On Tue, Apr 07, 2015 at 05:22:20PM +1000, Bruce Kellett wrote: > Russell Standish wrote: > >On Tue, Apr 07, 2015 at 12:51:30PM +1000, Bruce Kellett wrote: > >> > >>So no conscious moment, even in with a dovetailer in Platonia, can > >>ever be completely counterfactually correct, because there will > >>always be related sequences of states that never get to be computed > >>-- no completed infinities even in arithmetic. > > > >Hi Bruce, that's not quite right. All computations eventually get > >computed by the UD within a finite (but unbounded) number of > >computational steps. Only in a non-robust ontology does this not happen. > > I think you need to unpack this a little. The dovetailer is running > all possible programs. That is an infinite number of programs, much > less an infinite number of computational steps. How can you say that > there are only a finite number of steps? And I do not know what > finite but unbounded means in this context. It has meaning in > closed universe models, but scarcely in arithmetic?
Perhaps you need to study the UD algorithm. For any program x, there will be finitely numbered step on the algorithm when the first instruction is executed. Similarly for the nth step of program x. Presumably, for any given observer moment, only a finite number of steps are required to emulate that observer moment, so the UD will run enough of a given program to emulate any observer moment within a finite amount of CPU time. However it is unbounded, because if you pick a number N, there will be a program that is not even started by the time N steps of the UD have been executed. > > > >Perhaps you could argue that the infinite sum over all computations > >supporting a given observer moment will never complete in a finite > >time, but I think that poses a problem for computing the measure > >(already recognised as an open problem), rather than being an isue per > >se with UDA 1-7. > > I have difficulty relating the number of computational steps to any > physical time. This UD is running on arithmetic in Platonia. Each > step takes no time, it is merely a relation between numbers. But if > steps are numbered with successive integers, there is an infinite > number of them and it cannot complete. It is not a matter of time, > it is a matter of infinite integers: after any number of steps > there is still an infinite number left to complete. > > The measure problem is insoluble without some further input into the > model to restrict the possibilities. > I probably slip into using the term time for CPU time (which is an algorithmic resource). Of course, for physical computers, this is the same thing, albeit not necessarily linearly related. But when discussing platonic entities, one should be more careful... > Bruce > > -- > 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 http://groups.google.com/group/everything-list. > For more options, visit https://groups.google.com/d/optout. -- ---------------------------------------------------------------------------- Prof Russell Standish Phone 0425 253119 (mobile) Principal, High Performance Coders Visiting Professor of Mathematics [email protected] University of New South Wales http://www.hpcoders.com.au Latest project: The Amoeba's Secret (http://www.hpcoders.com.au/AmoebasSecret.html) ---------------------------------------------------------------------------- -- 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 http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
