On 9 August 2016 at 03:52, Brent Meeker <[email protected]> wrote:
> > > On 8/8/2016 6:18 AM, Stathis Papaioannou wrote: > > > > On Monday, 8 August 2016, Brent Meeker <[email protected]> wrote: > >> >> >> On 8/7/2016 11:20 AM, Bruno Marchal wrote: >> >>> Not necessarily. A digital computer also requires that time be digitized >>>> so that its registers run synchronously. Otherwise "the state" is ill >>>> defined. The finite speed of light means that spacially separated regions >>>> cannot be synchronous. Even if neurons were only ON or OFF, which they >>>> aren't, they have frequency modulation, they are not synchronous. >>>> >>> >>> Synchronous digital machine can emulate asynchronous digital machine, >>> and that is all what is needed for the reasoning. >>> >> >> If the time variable is continuous, i.e. can't be digitized, I don't >> think you are correct. >> > > If time is continuous, you would need infinite precision to exactly define > the timing of a neuron's excitation, so you are right, that would not be > digitisable. Practically, however, brains would have to have a non-zero > engineering tolerance, or they would be too unstable. The gravitational > attraction of a passing ant would slightly change the timing of neural > activity, leading to a change in mental state and behaviour. > > > I agree that brains must be essentially classical computers, but no > necessarily digital. The question arose as to what was contained in an > Observer Moment and whether, in an infinite universe there would > necessarily be infinitely many exact instances of the same OM. > Even in a continuum, there would be brain states and mental states that are effectively identical to an arbitrary level of precision. We maintain a sense of continuity of identity despite sometimes even gross changes to our brain. At some threshold there will be a perceptible change, but the threshold is not infinitesimal. > But having a continuous variable doesn't imply instability. First, the > passing ant is also instantiated infinitely many times. Second, if a small > cause has only a proportionately small effect then there is no > "instability", more likely the dynamics diverge as in deterministic chaos. > But in any case it would allow an aleph-1 order infinity of OMs which > would differ by infinitesimal amounts. > > But I also question the coherence of this idea. As discussed (at great > length) by Bruno and JKC, two or more identical brains must instantiate the > same experience, i.e. the same OM. So if there are only a finite number of > possible brain-states and universes are made of OMs, then there can only be > a finite number of finite universes. > A human brain can probably only have a finite number of thoughts, being of finite size, but a turing machine is not so limited. -- Stathis Papaioannou -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
