> speed of light and >>> >>> discovered that viewpoint would produce logical contradictions >>> , >>> and therefore CAN NOT EXIST. >> >> >> > >> No, he put itself at the place of a photon which does move at the speed >> of light, and concluded to the laws of relativity and to the fact that the >> photon can't have a mass non null. I think. >> > > Einstein figured that if the fundamental laws of physics were worth > anything then they must be true for any frame of reference, but from the > frame of reference of somebody moving at 186,000 miles a second all > electromagnetic waves would have a undulating shape that changes in space > but not in time and light would have zero velocity. But that would be > contrary to Maxwell's equations, therefore Einstein concluded that the > viewpoint of a observer moving at 186,000 miles a second CAN NOT EXIST. And > after that realization the rest of special relativity fell into place. > > > >> Many works of many physicists are built in part (at least) on unphysical >> foundation: mathematics. >> > > I can't think of one. It's true that before Einstein proved them wrong > people though non-Euclidean geometry was unphysical, but a place to stand > outside the multiverse will always be unphysical because if it was physical > it would be inside the multiverse. > > John k Clark > > > > > > -- > 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 https://groups.google.com/group/everything-list. > For more options, visit https://groups.google.com/d/optout. > > > http://iridia.ulb.ac.be/~marchal/ > > > > -- > You received this message because you a
Re: R: Re: R: Re: Non-locality and MWI
Here is a paper from the Journal of Cosmology, written by a comp sci professor at the University of Warwick, UK. I like it because of its logical flow, and, of course, no idea if its plausible, but it does correlate with MWI and the wave function, observers, and all that fun stuff of physics and computationalism. Anyone want to test drive this hypothesis and the logics? I like it, but don't know if this helps us? http://webcache.googleusercontent.com/search?q=cache:gSwPx43hKBsJ:journalofcosmology.com/JOC24/Forrest_Paper_2.pdf+&cd=2&hl=en&ct=clnk&gl=us -Original Message- From: Bruno Marchal To: everything-list Sent: Fri, Apr 29, 2016 8:19 am Subject: Re: R: Re: R: Re: Non-locality and MWI On 29 Apr 2016, at 09:41, 'scerir' via Everything List wrote: Da: spudboy100 via Everything List Data: 28/04/2016 21.46 A: Ogg: Re: R: Re: Non-locality and MWI Is there any practical technical use for MWI as applied science. Just asking? Dunno. Quantum computers? Maybe there is a Many Interpretations Conjecture :-) Interpretations of quantum mechanics, unlike Gods, are not jealous, and thus it is safe to believe in more than one at the same time. Well, only because we tolerate non-sense in religion. I am not sure we can do that for a long time. So if the many-worlds interpretation makes it easier to think about the research you're doing in April, and the Copenhagen interpretation makes it easier to think about the research you're doing in June, the Copenhagen interpretation is not going to smite you for praying to the many-worlds interpretation. At least I hope it won't, because otherwise I'm in big trouble. ---Peter Shor Same with religion. We need only to have, relatively to the facts, consistent views, with ourselves, and eventually with each others. I believe in every interpretation of quantum mechanics to the extent it points out the problem, and disbelieve in every interpretation to the extent it claims to have solved it. Good! I believe the same for the religions. Bruno --Scott Aaronson -- 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 https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. 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 https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. -- 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 https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: R: Re: Non-locality and MWI
Ok, thanks. Yes, I read Deutsches interp some years back. I also like his later, Constructor theory, but this is sort of off topic. -Original Message- From: Bruno Marchal To: everything-list Sent: Fri, Apr 29, 2016 8:09 am Subject: Re: R: Re: Non-locality and MWI On 29 Apr 2016, at 04:16, Stathis Papaioannou wrote: On 29 April 2016 at 07:27, spudboy100 via Everything List wrote: Hah! Well somebody will get rich of we take the Everett stuff as fact. Not likely myself for all this. Sincerely, Your humble clone Kill off the poor ones and then you're sure to be the rich one. That seems to me like cutting of the right part of a wooden rule to get only a left part. Spudboy, MWI is only an attempt to make sense of QM. Its practical application is the same as QM. Now David Deustch would mention Quantum computer, that he discovered thanks to the MWI. MWI = taken the reality of the superposed states seriously, as already the two slits experiment with one photon illustrates that we should do. For me, but also for Deutsch and for Everett MWI = QM-without collapse. Everett's published paper, even its long text, does not mention "many world" but only a new theory: the old one minus the physical collapse of the wave. Bruno -- Stathis Papaioannou -- 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 https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. 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 https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. -- 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 https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: R: Re: R: Re: Non-locality and MWI
