Re: Multiverse/fungibility

On 25 Mar 2013, at 02:50, Brett Hall wrote:

> On 25/03/2013, at 11:57, "urmenonhigh" <urmenonhigh-/[email protected]> wrote:
>
> >
> >
> > --- In [email protected], Alan Forrester  
> <alanmichaelforrester@...> wrote:
> > >
> > > On 24 Mar 2013, at 17:55, urmenonhigh <urmenonhigh@...> wrote:
> > >
> > > > --- In [email protected], Brett Hall  
> <brhalluk@> wrote:
> > > >>
> > > >> On 08/03/2013, at 5:20, "hibbsa" <hibbsa@> wrote:
> > > >>
> > > >>>
> > > >>> On BoI someone recommended this book
> > > >>> http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780199546961.0 
> \
> > > >>> 01.0001/acprof-9780199546961
> > > >>> <http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780199546961 
> .\
> > > >>> 001.0001/acprof-9780199546961>
> > > >>>
> > > >>> I looked at the chapters and didn't see anything about  fungibility...and
> > > >>> I guess Deutsch.
> > > >>>
> > > >>> I don't think MWI is correct, but....what do I do see is   that his -
> > > >>> Deutsch's - realization about fungibility is the most   important and
> > > >>> reasoned idea within MWI. You have to have it. You can't  explain the
> > > >>> wave-function as it is before it is interupted without  fungibility.
> > > >>>
> > > >>> Not wanting to teach people to suck eggs but clearly, if you go down a
> > > >>> thousand metres into granite, all on your own, and set up a   little
> > > >>> science lab and do the two-slit experiment. If you are   seeing an
> > > >>> interuption, and if the explanation is going to be MWI-  esque, then there
> > > >>> has to be a multiverse of other worlds, identical enough,   that someone
> > > >>> just like you, just went 1000 metres into granite with the   same just
> > > >>> the same kit and just the same ideas...such that he just did   that same
> > > >>> experiment in the same instance such that you all get the   wave function.
> > > >>>
> > > >>
> > > >> I think some of the language there is loose, but yes. That's   the idea. There exist copies of you in other universes. Right now   there are fungible copies of you which will become differentiated   from you because of choices you make and because quantum events differentiate universes in which copies of you exist.
> > > >
> > > > The above use of "fungible" lacks precision when attempting to   discuss any individual living sentient being. The ongoing acceptance   of this imprecision over the past twenty or thirty years has always   resulted in a strange and useless conundrum when attempting to apply   MWI to living sentient entities.
> > > > The quantum divergence would be so severe at the level of a  central nervous system (CNS) that any suggestion that fungible  copies of an individual's CNS exist is absurd. Any scientific  discussion of MWI that implies quantum copies of sentient beings are  fungible is philosophically meaningless.
> > > > Imagine a science fiction story in which a quantum copy of an  individual is held accountable for the transgressions of another  quantum copy because they were considered "fungible". Obviously an  objective interpretation of quantum behavior at the probabilistic  level is of limited scope when attempting to completely understand a  universe in which living sentient beings actually exist and whose  essential property is what they subjectively remember from a moment  ago.
> > >
> > >
> > > Two objects that are fungible are "identical in literally every  way except that there are two of them." (BoI, p. 265) Suppose there  are two distinct versions of Jim, one of which has done something  bad like murder Pete. The version of Jim that murdered Pete is not  the same as the version of Jim that did not murder Pete, so they are  not fungible.
> > >
> > > However, there are multiple fungible instances of each version  of Jim that is not fungible with other versions of Jim. Only  instances of a system that are fungible with one another can undergo  quantum interference. Many of the electrons, protons and other particles that compose a particular version of Jim are fungible and interfere with one another: this is required for the existence of   stable atoms.
> > >
> > > Alan
> > >
> > >
> > While many of the electrons, protons and other particles that  compose a particular version of Jim are fungible and interfere with  one another, they do so within a certain instantiation of "Jim".
> >
> So you admit that all of the electrons, protons and other particles  
> that compose Jim have fungible counterparts, but that together,  
> collectively, there is no fungible counterpart of Jim?
>
> Does this seem to you to be a strict logical contradiction? It does  
> to me.
>
> > This copy of "Jim" is the only Jim in question.
>
> No, it's not. Although...what's the question in question that you're  
> worried about?
>
> There are *copies* of Jim in question that are not Jim. Namely,  
> copies that are *not* fungible.
>
> Jim can have many fungible copies of himself that can differentiate  
> later and cease to be fungible. Copies that *are* fungible, I am not  
> sure about. Are my fungible copies me? I don't know. I don't know  
> that anyone does.
>
> The subjective experience of *being* Jim is not explained by this  
> theory. But then, it's not explained by any theory. The Nature of  
> Subjectivity - consciousness - is an open question.
>
That's not correct. Testable theories exist. It is just that the  
solution does not fit the mood of the time, plausibly since theology  
has been abandoned to political authorities, and progress are ignored.




> But prima facie, I do not see why this concept of fungibility or MWI  
> presents any new problems for philosophical questions about personal  
> identity.
>
> The same old problems apply. How can an objective universe give rise  
> to subjectivity? How are descriptions of how the world is - ever  
> communicate what it's like to actually be that which is described?  
> MWI and fungibility is altogether silent on this.
>
> Every scientific theory is. So what?
>

Scientific theory are silenced on this, because it threats the current  
physicalist paradigm, perhaps.




>
> > Attempting to discuss some other "Jim" in terms of MWI still  obscures the true nature of Jim's personhood
>
> Then tell us...what is the "true nature of Jim's personhood"?
>
> I assert that whatever it is, we don't have a good explanation of it  
> yet.
>
> It has something to do with Jim's ideas. It has something to do with  
> his ability to be a creative agent. It has something to do with his  
> subjective experience of qualia - his consciousness. But I've not  
> yet heard a satisfactory explanation of this that ties it all to  
> physics. As such, some non-existent theory cannot possibly refute  
> well-established physics.
>
> What theory of personhood do you have that would be inconsistent  
> with this view of the MWI?
> > and only leads to confusion and misunderstanding at a  
> philosophical level.
> >
> No. Objections to the MWI lead to confusion and misunderstanding "at  
> a philosophical level". And infact, every other level too. Whatever  
> the "true nature" of personhood turns out to be, my guess is it will  
> be entirely consistent with the MWI. One possibility is that it  
> refutes MWI...though I am not sure how that could be. An infinite  
> number of things could refute MWI, but I'm not worried until one  
> actually does. Meantime, our best theory is that physical reality is  
> explained by MWI.
>
> We don't have a theory of subjective personhood.
>
Computer science provides a theory. In fact it shows that simple (but  
subtle) machines already have a theory.

Bruno