Hi Bruno

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

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.   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.

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!  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.  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!

Hence if a UD is possible, 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.

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

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



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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