On Sunday, December 3, 2017 at 5:21:33 PM UTC, [email protected] wrote: > > > > On Sunday, December 3, 2017 at 2:07:17 PM UTC, Bruno Marchal wrote: >> >> >> On 01 Dec 2017, at 00:20, [email protected] wrote: >> >> >> >> On Thursday, November 30, 2017 at 11:16:07 PM UTC, [email protected] >> wrote: >>> >>> >>> >>> On Thursday, November 30, 2017 at 9:47:37 PM UTC, Bruce wrote: >>>> >>>> On 30/11/2017 10:59 pm, [email protected] wrote: >>>> >>>> On Thursday, November 30, 2017 at 11:42:51 AM UTC, Bruce wrote: >>>>> >>>>> On 30/11/2017 10:32 pm, [email protected] wrote: >>>>> >>>>> On Thursday, November 30, 2017 at 4:08:20 AM UTC-7, Bruce wrote: >>>>>> >>>>>> On 30/11/2017 9:53 pm, [email protected] wrote: >>>>>> >>>>>> On Wednesday, November 29, 2017 at 10:40:36 PM UTC, Bruce wrote: >>>>>> >>>>>> On 30/11/2017 5:31 am, John Clark wrote: >>>>>> >>>>>> On Tue, Nov 28, 2017 at 10:59 PM, Bruce Kellett < >>>>>> [email protected]> wrote: >>>>>> >>>>>> >>>>>> > >>>>>> I see no reason all the Everett worlds have the same physics, >>>>>> >>>>>> >>>>>> > >>>>>> Everettian worlds follow from assuming that the Schrödinger equation >>>>>> applies everywhere without exception, so that all physical evolution is >>>>>> unitary. A change in the underlying physics -- such as a change in the >>>>>> value of fundamental constants, Planck's constant or Newton's constant >>>>>> for >>>>>> example -- would not be unitary, so cannot occur in MWI. >>>>>> >>>>>> >>>>>> >>>>>> Why can't it be unitary?? Show me why if >>>>>> >>>>>> Newton's constant had any value other than >>>>>> >>>>>> 6.754* 10^-11 m3 kg^−1 s^−2 >>>>>> >>>>>> the sum of all quantum probabilities would no longer add up to >>>>>> exactly 1. If you can really do that then you've just derived Newton's >>>>>> constant directly from first principles and you should but a ticket to >>>>>> Stockholm right now because you're absolutely certain to win the next >>>>>> nobel >>>>>> Prize. >>>>>> >>>>>> Although unitarity does mean that probabilities always sum to unity, >>>>>>> that is a consequence of unitary evolution, not a definition of it. A >>>>>>> unitary transformation is one that can be reversed: so the unitary >>>>>>> operator >>>>>>> U can be written as exp(-iH), for example, and the complex conjugate >>>>>>> (or >>>>>>> the adjoint for hermitian operators) is the inverse transformation. >>>>>>> >>>>>> *Considering the evolution of the wf, if there exists a DE that >>>>>>> describes the collapse process, would it necessarily be nonlinear? Is >>>>>>> nonlinear a problem; that is, what is the downside to nonlinear? How >>>>>>> would >>>>>>> it effect the issue of hidden variables? TIA, AG * >>>>>>> >>>>>> >>>>> Collapse would be non-linear and non-unitary -- >>>>> intrinsically non-reversible. This is not necessarily a problem since >>>>> there >>>>> are plenty of non-linearities in physics. It has nothing to do with >>>>> hidden >>>>> variables. >>>>> >>>>> *Why would it be non linear? Brent claimed (on page 1)* >>>>> >>>>> >>>>> Page 1 of what? >>>>> >>>> >>>> >>>> *On Google it's organized as pages, now up to page 15. Go to top of >>>> thread and read second message by Brent. AG * >>>> >>>>> >>>>> * that if the QM could be made deterministic, say by a DE that >>>>> described collapse, it would imply awful consequences, such as the future >>>>> determining the past.* >>>>> >>>>> >>>>> No, it wouldn't imply that. >>>>> >>>>> * Would making QM into a deterministic theory imply an inconsistency >>>>> in the postulates of QM? TIA, AG* >>>>> >>>>> >>>>> QM in MWI is deterministic. Bohm's theory is deterministic, though >>>>> expressly non-local. Determinism is not really an issue. One world >>>>> theories >>>>> are intrinsically random, not deterministic. >>>>> >>>> >>>> *How can MWI be deterministic if it can't tell us what outcome we will >>>> observe in this world, or any other? AG* >>>> >>>> >>>> Because MWI says that all outcomes are realized, each in a separate >>>> world. Apparent randomness comes about because we don't know which world >>>> we >>>> will end up in (though we actually end up in all the worlds, so we, or our >>>> duplicates, observe all possible outcomes). >>>> >>>> Bruce >>>> >>> >> >> >> >> >> >> *OK. I wouldn't