On 29 Apr 2016, at 09:41, 'scerir' via Everything List wrote: Da: spudboy100 via Everything List Data: 28/04/2016 21.46 A: Ogg: Re: R: Re: Non-locality and MWI Is there any practical technical use for MWI as applied science. Just asking? Dunno. Quantum computers? Maybe there is a Many Interpretations Conjecture :-) Interpretations of quantum mechanics, unlike Gods, are not jealous, and thus it is safe to believe in more than one at the same time. Well, only because we tolerate non-sense in religion. I am not sure we can do that for a long time. So if the many-worlds interpretation makes it easier to think about the research you're doing in April, and the Copenhagen interpretation makes it easier to think about the research you're doing in June, the Copenhagen interpretation is not going to smite you for praying to the many-worlds interpretation. At least I hope it won't, because otherwise I'm in big trouble. ---Peter Shor Same with religion. We need only to have, relatively to the facts, consistent views, with ourselves, and eventually with each others. I believe in every interpretation of quantum mechanics to the extent it points out the problem, and disbelieve in every interpretation to the extent it claims to have solved it. Good! I believe the same for the religions. Bruno --Scott Aaronson -- 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 https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. 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 https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: R: Re: R: Re: Cryonics punched cards and the brain
On 15 Apr 2016, at 17:45, 'scerir' via Everything List wrote: On 14 Apr 2016, at 20:25, 'scerir' via Everything List wrote: MWI: "local" or not? There are papers *trying* to explain "local" in MWI. In example: http://philsci-archive.pitt.edu/504/2/cracow.pdf That's a good one, imo. .. .. Note that with computationalism, we might still expect some physical non-locality, and so it is my "physical intuition" which makes me skeptical. Despite I think that physics is only an appearance emerging from arithmetic see from inside by computable objects, I tend to infer from observation and reasoning that both QM and special relativity are plausibly correct, together with some minimal amount of physical realism (but not physical fundamentalism). Non locality would hurt badly that feeling. Physics would no more have any relation with a reality independent of ourself, and would go farer in weirdness than what we can expect from digital mechanism! Bruno Imo "local" (and perhaps also "deterministic") sounds crazy in MWI. "Separable" would be better? ? On the contrary. MWI restores locality and deteminacy in the 3p picture, and get indeterminacy and non-locality in the first person plural views, well in accord with computationalism. Right now, I'm reading something . “It appears that an understanding is possible via the notion of information. Information seen as the possibility of obtaining knowledge. Then quantum entanglement describes a situation where information exists about possible correlations between possible future results of possible future measurements without any information existing for the individual measurements. The latter explains quantum randomness, the first quantum entanglement. And both have significant consequences for our customary notions of causality. It remains to be seen what the consequences are for our notions of space and time, or space- time for that matter. Space-time itself cannot be above or beyond such considerations. I suggest we need a new deep analysis of space- time, a conceptual analysis maybe analogous to the one done by the Viennese physicist-philosopher Ernst Mach who kicked Newton’s absolute space and absolute time form their throne. The hope is that in the end we will have new physics analogous to Einstein’s new physics in the two theories of relativity.” --A. Zeilinger: http://edge.org/response-detail/26790 No problem with "information", except that the word is tarditionnally called in may different senses, and often blurr the distinction between the private meaning/intepretation of the 3p information, or just the 3p information like with Shannon. Then, the reasoning from computationalism, or from QM-without collapse, shows that you can't avoid the multidreams. If that is Zeilinger wish, I think it cannot be done. It would certainly make physics depart a lot of what we can expect from computationalism. 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 https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. 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 https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: R: Re: Non-locality and MWI
On 29 Apr 2016, at 04:16, Stathis Papaioannou wrote: On 29 April 2016 at 07:27, spudboy100 via Everything List > wrote: Hah! Well somebody will get rich of we take the Everett stuff as fact. Not likely myself for all this. Sincerely, Your humble clone Kill off the poor ones and then you're sure to be the rich one. That seems to me like cutting of the right part of a wooden rule to get only a left part. Spudboy, MWI is only an attempt to make sense of QM. Its practical application is the same as QM. Now David Deustch would mention Quantum computer, that he discovered thanks to the MWI. MWI = taken the reality of the superposed states seriously, as already the two slits experiment with one photon illustrates that we should do. For me, but also for Deutsch and for Everett MWI = QM-without collapse. Everett's published paper, even its long text, does not mention "many world" but only a new theory: the old one minus the physical collapse of the wave. Bruno -- Stathis Papaioannou -- 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 https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. 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 https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: R: Re: Non-locality and MWI
Ah! Now you speak of the policies of the Ruling Class, which need no physics, or many worlds, just self centered behavior. Also, chances are via Hugh Everett, because I am not already rich, I am one of the others, as being a rich clone is not my wave function. -Original Message- From: Stathis Papaioannou To: everything-list Sent: Thu, Apr 28, 2016 10:17 pm Subject: Re: R: Re: Non-locality and MWI On 29 April 2016 at 07:27, spudboy100 via Everything List wrote: Hah! Well somebody will get rich of we take the Everett stuff as fact. Not likely myself for all this. Sincerely, Your humble clone Kill off the poor ones and then you're sure to be the rich one. -- Stathis Papaioannou -- 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 https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. -- 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 https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Non-locality and MWI
