Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!uflorida!gatech!rutgers!sunybcs!lammens
From: lammens@sunybcs.uucp (Jo Lammens)
Newsgroups: comp.ai
Subject: Simulation and Understanding (was Re: Simulation verus reality)
Message-ID: <5254@cs.Buffalo.EDU>
Date: 13 Apr 89 18:28:24 GMT
References: <827@htsa.uucp> <5790@watdcsu.waterloo.edu> <5106@cs.Buffalo.EDU> <1259@rpi.edu>
Sender: nobody@cs.Buffalo.EDU
Reply-To: lammens@sunybcs.UUCP (Jo Lammens)
Organization: SUNY/Buffalo Computer Science
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>Perhaps I missed something by jumping in the middle of this, but it
>seems to me that all the articles posted on this Simulation vs Reality
>argument are talking about two fundamentally different concepts as if
>they were the same.  Understanding and simulation are not the same
>thing.  

I would not want to imply that they are the same. But I do think that
in order to simulate, there has to be understanding. In a previous
posting I used the analogy of trying to understand how an operating
system works by modeling (and simulating) the transistors that make up
the machine on which it runs. Suppose I know nothing about operating
systems nor computers, and I want to simulate an o.s. using some other
technology, say a mechanical construction with gears and pulleys etc.
If high-level understanding is not required to simulate, I would be
able to build my machine by studying the behaviour of the transistors,
and modeling them with the gears and the like. Even though I model a
transistor sufficiently precisely, and throw in a lot of them, do you
think I will ever get the simulated o.s. to work if I don't know how
it works or even what it's supposed to do? Going back to the original
theme of neurons and brain functions, do you think that throwing in a
lot of simulated neurons (I mean a whole lot) will automatically
result in brain functions, consciousness or what have you, if you
don't know what they are or even what they're supposed to do? This is
not a rethorical question.

>I don't know very many people, in fact I don't know any, who
>could accurately simluate a car, although I do know many who understand
>understand how it works.    I would argue that accurate simulation DOES
>require a model from as low a level as possible in order to behave
>exactly as the real thing being simulated.  

There are people who know how atoms 'work', but can they accurately
simulate a car? I agree that in order to obtain a very accurate
simulation it would have to include the lowest levels possible, but I
think it won't work if you leave out the higher levels. And then you
have to define what an accurate simulation is.

>Typically `high level'
>descriptions of functional groups of low level objects are mere
>generalizations of the function of the group, and thus only
>incorporate the default knowledge of that function.

I do not get this. Please explain.

Jo Lammens

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