Re: spooky action at a distance
Do we live in a universe in which future coin tosses will invariably result in heads, or one in which a mixture of results will occur? Of course, we live in both, but the latter constitutes a numerically much larger class of universes; one would imagine it would be the same with physical laws, including those governing wave-function collapse: That some laws would have a much larger measure, and would always be the ones we discover. -Chris C - Original Message - From: Hal Finney [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Thursday, November 13, 2003 5:30 PM Subject: Re: spooky action at a distance This list is dedicated to exploring the implications of the prospect that all universes exist. According to this principle, universes exist with all possible laws of physics. It follows that universes exist which follow the MWI; and universes exist where only one branch is real and where the other branches are eliminated. Universes exist where the transactional interpretation is true, and where Penrose's objective reduction happens. I'm tempted to even say that universes exist where the Copenhagen interpretation is true, but that seems to be more a refusal to ask questions than a genuine interpretation. Therefore it is somewhat pointless to argue about whether we are in one or another of these universes. In fact, I would claim that we are in all of these, at least all that are not logically inconsistent or incompatible with the data. That is, our conscious experience spans multiple universes; we are instantiated equally and equivalently in universes which have different laws of physics, but where the differences are so subtle that they have no effect on our observations. It may be that at some future time, we can perform an experiment which will provide evidence to eliminate or confirm some of these possible QM interpretations. At that time, our consciousness will differentiate, and we will go on in each of the separate universes, with separate consciousness. It is still useful to discuss whether the various interpretations work at all, and whether they are in fact compatible with our experimental results. But to go beyond that and to try to determine which one is true is, according to the multiverse philosophy, an empty exercise. All are true; all are instantiated in the multiverse, and we live in all of them. Hal
Re: spooky action at a distance
John Collins, [EMAIL PROTECTED], writes: Do we live in a universe in which future coin tosses will invariably result in heads, or one in which a mixture of results will occur? Of course, we live in both, but the latter constitutes a numerically much larger class of universes; one would imagine it would be the same with physical laws, including those governing wave-function collapse: That some laws would have a much larger measure, and would always be the ones we discover. That makes sense. So instead of arguing over whether wave-function collapse occurs, we should argue over what is the fraction of our experiences in which it occurs. Hal
Re: spooky action at a distance
Joao Leao: The association between non-locality and retrocausality (for lack of a better word) is anything but simple! In any case it has less to do with the flow of time than with its negation! [...] Bell's theorem shows that, given the hidden variable lambda, the result of the experiment at B is dependent on the angle of the measurement at A, *or* the the result of experiment at A is dependent on the angle of the measurement at B, *or* both. Now, because of symmetry, it must be both. Thus, if there are retrocausations (or influences, or weak signals as Ian Percival calls them) they are in both directions (and with the same probabilities). So yes, it is difficult to show that the flow of time is involved. Antoine Suarez (and the Geneva Group) speaks of a-temporal quantum effects. Now let us imagine this set-up. I suppose it can be useful also within the MWI, at least as a possible answer to the question If we live in all of them can we pick the cheapest one?. So I go on trying to describe this gedanken experiment (or perhaps lunacy). There is the usual SPDC source, two correlated photons, mirrors m1 and m2, one human observer, polarization detectors (measuring photon-1) and, very close, 4 boxes to collect photon-2. Of course the path of photon-1 is shorter that the path of photon-2, so there is a time-delay, for photon-2 going into one of those boxes (possible delayed choice here?). m1 /---source- detectors | | | \ boxes (1,2,3,4) m2 Now the observer can measure, with his detectors, or the linear polarization of his photon-1, or the circular polarization of his photon-1. Of course the observer, having measured his photon-1, can predict what is the polarization state of photon-2. There are 4 possibilities: linear/x, linear/y, circular/+, circular/-. Being very short the distance between detectors and boxes, the observer has time (due to that time-delay) to move there and pick up the right box (that one with the right label: linear/x, linear/y, circular/+, circular/-) and collect, into the right box, the photon-2 which is arriving. This is possible because he *knows* what was his *choice* while measuring, with detectors, the polarization state (linear *or* circular) of photon-1. And he also *knows* what was the measurement outcome for photon-1: i.e. linear/x, or circular/+, or ... This is also possible because the observer has *time* to move to the other location and pick up the right box, to collect photon-2. But before observer makes his *choice* the photons (and especially photon-2, which is late) were already flying. So you could ask: what was the polarization state of photon-2, before the observer made his choice measuring, with his detectors, the polarization state of photon-1? The answer seems to be that photon-2 fits equally well in both categories, that is to say: linear polarization and circular polarization. Thus neither of these properties can be ascribed to it as an objective property. Now you can also ask: what if I cut the path lenght of photon-2 and I make it equal to the path lenght of photon-1? It happens that the observer becomes unable to move from the detectors location to the boxes location, because there is no time-delay now. So, in these conmditions, the observer, loses control of the situation. His information remains hidden, or useless, ot impossible. But this, imo, does not mean that photons gain some objectiveness. Or not? Of course you excluded the possibility of (weak or strong) signals traveling FTL, from detectors or from photon-1 to photon-2. In example making the path lenght of photon-2 much much longer than the coherence lenght of the photon(s). But imagine that your procedure (here above) is not enough, and actually there is some FTL effect. The interesting point here is that any FTL effect from detectors or photon-1 makes actual, objective the state of photon-2 *before* its measurement.
