On 9 August 2016 at 03:52, Brent Meeker <meeke...@verizon.net> wrote:
> > > On 8/8/2016 6:18 AM, Stathis Papaioannou wrote: > > > > On Monday, 8 August 2016, Brent Meeker <meeke...@verizon.net> 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 everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
