On Sunday, December 3, 2017 at 2:07:17 PM UTC, Bruno Marchal wrote: > > > On 01 Dec 2017, at 00:20, [email protected] <javascript:> 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* > > 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] <javascript:>. > To post to this group, send email to [email protected] > <javascript:>. > 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.
