Re: Entanglement
On 5/19/2018 8:19 PM, agrayson2...@gmail.com wrote: On Saturday, May 19, 2018 at 3:59:03 PM UTC, Brent wrote: On 5/18/2018 10:53 PM, agrays...@gmail.com wrote: On Saturday, May 19, 2018 at 5:29:33 AM UTC, Brent wrote: On 5/18/2018 10:14 PM, agrays...@gmail.com wrote: *So why don't you draw the obvious inference? If those other worlds don't exist -- which if I can read English has been your passionate position all along -- then quantum measurements in this world, the only world, are statistical and hence NOT reversible in principle. AG* but it is different in each branch of the wave function, so reversing this branch does nothing for the others, and does not restore the original superposition. Thus the process is irreversible in principle (nomologically irreversible -- to reverse violates the laws of physics). *But if those other worlds don't exist, it makes no sense whatever to rely on them to establish irreversible in principle in this world (as distinguished from statistically irreversible or irreversible FAPP). It seems you want to have it both ways; that many worlds really don't exist. but quantum measurements in this world are irreversible in principle due the existence of many worlds. AG* You don't handle uncertainty well, do you. Brent You know, it's not a perfect analogy, but I don't believe that when I pull the one arm bandit with 64 million possible outcomes, that 64 million (minus one) worlds are created, each with an identical copy of me, getting those other outcomes. What do you believe? AG I believe I'll wait for a better theory. One that includes gravity and spacetime and consciousness. Brent I see. But you seem too ready to defend the MWI when it appears to imply irreversible in principle. Or do you accept Bruce's claim that the projection operator implies irreversible in principle? AG Either of them implies irreversiblity. Whether it is "in principle" depends on what principle you invoke, mathematics, practice, ...? MWI puts information in orthogonal subspaces where we exist in copies such that each copy can act only in one subspace and hence cannot put together the information from other subspaces. A projection operator is just a mathematical model of this confinement to one subspace. 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 https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Entanglement
On Saturday, May 19, 2018 at 3:59:03 PM UTC, Brent wrote: > > > > On 5/18/2018 10:53 PM, agrays...@gmail.com wrote: > > > > On Saturday, May 19, 2018 at 5:29:33 AM UTC, Brent wrote: >> >> >> >> On 5/18/2018 10:14 PM, agrays...@gmail.com wrote: >> >> >> *So why don't you draw the obvious inference? If those other worlds don't >> exist -- which if I can read English has been your passionate position all >> along -- then quantum measurements in this world, the only world, are >> statistical and hence NOT reversible in principle. AG* >> >> >>> but it is different in each branch of the wave function, so reversing >>> this branch does nothing for the others, and does not restore the original >>> superposition. Thus the process is irreversible in principle (nomologically >>> irreversible -- to reverse violates the laws of physics). >>> >> >> *But if those other worlds don't exist, it makes no sense whatever to >> rely on them to establish irreversible in principle in this world (as >> distinguished from statistically irreversible or irreversible FAPP). It >> seems you want to have it both ways; that many worlds really don't exist. >> but quantum measurements in this world are irreversible in principle due >> the existence of many worlds. AG* >> >> >> You don't handle uncertainty well, do you. >> >> Brent >> > > You know, it's not a perfect analogy, but I don't believe that when I pull > the one arm bandit with 64 million possible outcomes, that 64 million > (minus one) worlds are created, each with an identical copy of me, getting > those other outcomes. What do you believe? AG > > > I believe I'll wait for a better theory. One that includes gravity and > spacetime and consciousness. > > Brent > I see. But you seem too ready to defend the MWI when it appears to imply irreversible in principle. Or do you accept Bruce's claim that the projection operator implies irreversible in principle? AG -- 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: Entanglement
I believe I'll wait for a better theory. One that includes gravity and spacetime and consciousness. Brent "I saw that far within its depths there lies, by Love together in one volume bound, that which in leaves lies scattered through the world; substance and accident, and modes thereof, fused, as it were, in such a way, that that, whereof I speak, is but One Simple Light." -Dante, Divina Commedia, Paradiso, XXXIII, 85-90 "Nel suo profondo vidi che s'interna, legato con amore in un volume, ciò che per l'universo si squaderna: sustanze e accidenti e lor costume quasi conflati insieme, per tal modo che ciò ch'i' dico è un semplice lume!" -Dante, Divina Commedia, Paradiso, XXXIII, 85-90 -- 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: Entanglement
