Hi Nick,

On 23 Dec 2009, at 01:55, Nick Prince wrote:

> My background is in mathematical physics but I am trying to read up a
> bit of this new stuff as I go along.  Thank you for being patient with
> me.
> However, I think you have confirmed some things - let me know if any
> of these is fundamentally wrong.
> I want to put aside the platonic arithmetical UD for the moment but
> will come back to that.
> Just supposing that there is as yet NO UD operating.  Comp says it is
> possible to build a "concrete" one and in step 7 of your paper you say
> that the UD could provide infinitely  many possible consistent
> extensions of me.  (I am thinking of descriptions of simulated worlds
> with me in them  as  bit strings)  I quote you from the sane paper:
> "Then, it follows from the six preceding steps that it will generate
> all possible Turing machine states, infinitely often (why?), which (by
> comp) includes all your virtual reconstitutions corresponding to
> (hopefully) consistent extensions of yourself, in all possible
> (locally) emulable environments or computational histories. And this,
> with comp, even in the case you consider that your ‘‘generalised
> brain’’ (the ‘‘whatever’’ which is needed to be emulated by a  DU
> digital body/brain to survive) is the whole Milky Way galaxy. And we
> don’t need any Science Fiction like devices to make this concrete, if
> we make exception of the robust universe."
> Actually the kind of "teleportation" I am interested in, for reasons
> as you will see is the usual simple one which takes us from moment to
> moment.  I am being teleported into the next observer moment all the
> time ( if this is because I'm already being computed by a UD then as I
> say lets just ignore this possibility for now as you did in your
> paper).  If someone is blown to bits, then we have lost the chance to
> make a decent copy of them.  However, Once the “concrete” UD is run
> then it  computes all possible futures for all possible virtual
> extensions. Then there will be  an (infinitely many) extension(s) for
> the blown to bits person.  The blowing to bits is just the equivalent
> of the annhiallation part of your earlier steps.  So here we have the
> basic quantum immortality thing coming in again.

OK. TO be sure it is the "older" comp immortality, and it is an open  
problem if the quantum interference and immortality *is* a result of  
the comp interference and immortality. It looks like that, and up to  
now the math confirms formally the resemblance.

> However, if  it
> takes the UD a long time to generate sufficient extensions then the
> delay will be considerable before the blown to bits man continues
> consciousness - although to him it will seem instantaneous. From 3d
> person, well - they see the delay.

Yes. (would they live long enough)

> Now is the interesting bit.  Because this future UD creates all
> possible extensions of all possible states of the blown to bits man
> then what’s to stop him finding continuation with a consistent
> extension prior to the blowing up!

Sure. (that happens all the time, and that's why we have to justify  
the apparent stable laws from that).

> In other words every observer
> moment of his life (not just the one just before being blown up - but
> any  of them) could just as easily be followed by a suitable one in
> the virtual UD rather than one in the initial run of the universe.

Absolutely. Would a real *singular* concrete material universe exist,  
the probability to stay in that universe is zero.

> In
> conclusion,  from our ist person point of view we do not know whether
> our next observer moment will occur in the “real” universe or in a
> simulated one- this is 1-indeterminacy again.  If the UD can simulate
> all possible observer moments then it will have those associated with
> our very first sense of consciousness and hence we will have very
> quickly slipped, without knowing it, into the UD’s virtual world.  We
> never noticed any delay of course but there may have been a huge time
> difference assuming Russell’s time postulate has meaning here!

It has meaning, because it is neither physical time nor subjective  
time, but just the natural numbers with the successor operation, or  
the number of steps taken by the UD to reach the computational states.  
And the step 8 explains why, even if a real physical time exists, it  
just cannot compete with the UD "time".  It is no more than 0, 1, 2,  
3, ... or a set having a computable bijection with N.

> Hence if a UD is possible,

Well, the mathematical existence of the UD is a logical consequence of  
Church thesis + Turing's theorem in computer science.
There is number U such that for all x and y, phi_U(<x, y>) = phi_x(y).  
U can emulate x on y.
Once you can emulate all x, you can dovetail on all emulations  
possible, including those with oracles in some rings.

> then only the first observer moment(s) -or
> fraction of our conscious lives - were ever lived in a “basic/real”
> universe at all.  The rest is all simulation.  The very existence of a
> UD implies that we are in a simulation as Nick Bostrom has suggested.

Hmm... OK. To be precise, we belong to the infinities of computations  
which differ below our level of substitution, and which are similar  
above. This makes the apparent physical universe a priori NOT Turing  
emulable, or not entirely Turing emulable. But here too, QM confirms  
this: we cannot emulate with a Turing machine a beam of electrons all  
prepared  in the state "up+down" going through an up/down measuring  
apparatus, (without emulating the couple "observer + electron", but  
then we have to classically emulate all the "parallel worlds").

> If they exist platonically then it's all simulation and
> computationalism must be necessary rather than contingent.

OK. And some people are already convinced at that stage. But from a  
logical point of view, a materialist could argue that the seven step  
just shows that if comp is true, then the material universe is just  
not enough big, or not enough robust to implement the running of the  
UD. UDA would just show that materialism would imply our universe is  
The 8th step has two purposes:
- one is showing that the very idea of linking consciousness to  
physical activity is a non sense (despite the strong appeal for such  
an idea, even through comp at first sight),
- and the second is to prevent the above move toward a small universe.  
It shows that with comp, we have to link consciousness, not to  
material physical activity, nor even to any singular universal machine  
computation, but to an infinity of computations, and we have to  
understand that by "computation" we don't mean anything physical. A  
computation is the doing of any universal machine: it is defined by  
the "pure" additive-multiplicative relations between positive  
integers---- or by anything recursively equivalent (as defined in  
theoretical computer science), like the "pure" abstractive-applicative  
relations between the SK-combinators.

