Re: AUH/MWI/UDA (Was: Everything is Just a Memory)

From: Alastair Malcolm <amalcolm.domain.name.hidden>
Date: Sat, 19 Feb 2000 12:01:16 -0000

Bruno,

>From your last post I am getting a better picture of your scheme, but I
would like to ask: your arithmetic platonism seems to provide the ontology
for the computational generation of universes, but does *it* also provide
the digital limitations inherent in computationalism - for example, does it
permit pi? sqrt(2)? the rest of the irrational numbers?

I would still argue that your statement [A] below is not correct without
additional assumptions (since your COMP premises do not preclude the
*logical* possibility that there might happen to be minds in a conventional
physics universe whilst we exist in a COMP-generated universe (note the LHS
specifies AR only as contingently true, not *necessarily* true)), but this
criticism is not so important for me now.

>>> COMP -> [](such a theory [potential Everett rival] comes from COMP) [A]
>>>
>>
>>Does COMP require (I) the objective world (3-world in your terms?) to be
>>quantisable/digitisable, or (II) only to the extent that it is
>>phenomenologically indistinguishable from a continuous world (in the
>>1-world?)?
>
>COMP does not require that the objective world is quantisable/digitisable.
>
>Eventually it follows from comp that there are no 3-worlds. Only 1-worlds
>or 1-plural worlds (shared histories).
>
>And (about II) comp entails that 1-world(s) have continuous features
>(spectra).
>
>>If (II), then we could have a theory describing the world, which, when
>>explicated, specifies a world which includes continua.
>
>Which world ? I don't understand. With comp I don't need to include
>any continuum, I got it for free.

>From [A] I am saying there could be theories in other logically possible
worlds (including those specifying continua) outside the context of COMP,
without invalidating COMP for our world. (Again, this becomes a technical
point about [A] rather than a central criticism.)

>>Then your statement
>>above, without additional assumptions, would be false (that is, we could
>>have a theory whose corresponding world is subjectively indistinguishable
>>from that corresponding to a COMP-derived theory (which might have to be
>>complex and ad-hoc in order to support this indistinguishability), but
which
>>in its explicated form is not itself precisely derivable from COMP).
>
>How could "the" theory derived from COMP be ad hoc?
>If it is derived it cannot be ad hoc. No theorem can be ad hoc. You
>don't choose theorem.
>What do you mean exactly by the "explicated form" of a (world?)-theory?

I mean ad hoc in the sense of being a contrived choice out of all possible
theories in order to satisfy a specific requirement. One example would be
the ancient theory whereby angels were responsible for pushing planets on
their particular trajectories in the sky.

An explicated theory is simply an explicit specification of its constituent
theorems. Example: the circumference of a circle of radius 1 unit is 2*pi
units - presumably COMP could not precisely generate the circumference
specified by this theorem.

>>> (COMP + MWI) -> [](COMP -> MWI) [B]
>>
>>For the LHS, do you mean (a) MWI is true in the sense of being
*consistent*
>>in our world (but not necessarily actually *applying* to our world) or (b)
>>MWI is actualy applicable to our world?
>
>I mean MWI is actualy applicable to our many-worlds (many-histories).
>The expression "our world" could be misleading here. Thus I mean (a).
>
>>If (a), I agree, but can't see what point you are trying to make.
>
>The point is that COMP *is* the theory (the TOE, in a large sense of
>"theory"). If comp -> MWI', and MWI', MWI, then empirical confirmations
>of MWI would weaken or refute comp, and empirical evidence for MWI'
>would provide evidence for comp.

I am afraid I find your comments rather confusing and contradictory. If, as
you say, MWI is applicable to our (many) worlds, then (b) should hold, not
(a). For "comp -> MWI', and MWI', MWI ", then you seem to be changing the
meaning of "MWI' " (the first mention implies *application* to our world -
try using something like A(MWI')? the second merely that it is consistent -
try C(MWI')?). But I agree that there is enormous scope for confusion here
between the worlds of MWI, of COMP, and of [].

Alastair
Received on Sat Feb 19 2000 - 04:09:40 PST