On Sat, Aug 27, 2016 at 11:38 PM, Charles Goodwin <[email protected]> wrote: > Hi everyone and everything, I was discussing comp and similar things with > Liz the other day and we came across a sticking point in what I think (from > memory) is step 7 of the UDA. Maybe you can help? > > I'm assuming AR, "Yes, Doctor" and so on. At step 7 we reach the point where > we assume that a physical Universal Dovetailer can be created and that it > runs forever, and ask what is the probability that my observer moments are > generated by it, rather than by my brain. > > Now ISTM that the UD will have an infinite number of possible programmes to > run, so even if it runs forever, how does it get on to the second step in > any of them?
Every program can be mapped to a natural number (intuitively, imagine the binary encoding of a program in any Turing-complete language). With something akin to the binary encoding (more abstractly, you can do this to the state table of a Universal Turing Machine), program size increases with their numbers. Then the dovetailer proceeds like so: - execute step 1 of program 1 - execute step 2 of program 1 - execute step 1 of program 2 - execute step 3 of program 1 - execute step 2 of program 2 - execute step 1 of program 3 ... So it will only take finite time for all the computable programs of up to a certain size to finish. Telmo. > > -- > 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. -- 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.