Re: spooky action at a distance
scerir wrote: Joao Leao: > The association between non-locality and "retrocausality" > (for lack of a better word) is anything but simple! In any > case it has less to do with the flow of time than with its > negation! [...] Bell's theorem shows that, given the hidden variable lambda, the result of the experiment at B is dependent on the angle of the measurement at A, *or* the the result of experiment at A is dependent on the angle of the measurement at B, *or* both. Now, because of symmetry, it must be both. Thus, if there are "retrocausations" (or "influences", or "weak signals" as Ian Percival calls them) they are in both directions (and with the same probabilities). So yes, it is difficult to show that the flow of time is involved. Antoine Suarez (and the Geneva Group) speaks of a-temporal quantum effects. That is a defensible poin-of-view. The "time symmetric" approach does not conceive the measurement in these terms though!It requires the actual symmetrization of the coincidence measurements, what the Aharonov school calls "pre- and post-selection". This is a way of symmetrizing the initial with the final conditions... Your proposal below is not lunatic in the least bit, though! It has been mentioned in the literature several many times. I just don't have the references handy. (but check http://arXiv.org/abs/quant-ph/9511002 ) It is a tricky point to reconcile it with the usual description but it can be done. You have to bear in mind that the correlations can only be exacted a-posteriori from the coincidence counts. A single pairwise detection will not provide you with any retrodictory inference about an actual value being set before you choose the basis of observation. (This is an instance of a delayed choice experiment by the way.) Now let us imagine this set-up. I suppose it can be useful also within the MWI, at least as a possible answer to the question "If we live in all of them can we pick the cheapest one?". So I go on trying to describe this gedanken experiment (or perhaps lunacy). There is the usual SPDC source, two correlated photons, mirrors m1 and m2, one human observer, polarization detectors (measuring photon-1) and, very close, 4 boxes to collect photon-2. Of course the path of photon-1 is shorter that the path of photon-2, so there is a time-delay, for photon-2 going into one of those boxes (possible delayed choice here?). m1 /---source-->-->- detectors | | | \-->->- boxes (1,2,3,4) m2 Now the observer can measure, with his detectors, or the linear polarization of his photon-1, or the circular polarization of his photon-1. Of course the observer, having measured his photon-1, can predict what is the polarization state of photon-2. There are 4 possibilities: linear/x, linear/y, circular/+, circular/-. Being very short the distance between detectors and boxes, the observer has time (due to that time-delay) to move there and pick up the right box (that one with the right label: linear/x, linear/y, circular/+, circular/-) and collect, into the right box, the photon-2 which is arriving. This is possible because he *knows* what was his *choice* while measuring, with detectors, the polarization state (linear *or* circular) of photon-1. And he also *knows* what was the measurement outcome for photon-1: i.e. linear/x, or circular/+, or ... This is also possible because the observer has *time* to move to the other location and pick up the right box, to collect photon-2. But before observer makes his *choice* the photons (and especially photon-2, which is "late") were already flying. So you could ask: what was the polarization state of photon-2, before the observer made his choice measuring, with his detectors, the polarization state of photon-1? The answer seems to be that photon-2 fits equally well in both categories, that is to say: linear polarization and circular polarization. Thus neither of these properties can be ascribed to it as an objective property. Now you can also ask: what if I cut the path lenght of photon-2 and I make it equal to the path lenght of photon-1? It happens that the observer becomes unable to move from the detectors location to the boxes location, because there is no time-delay now. So, in these conmditions, the observer, loses control of the situation. His information remains hidden, or useless, ot impossible. But this, imo, does not mean that photons gain some objectiveness. Or not? Not really. I mean, what is at stake is not the objectiveness of the photons but of the value of their polarization in either base (or both). The fact that you may have stored a value that you did not know while you waited to "objectify" it does not particular help you... Of course you excluded the possibility of (weak or strong) signals traveling FTL, from detectors or from photon-1 to photon-2. In example making the path lenght of photon-2 much much longer than the coherence lenght of the photon(s). But imagine that your
Re: spooky action at a distance
