Re: Turing Machines and Physical Computation

From: Kent Paul Dolan (xanthian_at_well.com)
Date: 11/21/04 

Date: Sun, 21 Nov 2004 03:41:25 +0000 (UTC)

"Eray Ozkural exa" <examachine@gmail.com> wrote

> Hi Stephen,

> I would have expected a thoughtful reply.

Perhaps if you had avoided wandering off in
the weeds again you would have received one?

The reactions you receive from others are the
reactions _you_ _provoke_ by _your_ behavior.

This is a constant of the universe.

Failing to understand that permanent reality has a
technical name: "autism".

> "Stephen Harris" <cyberguard1048-usenet@yahoo.com> wrote:
>> "Eray Ozkural exa" <examachine@gmail.com> wrote:

>>> I have had such a discussion with an extremely intelligent and
>>> experienced mathematician. He told me that PCs are not Turing
>>> Machines, because they

Turing Machines, not PCs.

>>> have "an infinite tape".

>>> I think he did not know anything about
>>> descriptive complexity.

And I think this is merely another example of you
failing to pay attention in class.

>>> This infinite portion of the tape consists
>>> entirely of blank symbols, and therefore has
>>> descriptive complexity O(1),

Ummm, no, that doesn't even make sense, since "the
infinite portion of the tape" does not have a known
starting position. There are Turing Machine programs
which will overwrite any mark you place on the tape
and say, "from here on out, I can describe this with
O(1) complexity", so that refuge is unavailable to
you as a way to limit the complexity of describing
the tape as a whole.

>>> which is easily realized by a physical system.

Again, you snoozed when you should have been taking
notes. Not being realizable in any physical system
is one well known attribute of Turing Machines.

>>> When I told him about Ullman's indefinite
>>> growing argument, he objected "But when the
>>> universe is filled up, it cannot grow any more!
>>> Then, it is not infinite", to which I responded
>>> "Yes, but there is *nothing* that is larger than
>>> the universe." To assume the contrary would be
>>> theology, which I despise.

The problem being that it is precisely what _you_
are doing, trying to limit abstract devices to the
bounds appropriate to mere physical reality, that is
"theology".

You cannot both limit the construct you are
discussing to the bounds of the physical universe,
and pretend that you are still discussing Turing
Machines, which specifically have no such
limitations.

You can call your construct an "Eray Machine" if you
choose, but much like the "Olcott Machines"
previously proposed here, your devices will be toys,
of no intellectual interest whatever, where Alan
Turing's invention is one of the most powerful
constructs ever produced by the human mind, and
finds constant new applications.

>> Turing Machines are idealized which means they
>> are not physically realized.

> What a nice assertion.

That is not an "assertion", that is a "definition".
Perhaps alertness during your classes would have
taught you the difference?

> A TM is just the specification of a very low level
> machine code, that's all there is to it.

Well, no. Perhaps, rather than filling Usenet with
endless more reams of pointless blather, you could
go find out _on your own_ what a Turing machine is,
and what that implies, rather than conducting
another bulldog defense of your chosen battlefield
of "intensely applied ignorance" here in this venue,
and spare the rest of us the misery of wading
through your endless time wasting eructions?

> It's just another model of computation, and not an
> extremely telling or useful one.

My, you have a lot of opinions grounded in utter
ignorance. That one alone should have prevented your
ever receiving a PhD in the computer desmesne.

> Thinking about Turing Machines which have not been
> realized yet does not mean that these things
> cannot be implemented.

Your "these things" is a reference without a
referent.

> Besides, a bounded size FSA simulator, too, is a
> Turing Machine...

You have two concepts too muddled to be easily
separated, like siamese twins. Perhaps you could
borrow some class notes from someone who bothered to
pay attention in school?

> You people overlook this simple point, I wonder
> why.

Perhaps because "we people" set enough value on our
education to be mentally present in class as well as
physically there?

> Now, I recall that you made this strange argument
> about Turing Machines being able to do things that
> real computers cannot, because they have an
> infinite tape. What an observation.

Again, you bemusedly give your mere ignorance-based
_opinion_ the same stature as the received wisdom of
the computer science theory community. That may
amuse you, but it makes you clearly and publically
the idiot you are so determined to be, also.
 
>> TMs are not meant to have physical constraints
>> applied to them.

> Another assertion.

Again you confuse opinion with definition. That is
no more an "assertion" than is "gravity works".

> Ignoring physical plausibility directly opposes
> physicalism.

So what? When you go wandering off into the weeds
where your abberant philosophy lives, you leave
Turing Machines, and computer theory, far behind.

Turing Machines are under precisely _no_ obligation
to be physically realizable. They teach this point
in school, Eray, where were you at the time?

> When we start talking about immaterial things, we
> are not making scientific statements, we are
> making metaphysical ones, and that is not a good
> sign if the metaphysical statements depict worlds
> that are not physically similar to our own.

I'm pretty sure at this point you have stepped well
past the bounds of sane thinking. You are trying to
limit "science" to "physical science", and that
limitation only exists in your own mind.

> It is a matter of degree, which we can observe.

That statement is a meaningless noise.

> The question is: how far from reality? The further
> you talk, the less real your statements are, not
> just as real!

Again, you are expressing some degree of insanity,
no degree of intelligence or attention to your
education, here.

I refuse to waste more time on your inane drivel.

This should be clues enough you need to go back and
_learn_ that which you have inappropriately already
claimed credit to have learned with your accepting a
PhD.

[snip]

xanthian, disgusted. 

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