Re: Boltzmann Brains, consciousness and the arrow of time

From: GŁnther Greindl <>
Date: Wed, 07 Jan 2009 22:47:02 +0100

Hi Bruno,

thanks for your comments, I interleave my response.

>> showed a glimpse of the vastness of the UD. And, I agree, _in the limit_
>> there will be an infinite number of histories. So, as we have to also
>> take into account infinite delay, we must take this limit into account
>> and have infinite histories going through a "state" (do I understand you
>> correctly?).
> I guess you were meaning that we have to take into account an infinity
> of arbitrary long (but finite) delays. OK.

Hmm, if we have an infinity of arbitrary long but finite delays, then I
can only see aleph_0 histories (because we never take the "step to
infinity" - we can enumerate all histories.

Only if we take the "step to infinity" (as in Cantor diagonalization,
were we presuppose the complete listing of the reals and the diagonal
does not fit "at infinity") would we get 2^aleph_0 histories - or am I
missing something here?

> I will let you elaborate on this. But note that if my consciousness
> "here and now" supervenes on "past activity",

I will elaborate, but please give me time till February, before I will
not be able to work on this.

>then the comp substitution
> level has to be very "low" indeed.

Yes, very low, that was the idea.

> You will also need a notion of "block
> universe". The comp doctor will have to be able to manipulate
> "time-lines".

No, it is only that he will have to respect "relative embeddings" -
scanning and reconsitution will only be correct regarding _this_
universe and very similar universes, but not with regard to arbitrary
computations in Platonia.

>Remember that even deep, in the sense of Bennett(*) ,
> computer state, can be copied efficiently, so that when you say that
> (*) Bennett, C. H. (1988). Logical Depth and Physical Complexity. In
> Herken, R., editor, /The Universal Turing Machine A Half-Century
> Survey/, pages 227-258. Oxford University Press.

Thanks for the reference, I will consider this...

>> If we assume the whole universe to be an automaton, also it's
>> inhabitants would be "mechanical" =effectively computable of course -
>> but maybe they could then not be duplicated, because, when person A were
>> trying to make a scan of the properties of person B, the universe as a
>> whole would move into different states and make complementary
>> observables - which _could_ be necessary for a duplication - unavailable.
> OK. But your level has to be really at the bottom, not only below the
> quantum level. I recall you that the no-cloning theorem does not prevent
> us to be quantum computer. Right: we cannot say yes to any doctor, yet
> UDA goes through because at the seventh step the "copy need" is
> eliminated. We need only turing emulability, because quantum states,
> although not copyable, are "preparable" (in the quantum "prepare" sense)
> in many exemplaries, and indeed the UD does doevetail on all quantum
> computations.


> I think that your bottom really means: my brain is the whole of reality.

In the sense that the brain state depends on the whole of reality, and
if my brain state (or anyone elses) changes then the whole universe
transitions into a new state, yes, but not in the solipsitic form.

>> This may only work if consciousness supervenes not on "isolated"
>> computations, but only if it is embedded in computations constructing
>> whole universes - but then again, we can't exclude this a priori.
>> And we would still have to consider many worlds, but these would then
>> indeed be _worlds_ and not only OMs with incoming/outgoing histories (of
>> course it would still seem this way from the concrete OM, but with
>> greatly reduced danger of white rabbits) - the laws of physics would not
>> emerge for OM's stranded in the UD deployment but for OM's embedded
>> already in highly structured computational environments - we would only
>> have to take into account duplications of OM's where also whole
>> universes are duplicated.
> Hmmm.... (I guess I use "OM" in a larger sense: those worlds remain
> computable (assuming comp and "bottom-level") and, as such, are
> generated by the UD). I guess I should not!

Could you please clarify what exactly you mean with OM? Maybe this can
clear up some misunderstandings?

> Well, if the quantum laws are derived from comp, then the "platonic
> histories" are manipulable in a sense similar to the use of parallel
> universe (or superposition states) in a quantum computer. Also, the comp
> Platonia need not be greater that Sigma_1 Arithmetical truth (which is
> a tiny part of arithmetical truth, itself a tiny part of mathematical
> truth): the deployment is really just the constructives consequences of
> 0, succession, addition and multiplication. And it is big as seen and
> infered from inside, cf Hubble and ... the quantum multiverse. The
> inaccessibility for manipulation is more of the type: no one can make 17
> even, not even a God.


Best Wishes,

You received this message because you are subscribed to the Google Groups "Everything List" group.
To post to this group, send email to
To unsubscribe from this group, send email to
For more options, visit this group at
Received on Wed Jan 07 2009 - 16:49:57 PST

This archive was generated by hypermail 2.3.0 : Fri Feb 16 2018 - 13:20:15 PST