Or conceivably could an SAS in a classically deterministic universe surmise something like a Level III multiverse, from considerations of the (ontological?) status(es) of terms of alternatives, alternatives of the types studied in logic (e.g. multivalue logic), mathematical theory of probability, (pure) mathematical theory of information -- such disciplines as consider structures of alternatives that exhaust the possibilities (a la p or ~p)? I think so; in principle some mathematician could explore the implications of the Schrodinger equation (or whatever mathematics turns out to underly our universe), just as we play with toy universes such as Conway's Life. Wolfram has spent years looking at cellular automata to try to see which ones might produce structure and, by implication, life and SAS's. Our tools are not strong enough to get very far with this, but in the future we might even simulate universes far enough elong that life evolves. And someone in a deterministic universe might eventually simulate our own. In fact we could be living there, in a sense. That makes sense to my addled head. Another possibility seems to be that an SAS seems fated to describe nature with quantum mechanics. I found this (excerpted below) while Googling around, it's from something by list member Russell Standish, also mentioning list member Bruno Marchal. If it's right, then quantum mechanics is entailed by probability theory combined with one or another set of not-distinctively-quantum-mechanical ideas, including the idea of an observer that seems to be more than just a detector, an observer who can relate various collateral observations together through time (a psychological experience of time in order to do the observations). Anyway, this stuff is apparently old hat around here! I guess I should have been paying more attention. (It's quite remarkable to have the schroedinger equation popping out of a combination of probability theory an assumption of time experience. I hope I'm not off-base to be reminded of special relativity's kinematics coming out of a combination of a finite signal speed limit assumptions of space, time, an observer.) If any SAS by combining probability theory with assumptions of time experience etc will arrive at the schroedinger equation, does this mean that an SAS can't learn of living in a classically deterministic universe even if the SAS does live in one? Or does it mean that probability theory plus observer, time experience, etc. rule out classically deterministic universes in which observations can take place? - Ben Udell A new revolution in physics http://parallel.hpc.unsw.edu.au/rks/docs/revolution/revolution.html Excerpt, regarding the application of the anthropic principle. : 66 So lets try a physicist's approach, which is to assume a few, fairly uncontroversial things about consciousness, without pretending to know the full story, and see how far this gets us. Let us assume two things in particular -- that the observer observes by selecting a partial description from the ensemble, and that there is a psychological experiennce of time in order to do the observations. If one additionally assumes the standard axioms of probability theory, and then crank the handle, Schrödinger's equation pops out, along with most of the structure of Quantum Mechanics[15]! Surprising as this result may be, two other scientists have independently come to similar conclusions, each with a slightly different set of starting ingredients. Bruno Marchal[8,9] started by assuming a particular form of computationalism, as well as what he calls Arithmetic Platonism (essentially a plenitude structure like above), and strong form of the Church Turing thesis, and ended up predicting that the observers knowledge should obey quantum logic. Roy Frieden[7] started with an observer embedded in 4-D Minkowski space-time, and asked what happens out of game where nature tries to hide its true reality from the observer. Probability theory enters through the concept of Fisher Information. In the most general form of the problem, he ends up with the Klein-Gordon equation, a covariant form of the Schrödinger equation. It is as if, in the words of Marchal, Physics is but a branch of (machine) psychology. Even though each of these efforts are tentative, and the details differ, there does seem to be an elephant' that blind men are discovering. The observer was seen to be an integral part of physics as a consequence of quantum mechanics. Do we have the courage to complete the journey and realise that the physics is defined by the observer? 99
Re: spooky action at a distance
David Barrett-Lennard Isn't non-locality simply associated with the ability for the future to affect the past? Imo future and past means time, and light cones, etc. If there is no flow of time, there is no past, and no future. But I may be wrong. Because, at this level, as pointed out long ago by Finkelstein it is difficult to distinguish between subject and object. So it is possible a self-interaction (self-reference!) governed by some internal parameter, instead of time. This reminds me of an unknown italian poet (XVIII sec.) who wrote: Era il tempo che il tempo ancor nun era tempo. Unfortunately this poet is so little known that I also forgot his name! Anyway my poor translation is: Once upon a time the time wasn't yet time. Finkelstein: The Physics of Logic [in Paradigms and Paradoxes, ed. R. G. Colodny, 1971, pag. 60]: There is, to be sure, a genuine problem in the phenomenon of quantum measurement, but I will not discuss it here. It concerns *introspective* systems, were subject = object so that the basic conception of a single subject observing an ensemble of objects must be modified.
