X-Message-Number: 7887
From:  (Thomas Donaldson)
Subject: a.bit.more
Date: Wed, 19 Mar 1997 00:00:23 -0800 (PST)

Hi again!

Thinking about my last posting, I decided that a bit of amplification was
needed. Here it is.	 

We take for granted the notion of a digital computer, perhaps because they
are all around us now. But what do our computers really do? Basically they
are devices which move symbols around, and change them according to rules
which we (or the programmer of the program we are running) have set up.

Yes, this is an abstraction of the real computers, which are electrical
devices. The symbols too are small charges or the absence of a charge ---
or various other changes. If the computer takes its information and program
off a disk, and reads the result back onto the disk, then it is essentially
moving and modifying a large set of very small magnets.

Put in these terms, the meaning of what any computer does is provided by
its user. By now, also, that is too easily forgotten. If we store a digital
image on a magnetic disk, then there is no INTRINSIC relation between what
we see and the large number of small magnets with north and south poles
pointing in different directions. It all depends on the user, who interprets
the image on his screen as a picture.

The world, however, does not consist of symbols. It consists of objects
moving about and reacting to various forces, etc etc. The difference between
the motion of the planets and a computer simulation of their motion is a 
difference between the motion of objects in the world, and an entirely
arbitrary motion of bits in a computer according to the scheme we have
put into the computer. Not only doesn't the world consist of symbols
(which are arbitrarily assigned by us) but no representation of it in 
symbols can ever capture it fully. The difference is that between the story
of an accident in a newspaper and the accident itself. And (say if we 
want to do computer graphics, all the processing power and clever algorithms
we use come from the fact that we are REPRESENTING the world, we are not
creating it. And the world itself does not do any computation at all when
the planets move in their paths. None is needed).

When we say that a computer is a DIGITAL computer we are saying that we will
symbolically represent various numbers and values in the real world by
numbers in one or more special systems invented for that purpose. Anyone who
tries to calculate with floating point numbers will know very well just
how much there is a symbolic representation here. 

I have said that I would not object to STORAGE in a computer. Yes, an
object can be stored in a computer, so long as those storing it agree on
the set of symbols used, and have both a system to read the object into
that set of symbols and to read it out again into a real object. Without all
three of these conditions, my storage will fail. Moreover, the neurons 
which make up my brain might be replaced by more advanced versions, without
any issues arising. Why should they? It is as if we replace one real machine
by another "better" one (what would make our neurons more advanced is an 
issue not pertinent here).

However, any computer simulation of me, no matter how exact, continues to
consist of the moving about of bits in a medium. I have no more reason to
believe that this computer simulation is conscious than I have to believe
that the characters in a film are conscious. That film is no more than 
specks of color on a large number of different pictures, so arranged that
it will look like a sight of the world. The number of specks, the complexity
of the plot, the merits of the acting --- none of these mean that the 
characters are actually real people.

If you mean by uploading that I might someday be STORED in a computer, 
that's fine. But to simulate me in a computer? That is no more possible 
than to make a film in which the characters are real.

Is this Chapter 5 about uploading? Perhaps.

			Long long life,

				Thomas Donaldson


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