Re: Poll: Are PCs Turing Machines?
From: |-|erc (h_at_r.c)
Date: 12/14/04
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Date: Tue, 14 Dec 2004 09:39:17 +1000
"Mark Nudelman" <markn@greenwoodsoftware.com> wrote in
> > Interesting, because you assume based on present knowledge that there
> > exists at least one calculation that always and forever will require
> > an unbounded number of digits.
>
> Yes, I do make such an assumption. This assumption seems fairly trivial.
> In my example, I don't even care about the calculation itself, only that the
> input is a 10^1000 digit number. There's no conceivable way to even store
> such a number without a corresponding amount of memory.
>
> > This may be true OR it may be an artifact of our knowledge. In the
> > case of pi the dependency, I understand, is on something called the
> > Riemann hypothesis, the solution of which may crack the problem of
> > digit patterns recurring in pi, in which case, a TM could calculate
> > it to arbitrary precision WITHOUT running out of "storage".
>
> I don't think the randomness of digits in pi has anything to do with the RH,
> but I could be wrong. But calculating pi wasn't my example.
>
> > Whether a PC simulates a Turing machine is a question unrelated to
> > physical and empirical data. You see, the assertion that the
> > universe's particle count is finite is an empirical assertion, not
> > true in all possible worlds because an infinite universe is
> > physically possible, if not verifiable.
>
> This is true, but the question was, "can a PC simulate a TM". I assumed
> "PC" meant a real PC, existing in our universe. If you want to hypothesize
> a universe in which there is an infinite amount of matter, which can be
> formed into an infinite amount of memory units in a finite time, and in
> which there is no speed-of-light limit on information transfer, then, yeah,
> a PC can probably simulate a TM. But I don't think that was the question
> that was asked.
>
Argument 1
The question is: Is there a TM that logically represents a PC?
or, for any PC, is there a TM that logically represents it?
ie. are PC's Turing Machines?
as in, are Traffic Lights automations?
YES
Argument 2.
Everything possible in the real world can be represented / simulated functionally.
All functions can be represented by TMs.
Therefore anything can be represented by a TM.
Therefore PC's can be represented by a TM.
Therefore PC's are TM's.
Most people have the infinite memory argument backwards.
Is a TM a #FSM? NO a FSM would run out of memory for many TM's.
Herc
#FSM = finite state machine
- Previous message: Kent Paul Dolan: "Re: [OT] (was): Robust Algorithms"
- In reply to: Mark Nudelman: "Re: Poll: Are PCs Turing Machines?"
- Next in thread: |-|erc: "Re: Poll: Are PCs Turing Machines?"
- Reply: |-|erc: "Re: Poll: Are PCs Turing Machines?"
- Reply: peter_douglass: "Re: Poll: Are PCs Turing Machines?"
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