Re: spooky action at a distance
David Barrett-Lennard According to QM, in small systems evolving according to the Hamiltonian, time certainly exists but there is no arrow of time within the scope of the experiment. In such small systems we can run the movie backwards and everything looks normal. Yes, but how small? Because now they perform experiments over large distance. Not just the 45 meters of the old Jasin interferometer. But 10 km. or even 100 km. And still they find interferences. (Of course those beams are correlated and well protected!). In general the argument 'contra' the transactional interpretation is this one below (in this case, by Anton Zeilinger). But I do not know well enough Cramer's interpretation. So I cannot judge. In the Transactional Interpretation the state vector is considered to be a real physical wave emitted as an offer wave based on the preparation procedure of the experiment. The interaction then comes to a close through the emission of the confirmation wave by what is usually called the collapse of the wave function. The quantum particle, e.g. the photon, electron etc., is then considered to be identical with the finished transaction. It is fundamental to that interpretation that where the closure of the transaction takes place is an unexplained input to the process.
Re: spooky action at a distance
scerir wrote: David Barrett-Lennard > According to QM, in small systems evolving according to the Hamiltonian, > time certainly exists but there is no arrow of time within the scope of > the experiment. In such small systems we can run the movie backwards > and everything looks normal. Yes, but how small? Because now they perform experiments over large distance. Not just the 45 meters of the old Jasin interferometer. But 10 km. or even 100 km. And still they find interferences. (Of course those beams are correlated and well protected!). In general the argument 'contra' the transactional interpretation is this one below (in this case, by Anton Zeilinger). But I do not know well enough Cramer's interpretation. So I cannot judge. In the Transactional Interpretation the state vector is considered to be a real physical wave emitted as an "offer wave" based on the preparation procedure of the experiment. The interaction then comes to a close through the emission of the "confirmation wave" by what is usually called the collapse of the wave function. The quantum particle, e.g. the photon, electron etc., is then considered to be identical with the finished transaction. It is fundamental to that interpretation that where the closure of the transaction takes place is an unexplained input to the process.> The "transactional interpretation" is unduly "realistic"! A better conception of a "bi-causal" determination of EPR correlations is provided by the so-called "2-state approach"of Aharovov et al. which has the added thrill that it makes verifiable predictions beyond the conventional QMformalism. Check http://arXiv.org/abs/quant-ph/9501011 Both the "protective" and the "weak-value" experiments associated with this idea are now being tried out... -Joao -- Joao Pedro Leao ::: [EMAIL PROTECTED] Harvard-Smithsonian Center for Astrophysics 1815 Massachussetts Av. , Cambridge MA 02140 Work Phone: (617)-496-7990 extension 124 Cell-Phone: (617)-817-1800 -- "All generalizations are abusive (specially this one!)" ---
Re: spooky action at a distance
scerir wrote: David Barrett-Lennard > Isn't "non-locality" simply associated with > the ability for the "future" to affect the "past"? Imo future and past means time, and light cones, etc. If there is no flow of time, there is no past, and no future. The association between non-locality and "retrocausality" (for lack of a better word) is anything but simple!In any case it has less to do with the flow of time than with its negation!It is better understood in the context of the "block-universe" conception in which time does not flow at all but all events are somehow coextensive... Granted this is easier to project into euclidean space-time than into minkowski space-time but not impossible. But I may be wrong. Because, at this level, as pointed out long ago by Finkelstein it is difficult to distinguish between subject and object. So it is possible a self-interaction (self-reference!) governed by some internal parameter, instead of time. This reminds me of an unknown italian poet (XVIII sec.) who wrote: "Era il tempo che il tempo ancor nun era tempo". Unfortunately this poet is so little known that I also forgot his name! Anyway my poor translation is: "Once upon a time the time wasn't yet time." Finkelstein: "The Physics of Logic" [in "Paradigms and Paradoxes", ed. R. G. Colodny, 1971, pag. 60]: "There is, to be sure, a genuine problem in the phenomenon of quantum measurement, but I will not discuss it here. It concerns *introspective* systems, were subject = object so that the basic conception of a single subject observing an ensemble of objects must be modified." Finkelstein's observation may be correct about measurement in general but I don't see where it has anything to do with the possible bearing on retrocausation! -- Joao Pedro Leao ::: [EMAIL PROTECTED] Harvard-Smithsonian Center for Astrophysics 1815 Massachussetts Av. , Cambridge MA 02140 Work Phone: (617)-496-7990 extension 124 Cell-Phone: (617)-817-1800 -- "All generalizations are abusive (specially this one!)" ---
Re: spooky action at a distance
This list is dedicated to exploring the implications of the prospect that all universes exist. According to this principle, universes exist with all possible laws of physics. It follows that universes exist which follow the MWI; and universes exist where only one branch is real and where the other branches are eliminated. Universes exist where the transactional interpretation is true, and where Penrose's objective reduction happens. I'm tempted to even say that universes exist where the Copenhagen interpretation is true, but that seems to be more a refusal to ask questions than a genuine interpretation. Therefore it is somewhat pointless to argue about whether we are in one or another of these universes. In fact, I would claim that we are in all of these, at least all that are not logically inconsistent or incompatible with the data. That is, our conscious experience spans multiple universes; we are instantiated equally and equivalently in universes which have different laws of physics, but where the differences are so subtle that they have no effect on our observations. It may be that at some future time, we can perform an experiment which will provide evidence to eliminate or confirm some of these possible QM interpretations. At that time, our consciousness will differentiate, and we will go on in each of the separate universes, with separate consciousness. It is still useful to discuss whether the various interpretations work at all, and whether they are in fact compatible with our experimental results. But to go beyond that and to try to determine which one is true is, according to the multiverse philosophy, an empty exercise. All are true; all are instantiated in the multiverse, and we live in all of them. Hal
Re: spooky action at a distance
http://arXiv.org/abs/quant-ph/9501011 Both the protective and the weak-value experiments associated with this idea are now being tried out... -Joao Yes and they are testing the famous 3-quantum-boxes paradox http://arxiv.org/abs/quant-ph/0310091 with related negative probabilities! Can a falling tree make a noise in two forests at the same time? Regards, s.
