AI and cognitive psychology rant (getting more and more OT - tell me if I should shut up)

[Stephen Horne]

On Sat, 01 Nov 2003 17:39:54 GMT, "Andrew Dalke"
<adalke at mindspring.com> wrote:

>> How come then that the sciences have been so uncanningly effective
>> given that they are such an arbitrary choice within the knowable? The
>> answer is of course that there are a lot of other possible sciences,
>> completely unrelated to our own that would have been just as effective
>> as -or even more effective than- our current sciences, had they been
>> pursued with equal persistence during the same amount of time over a
>> lot of generations.
>
>I don't follow your argument that this occurs "of course."
>
>It's not for a dearth of ideas.  Humans did try other possible
>sciences over the last few millenia.  Despite centuries of effort,
>alchemy never became more than a descriptive science, and
>despite millenia of attempts, animal sacrifices never improved
>crop yields, and reading goat entrails didn't yield any better
>weather predictions.

;-)

Actually I missed this point in Antons post, being already primed to
be bugged by his last paragraph or two, so I will reply to it here.

The choice was not arbitrary by any stretch of the imagination. We
could not construct the models described by quantum mechanics or
relatively until we had a good understanding of classical mechanics.
We cannot percieve either quantum or relativistic effects directly, so
they could not be the earliest models. We needed sufficient scientific
understanding and practical technology to be able to observe these
effects at all.

I doubt anyone could form a sensible theory of electricity, for
instance, if the only experience of electricity that they could
perceive was of phenomena such as lightning and flames. No wonder it
was all blamed on angry gods!

And yes, even classical mechanics could not have been our first model
for simple commonsense reasons. How often, for instance, did ancient
Greeks get to observe objects moving through a frictionless
environment?

>On the other hand, there are different but equivalent ways to
>express known physics.  For example, Hamiltonian and Newtonian
>mechanics, or matrix vs. wave forms of classical quantum mechanics.
>These are alternative ways to express the same physics, and some
>are easier to use for a given problem than another.  Just like a
>sun-centered system is easier for some calculations than a "my house"
>centered one.

Rather similar to the idea of using different metaphors to explain the
same model, though you are looking at maths rather than language.

>On the third hand, there are new theoretical models, like string
>theory, which are different than the models we use.  But they are
>not "completely unrelated" and yield our standard models given
>suitable approximations.

Agreed. Just as quantum mechanics and relativity both yield a close
approximation of classical mechanics within certain limits, and just
as classical mechanics yields something close to 'intuitive physics'
within the limits of most peoples everyday lives.

>On the fourth hand, Wolfram argues that cellular automata
>provide such a new way of doing science as you argue.  But
>my intuition (brainw^Wtrained as it is by the current scientific
>viewpoint) doesn't agree.

I just love the way that a guy who got rich selling software to do
fiddly maths jobs such as working with systems of differential
equations has suddenly decided that all that fiddly maths is
completely the wrong way to go ;-)

But even if, at some level, the universe is a cellular automata, I
don't see that meaning that the fiddly maths can be abandoned. The
fiddly maths is generally an artifact of removing detail in a sense,
after all - we use the formula for the entire path, for instance,
rather than listing all the points that make up the path. And the list
of points, like the list of states of the cells, lacks explanatory
power.

>> The effectiveness of the current natural sciences is a perceptual
>> artifact caused by our biased history. From a lot of different
>> directions messages are coming in now, all saying more or less the
>> same: "If asking certain questions, one gets answers to these
>> questions in a certain way, but if asking different questions one gets
>> different answers, sometimes even contradicting the answers to the
>> other questions".
>>
>> This might seem mystic or strange but one can see these things
>> everywhere, if one asks that kind of questions :-)
>
>Or it means that asking those questions is meaningless.

I wouldn't go so far. No model (at least none we have yet) is perfect,
so different models are bound to contradict each other - particularly
when you push them beyond their limits. Extrapolation is always less
reliable than interpolation, so it is best not to use a model to
extrapolate beyond the range where experiment has shown it to apply.

But there is clearly a baseline reality which these models are seeking
to approximate.

As I mentioned earlier, when a primitive person tries to understand
how your car works, the engine does not turn into a demon. The
technology based on our current scientific understanding works,
whatever you personally happen to believe.

>For a simpler case .. what is the center of the universe?  All locations
>are equally correct.  Is it mystic then that there can be multiple
>different answers or is simply that the question isn't well defined?

Hmmm - I suppose this depends what you mean by center. If you mean
'origin' in the graph-plotting sense, then you are right, of course.

But my understanding is that the universe, so far as anyone can tell,
is either an infinite space or finite without bounds. In either case,
there is no such thing as a center.

I find the 'infinite' theory dubious - if the expansion rate has
remained finite since the big bang, then how can space have grown to
become infinite? The only way I can understand it is if space was
always infinite. That wouldn't necessarily mean it can't 'expand',
just as it isn't necessarily impossible to multiply infinity by two.

I guess 'expansion' relating to the universe is a metaphor too, really
- after all, the universe isn't an object within some other space. The
'expansion' is really just rewriting of the scale factors on the
dimension axes of the universe, I suppose. That being why the speed of
light isn't a problem in inflation - nothing is actually moving faster
than the speed of light, even though the distances between things is
expanding faster than the speed of light.

Hmmm - I wonder if 'expansion' or 'scale' is a continuous value in
space-time, like curvature? Well, I guess it must be really - just
write the model in those terms and hey presto - but what I mean, I
guess, is "is there a function that can define that 'scale' in terms
of local physics to explain things we don't currently have an
explanation for?".

>> One example would be the role the observer plays in quantum mechanics,
>> but something closer to a programmer would be the way static or
>> dynamic typing influence the way one thinks about designing a computer
>> program.

<snip>

>And I don't see how the reference to QM affects the argument.  Then
>again, I've no problems living in a collapsing wave function.

I suspect this is the 'conscious mind has special role as observer'
thing again. And as has already stated, there are other explanations
of waveform collapse that don't require consciousness to take a
special role. Explanations that make more sense, as the observer never
had any control over how the waveform collapses - it is a mechanical
process that follows clearly defined non-mystical rules.


-- 
Steve Horne

steve at ninereeds dot fsnet dot co dot uk