On 5/18/2018 10:53 PM, agrayson2...@gmail.com wrote: On Saturday, May 19, 2018 at 5:29:33 AM UTC, Brent wrote: On 5/18/2018 10:14 PM, agrays...@gmail.com wrote: *So why don't you draw the obvious inference? If those other worlds don't exist -- which if I can read English has been your passionate position all along -- then quantum measurements in this world, the only world, are statistical and hence NOT reversible in principle. AG* but it is different in each branch of the wave function, so reversing this branch does nothing for the others, and does not restore the original superposition. Thus the process is irreversible in principle (nomologically irreversible -- to reverse violates the laws of physics). *But if those other worlds don't exist, it makes no sense whatever to rely on them to establish irreversible in principle in this world (as distinguished from statistically irreversible or irreversible FAPP). It seems you want to have it both ways; that many worlds really don't exist. but quantum measurements in this world are irreversible in principle due the existence of many worlds. AG* You don't handle uncertainty well, do you. Brent You know, it's not a perfect analogy, but I don't believe that when I pull the one arm bandit with 64 million possible outcomes, that 64 million (minus one) worlds are created, each with an identical copy of me, getting those other outcomes. What do you believe? AG I believe I'll wait for a better theory. One that includes gravity and spacetime and consciousness. 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 https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: Entanglement
On Saturday, May 19, 2018 at 5:14:10 AM UTC, agrays...@gmail.com wrote: > > > > On Friday, May 4, 2018 at 4:22:47 AM UTC, Bruce wrote: >> >> From: >> >> >> On Thursday, May 3, 2018 at 11:52:00 PM UTC, Bruce wrote: >>> >>> From: Brent Meeker >>> >>> >>> On 5/3/2018 4:03 PM, Bruce Kellett wrote: >>> >>> The problem, of course, is that this unitary operator is formed in the >>> multiverse, so to form its inverse we have to have access to the other >>> worlds of the multiverse. And this is impossible because of the linearity >>> of the SE. So although the mathematics of unitary transformations is >>> perfectly reversible, measurements are not reversible in principle in the >>> one world we find ourselves to inhabit. >>> >>> >>> I think we need a more precise term than "in principle" which could >>> confuesed with "mathematically". You really mean reversal is >>> *nomologically* impossible even though it's *mathematically* >>> reversible. It's more impossible that *FAPP* or *statistically* but >>> not *logically* impossible. :-) >>> >>> >>> Not doable "in principle" just means that there is no conceivable way in >>> which it could be done. It is not just a matter of difficulty, or that it >>> would take longer than the lifetime of the universe. It is actually >>> impossible. Quantum mechanics does not imply that all things that are >>> logically possible are nomologically possible, or could be achieved in >>> practice. That is why Saibal's claim that there exists a unitary operator >>> that does what he wants is rather empty -- there are an infinite number of >>> unitary operators that are not realizable in practice. And this limitation >>> is a limitation "in principle". >>> >>> Bruce >>> >> >> *If you take the view that quantum reality is irreducibly random, it >> MEANS that there is no process in nature that can explain how a random >> event could occur, for if such a process existed, it would contradict >> "irreducibly random". Bruce seems to take the view that all measurements >> are irreversible in principle. That might not be true. For example, suppose >> the temperature of a system decreases. Isn't it hypothetically possible to >> imagine a time reversal of all the IR photons which caused the cooling, to >> reunite with the original system and restore the previous higher >> temperature? If so, the cooling process in this example is reversible >> albeit hugely improbable -- which I refer to as statistically reversible, >> or irreversible FAPP. I think Bruce can give an example of a measurement >> which is time irreversible in principle, that is, impossible to time >> reverse. AG* >> >> >> Classical situations involving the second law of thermodynamics >> (increasing entropy) are reversible, though reversal is improbable because >> the second law is statistical. The situation in quantum mechanics is >> different when we have a measurement with several different possible >> outcomes. In MWI these outcomes are in different branches, and we cannot >> reach into these worlds to reverse things there. Decoherence in this branch >> is certainly statistical, and so it is in all branches, >> > > *So why don't you draw the obvious inference? If those other worlds don't > exist -- which if I can read English has been your passionate position all > along -- then quantum measurements in this world, the only world, are > statistical and hence NOT reversible in principle. AG* > > >> but it is different in each branch of the wave function, so reversing >> this branch does nothing for the others, and does not restore the original >> superposition. Thus the process is irreversible in principle (nomologically >> irreversible -- to reverse violates the laws of physics). >> > > > *But if those other worlds don't exist, it makes no sense whatever to rely > on them to establish irreversible in principle in this world (as > distinguished from statistically irreversible or irreversible FAPP). It > seems you want to have it both ways; that many worlds really don't exist. > but quantum measurements in this world are irreversible in principle due > the existence of many worlds. AG* > *I suppose you could adopt the view that the other "branches" aren't other worlds, but are similarly inaccessible once a measurement occurs. But then you still have the unsolved problem of explaining what exactly is lost, and how, when a measurement occurs. Appealing to the properties of the projection operator is not enough IMO since it might just be, and probably is, a bookkeeping device in the CI to deal with the apparent collapse of the wf. That's what I meant earlier when I wrote that appealing to the properties of the projection operator is not a strong (or indeed any) argument for irreversibility in principle, insofar as it's really just a restatement of what you believe. AG * > >> Bruce >> > -- You received this message because you are subscribed to the Google Groups "Everyth