Re: spooky action at a distance
Hal Finney wrote: This list is dedicated to exploring the implications of the prospect that all universes exist. According to this principle, universes exist with all possible laws of physics. It follows that universes exist which follow the MWI; and universes exist where only one branch is real and where the other branches are eliminated. Universes exist where the transactional interpretation is true, and where Penrose's "objective reduction" happens. I'm tempted to even say that universes exist where the Copenhagen interpretation is true, but that seems to be more a refusal to ask questions than a genuine interpretation. Therefore it is somewhat pointless to argue about whether we are in one or another of these universes. In fact, I would claim that we are in all of these, at least all that are not logically inconsistent or incompatible with the data. That is, our conscious experience spans multiple universes; we are instantiated equally and equivalently in universes which have different laws of physics, but where the differences are so subtle that they have no effect on our observations. You may already be living in all of these universes, Hal, but I would rather stay in mine, for the moment, if you don't mind! Even in a "plenitudinal" or "platitudinal" metaverse in which all the conceivable laws of physics are realized somwhere, there is no call for all the interpretations of quantum mechanics to be "true"! Interpretations of QM are not laws, much less mathematical structures in the sense of Tegmarks Level 4! In your Metaverse, let us call it the HAL-metaverse, I agree there is no much point in discussing which interpretation is correct but it is equally pointless to carry on any scientific arguments or experiments given that complete pluralism reigns!!! I am sure all those democrats running for office will be happy to know they will all be elected in some world... It may be that at some future time, we can perform an experiment which will provide evidence to eliminate or confirm some of these possible QM interpretations. At that time, our consciousness will differentiate, and we will go on in each of the separate universes, with separate consciousness. It is still useful to discuss whether the various interpretations work at all, and whether they are in fact compatible with our experimental results. But to go beyond that and to try to determine which one is "true" is, according to the multiverse philosophy, an empty exercise. All are true; all are instantiated in the multiverse, and we live in all of them. Hal Tell me:If we live in all of them can we pick the cheapest one? Than I would be interested... -Joao -- Joao Pedro Leao ::: [EMAIL PROTECTED] Harvard-Smithsonian Center for Astrophysics 1815 Massachussetts Av. , Cambridge MA 02140 Work Phone: (617)-496-7990 extension 124 Cell-Phone: (617)-817-1800 -- "All generalizations are abusive (specially this one!)" ---
Re: spooky action at a distance
As I recall, Tegmark also said that there would be classically deterministic universes, with no quantum physics at all. So, it seems that an SAS in such a universe would have no reason to surmise a Level III multiverse. It makes you wonder what things we SASs don't know about, that might have led us to surmise still further Levels of the multiverse. Or conceivably could an SAS in a classically deterministic universe surmise something like a Level III multiverse, from considerations of the (ontological?) status(es) of terms of alternatives of the types studied logic (e.g. multivalue logic), mathematical theory of probability, (pure) mathematical theory of information -- such disciplines as consider structures of alternatives that exhaust the possibilities (a la p or ~p)? (Note: These fields seem distinguishable from other areas of math also by being concerned with drawing what tend to be irreversibly deductive conclusions -- I mean as distinguished from the reversible equational reasonings which preserve information help allow a same mathematical object to be pursued applied under quite diverse aspects -- so, if there is an area of variational math or optimization which has this irreversible deductions tendency, it should probably be included among them, but I'm not a mathematician don't know whether there is.). - Benjamin Udell - Original Message - From: Hal Finney [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Thursday, November 13, 2003 12:30 PM Subject: Re: spooky action at a distance This list is dedicated to exploring the implications of the prospect that all universes exist. According to this principle, universes exist with all possible laws of physics. It follows that universes exist which follow the MWI; and universes exist where only one branch is real and where the other branches are eliminated. Universes exist where the transactional interpretation is true, and where Penrose's objective reduction happens. I'm tempted to even say that universes exist where the Copenhagen interpretation is true, but that seems to be more a refusal to ask questions than a genuine interpretation. Therefore it is somewhat pointless to argue about whether we are in one or another of these universes. In fact, I would claim that we are in all of these, at least all that are not logically inconsistent or incompatible with the data. That is, our conscious experience spans multiple universes; we are instantiated equally and equivalently in universes which have different laws of physics, but where the differences are so subtle that they have no effect on our observations. It may be that at some future time, we can perform an experiment which will provide evidence to eliminate or confirm some of these possible QM interpretations. At that time, our consciousness will differentiate, and we will go on in each of the separate universes, with separate consciousness. It is still useful to discuss whether the various interpretations work at all, and whether they are in fact compatible with our experimental results. But to go beyond that and to try to determine which one is true is, according to the multiverse philosophy, an empty exercise. All are true; all are instantiated in the multiverse, and we live in all of them. Hal
