Quentin Anciaux-2 wrote: > > 2012/9/11 benjayk <benjamin.jaku...@googlemail.com> > >> >> >> Quentin Anciaux-2 wrote: >> > >> > 2012/9/10 benjayk <benjamin.jaku...@googlemail.com> >> > >> >> >> >> >> >> > > No program can determine its hardware. This is a consequence of >> the >> >> > > Church >> >> > > Turing thesis. The particular machine at the lowest level has no >> >> > bearing >> >> > > (from the program's perspective). >> >> > If that is true, we can show that CT must be false, because we *can* >> >> > define >> >> > a "meta-program" that has access to (part of) its own hardware >> (which >> >> > still >> >> > is intuitively computable - we can even implement it on a computer). >> >> > >> >> >> >> It's false, the program *can't* know that the hardware it has access >> to >> >> is >> >> the *real* hardware and not a simulated hardware. The program has only >> >> access to hardware through IO, and it can't tell (as never ever) from >> >> that >> >> interface if what's outside is the *real* outside or simulated >> outside. >> >> <\quote> >> >> Yes that is true. If anything it is true because the hardware is not >> even >> >> clearly determined at the base level (quantum uncertainty). >> >> I should have expressed myself more accurately and written " >> "hardware" >> " >> >> or >> >> "relative 'hardware'". We can define a (meta-)programs that have >> access >> >> to >> >> their "hardware" in the sense of knowing what they are running on >> >> relative >> >> to some notion of "hardware". They cannot be emulated using universal >> >> turing >> >> machines >> > >> > >> > Then it's not a program if it can't run on a universal turing machine. >> > >> The funny thing is, it *can* run on a universal turing machine. Just that >> it >> may lose relative correctness if we do that. > > > Then you must be wrong... I don't understand your point. If it's a program > it has access to the "outside" through IO, hence it is impossible for a > program to differentiate "real" outside from simulated outside... It's a > simple fact, so either you're wrong or what you're describing is not a > program, not an algorithm and not a computation. OK, it depends on what you mean by "program". If you presume that a program can't access its "hardware", then what I am describing is indeed not a program.
But most definitions don't preclude that. Carrying out instructions precisely and step-by-step can be done with or without access to your hardware. Anyway, meta-programs can be instantiated using real computer (a program can, in principle, know and utilize part of a more basic computational layer if programmed correctly), so we at least know that real computers are beyond turing machines. benjayk -- View this message in context: http://old.nabble.com/Why-the-Church-Turing-thesis--tp34348236p34417676.html Sent from the Everything List mailing list archive at Nabble.com. -- You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to everything-list@googlegroups.com. To unsubscribe from this group, send email to everything-list+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/everything-list?hl=en.