Re: Multiverse/fungibility

On 24 Mar 2013, at 17:55, urmenonhigh <urmenonhigh-/[email protected]> 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