2012/9/11 benjayk <benjamin.jaku...@googlemail.com> > > > Quentin Anciaux-2 wrote: > > > > 2012/9/11 benjayk <benjamin.jaku...@googlemail.com> > > > >> > >> > >> 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", > > > > > > I *do not presume it*... it's a *fact*. > > > > > Well, I presented a model of a program that can do that (on some level, not > on the level of physical hardware), and is a program in the most > fundamental > way (doing step-by-step execution of instructions). > All you need is a program hierarchy where some programs have access to > programs that are below them in the hierarchy (which are the "hardware" > though not the *hardware*). >
What's your point ? How the simulated hardware would fail ? It's impossible, so until you're clearer (your point is totally fuzzy), I stick to "you must be wrong". > > So apparently it is not so much a fact about programs in a common sense > way, > but about a narrow conception of what programs can be. > > benjayk > -- > View this message in context: > http://old.nabble.com/Why-the-Church-Turing-thesis--tp34348236p34417762.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. > > -- All those moments will be lost in time, like tears in rain. -- 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.