Re: spooky action at a distance
CORRECTION -- sorry -- Ben Udell. As I recall, Tegmark also said that there would be classically deterministic universes, with no quantum physics at all. So, it seems that an SAS in such a universe would have no reason to surmise a Level III multiverse. It makes you wonder what things we SASs don't know about, that might have led us to surmise still further Levels of the multiverse. Or conceivably could an SAS in a classically deterministic universe surmise something like a Level III multiverse, from considerations of the (ontological?) status(es) of terms of alternatives, alternatives of the types studied in logic (e.g. multivalue logic), mathematical theory of probability, (pure) mathematical theory of information -- such disciplines as consider structures of alternatives that exhaust the possibilities (a la p or ~p)? (Note: These fields seem distinguishable from other areas of math also by being concerned with drawing what tend to be irreversibly deductive conclusions -- I mean as distinguished from the reversible equational reasonings which preserve information help allow a same mathematical object to be pursued applied under quite diverse aspects -- so, if there is an area of variational math or optimization which has this irreversible deductions tendency, it should probably be included among them, but I'm not a mathematician don't know whether there is.). - Benjamin Udell - Original Message - From: Hal Finney [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Thursday, November 13, 2003 12:30 PM Subject: Re: spooky action at a distance This list is dedicated to exploring the implications of the prospect that all universes exist. According to this principle, universes exist with all possible laws of physics. It follows that universes exist which follow the MWI; and universes exist where only one branch is real and where the other branches are eliminated. Universes exist where the transactional interpretation is true, and where Penrose's objective reduction happens. I'm tempted to even say that universes exist where the Copenhagen interpretation is true, but that seems to be more a refusal to ask questions than a genuine interpretation. Therefore it is somewhat pointless to argue about whether we are in one or another of these universes. In fact, I would claim that we are in all of these, at least all that are not logically inconsistent or incompatible with the data. That is, our conscious experience spans multiple universes; we are instantiated equally and equivalently in universes which have different laws of physics, but where the differences are so subtle that they have no effect on our observations. It may be that at some future time, we can perform an experiment which will provide evidence to eliminate or confirm some of these possible QM interpretations. At that time, our consciousness will differentiate, and we will go on in each of the separate universes, with separate consciousness. It is still useful to discuss whether the various interpretations work at all, and whether they are in fact compatible with our experimental results. But to go beyond that and to try to determine which one is true is, according to the multiverse philosophy, an empty exercise. All are true; all are instantiated in the multiverse, and we live in all of them. Hal
Re: spooky action at a distance
Benjamin Udell, [EMAIL PROTECTED], writes: As I recall, Tegmark also said that there would be classically deterministic universes, with no quantum physics at all. So, it seems that an SAS in such a universe would have no reason to surmise a Level III multiverse. It makes you wonder what things we SASs don't know about, that might have led us to surmise still further Levels of the multiverse. That's a good point. Historically, scientists initially assumed a deterministic universe (which is why we call it classical!). It was only when indeterminism was forced on them by the bizarre experimental results in the late 19th and early 20th centuries that they changed their minds. I don't know if any philosophers of earlier eras conceived of anything like the MWI. Or conceivably could an SAS in a classically deterministic universe surmise something like a Level III multiverse, from considerations of the (ontological?) status(es) of terms of alternatives, alternatives of the types studied in logic (e.g. multivalue logic), mathematical theory of probability, (pure) mathematical theory of information -- such disciplines as consider structures of alternatives that exhaust the possibilities (a la p or ~p)? I think so; in principle some mathematician could explore the implications of the Schrodinger equation (or whatever mathematics turns out to underly