> On 23 Apr 2019, at 19:54, 'Cosmin Visan' via Everything List > <everything-list@googlegroups.com> wrote: > > That's just a random definition that doesn't mean anything. > > On Friday, 19 April 2019 12:27:18 UTC+3, Bruno Marchal wrote: > With mechanism, the observer is just a number/machine, relative to some > other numbers/machines.
You ignore that the notion of computation is a purely arithmetical notion. Fix one universal machinery (an enumeration of all programs in some Turing universal formalism, like the recursive enumeration of the program (with one natural number input) of the programs written in LISP, say, or take the combinator (see the recent thread on them). I note phi_i the corresponding functions (computes by those programs). We can identify the natural number I with the program computing ph_i, then a universal number u is a program such that phi_i(<x, y>) = phi_x(y). U emulates x on y, and is universal, as it does that for all x. <x, y> is a fixed bijection between NxN and N. The number is the code that the digitalist surgeon might temporarily put on some disk, and which will be emulated by Nature when you are reconstituted, like after a Digital brain transplant (which is possible, as I assume Mechanism). Note that the relation phi_x(y) = z is definable in pure arithmetic. No need of any assumption in physics to define the notion of digital machine. You might need to study some introduction to theoretical computer science, like the very good book by N. Cutland https://www.amazon.com/Computability-Introduction-Recursive-Function-Theory/dp/0521294657 <https://www.amazon.com/Computability-Introduction-Recursive-Function-Theory/dp/0521294657> Bruno > > -- > 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 > <mailto:everything-list+unsubscr...@googlegroups.com>. > To post to this group, send email to everything-list@googlegroups.com > <mailto:everything-list@googlegroups.com>. > Visit this group at https://groups.google.com/group/everything-list > <https://groups.google.com/group/everything-list>. > For more options, visit https://groups.google.com/d/optout > <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 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.
