Lame discussion about TM (was Re: How many of you like HP41C calculators?)

From: der Mouse <mouse_at_Rodents.Montreal.QC.CA>
Date: Sat Nov 22 16:21:28 2003

>> [...] aside from leaving analog computers out in the cold, [...]
> Again, analog computers are not computers in a Turing sense

Right. To me, this indicates how constraining the Turing sense of
computation is (and people such as you trying to even exclude them from
the very term "computer" is an indication how pervasive this equating
of computation with Turing-equivalent computation is).

> or any sense in which we think of digital computers.

Right again.

> In this case, "analog" is not an opposite of "digital".

I disgaree - at least until we find a third paradigm which supports
automated computation, at which point "opposite" will no longer be an
appropriate word.

> It means that you design an analog of something you are attempting to
> model using for example electricity, water, etc. Think of them as
> physical "simulators" rather than computers.

This is equally true of a lot of the uses of digital computers. Most
finite-element simulations qualify, for example.

This does not make them non-computers. A computer is that which
computes, and analog computers compute; they just use different means
to do so, means which are better suited to a comparatively small class
of problems (and much worse suited to a different, much larger, class).

While it is logically coherent to attempt to redefine "computer" as you
appear to be trying to (roughly, as "that which is equivalent to a
Turing machine except for memory size limitations"), it is a wholly
artificial, not particularly useful, and not historically supported
redefinition.

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Received on Sat Nov 22 2003 - 16:21:28 GMT