use "deterministic" to describe that situation, but >> that's neither here nor there. More important is Brent's reply to my >> question which started this discussion thread. He stated that a >> deterministic ONE WORLD version of QM would have dire effects, such as the >> future influencing the past. His exact words are in the 2nd message in this >> discussion. You don't seem to share this view. I know that Bohm developed a >> deterministic version of QM which is expressly non-local and not covariant. >> I don't think it's what Brent was referring to. Also, I noticed that Bruno, >> our resident enthusiast of arithmetic as the solution to all enigmas,* >> >> >> That is very elegant mathematically, but I am not necessarily enthusiast >> about this, and sometimes I call Mechanism terrifying thinking. At the >> first sight it entails that agonies are infinite, as your consciousness >> survives in the closest environment/computations logically possible, and >> there are an infinity of them. Nothing funny there. >> >> The point is that it is a logical consequence of what is perhaps the >> oldest hypothesis in science: that life is a mechanism. Of course, the >> infinite agony might end ... because things are more subtle when doing the >> math, so no need to despair prematurely of mechanism either. Computer >> science suggests some "jumps", which makes the prediction there very >> difficult, but all in all, sometimes I wish death is an end. That is made >> impossible with mechanism, as Descartes and many others intuited correctly. >> > > *By "mechanism", I see you mean "materialism", the theory that life and > consciousness can be explained by the motion and interaction of atoms and > molecules. I see no evidence that death is not implied by materialism. I've > experienced the passing away of many, and its permanence is very > convincing. Moreover, cut a nerve and sensation ceases; be injected with an > anesthetic and one loses consciousness in a matter of seconds. All pretty > convincing that materialism is on the right track, as opposed to > speculation and fantasies about mathematics and arithmetic. AG* >
*Just to be clear; I am not a simplistic materialist. I don't believe there's any "substance" out there. Rather, I think there's a geometry of space which precludes movement in some directions, thus producing the illusion of solidity. AG * > > >> This entails also that, in physics, Everett, who used a rough informal >> form of Mechanism, has done only one half of the work. It remains to >> explain the wave itself phenomenologically. It is not a matter of choice >> but of intellectual rigor. Invoking Primary Matter in a mechanist >> metaphysics is as much wrong than invoking God in the explanation of the >> existence of the universe. It just doesn't work. It is not logically valid. >> That does not mean that God does not exist, but it means that it cannot be >> used in explanation, nor in moral (!). The case of Pirmary Matter is worst, >> it leads to inconsistencies (with even very weak form of Mechanism). >> >> >> >> >> >> * stated that Weinberg showed that a non-linear SWE to explain collapse >> would imply that the laws of thermodynamics are flawed. Is this your >> understanding? * >> >> >> Somehow, yes. Weinberg wrote a paper(*) showing that if we assume that >> the fundamental wave equation is non linear, and still getting the QM >> predictions already verified, then the "parallel universes" can interact >> with each others, and that this possibility entails the need to abandon >> almost all of today's physics. The conclusion is that it is foolish to try >> to solve the conceptual problem of QM by searching a non linear equation in >> place to the usual linear one. Even Bohm add a non linear potential, but >> keep the linear SWE. >> >> Bruno >> >> (*) I don't find my old photocopy, but I am pretty sure you will find it >> (and many related papers) by searching on "weinberg's nonlinear quantum >> mechanics". >> >> >> >> *TIA, 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 [email protected]. >> To post to this group, send email to [email protected]. >> 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 [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