our universe), just as we play with toy universes such as Conway's Life. Wolfram has spent years looking at cellular automata to try to see which ones might produce structure and, by implication, life and SAS's. Our tools are not strong enough to get very far with this, but in the future we might even simulate universes far enough elong that life evolves. And someone in a deterministic universe might eventually simulate our own. In fact we could be living there, in a sense. And it is possible, as you suggest above, that we might eventually discover or invent or create universes which have other forms of multiplicity than either the everything-exists (level 4) multiverse or the MWI (level 3). For example, one could imagine a universe where you could create a split any time you wanted to, and talk to the other branch for a short time, enough to be convinced that it is real, before the two branches are irrevocably separated. That would be the have you cake and eat it too universe. Hal
RE: spooky action at a distance
I'm sure we all agree that QM on its own is not the full story. Ditto with GR. Has anyone claimed to come up with a self consistent, complete description of our universe? Saying that all universes exist which follow the MWI is putting too much faith in a partial (and perhaps merely approximate) model of our universe. With your line of reasoning you would say that people's consciousness differentiated at the time QM displaced classical physics. Surely QM was waiting to be discovered? For this reason, I think it is important that we look for better ontologies of QM. Even though these different interpretations make the same predictions today, they affect the way we reason about things - and our ability to extend the model in new directions. Anton Zeilinger has brought up the example of Einstein's publication of special relativity which provided the missing ontology - when most of the equations had already been provided by Lorentz, Fitzgerald etc. There is no doubt that this ontology had enormous benefit. - David -Original Message- From: Hal Finney [mailto:[EMAIL PROTECTED] Sent: Friday, 14 November 2003 1:31 AM To: [EMAIL PROTECTED] Subject: Re: spooky action at a distance This list is dedicated to exploring the implications of the prospect that all universes exist. According to this principle, universes exist with all possible laws of physics. It follows that universes exist which follow the MWI; and universes exist where only one branch is real and where the other branches are eliminated. Universes exist where the transactional interpretation is true, and where Penrose's objective reduction happens. I'm tempted to even say that universes exist where the Copenhagen interpretation is true, but that seems to be more a refusal to ask questions than a genuine interpretation. Therefore it is somewhat pointless to argue about whether we are in one or another of these universes. In fact, I would claim that we are in all of these, at least all that are not logically inconsistent or incompatible with the data. That is, our conscious experience spans multiple universes; we are instantiated equally and equivalently in universes which have different laws of physics, but where the differences are so subtle that they have no effect on our observations. It may be that at some future time, we can perform an experiment which will provide evidence to eliminate or confirm some of these possible QM interpretations. At that time, our consciousness will differentiate, and we will go on in each of the separate universes, with separate consciousness. It is still useful to discuss whether the various interpretations work at all, and whether they are in fact compatible with our experimental results. But to go beyond that and to try to determine which one is true is, according to the multiverse philosophy, an empty exercise. All are true; all are instantiated in the multiverse, and we live in all of them. Hal
RE: spooky action at a distance
By small I meant small number of particles. - David -Original Message- From: scerir [mailto:[EMAIL PROTECTED] Sent: Thursday, 13 November 2003 6:06 PM To: [EMAIL PROTECTED] Subject: Re: spooky action at a distance David Barrett-Lennard According to QM, in small systems evolving according to the Hamiltonian, time certainly exists but there is no arrow of time within the scope of the experiment. In such small systems we can run the movie backwards and everything looks normal. Yes, but how small? Because now they perform experiments over large distance. Not just the 45 meters of the old Jasin interferometer. But 10 km. or even 100 km. And still they find interferences. (Of course those beams are correlated and well protected!). In general the argument 'contra' the transactional interpretation is this one below (in this case, by Anton Zeilinger). But I do not know well enough Cramer's interpretation. So I cannot judge. In the Transactional Interpretation the state vector is considered to be a real physical wave emitted as an offer wave based on the preparation procedure of the experiment. The interaction then comes to a close through the emission of the confirmation wave by what is usually called the collapse of the wave function. The quantum particle, e.g. the photon, electron etc., is then considered to be identical with the finished transaction. It is fundamental to that interpretation that where the closure of the transaction takes place is an unexplained input to the process.
