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Article 4371 of comp.ai.philosophy:
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>From: santas@inf.ethz.ch (Philip Santas)
Newsgroups: comp.ai.philosophy
Subject: Re: Definition of understanding
Message-ID: <1992Mar10.143639.10130@neptune.inf.ethz.ch>
Date: 10 Mar 92 14:36:39 GMT
References: <1992Mar2.172515.15389@psych.toronto.edu> <1992Mar2.190455.17079@mp.cs.niu.edu> <1992Mar2.214012.22715@psych.toronto.edu>
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In article <1992Mar2.214012.22715@psych.toronto.edu> michael@psych.toronto.edu (Michael Gemar) writes:
>Let's take an example from physics.  You teach a child how to calculate
>the potential energy of a pendulum by the formula:
>
>PE = 1/2 k x^2
>
>where PE = potential energy
>       k = spring constant
>       x = displacement from equilibrium
>
>You do so as a purely mechanical operation.  If asked, he would answer
>that he knows nothing about potential energy, or spring constants, or
>the like.
>
>You then say, "Aha, but the *system* that calculates potential energy
>in a spring does!"  However, someone who knows electrostatics says,
>"But wait!  That's also the formula for calculating the electrostatic
>energy *in a capacitor*.  Simply *interpret* k as C (capacitance) and
>x as V (potential across the capacitor plates)."  *Now* what does the
>system "understand"?  Only pendulums?  Only capacitors?  Pendulums *and*
>capacitors?  I'd vote for neither, myself.

If the system has as input only the mathematical formula, it is
possible that you get a variety of solutions according to the input.
k can be number of number of cars, and x anything else.

The human or the computer needs the definitions that you add after the 
formula. This means that we talk about mechanical and not electrical
energy.

>BTW, this is a good example of how interpretation can play a large role
>in the attribution of "understanding" to a program.  If an electronics
>engineer had a program he used to calculate the PE of a capacitor, he or she
>would probably say that the program *actually did calculate electrostatic
>energy*.  But it doesn't.  It merely submits the inputs to certain syntactic
>rules, and provides outputs.  The *exact same program* could be used to
>calculate the potential energy in a spring system.  The program itself
>does not *refer* to capacitors - it doesn't "refer" to anything.  It is
>only our *interpretation* of the inputs and outputs which give meaning.

Your formula itself does not refer to capacitors either. It is the set
of definitions of the variables that clear things up

Philip Santas

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email: santas@inf.ethz.ch				 Philip Santas
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