On 28 Apr 2016, at 03:33, Bruce Kellett wrote: On 27/04/2016 4:57 pm, Bruno Marchal wrote: On 27 Apr 2016, at 06:49, Bruce Kellett wrote: On 27/04/2016 1:51 pm, Brent Meeker wrote: That's pretty much the many-universes model that Bruno proposes. But it's non-local in the sense that the "matching scheme" must take account of which measurements are compatible, i.e. it "knows" the results even while they are spacelike separated. Exactly, the model assumes the results it is trying to get. It is not a local physical model because the statistics do not originate locally. The statistic did originate locally. Alice and Bob did prepare the singlet state locally, and then travel away. That is not strictly correct. The singlet state is conventionally prepared centrally between A and B so that the measurements can be made at spacelike separation. That would not be possible if A and B jointly prepare the state then move away. The measurement? OK. Not the preparation. They are in infinitely many worlds, and in each with opposite spin. There are only two possible spin states for each -- so there are really only two distinct possible worlds. Multiplying copies of these two does not seem to accomplish much. There is an infinity of possible states for each. There is an infinity of possible distinct possible worlds. In each one A's and B's particle spin are opposite/correlated, but neither Alice nor Bob can know which one. The cos^2(theta) is given by the math of the 1/sqrt(2)AB(I+>I-> - I- >I+>)) = 1/sqrt(2)ABI+>I-> - 1/sqrt(2)ABI->I+>. With your explanation to Jesse, I keep the feeling that you talk like if Alice or Bob reduce the wave after their measurement, but they just localize themselves in the relative branches. Certainly, the cos^2(theta/2) comes from applying the standard quantum rules to the singlet state |psi> = (|+>|-> - |->|+>)/sqrt(2) (adding AB to this state adds nothing). We need them to get all the statistics correct. I think it would be instructive to actually go through the usual quantum derivation of the correlations because what you call "reducing the wave after the measurement" is actually the result of applying the standard quantum rules. It has nothing to do with so- called 'collapse' interpretations: it is simply in the theory. Well, either the meaurement give specific outcome, or, if there is no physical collapse it is only an entanglement between A (or B) with the singlet state. That is why A and B are needed in the derivation. Quantum rules for measurement say that the initial state can be expanded in the basis corresponding to the particular measurement in question (contextuality). That is what the state |psi> above is -- the quantum expansion of the singlet state in the basis in which say Alice is doing her measurement. OK, but that state does not represent two possible worlds. It looks like that for Alice because she has decided to make the measurement "in that base", but, as we know, the correlation does not depend on the choice of Alice's measurement. She will just entangled herself with the singlet state, whatever the base or measuring apparatus is. Quantum rules then say that the result of the measurement (after decoherence has fully operated) Decoherence is only the contagion of the superposition to the observer and/or his/her environment. It does not lead to a classical universe. That is only what the infinitely many Alice will phenomenologivally realize. is one of the eigenstates in the expansion, and the measurement result is the corresponding eigenvalue. In our case, there are two possibilities for Alice after her measurement is complete: result '+', with corresponding eigenstate |+>|->, or '-', with corresponding eigenstate |->|+>. There are no other possibilities, and Alice has a 50% chance of obtaining either result, or of being in the corresponding branch of the evolved wave function. That is correct phenomenologically. But QM-without collapse just say that we get a new Ipsi> equal to A(|+>|-> - |->|+>)/sqrt(2) = (A|+>|-> - A|->|+>)/sqrt(2). At no moment is Alice in front of only |+>|-> or |->|+>. The singlet state never disappear. The question now arises as to how the formalism describes Bob's measurement, assuming that it follows that of Alice (there will always be a Lorentz frame in which that is true for spacelike separations. For timelike separations, it is either true, or we reverse the A/B labels so that it is true.) Since the description of the state does not depend on the separation between A and B, after A gets '+' and her eigenstate is |+>|->, Bob must measure the state |- > in the direction of his magnet. To get the relative probabilities for his results, we must rotate the eigenfunction from Alice's basis to the basis appropriate for Bob's measurement. This is the standard rotation of a spinor,
R: Re: R: Re: Non-locality and MWI
Da: spudboy100 via Everything List Data: 28/04/2016 21.46 A: Ogg: Re: R: Re: Non-locality and MWI Is there any practical technical use for MWI as applied science. Just asking? Dunno. Quantum computers? Maybe there is a Many Interpretations Conjecture :-) Interpretations of quantum mechanics, unlike Gods, are not jealous, and thus it is safe to believe in more than one at the same time. So if the many-worlds interpretation makes it easier to think about the research you're doing in April, and the Copenhagen interpretation makes it easier to think about the research you're doing in June, the Copenhagen interpretation is not going to smite you for praying to the many-worlds interpretation. At least I hope it won't, because otherwise I'm in big trouble. ---Peter Shor I believe in every interpretation of quantum mechanics to the extent it points outthe problem, and disbelieve in every interpretation to the extent it claims to have solved it.--Scott Aaronson -- 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 https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