Re: spooky action at a distance
Norman Samish wrote: I've been reading about "spooky action at a distance" at http://www.ncsu.edu/felder-public/kenny/papers/bell.html and several other sites. "Spooky action-at-a-distance" is a catchy but misleading description of EPR-Bell type quantum correlations because there is no effective "action" or signalling passing between the two correllated particles or subsystems involved. "Passion-at-a-distance" is an entirely better description of what takes place: a certain statistical resilience between the values of time-like separated subsystems that remain bound in an entangled state... I'm told that non-locality is a phenomenon that is proven. A review of experiments makes it clear that "spooky action at a distance is part of nature." But doesn't this violate the rule that nothing can travel faster than the speed of light? Well, no, it does not - because of a technicality. Not a exactly a "technicality" in the sense you intend it. The rule is that "no signal can travel faster than c"but there is no signalling involved in the reservation of these correlations. Nevertheless, how might one of "entangled" particles, even though separated by light-years, react instantaneously to a measurement done to its sibling? I've seen no hypothesis. The answer is, apparently, one of many Quantum Mysteries. It is only a mystery if you try and reason classically about it. Quantum mechanics makes this type of correlation a more "natural" thing than, say, the causal succession of events linking action to effect. It is this later one that needs to be explained from the Qunatum Mechanical point-of-view. This is unsatisfying. I would like to hear speculations on non-locality. We are told that string theory needs 11 dimensions - could it be, for example, that there is another dimension in which the entangled particles are adjacent to each other? The type of unsatisfaction that you display can be mended with what are called "non-local hidden-variable theories", which unfortunately must invoke other "unpleasantnesses", such as non-local potentials. Other dimensions may seem an intuitively appealing option out of this connundrum but not the kind of extra dimensions invoked by string theory, which must be compactified (="curled up locally")at some point. Large extra dimensions may be more accommodating but somehow that has not been tried as of yet. If the EPR correlations were "actions" rather than "passions" that would be somewhat easier to implement. But it is hard to understand why these extra dimensions would have been constrained in this particular way... Norman Kindly, -Joao -- Joao Pedro Leao ::: [EMAIL PROTECTED] Harvard-Smithsonian Center for Astrophysics 1815 Massachussetts Av. , Cambridge MA 02140 Work Phone: (617)-496-7990 extension 124 Cell-Phone: (617)-817-1800 -- "All generalizations are abusive (specially this one!)" ---
Re: spooky action at a distance
We are told that string theory needs 11 dimensions - could it be, for example, that there is another dimension in which the entangled particles are adjacent to each other? Norman Of course here we are speaking of spooky actions as possible *physical* effects, involving, or not, superluminal informations. So we are not speaking of spooky actions as *epistemological* effects (such as Rothstein, Page, Hardy, Peres, Cerf, Mermin, etc. described many times, and also Bohr, but in obscure terms). An interesting way of accepting *physical* non-locality (better, non-separability) has been proposed by Ne'eman [Found. Physics, 16, (1986), 361]. Ne'eman assumes that gauge theories should be regarded as geometric constructs, that is to say fiber bundle manifolds. One can construct a strongly correlated manifold (called principal fiber bundle) in which a structure group have global characteristic, such that operators are non-localized. Ne'eman says that what makes QM so weird is just our habit to visualize events in the usual space, and not in abstract spaces. Another possibility is that one suggested by Feynman [Int. J. Theor. Phys., 21, (1982), 467] and Mueckenheim [Phys. Rep., 133, (1986), 337] and Scully, Walther, and Schleich (1994), that is to say the 'negative probability solution'. This solution, imo, is something in between the *physical* and the *epistemological*. But it is not new. Dirac [Proc. Roy. Soc., 180A, (1941), 1] wrote Thus negative energies and probabilities should be considered simply as things which do not appear in experimental results. And of course there is also Costa de Beauregard's theory about retrocausation, and many more similar models.
Re: spooky action at a distance
Norman Samish: This is unsatisfying. Yes. It is also called the conspiracy between QM and SR. I would like to hear speculations on non-locality. There are many in QM. I mean many non-localities. In example the famous 'collapse', the 'Aharonov-Bohm' effect (also with neutral particles), the EPR non-separability, and there are non-localities involving time (interferences in time, quantum beats, Franson interferometers, etc.), and also effects, like the 'delayed choice', possibly related to the 'block universe', or 'holism', or 'wholeness', or time-like non separability. And there are also 'delocalizations'(non just superpositions) in the 'weak measurement' approach (measurements which give little information). And there are - how can I say? - topological (?) non-localities too. Imagine a two-slit apparatus. You can also think this two-slit apparatus as a 'superposizion' of two *physical* complementary *pieces*. Not just hole 1 + hole 2. But something like mattervoid void + matter mattervoid of course with the right measures and shapes! Now imagine to locate one piece in a location and the other piece in another location. You get a sort of 'non-local' two-slit apparatus. Now if a photon beam goes through one of those pieces above and a correlated photon beam goes through the other piece you get an interference effect, due to the 'non-local' two-slit apparatus. Of course all the above are not 'speculations' about non-locality but performed experiments, showing several faces of non-locality. For useful speculations you can also read the Bohrian and instrumentalist Asher Peres (no physical collapse) and the 'philosopher' Suarez (a-temporal quantum)
Re: spooky action at a distance
forgot the links :-) Antoine Suarez http://arxiv.org/abs/quant-ph/0311004 Asher Peres http://arxiv.org/abs/quant-ph/0310010
