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

[Stephen Horne]

On Sun, 02 Nov 2003 08:36:09 GMT, "Andrew Dalke"
<adalke at mindspring.com> wrote:

>Stephen Horne:
>> We cannot percieve either quantum or relativistic effects directly, so
>> they could not be the earliest models.
>
>[In general I agree with your post.  Just some comments.]
>
>What about superfluid helium?

Superfluid helium is a macroscopic phenomenon - it may be explained in
terms of QM effects, but that doesn't make it a quantum effect in
itself any more than more everyday macroscopic effects (which can also
be described in QM terms). If superfluid helium is your only clue, it
will tell you no more about quantum effects than e.g. lightening tells
you about the properties of an electron.

Besides, you need the science and technology to achieve very low
temperatures before you can observe superfluid helium. It may be
pretty cold in the winter, but even so we don't often see superfluid
helium laying around ;-)

>> 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?
>
>Every clear night.

Yes, but they mostly thought the planets obeyed different laws to the
things that could see up close. Besides, with an Earth-centric model,
it is pretty hard to see the simple patterns of motion - and of course
even if they did, gravity is still confusing the issue. Don't forget
that it was actually quite a big leap of understanding when Newton
realised that the planets followed elliptical orbits because of the
same force that made apples fall from trees - it is only from the
perspective of having been told this since the age of 12 that it seems
obvious.

It was quite a revelation to discover that the physics of the cosmos
were actually the same physics we experience on the ground.

>True.  But some questions are meaningless.  "Wave or particle?"
>"Where is the center of a black hole?"  "What would happen if you
>were driving at the speed of light and turned the headlights on?"

Absolutely.

"Wave" and "particle" should be seen as metaphors, each describing a
subset of the properties of subatomic particles. The 'duality' is an
artifact of the metaphors.

The centre of a black hole exists, in a sense, but we can never
observe it because it is inside the event horizon, and as time itself
stops at the event horizon (from the perspective of any outside
observer) there is even good reason for claiming that the space inside
the event horizon doesn't exist.

>Michele is a better one for this topic.  My point was just that many
>different answers doesn't necessarily imply a mystic explanation.

Yes, sorry - I was just following a random tangent.

>I read a popular account of "branes", membrane theory, which
>was interesting.  I don't know enough to describe it, other than
>that the universe was created from high-dimensional membranes
>hitting each other.

I read a book about string and brane theory some time ago - I guess
possibly the same one, though it has vanished into book-borrowing
space as all the best books do so I can't tell you the title. 

Lots of theory about possible geometries and topologies of many
dimensional space-time and how they could change from one another.
They didn't address the issue of how they could change at all, given
that time existed within the geometry rather than outside of it, and
for that among other reasons my impression was that it was a
fascinating read that nevertheless left me with no more clue than I
had to start with.

I would at least have appreciated a definition of supersymmetry,
rather than the usual 'its too abstract for your puny mind' copout.


-- 
Steve Horne

steve at ninereeds dot fsnet dot co dot uk