> It's a very fumbling line of thinking but it helps me to learn about
> things as I go along.

Cool. Ask any questions. Best,


> On Dec 22, 6:41 pm, Bruno Marchal <marc...@ulb.ac.be> wrote:
>> On 22 Dec 2009, at 18:48, Nick P wrote:
>>>>> Hence by it generating all possible emulations of
>>>>> stages of my life) that I could just as easily experience for my
>>>>> next
>>>>> OM as opposed to the one i would expect to experience on the  
>>>>> current
>>>>> wetware (or whateverware I'm running on if we are in fact already
>>>>> software constructs in a simulation).
>>>> This is weird. From some "absolute", non machine accessible view
>>>> point, you can expect anything. Perhaps.
>>> Assuming that comp is true, then I am not sure why you think it is
>>> weird.  Perhaps I have not explained myself very well.  First of all
>>> please check that my understanding of computationalism is correct.  
>>> By
>>> comp I mean (loosly)that I am assuming that any conscious being  
>>> can be
>>> simulated on some form of computer.  Currently my consciousness is
>>> running on the substrate provided by my brain (hardware).  If the
>>> underlying reality is a much more fundamental (unknown) substrate  
>>> then
>>> fine because this shouldn’t invalidate what I’m saying.  Now If I  
>>> want
>>> to be teleported from Brussels  to Moskow then sufficient  
>>> information
>>> must be coded for my reconstitution later on. This may or may not be
>>> possible because it may turn out that the accessing of my final  
>>> state
>>> in Brussels  destroys my brain before the detailed brain state was
>>> properly copied.  Worse still, suppose someone loses whatever coded
>>> data they did have of me such that the reconstitution becomes
>>> impossible.  What I am trying to say is that if comp is true then at
>>> least I can be confident that some consistent extension of me could
>>> exist in the future provided the robust physical universe you  
>>> speak of
>>> exists such that a suitable UD can actually be built.
>> OK. (and then step 8 explains why the initial universe is no more
>> useful, the arithmetical UD is enough).
>> Also, it is perhaps always one next  1-observer moment, but also
>> always an infinity of 3-observer moments. The UD is terribly
>> redundant, and anything it does, it will repeat it infinitely  
>> often. A
>> compactification of it looks really like the border of the Mandelbrot
>> set. The closer you look, the more complex it appears.
>>  http://www.youtube.com/watch?v=g9iOORSU9zk
>>> Once built then
>>> there would exist at least one consistent extension of me (including
>>> the milky way if this  level of entanglement is to be necessary to
>>> adequately ensure this is the most probable next state of my
>>> consciousness) in the UD which will enable me to experience my next
>>> Observer Moment (after the last one in Brussells).
>> Infinitely one. "in the UD" means "third person describable (in
>> principle) by an outside observers".
>> The probable next 1-moment is a winner among those 3-moments.
>>>> But from your current "here and now" experience, you have to expect
>>>> the most probable relative computation(s) (among all generated in  
>>>> the
>>>> UD going through your current state. You have to take into account
>>>> the
>>>> first person indeterminacy intrinsic to the UD (or elementary
>>>> arithmetic, combinators, etc.).
>>> As pointed out above, somewhere in the UD there WILL be a possible
>>> world (Obs moment) which will best provide the consistent extension
>>> which will give me a sense of continuity with myself at Brussels –  
>>> but
>>> it will be a long way into the future.  This is like your delay
>>> scenario in the SANE paper.
>> Yes, and we cannot be aware of those delays. And the step 8  
>> discharges
>> the need of the "robust concrete universe". A tiny part of
>> arithmetical truth will play that role.
>>>> That is why, if you prefer to use the simpler (and very well
>>>> verified)
>>>> quantum theory, the honest mechanist has to justify it from
>>>> elementary
>>>> arithmetic as seen from the lobian (self-aware in the Gödel-Löb-
>>>> Smullyan sense).
>>>> The needed mathematical restriction on the ideal self-referential
>>>> correct universal machine, makes it possible to see the shadows of
>>>> the
>>>> reason of the "negative probabilities (amplitude).
>>> Hmmm.  I’m really sorry but I’m not understanding this.
>> It is normal. You need to read Gödel 1931, Löb, 1955, Solovay 1976, +
>> Everett 1957. (and the needed books or courses). It is why I separate
>> UDA from AUDA. UDA needs some amount of familiarity with computers,
>> but AUDA needs mathematical logics (which is not very well known).
>>>> We have to justify the stable appearance of the current wetware (or
>>>> whateverware) from our being software constructs (numbers, relative
>>>> variable numbers) executed (in the math sense) by infinitely many
>>>> universal machines.
>>>> In a sense, below our substitution level, all universal machines
>>>> compete.
>>> Yes I think I understand this bit because you are saying that that
>>> there may be (infinitely) many UD’s (already existing for all we
>>> know)?
>> Any UD generates all other UDs, infinitely often.
>> It is really like the mandelbrot set.
>>> I’ll wait for a response before I bring up a complication which is a
>>> spanner in the works which probably you have already pre empted as
>>> indicated by your last sentence.
>>> I am very grateful for your comments.  Forgive me if I am not  
>>> quick at
>>> picking things up but I have swopped fields to some extent and I am
>>> finding this area fascinating but difficult!
>> It is not easy at all. You are welcome,
>> Bruno
>> http://iridia.ulb.ac.be/~marchal/- Hide quoted text -
>> - Show quoted text -
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