> > 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 (in general - in specific instances, where the hardware is fixed on the right level, they might be). They can be simulated, though, but in this case the simulation may be incorrect in the given context and we have to put it into the right context to see what it is actually emulating (not the meta-program itself, just its behaviour relative to some other context). We can also define an infinite hierarchy of meta-meta-....-programs (n metas) to show that there is no universal notion of computation at all. There is always a notion of computation that is more powerful than the current one, because it can reflect more deeply upon its own "hardware". See my post concerning meta-programs for further details. -- View this message in context: http://old.nabble.com/Why-the-Church-Turing-thesis--tp34348236p34413719.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 [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/everything-list?hl=en.
